Fermi Gamma-ray Space Telescope

NASA's Fermi Gamma-ray Space Telescope has completed its primary mission, and it will continue to explore the high-energy cosmos in unprecedented detail. These pages gather together media products associated with Fermi news releases starting before its 2008 launch, when it was known as GLAST.

Fermi detects gamma rays, the most powerful form of light, with energies thousands to billions of times greater than the visible spectrum.

The mission has discovered pulsars, proved that supernova remnants can accelerate particles to near the speed of light, monitored eruptions of black holes in distant galaxies, and found giant bubbles linked to the central black hole in our own galaxy.

For more information about the Fermi mission, visit its NASA webpage.

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News Stories

Video, images and other media supporting Fermi Gamma-ray Space Telescope news products.
  • NASA Missions Unveil Magnetar Eruptions in Nearby Galaxies
    2021.01.13
    On April 15, 2020, a brief burst of high-energy light swept through the solar system, triggering instruments on many NASA missions. Now, multiple international science teams conclude that the blast came from a supermagnetized stellar remnant known as a magnetar located in a neighboring galaxy. This finding confirms long-held suspicions that some gamma-ray bursts (GRBs) – cosmic eruptions detected somewhere in the sky almost daily – are in fact powerful flares from magnetars relatively close to home. The April 15 event is a game changer because its estimated location lies entirely within the disk of the galaxy NGC 253, located 11.4 million light-years away GRBs, the most powerful explosions in the cosmos, can be detected across billions of light-years. Those lasting less than about two seconds, called short GRBs, occur when a pair of orbiting neutron stars both the crushed remnants of exploded stars spiral into each other and merge. Magnetars are neutron stars with the strongest-known magnetic fields, with up to a thousand times the intensity of typical neutron stars and up to 10 trillion times the strength of a refrigerator magnet. Rarely, magnetars produce enormous eruptions called giant flares that produce gamma rays, the highest-energy form of light. Shortly before 4:42 a.m. EDT on April 15, a powerful burst of X-rays and gamma rays triggered, in turn, instruments on NASA's Mars Odyssey mission, Wind satellite, and Fermi Gamma-ray Space Telescope. A ground-based analysis of data from NASA's Neil Gehrels Swift Observatory show that it also detected the event. The pulse of radiation lasted just 140 milliseconds, as fast as a blink of the eye or a finger snap. Fermi's Large Area Telescope (LAT) also detected high-energy gamma rays up to several minutes after this pulse, a surprising finding. Analysis of Fermi and Swift data indicate that the outburst launched a blob of electrons and positrons moving at about 99% the speed of light. The blob expanded as it traveled, following closely behind the light emitted by the giant flare. After a few days, scientists say, they reached the boundary separating the magnetar's region of influence from interstellar space. The light passed through, followed many seconds later by the greatly expanded cloud. This material induced shock waves in gas piled up at the boundary, and the interaction produced the highest-energy emission detected by the LAT.
  • NASA Missions Team Up to Study Unique Magnetar Outburst
    2020.11.04
    On April 28, a supermagnetized stellar remnant known as a magnetar blasted out a simultaneous mix of X-ray and radio signals never observed before. The flare-up included the first fast radio burst (FRB) ever seen from within our Milky Way galaxy and shows that magnetars can produce these mysterious and powerful radio blasts previously only seen in other galaxies. A magnetar is a type of isolated neutron star, the crushed, city-size remains of a star many times more massive than our Sun. What makes a magnetar so special is its intense magnetic field. The field can be 10 trillion times stronger than a refrigerator magnet's and up to a thousand times stronger than a typical neutron star's. This represents an enormous storehouse of energy that astronomers suspect powers magnetar outbursts. The X-ray portion of the synchronous bursts was detected by several satellites, including NASA's Wind mission. The radio component was discovered by the Canadian Hydrogen Intensity Mapping Experiment (CHIME), a radio telescope located at Dominion Radio Astrophysical Observatory in British Columbia and led by several Canadian universities. It was also detected by the NASA-funded Survey for Transient Astronomical Radio Emission 2 (STARE2), a trio of detectors in California and Utah operated by Caltech and NASA’s Jet Propulsion Laboratory in Southern California. The STARE2 data showed that the burst's energy was comparable to FRBs. By the time these bursts occurred, astronomers had already been monitoring their source, a magnetar named SGR 1935+2154, for more than half a day using NASA's Neil Gehrels Swift Observatory, Fermi Gamma-ray Space Telescope, and the Neutron star Interior Composition Explorer (NICER) X-ray telescope mounted atop the International Space Station. About 13 hours later, when the magnetar was out of view for Swift, Fermi and NICER, a special X-ray burst erupted. The blast was seen by the European Space Agency’s INTEGRAL mission, the China National Space Administration’s Huiyan X-ray satellite, and the Russian Konus instrument on Wind. As the half-second-long X-ray burst flared, CHIME and STARE2 detected the radio burst, which lasted only a thousandth of a second. Taken together, the observations strongly suggest that the magnetar produced the Milky Way galaxy's equivalent of an FRB, which means magnetars in other galaxies likely produce at least some of these signals.
  • Young Active Galaxy with ‘TIE Fighter’ Shape
    2020.08.25
    Not so long ago, astronomers mapped a galaxy far, far away using radio waves and found it looked strikingly similar to Darth Vader’s TIE fighter spacecraft in “Star Wars: Episode IV – A New Hope.” In the process, they discovered the object, called TXS 0128+554, experienced two powerful bouts of activity in the last century.

    Around five years ago, NASA’s Fermi Gamma-ray Space Telescope reported that TXS 0128+554 (TXS 0128 for short) is a faint source of gamma rays, the highest-energy form of light. Scientists have since taken a closer look using the Very Long Baseline Array (VLBA) and NASA’s Chandra X-ray Observatory.

    TXS 0128 lies 500 million light-years away in the constellation Cassiopeia, anchored by a supermassive black hole around 1 billion times the Sun’s mass. It’s classified as an active galaxy, which means all its stars together can’t account for the amount of light it emits.

    Researchers added the galaxy to a long-running survey conducted by the VLBA, a network of radio antennas operated by the National Radio Astronomy Observatory stretching from Hawaii to the U.S. Virgin Islands.

    The array’s measurements provide a detailed map of TXS 0128 at different radio frequencies. The radio structure they revealed spans 35 light-years across and tilts about 50 degrees out of our line of sight. This angle means the jets aren’t pointed directly at us and may explain why the galaxy is so dim in gamma rays.

    The radio emission also sheds light on the location of the galaxy’s gamma-ray signal. Many theorists predicted that young, radio-bright active galaxies produce gamma rays when their jets of high-energy particles collide with intergalactic gas. But in TXS 0128’s case, at least, the particles don’t produce enough combined energy to generate the detected gamma rays. Instead, Lister’s team thinks the galaxy’s jets produce gamma rays closer to the core, like the majority of active galaxies Fermi sees.

  • NASA’s Fermi Finds Vast ‘Halo’ Around Nearby Pulsar
    2019.12.19
    A new study of observations from NASA’s Fermi Gamma-ray Space Telescope has discovered a faint but sprawling glow around a nearby pulsar. If visible to the human eye, this gamma-ray “halo” would appear larger in the sky than the famed Big Dipper star pattern. This structure may provide the solution to a long-standing mystery about the amount of antimatter in our neighborhood. Astronomers have been vexed by a decade-long puzzle about one type of cosmic particle arriving from beyond the solar system. Positrons, the antimatter version of electrons, turn out to unusually abundant near Earth. A neutron star is the crushed core left behind when a star much more massive than the Sun runs out of fuel, collapses under its own weight and explodes as a supernova. We see some neutron stars as pulsars, rapidly spinning objects emitting beams of radio waves, light, X-rays and gamma rays that, much like a lighthouse, regularly sweep across our line of sight. Geminga (pronounced geh-MING-ga) is among the brightest pulsars at gamma-ray energies. To study its halo, scientists had to subtract out all other sources of gamma rays, including diffuse light produced by cosmic ray collisions with interstellar gas clouds. Ten different models of interstellar emission were evaluated. What remained when these sources were removed was a vast, oblong glow spanning some 20 degrees — about 40 times the apparent size of a full Moon — at an energy of 10 billion electron volts (GeV), and even larger at lower energies. The team determined that Geminga alone could be responsible for as much as 20% of the high-energy positrons seen by other space experiments. Extrapolating this to the cumulative emission of positrons from all pulsars in our galaxy, the scientists say it’s clear that pulsars remain the best explanation for the observed excess of positrons.
  • A New Era in Gamma-ray Science
    2019.11.20
    A pair of distant explosions discovered by NASA’s Fermi Gamma-ray Space Telescope and Neil Gehrels Swift Observatory have produced the highest-energy light yet seen from these events, called gamma-ray bursts (GRBs). The detections, made by two different ground-based observatories, provide new insights into the mechanisms driving gamma-ray bursts. Astronomers first recognized the GRB phenomenon 46 years ago. The blasts appear at random locations in the sky about once a day, on average. The most common type of GRB occurs when a star much more massive than the Sun runs out of fuel. Its core collapses and forms a black hole, which then blasts jets of particles outward at nearly the speed of light. These jets pierce the star and continue into space. They produce an initial pulse of gamma rays — the most energetic form of light — that typically lasts about a minute. As the jets race outward, they interact with surrounding gas and emit light across the spectrum, from radio to gamma rays. These so-called afterglows can be detected up to months — and rarely, even years — after the burst at longer wavelengths. Much of what astronomers have learned about GRBs over the past couple of decades has come from observing their afterglows at lower energies. Now, thanks to these new ground-based detections, they're seeing the gamma rays from GRBs in a whole new way. On Jan. 14, 2019, just before 4 p.m. EST, both the Fermi and Swift satellites detected a spike of gamma rays from the constellation Fornax. The missions alerted the astronomical community to the location of the burst, dubbed GRB 190114C. One facility receiving the alerts was the Major Atmospheric Gamma Imaging Cherenkov (MAGIC) observatory, located on La Palma in the Canary Islands, Spain. Both of its 17-meter telescopes automatically turned to the site of the fading burst. They began observing the GRB just 50 seconds after it was detected and captured the most energetic gamma rays yet seen from these events. The energy of visible light ranges from about 2 to 3 electron volts. In 2013, Fermi’s Large Area Telescope detected light reaching an energy of 95 billion electron volts (GeV), then the highest seen from a burst. This falls just shy of 100 GeV, the threshold for so-called very high-energy (VHE) gamma rays. With GRB 190114C, MAGIC became the first facility to report unambiguous VHE emission, with energies up to a trillion electron volts. That’s 10 times the peak energy Fermi has seen to date. Data from a different burst, which Fermi and Swift both discovered, confirm afterglows reach these energies. Ten hours after the alerts, the High Energy Stereoscopic System (H.E.S.S.) pointed its large, 28-meter gamma-ray telescope to the location of the burst, called GRB 180720B. A careful analysis carried out during the weeks following the event revealed that H.E.S.S. clearly detected VHE gamma rays with energies up to 440 GeV. Even more remarkable, the glow continued for two hours following the start of the observation. Catching this emission so long after the GRB’s detection is both a surprise and an important new discovery.
  • Fermi Sees the Moon in Gamma Rays
    2019.08.15
    If our eyes could see high-energy radiation called gamma rays, the Moon would appear brighter than the Sun! That’s how NASA’s Fermi Gamma-ray Space Telescope has seen our neighbor in space for the past decade. Gamma-ray observations are not sensitive enough to clearly see the shape of the Moon’s disk or any surface features. Instead, Fermi’s Large Area Telescope (LAT) detects a prominent glow centered on the Moon’s position in the sky. Scientists have been analyzing the Moon’s gamma-ray glow as a way of better understanding another type of radiation from space: fast-moving particles called cosmic rays. Cosmic rays are mostly protons accelerated by some of the most energetic phenomena in the universe. Because the particles are electrically charged, they’re strongly affected by magnetic fields, which the Moon lacks. As a result, even low-energy cosmic rays can reach the surface, turning the Moon into a handy space-based particle detector. When cosmic rays strike, they interact with the powdery surface of the Moon, called the regolith, to produce gamma-ray emission. The Moon absorbs most of these gamma rays, but some of them escape. Mazziotta and Loparco analyzed Fermi LAT lunar observations to show how the view has improved during the mission. They rounded up data for gamma rays with energies above 31 million electron volts — 10 million times greater than the energy of visible light — and organized them over time, showing how longer exposures improve the view. Seen at these energies, the Moon would never go through its monthly cycle of phases and would always look full.
  • Ten Years of High-Energy Gamma-ray Bursts
    2019.06.13
    For a decade, NASA’s Fermi Gamma-ray Space Telescope has scanned the sky for gamma-ray bursts (GRBs), the universe’s most luminous explosions. A new catalog of the highest-energy blasts provides scientists with fresh insights into how they work. GRBs emit gamma rays, the highest-energy form of light. Most GRBs occurs when some types of massive stars run out of fuel and collapse to create new black holes. Others happen when two neutron stars, superdense remnants of stellar explosions, merge. Both kinds of cataclysmic events create jets of particles that move near the speed of light. The gamma rays are produced in collisions of fast-moving material inside the jets and when the jets interact with the environment around the star. Astronomers can distinguish the two GRB classes by the duration of their lower-energy gamma rays. Short bursts from neutron star mergers last less than 2 seconds, while long bursts typically continue for a minute or more. The new catalog, which includes 17 short and 169 long bursts, describes 186 events seen by Fermi’s Large Area Telescope (LAT) over the last 10 years. The LAT sees about one-fifth of the sky at any time and records gamma rays with energies above 30 million electron volts (MeV) — millions of times the energy of visible light. Fermi’s other instrument, the Gamma-ray Burst Monitor (GBM), sees the entire sky that isn’t blocked by Earth and detects lower-energy emission. All told, the GBM has detected more than 2,300 GRBs so far.
    GRB 130427A set the record for the highest-energy individual gamma ray detected by the LAT instrument. It also holds the record for the most gamma rays — 17 — with energies above 10 billion electron volts. The animation below illustrates the formation of a long GRB and its gamma-ray jets.

    GRB 090510 helped test Einstein’s theory that all forms of light travel through the vacuum of space at the same speed. Learn more about the event in the video below, starting at 0:59.
  • NASA’s Fermi Satellite Clocks a ‘Cannonball’ Pulsar
    2019.03.19
    Astronomers using NASA’s Fermi Gamma-ray Space Telescope and the National Science Foundation's Karl G. Jansky Very Large Array (VLA) have found a pulsar hurtling through space at nearly 2.5 million miles an hour -- so fast it could travel the distance between Earth and the Moon in just 6 minutes. Pulsars are superdense, rapidly spinning neutron stars left behind when a massive star explodes. This one, dubbed PSR J0002+6216 (J0002 for short), sports a radio-emitting tail pointing directly toward the expanding debris from a recent supernova explosion. Thanks to its narrow dart-like tail and a fortuitous viewing angle, astronomers can trace this pulsar straight back to its birthplace. Further study of J0002 will help us better understand how these explosions are able to ‘kick’ neutron stars to such high speed. The pulsar is located about 6,500 light-years away in the constellation Cassiopeia. It was discovered in 2017 by a citizen-science project called Einstein@Home, which uses downtime on the computers of volunteers to process Fermi gamma-ray data and has identified 23 gamma-ray pulsars to date. J0002 spins 8.7 times a second, producing a pulse of gamma rays with each rotation, and has about 1.5 times the mass of the Sun. The pulsar lies about 53 light-years from the center of a supernova remnant called CTB 1. Its rapid motion through interstellar gas results in shock waves that produce the tail of magnetic energy and accelerated particles detected at radio wavelengths using the VLA. The tail extends 13 light-years and clearly points back to the center of CTB 1. Using Fermi data and a technique called pulsar timing, the team was able to measure how quickly and in what direction the pulsar was moving across our line of sight thanks to Fermi's 10-year data covering the entire sky. J0002 is speeding through space five times faster than the average pulsar and faster than 99 percent of those with measured speeds. It will eventually escape our galaxy.
  • Tracing the History of Starlight with NASA's Fermi Mission
    2018.11.29
    Scientists using data from NASA’s Fermi Gamma-ray Space Telescope have measured all the starlight produced over 90 percent of the universe’s history. The analysis, which examines the gamma-ray output of distant galaxies, estimates the formation rate of stars and provides a reference for future missions that will explore the still-murky early days of stellar evolution. One of the main goals of the Fermi mission is to assess the extragalactic background light (EBL), a cosmic fog composed of all the ultraviolet, visible and infrared light stars have created over the universe’s history. Because starlight continues to travel across the cosmos long after its sources have burned out, measuring the EBL allows astronomers to study stellar formation and evolution separately from the stars themselves. The collision between a high-energy gamma ray and infrared light transforms the energy into a pair of particles, an electron and its antimatter counterpart, a positron. The same process occurs when medium-energy gamma rays interact with visible light, and low-energy gamma rays interact with ultraviolet light. Enough of these interactions occur over cosmic distances that the farther back scientists look, the more evident their effects become on gamma-ray sources, enabling a deep probe of the universe’s stellar content. The scientists examined gamma-ray signals from 739 blazars — galaxies with monster black holes at their centers — collected over nine years by Fermi’s Large Area Telescope (LAT). The measurement quintuples the number of blazars used in an earlier Fermi EBL analysis published in 2012 and includes new calculations of how the EBL builds over time, revealing the peak of star formation around 10 billion years ago.
  • NASA's Fermi Mission Shows How Luck Favors the Prepared
    2018.11.08
    In 2017, NASA’s Fermi Gamma-ray Space Telescope played a pivotal role in two important breakthroughs occurring just five weeks apart. But what might seem like extraordinary good luck is really the product of research, analysis, preparation and development extending back more than a century. This video timeline explores the historical progress of research into three cosmic messengers -- gravitational waves, gamma rays and neutrinos -- that Fermi helped bring together. For some of the video content used in this timeline, see this page.
  • Simulations Create New Insights Into Pulsars
    2018.10.10
    Scientists studying what amounts to a computer-simulated “pulsar in a box” are gaining a more detailed understanding of the complex, high-energy environment around spinning neutron stars, also called pulsars. The model traces the paths of charged particles in magnetic and electric fields near the neutron star, revealing behaviors that may help explain how pulsars emit gamma-ray and radio pulses with ultraprecise timing. A pulsar is the crushed core of a massive star that exploded as a supernova. The core is so compressed that more mass than the Sun's squeezes into a ball no wider than Manhattan Island in New York City. This process also revs up its rotation and strengthens its magnetic and electric fields. Various physical processes ensure that most of the particles around a pulsar are either electrons or their antimatter counterparts, positrons. To trace the behavior and energies of these particles, the researchers used a comparatively new type of pulsar model called a “particle in cell” (PIC) simulation. The PIC technique lets scientists explore the pulsar from first principles, starting with a spinning, magnetized neutron star. The computer code injects electrons and positrons at the pulsar's surface and tracks how they interact with the electric and magnetic fields. It's computationally intensive because the particle motions affect the fields and the fields affect the particles, and everything is moving near the speed of light. The simulation shows that most of the electrons tend to race outward from the magnetic poles. Some medium-energy electrons scatter wildly, even heading back to the pulsar. The positrons, on the other hand, mostly flow out at lower latitudes, forming a relatively thin structure called the current sheet. In fact, the highest-energy positrons here — less than 0.1 percent of the total — are capable of producing gamma rays similar to those detected by NASA's Fermi Gamma-ray Space Telescope, which has discovered 216 gamma-ray pulsars. The simulation ran on the Discover supercomputer at NASA’s Center for Climate Simulation at NASA's Goddard Space Flight Center in Greenbelt, Maryland, and the Pleiades supercomputer at NASA’s Ames Research Center in Silicon Valley, California. The model actually tracks “macroparticles,” each of which represents many trillions of electrons or positrons.
  • Fermi News Stories
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    All of the Fermi Gamma-ray Space Telescope's news releases in chronological order

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  • NASA Missions Unveil Magnetar Eruptions in Nearby Galaxies
    2021.01.13
    On April 15, 2020, a brief burst of high-energy light swept through the solar system, triggering instruments on several NASA and European missions. Now, multiple international science teams conclude that the blast came from a supermagnetized stellar remnant known as a magnetar located in a neighboring galaxy. This finding confirms long-held suspicions that some gamma-ray bursts (GRBs) – cosmic eruptions detected somewhere in the sky almost daily – are in fact powerful flares from magnetars relatively close to home. The April 15 event, cataloged as GRB 200415A, is a game changer because, for the first time, the burst's estimated location is almost entirely within the disk of one galaxy – NGC 253, located 11.4 million light-years away. This is the most precise position yet established for a giant flare located well beyond our galaxy. GRBs, the most powerful explosions in the cosmos, can be detected across billions of light-years. Those lasting less than about two seconds, called short GRBs, occur when a pair of orbiting neutron stars both the crushed remnants of exploded stars spiral into each other and merge. Magnetars are neutron stars with the strongest-known magnetic fields, with up to a thousand times the intensity of typical neutron stars and up to 10 trillion times the strength of a refrigerator magnet. Rarely, magnetars produce enormous eruptions called giant flares that produce gamma rays, the highest-energy form of light. Shortly before 4:42 a.m. EDT on April 15, a powerful burst of X-rays and gamma rays triggered, in turn, instruments on NASA's Mars Odyssey mission, Wind satellite, and Fermi Gamma-ray Space Telescope. A ground-based analysis of data from NASA's Neil Gehrels Swift Observatory show that it also detected the event. The pulse of radiation lasted just 140 milliseconds, as fast as a blink of the eye or a finger snap. Fermi's Large Area Telescope (LAT) also detected high-energy gamma rays up to several minutes after this pulse, a surprising finding. Analysis of Fermi and Swift data indicate that the outburst launched a blob of electrons and positrons moving at about 99% the speed of light. The blob expanded as it traveled, following closely behind the light emitted by the giant flare. After a few days, scientists say, they reached the boundary separating the magnetar's region of influence from interstellar space. The light passed through, followed many seconds later by the greatly expanded cloud. This material induced shock waves in gas piled up at the boundary, and the interaction produced the highest-energy emission detected by the LAT.
  • NASA Missions Team Up to Study Unique Magnetar Outburst
    2020.11.04
    On April 28, a supermagnetized stellar remnant known as a magnetar blasted out a simultaneous mix of X-ray and radio signals never observed before. The flare-up included the first fast radio burst (FRB) ever seen from within our Milky Way galaxy and shows that magnetars can produce these mysterious and powerful radio blasts previously only seen in other galaxies. A magnetar is a type of isolated neutron star, the crushed, city-size remains of a star many times more massive than our Sun. What makes a magnetar so special is its intense magnetic field. The field can be 10 trillion times stronger than a refrigerator magnet's and up to a thousand times stronger than a typical neutron star's. This represents an enormous storehouse of energy that astronomers suspect powers magnetar outbursts. The X-ray portion of the synchronous bursts was detected by several satellites, including NASA's Wind mission. The radio component was discovered by the Canadian Hydrogen Intensity Mapping Experiment (CHIME), a radio telescope located at Dominion Radio Astrophysical Observatory in British Columbia and led by several Canadian universities. It was also detected by the NASA-funded Survey for Transient Astronomical Radio Emission 2 (STARE2), a trio of detectors in California and Utah operated by Caltech and NASA’s Jet Propulsion Laboratory in Southern California. The STARE2 data showed that the burst's energy was comparable to FRBs. By the time these bursts occurred, astronomers had already been monitoring their source, a magnetar named SGR 1935+2154, for more than half a day using NASA's Neil Gehrels Swift Observatory, Fermi Gamma-ray Space Telescope, and the Neutron star Interior Composition Explorer (NICER) X-ray telescope mounted atop the International Space Station. About 13 hours later, when the magnetar was out of view for Swift, Fermi and NICER, a special X-ray burst erupted. The blast was seen by the European Space Agency’s INTEGRAL mission, the China National Space Administration’s Huiyan X-ray satellite, and the Russian Konus instrument on Wind. As the half-second-long X-ray burst flared, CHIME and STARE2 detected the radio burst, which lasted only a thousandth of a second. Taken together, the observations strongly suggest that the magnetar produced the Milky Way galaxy's equivalent of an FRB, which means magnetars in other galaxies likely produce at least some of these signals.
  • Build Your Own Fermi Satellite
    2020.04.23
    Building paper models of spacecraft is a fun, interactive way to learn more about NASA's missions. Watch this video to see how NASA's Fermi Gamma-ray Space Telescope paper model comes together, then try making your own. (If you like this project, you can explore making models of other NASA spacecraft here. Launched on June 11, 2008, Fermi observes the cosmos using the highest-energy form of light. Mapping the entire sky every three hours, Fermi provides an important window into the most extreme phenomena of the universe, from gamma-ray bursts and black-hole jets to pulsars, supernova remnants and the origins of cosmic rays. Want to know more about Fermi? Check out these links: Fermi news Fermi: Our Eyes on the Gamma-Ray Sky Fermi Learning Center And watch #NASAatHome to find out about some other fun ways to interact with NASA science and missions at home.
  • NASA Missions Study a Nova's Shock Waves
    2020.04.13
    Unprecedented observations of a nova outburst in 2018 by a trio of satellites, including NASA’s Fermi and NuSTAR space telescopes, have captured the first direct evidence that most of the explosion’s visible light arose from shock waves — abrupt changes of pressure and temperature formed in the explosion debris. A nova is a sudden, short-lived brightening of an otherwise inconspicuous star. It occurs when a stream of hydrogen from a companion star flows onto the surface of a white dwarf, a compact stellar cinder not much larger than Earth. The 2018 outburst originated from a star system later dubbed V906 Carinae, which lies about 13,000 light-years away in the constellation Carina. Over time — perhaps tens of thousands of years for a so-called classical nova like V906 Carinae — the white dwarf’s deepening hydrogen layer reaches critical temperatures and pressures. It then erupts in a runaway reaction that blows off all of the accumulated material. Fermi detected its first nova in 2010 and has observed 14 to date. Gamma rays — the highest-energy form of light — require processes that accelerate subatomic particles to extreme energies, which happens in shock waves. When these particles interact with each other and with other matter, they produce gamma rays. Because the gamma rays appear at about the same time as a nova's peak in visible light, astronomers concluded that shock waves play a more fundamental role in the explosion and its aftermath. The Fermi and BRITE data show flares in both wavelengths at about the same time, so they must share the same source — shock waves in the fast-moving debris. Observations of one flare using NASA’s NuSTAR space telescope showed a much lower level of X-rays compared to the higher-energy Fermi data, likely because the nova ejecta absorbed most of the X-rays. High-energy light from the shock waves was repeatedly absorbed and reradiated at lower energies within the nova debris, ultimately only escaping at visible wavelengths. Astronomers have proposed shock waves as a way to explain the power radiated by various kinds of short-lived events, such as stellar mergers, supernovae — the much bigger blasts associated with the destruction of stars — and tidal disruption events, where black holes shred passing stars. Further studies of nearby novae will serve as laboratories for better understanding the roles shock waves play in other more powerful and more distant events.
  • NASA’s Fermi Finds Vast ‘Halo’ Around Nearby Pulsar
    2019.12.19
    A new study of observations from NASA’s Fermi Gamma-ray Space Telescope has discovered a faint but sprawling glow around a nearby pulsar. If visible to the human eye, this gamma-ray “halo” would appear larger in the sky than the famed Big Dipper star pattern. This structure may provide the solution to a long-standing mystery about the amount of antimatter in our neighborhood. Astronomers have been vexed by a decade-long puzzle about one type of cosmic particle arriving from beyond the solar system. Positrons, the antimatter version of electrons, turn out to unusually abundant near Earth. A neutron star is the crushed core left behind when a star much more massive than the Sun runs out of fuel, collapses under its own weight and explodes as a supernova. We see some neutron stars as pulsars, rapidly spinning objects emitting beams of radio waves, light, X-rays and gamma rays that, much like a lighthouse, regularly sweep across our line of sight. Geminga (pronounced geh-MING-ga) is among the brightest pulsars at gamma-ray energies. To study its halo, scientists had to subtract out all other sources of gamma rays, including diffuse light produced by cosmic ray collisions with interstellar gas clouds. Ten different models of interstellar emission were evaluated. What remained when these sources were removed was a vast, oblong glow spanning some 20 degrees — about 40 times the apparent size of a full Moon — at an energy of 10 billion electron volts (GeV), and even larger at lower energies. The team determined that Geminga alone could be responsible for as much as 20% of the high-energy positrons seen by other space experiments. Extrapolating this to the cumulative emission of positrons from all pulsars in our galaxy, the scientists say it’s clear that pulsars remain the best explanation for the observed excess of positrons.
  • NASA’s Fermi Satellite Clocks a ‘Cannonball' Pulsar
    2019.03.19
    Astronomers using NASA’s Fermi Gamma-ray Space Telescope and the National Science Foundation's Karl G. Jansky Very Large Array (VLA) have found a pulsar hurtling through space at nearly 2.5 million miles an hour -- so fast it could travel the distance between Earth and the Moon in just 6 minutes. Pulsars are superdense, rapidly spinning neutron stars left behind when a massive star explodes. This one, dubbed PSR J0002+6216 (J0002 for short), sports a radio-emitting tail pointing directly toward the expanding debris from a recent supernova explosion. Thanks to its narrow dart-like tail and a fortuitous viewing angle, astronomers can trace this pulsar straight back to its birthplace. Further study of J0002 will help us better understand how these explosions are able to ‘kick’ neutron stars to such high speed. The pulsar is located about 6,500 light-years away in the constellation Cassiopeia. It was discovered in 2017 by a citizen-science project called Einstein@Home, which uses downtime on the computers of volunteers to process Fermi gamma-ray data and has identified 23 gamma-ray pulsars to date. J0002 spins 8.7 times a second, producing a pulse of gamma rays with each rotation, and has about 1.5 times the mass of the Sun. The pulsar lies about 53 light-years from the center of a supernova remnant called CTB 1. Its rapid motion through interstellar gas results in shock waves that produce the tail of magnetic energy and accelerated particles detected at radio wavelengths using the VLA. The tail extends 13 light-years and clearly points back to the center of CTB 1. Using Fermi data and a technique called pulsar timing, the team was able to measure how quickly and in what direction the pulsar was moving across our line of sight thanks to Fermi's 10-year data covering the entire sky. J0002 is speeding through space five times faster than the average pulsar and faster than 99 percent of those with measured speeds. It will eventually escape our galaxy.
  • NASA’s Fermi Mission Shows How Luck Favors the Prepared
    2018.11.08
    In 2017, NASA’s Fermi Gamma-ray Space Telescope played a pivotal role in two important breakthroughs occurring just five weeks apart. But what might seem like extraordinary good luck is really the product of research, analysis, preparation and development extending back more than a century. This video timeline explores the historical progress of research into three cosmic messengers -- gravitational waves, gamma rays and neutrinos -- that Fermi helped bring together. For some of the video content used in this timeline, see this page.
  • Simulations Create New Insights Into Pulsars
    2018.10.10
    Scientists studying what amounts to a computer-simulated “pulsar in a box” are gaining a more detailed understanding of the complex, high-energy environment around spinning neutron stars, also called pulsars. The model traces the paths of charged particles in magnetic and electric fields near the neutron star, revealing behaviors that may help explain how pulsars emit gamma-ray and radio pulses with ultraprecise timing. A pulsar is the crushed core of a massive star that exploded as a supernova. The core is so compressed that more mass than the Sun's squeezes into a ball no wider than Manhattan Island in New York City. This process also revvs up its rotation and strengthens its magnetic and electric fields. Various physical processes ensure that most of the particles around a pulsar are either electrons or their antimatter counterparts, positrons. To trace the behavior and energies of these particles, the researchers used a comparatively new type of pulsar model called a “particle in cell” (PIC) simulation. The PIC technique lets scientists explore the pulsar from first principles, starting with a spinning, magnetized meutron star. The computer code injects electrons and positrons at the pulsar's surface and tracks how they interact with the electric and magnetic fields. It's computationally intensive because the particle motions affect the fields and the fields affect the particles, and everything is moving near the speed of light. The simulation shows that most of the electrons tend to race outward from the magnetic poles. Some medium-energy electrons scatter wildly, even heading back to the pulsar. The positrons, on the other hand, mostly flow out at lower latitudes, forming a relatively thin structure called the current sheet. In fact, the highest-energy positrons here -- less than 0.1 percent of the total -- are capable of producing gamma rays similar to those detected by NASA's Fermi Gamma-ray Space Telescope, which has discovered 216 gamma-ray pulsars. The simulation ran on the Discover supercomputer at NASA’s Center for Climate Simulation at NASA's Goddard Space Flight Center in Greeneblt, Maryland, and the Pleiades supercomputer at NASA’s Ames Research Center in Silicon Valley, California. The model actually tracks “macroparticles,” each of which represents many trillions of electrons or positrons.
  • NASA's Fermi Links Cosmic Neutrino to Monster Black Hole
    2018.07.12
    For the first time ever, scientists using NASA’s Fermi Gamma-ray Space Telescope have found the source of a high-energy neutrino from outside our galaxy. This neutrino travelled 3.7 billion years at nearly light speed before being detected on Earth -- farther than any other neutrino we know the origin of. High-energy neutrinos are hard-to-catch particles that scientists think are created by the most powerful events in the cosmos, like galaxy mergers and material falling onto supermassive black holes. They travel a whisker shy of the speed of light and rarely interact with other matter, so they can travel unimpeded across billions of light-years. On Sept. 22, 2017, the IceCube Neutrino Observatory at the South Pole detected signs of a neutrino striking the Antarctic ice with an energy of about 300 trillion electron volts -- more than 45 times the energy achievable in the most powerful particle accelerator on Earth. This high energy strongly suggested that the neutrino had to be from beyond our solar system. Backtracking the path through IceCube indicated where in the sky the neutrino came from, and automated alerts notified astronomers around the globe to search this region for flares or outbursts that could be associated with the event. Data from Fermi’s Large Area Telescope revealed enhanced gamma-ray emission from a well-known active galaxy at the time the neutrino arrived. This active galaxy is a type called a blazar, where a supermassive black hole with millions to billions of times the Sun’s mass that blasts particle jets outward in opposite directions at nearly the speed of light. Blazars are especially bright and active because one of these jets happens to point almost directly toward Earth. Fermi showed that at the time of the neutrino detection, the blazar TXS 0506+056 was the most active it had been in a decade. The discovery is a giant leap forward in a growing field called multimessenger astronomy, where new cosmic signals like neutrinos and gravitational waves are definitively linked to sources that emit light.
  • Fermi Satellite Celebrates 10 Years of Discoveries
    2018.06.11
    On June 11, NASA’s Fermi Gamma-ray Space Telescope celebrates a decade of using gamma rays, the highest-energy form of light in the cosmos, to study black holes, neutron stars, and other extreme cosmic objects and events. Fermi’s main instrument, the Large Area Telescope (LAT), has observed more than 5,000 individual gamma-ray sources. In 1949, Enrico Fermi — an Italian-American pioneer in high-energy physics and Nobel laureate for whom the mission was named — suggested that cosmic rays, particles traveling at nearly the speed of light, could be propelled by supernova shock waves. In 2013, Fermi’s LAT used gamma rays to prove these stellar remnants are at least one source of the speedy particles. Fermi’s all-sky map, produced by the LAT, has revealed two massive structures extending above and below the plane of the Milky Way. These two “bubbles” span 50,000 light-years and were probably produced by the supermassive black hole at the center of the galaxy only a few million years ago. The Gamma-ray Burst Monitor (GBM), Fermi’s secondary instrument, can see the entire sky at any instant, except the portion blocked by Earth. The satellite has observed over 2,300 gamma-ray bursts, the most luminous events in the universe. Gamma-ray bursts occur when massive stars collapse or neutron stars or black holes merge and drive jets of particles at nearly the speed of light. In those jets, matter travels at different speeds and collides, emitting gamma rays. On Aug. 17, 2017, Fermi detected a gamma-ray burst from a powerful explosion in the constellation Hydra. At almost the same time, the National Science Foundation’s Laser Interferometer Gravitational-wave Observatory detected ripples in space-time from the same event, the merger of two neutron stars. This was the first time light and gravitational waves were detected from the same source. Scientists also used another gamma-ray burst detected by Fermi to confirm Einstein’s theory that space-time is smooth and continuous.
  • Doomed Neutron Stars Create Blast of Light and Gravitational Waves
    2017.10.16
    For the first time, NASA scientists have detected light tied to a gravitational-wave event, thanks to two merging neutron stars in the galaxy NGC 4993, located about 130 million light-years from Earth in the constellation Hydra. Shortly after 8:41 a.m. EDT on Aug. 17, NASA's Fermi Gamma-ray Space Telescope picked up a pulse of high-energy light from a powerful explosion, which was immediately reported to astronomers around the globe as a short gamma-ray burst. The scientists at the National Science Foundation’s Laser Interferometer Gravitational-wave Observatory (LIGO) detected gravitational waves dubbed GW170817 from a pair of smashing stars tied to the gamma-ray burst, encouraging astronomers to look for the aftermath of the explosion. Shortly thereafter, the burst was detected as part of a follow-up analysis by ESA’s (European Space Agency’s) INTEGRAL satellite. NASA's Swift, Hubble, Chandra and Spitzer missions, along with dozens of ground-based observatories, including the NASA-funded Pan-STARRS survey, later captured the fading glow of the blast's expanding debris. Neutron stars are the crushed, leftover cores of massive stars that previously exploded as supernovas long ago. The merging stars likely had masses between 10 and 60 percent greater than that of our Sun, but they were no wider than Washington, D.C. The pair whirled around each other hundreds of times a second, producing gravitational waves at the same frequency. As they drew closer and orbited faster, the stars eventually broke apart and merged, producing both a gamma-ray burst and a rarely seen flare-up called a "kilonova." Neutron star mergers produce a wide variety of light because the objects form a maelstrom of hot debris when they collide. Merging black holes -- the types of events LIGO and its European counterpart, Virgo, have previously seen -- very likely consume any matter around them long before they crash, so we don't expect the same kind of light show. Within hours of the initial Fermi detection, LIGO and the Virgo detector at the European Gravitational Observatory near Pisa, Italy, greatly refined the event's position in the sky with additional analysis of gravitational wave data. Ground-based observatories then quickly located a new optical and infrared source -- the kilonova -- in NGC 4993. To Fermi, this appeared to be a typical short gamma-ray burst, but it occurred less than one-tenth as far away as any other short burst with a known distance, making it among the faintest known. Astronomers are still trying to figure out why this burst is so odd, and how this event relates to the more luminous gamma-ray bursts seen at much greater distances. NASA’s Swift, Hubble and Spitzer missions followed the evolution of the kilonova to better understand the composition of this slower-moving material, while Chandra searched for X-rays associated with the remains of the ultra-fast jet.

Stills/Graphics

These pages contain still images, illustrations and graphics.
  • Poster: Fermi's Gamma-ray Cosmos
    2015.10.09
    This poster summarizes the career to date of NASA's Fermi Gamma-ray Space Telescope. The central image is a map of the whole sky at gamma-ray wavelengths accumulated over six years of operations. The poster also discusses other Fermi findings, including a black widow pulsar, the Fermi Bubbles rising thousands of light-years out of our galaxy's center, a giant gamma-ray flare from the Crab Nebula, and many more.

    The poster is available in a variety of resolutions.

    Credit: NASA/Fermi/Sonoma State University/A. Simonnet

  • Fermi Satellite Celebrates 10 Years of Discoveries
    2018.06.11
    On June 11, NASA’s Fermi Gamma-ray Space Telescope celebrates a decade of using gamma rays, the highest-energy form of light in the cosmos, to study black holes, neutron stars, and other extreme cosmic objects and events. Fermi’s main instrument, the Large Area Telescope (LAT), has observed more than 5,000 individual gamma-ray sources. In 1949, Enrico Fermi — an Italian-American pioneer in high-energy physics and Nobel laureate for whom the mission was named — suggested that cosmic rays, particles traveling at nearly the speed of light, could be propelled by supernova shock waves. In 2013, Fermi’s LAT used gamma rays to prove these stellar remnants are at least one source of the speedy particles. Fermi’s all-sky map, produced by the LAT, has revealed two massive structures extending above and below the plane of the Milky Way. These two “bubbles” span 50,000 light-years and were probably produced by the supermassive black hole at the center of the galaxy only a few million years ago. The Gamma-ray Burst Monitor (GBM), Fermi’s secondary instrument, can see the entire sky at any instant, except the portion blocked by Earth. The satellite has observed over 2,300 gamma-ray bursts, the most luminous events in the universe. Gamma-ray bursts occur when massive stars collapse or neutron stars or black holes merge and drive jets of particles at nearly the speed of light. In those jets, matter travels at different speeds and collides, emitting gamma rays. On Aug. 17, 2017, Fermi detected a gamma-ray burst from a powerful explosion in the constellation Hydra. At almost the same time, the National Science Foundation’s Laser Interferometer Gravitational-wave Observatory detected ripples in space-time from the same event, the merger of two neutron stars. This was the first time light and gravitational waves were detected from the same source. Scientists also used another gamma-ray burst detected by Fermi to confirm Einstein’s theory that space-time is smooth and continuous.
  • Ten Years of High-Energy Gamma-ray Bursts
    2019.06.13
    For a decade, NASA’s Fermi Gamma-ray Space Telescope has scanned the sky for gamma-ray bursts (GRBs), the universe’s most luminous explosions. A new catalog of the highest-energy blasts provides scientists with fresh insights into how they work. GRBs emit gamma rays, the highest-energy form of light. Most GRBs occurs when some types of massive stars run out of fuel and collapse to create new black holes. Others happen when two neutron stars, superdense remnants of stellar explosions, merge. Both kinds of cataclysmic events create jets of particles that move near the speed of light. The gamma rays are produced in collisions of fast-moving material inside the jets and when the jets interact with the environment around the star. Astronomers can distinguish the two GRB classes by the duration of their lower-energy gamma rays. Short bursts from neutron star mergers last less than 2 seconds, while long bursts typically continue for a minute or more. The new catalog, which includes 17 short and 169 long bursts, describes 186 events seen by Fermi’s Large Area Telescope (LAT) over the last 10 years. The LAT sees about one-fifth of the sky at any time and records gamma rays with energies above 30 million electron volts (MeV) — millions of times the energy of visible light. Fermi’s other instrument, the Gamma-ray Burst Monitor (GBM), sees the entire sky that isn’t blocked by Earth and detects lower-energy emission. All told, the GBM has detected more than 2,300 GRBs so far.
    GRB 130427A set the record for the highest-energy individual gamma ray detected by the LAT instrument. It also holds the record for the most gamma rays — 17 — with energies above 10 billion electron volts. The animation below illustrates the formation of a long GRB and its gamma-ray jets.

    GRB 090510 helped test Einstein’s theory that all forms of light travel through the vacuum of space at the same speed. Learn more about the event in the video below, starting at 0:59.
  • Fermi Sees the Moon in Gamma Rays
    2019.08.15
    If our eyes could see high-energy radiation called gamma rays, the Moon would appear brighter than the Sun! That’s how NASA’s Fermi Gamma-ray Space Telescope has seen our neighbor in space for the past decade. Gamma-ray observations are not sensitive enough to clearly see the shape of the Moon’s disk or any surface features. Instead, Fermi’s Large Area Telescope (LAT) detects a prominent glow centered on the Moon’s position in the sky. Scientists have been analyzing the Moon’s gamma-ray glow as a way of better understanding another type of radiation from space: fast-moving particles called cosmic rays. Cosmic rays are mostly protons accelerated by some of the most energetic phenomena in the universe. Because the particles are electrically charged, they’re strongly affected by magnetic fields, which the Moon lacks. As a result, even low-energy cosmic rays can reach the surface, turning the Moon into a handy space-based particle detector. When cosmic rays strike, they interact with the powdery surface of the Moon, called the regolith, to produce gamma-ray emission. The Moon absorbs most of these gamma rays, but some of them escape. Mazziotta and Loparco analyzed Fermi LAT lunar observations to show how the view has improved during the mission. They rounded up data for gamma rays with energies above 31 million electron volts — 10 million times greater than the energy of visible light — and organized them over time, showing how longer exposures improve the view. Seen at these energies, the Moon would never go through its monthly cycle of phases and would always look full.
  • A New Era in Gamma-ray Science
    2019.11.20
    A pair of distant explosions discovered by NASA’s Fermi Gamma-ray Space Telescope and Neil Gehrels Swift Observatory have produced the highest-energy light yet seen from these events, called gamma-ray bursts (GRBs). The detections, made by two different ground-based observatories, provide new insights into the mechanisms driving gamma-ray bursts. Astronomers first recognized the GRB phenomenon 46 years ago. The blasts appear at random locations in the sky about once a day, on average. The most common type of GRB occurs when a star much more massive than the Sun runs out of fuel. Its core collapses and forms a black hole, which then blasts jets of particles outward at nearly the speed of light. These jets pierce the star and continue into space. They produce an initial pulse of gamma rays — the most energetic form of light — that typically lasts about a minute. As the jets race outward, they interact with surrounding gas and emit light across the spectrum, from radio to gamma rays. These so-called afterglows can be detected up to months — and rarely, even years — after the burst at longer wavelengths. Much of what astronomers have learned about GRBs over the past couple of decades has come from observing their afterglows at lower energies. Now, thanks to these new ground-based detections, they're seeing the gamma rays from GRBs in a whole new way. On Jan. 14, 2019, just before 4 p.m. EST, both the Fermi and Swift satellites detected a spike of gamma rays from the constellation Fornax. The missions alerted the astronomical community to the location of the burst, dubbed GRB 190114C. One facility receiving the alerts was the Major Atmospheric Gamma Imaging Cherenkov (MAGIC) observatory, located on La Palma in the Canary Islands, Spain. Both of its 17-meter telescopes automatically turned to the site of the fading burst. They began observing the GRB just 50 seconds after it was detected and captured the most energetic gamma rays yet seen from these events. The energy of visible light ranges from about 2 to 3 electron volts. In 2013, Fermi’s Large Area Telescope detected light reaching an energy of 95 billion electron volts (GeV), then the highest seen from a burst. This falls just shy of 100 GeV, the threshold for so-called very high-energy (VHE) gamma rays. With GRB 190114C, MAGIC became the first facility to report unambiguous VHE emission, with energies up to a trillion electron volts. That’s 10 times the peak energy Fermi has seen to date. Data from a different burst, which Fermi and Swift both discovered, confirm afterglows reach these energies. Ten hours after the alerts, the High Energy Stereoscopic System (H.E.S.S.) pointed its large, 28-meter gamma-ray telescope to the location of the burst, called GRB 180720B. A careful analysis carried out during the weeks following the event revealed that H.E.S.S. clearly detected VHE gamma rays with energies up to 440 GeV. Even more remarkable, the glow continued for two hours following the start of the observation. Catching this emission so long after the GRB’s detection is both a surprise and an important new discovery.
  • Fermi Scientists Introduce Gamma-ray Constellations
    2018.10.17
    Scientists with NASA’s Fermi Gamma-ray Space Telescope have devised a set of modern constellations constructed from sources in the gamma-ray sky to celebrate the mission’s 10th year of operations. The new constellations include a few characters from modern myths. Among them are the Little Prince, the time-warping TARDIS from “Doctor Who,” Godzilla and his heat ray, the antimatter-powered U.S.S. Enterprise from “Star Trek: The Original Series” and the Hulk, the product of a gamma-ray experiment gone awry. One way or another, all of the gamma-ray constellations tie into Fermi science. Long ago, sky watchers linked the brightest stars into patterns reflecting animals, heroes, monsters and even scientific instruments into what is now an official collection of 88 constellations. By 2015, Fermi's Large Area Telescope had mapped some 3,000 gamma-ray sources -- 10 times the number known before the mission. For the first time, the number of known gamma-ray sources was comparable to the number of bright stars in the traditional constellations, inspiring the team to develop a set for the high-energy sky. The 21 gamma-ray constellations include famous landmarks in countries contributing to Fermi science. Others represent scientific ideas or tools, from Schrödinger’s Cat -- both alive and dead, thanks to quantum physics -- to Albert Einstein, Radio Telescope and Black Widow Spider, the namesake of a class of pulsars that evaporate their unfortunate companion stars. A web-based interactive showcases the constellations on an image of the whole gamma-ray sky mapped by Fermi.
  • Fermi discovers giant gamma-ray bubbles in the Milky Way
    2010.11.09
    Using data from NASA's Fermi Gamma-ray Space Telescope, scientists have recently discovered a gigantic, mysterious structure in our galaxy. This never-before-seen feature looks like a pair of bubbles extending above and below our galaxy's center.

    But these enormous gamma-ray emitting lobes aren't immediately visible in the Fermi all-sky map. However, by processing the data, a group of scientists was able to bring these unexpected structures into sharp relief.

    Each lobe is 25,000 light-years tall and the whole structure may be only a few million years old. Within the bubbles, extremely energetic electrons are interacting with lower-energy light to create gamma rays, but right now, no one knows the source of these electrons.

    Are the bubbles remnants of a massive burst of star formation? Leftovers from an eruption by the supermassive black hole at our galaxy's center? Or or did these forces work in tandem to produce them? Scientists aren't sure yet, but the more they learn about this amazing structure, the better we'll understand the Milky Way.

    For an animation that shows the inverse Compton scattering responsible for the gamma rays, go to #10690.

    For an animation that shows an artist's interpretation of the Milky Way galaxy and the lobes, go to#10691.

  • Terrestrial Gamma-ray Flashes Create Antimatter
    2011.01.10
    NASA's Fermi Gamma-ray Space Telescope has detected beams of antimatter launched by thunderstorms. Acting like enormous particle accelerators, the storms can emit gamma-ray flashes, called TGFs, and high-energy electrons and positrons. Scientists now think that most TGFs produce particle beams and antimatter.

    For additional animations showing bremsstrahlung and pair production gamma ray reactions, go here.

    For more visualizations showing Fermi's TGF detections, go to#3747, #3748, and #3756.

    For animations of the Fermi spacecraft and matter/antimatter, go to#10707 and #10651.

  • Fermi's Latest Gamma-ray Census Highlights Cosmic Mysteries
    2011.09.09
    Every three hours, NASA's Fermi Gamma-ray Space Telescope scans the entire sky and deepens its portrait of the high-energy universe. Every year, the satellite's scientists reanalyze all of the data it has collected, exploiting updated analysis methods to tease out new sources. These relatively steady sources are in addition to the numerous transient events Fermi detects, such as gamma-ray bursts in the distant universe and flares from the sun.

    Earlier this year, the Fermi team released its second catalog of sources detected by the satellite's Large Area Telescope (LAT), producing an inventory of 1,873 objects shining with the highest-energy form of light. More than half of these sources are active galaxies whose supermassive black hole centers are causing the gamma-ray emissions.

  • Fermi Stills
    Gallery
    A collection of Fermi-related still images, illustrations, graphics and short clips.

Spacecraft

  • Fermi Gamma-ray Space Telescope Spacecraft Animation
    2021.02.19
    NASA's Fermi Gamma-ray Space Telescope is a powerful space observatory that opens a wide window on the universe. Gamma rays are the highest-energy form of light, and the gamma-ray sky is spectacularly different from the one we perceive with our own eyes. Fermi enables scientists to answer persistent questions across a broad range of topics, including supermassive black-hole systems, pulsars, the origin of cosmic rays, and searches for signals of new physics.
  • The GLAST (Fermi) Spacecraft in Orbit
    2007.09.14
    GLAST will be launched into a circular orbit around the Earth at an altitude of about 560 km (350 miles). At that altitude, the observatory will circle Earth every 90 minutes. In sky-survey mode, GLAST will be able to view the entire sky in just two orbits, or about 3 hours. Because gamma rays in the GLAST's energy band are unable to penetrate the Earth's atmostphere, it is essential that GLAST perform its observations from space.
  • 360 Degrees of GLAST
    2007.09.14
    GLAST will carry two instruments: the Large Area Telescope (LAT) and the GLAST Burst Monitor (GBM). The LAT is GLAST's primary instrument and consists of four components: the Tracker, the Calorimeter, the Anticoincidence Detector (ACD), and the Data Acquisition System (DAQ). These instrument components working together will detect gamma rays by using Einstein's famous equation (E=mc(squared) in a technique known as pair production. The GLAST Burst Monitor is a complementary instrument and consists of low-energy detectors, high-energy detectors, and data processing unit. The GBM can see all directions at once, except for the area where Earth blocks its view. When the GBM detects a bright gamma-ray burst, it immediately sends a signal to the LAT to observe that area of the sky.
  • Fermi's LAT Instrument
    2012.02.25
    Fermi's Large Area Telescope (LAT) detects particles produced in a physical process known as pair production that epitomizes Einstein's famous equation, E=mc2. When a gamma ray, which is pure energy (E), slams into a layer of tungsten in one of the tracking towers that compose the LAT, it creates mass (m) in the form of a pair of subatomic particles, an electron and its antimatter counterpart, a positron. Several layers of high-precision silicon detectors track the particles as they move through the instrument. The direction of the incoming gamma ray is determined by projecting the particle paths backward. The particles travel through the trackers until they reach a separate detector called a calorimeter, which absorbs and measures their energies. The LAT produces gamma-ray images of astronomical objects, while also determining the energy of each detected gamma ray.
  • Fermi Terrestrial Gamma-ray Flash (TGF) Animations
    2011.01.10
    NASA's Fermi Gamma-ray Space Telescope has detected beams of antimatter launched by thunderstorms. Acting like enormous particle accelerators, the storms can emit gamma-ray flashes, called TGFs, and high-energy electrons and positrons. Scientists now think that most TGFs produce particle beams and antimatter.
  • Fermi Collision Avoidance Animations
    2013.04.30
    Animations of the Fermi Gamma-ray Space Telescope and the Cosmos 1805 Tselina-D Soviet satellite from the Fermi Collision Avoidance video.
  • Fermi's Gamma-ray Burst Monitor
    2018.08.17
    The Gamma-ray Burst Monitor (GBM) is one of the instruments aboard the Fermi Gamma-ray Space Telescope. The GBM studies gamma-ray bursts, the most powerful explosions in the universe, as well as other flashes of gamma rays. Gamma-ray bursts are created when massive stars collapse into black holes or when two superdense stars merge, also producing a black hole. The GBM sees these bursts across the entire sky, and scientists are using its observations to learn more about the universe.

    Music:

    The Success by Keys of Moon | https://soundcloud.com/keysofmoon

    Music promoted by https://www.free-stock-music.com

    Creative Commons Attribution 3.0 Unported License

    https://creativecommons.org/licenses/by/3.0/deed.en_US

    Watch this video on the NASA Goddard YouTube channel.

    Complete transcript available.

  • GLAST's New Window on the Universe
    2007.09.14
    The Universe is home to numerous extoic and beautiful phenomena, some of which can generate inconceiveable amounts of energy. GLAST (Gamma-ray Large Area Telescope) will open this high-energy world as the first imaging gamma-ray observatory to survey the entire sky every day and with high sensitivity. Astronomers will gain a superior tool to study how black holes, notorious for pulling matter in, can accelerate jets of gas outward at fantastic speeds. Physicists will be able to search for signals of new fundamental processes that are inaccessable in ground-based accelerators and observatories. And scientists will have a unique opportunity to learn about the every-changing Universe at extreme energies.
  • GLAST Launch and Deployment
    2007.09.14
    GLAST's launch is scheduled for early 2008 from Cape Canaveral Air Station on Florida's eastern coast. GLAST will be carried on a Delta II Heavy launch vehicle, with 9 solid rocket boosters. The solids are actually from the Delta III series (hence the term 'heavy'), mounted on a Delta II. It has a 10-foot fairing and two stages. Stowed in the launch vehicle, the spacecraft is 9.2 feet (2.8 meters) high by 8.2 feet (2.5 meters) in diameter. Once deployed, GLAST becomes a little bit taller and much wider (15 meters) with the Ku-band antenna deployed and the solar arrays extended.
  • Fermi Improves Its Vision For Thunderstorm Gamma-ray Flashes
    2012.12.06
    Thanks to improved data analysis techniques and a new operating mode, the Gamma-ray Burst Monitor (GBM) aboard NASA's Fermi Gamma-ray Space Telescope is now 10 times better at catching the brief outbursts of high-energy light mysteriously produced above thunderstorms.

    The outbursts, known as terrestrial gamma-ray flashes (TGFs), last only a few thousandths of a second, but their gamma rays rank among the highest-energy light that naturally occurs on Earth. The enhanced GBM discovery rate helped scientists show most TGFs also generate a strong burst of radio waves, a finding that will change how scientists study this poorly understood phenomenon.

    Lightning emits a broad range of very low frequency (VLF) radio waves, often heard as pop-and-crackle static when listening to AM radio. The World Wide Lightning Location Network (WWLLN), a research collaboration operated by the University of Washington in Seattle, routinely detects these radio signals and uses them to pinpoint the location of lightning discharges anywhere on the globe to within about 12 miles (20 km).

    Scientists have known for a long time TGFs were linked to strong VLF bursts, but they interpreted these signals as originating from lightning strokes somehow associated with the gamma-ray emission.

    "Instead, we've found when a strong radio burst occurs almost simultaneously with a TGF, the radio emission is coming from the TGF itself," said co-author Michael Briggs, a member of the GBM team.

    The researchers identified much weaker radio bursts that occur up to several thousandths of a second before or after a TGF. They interpret these signals as intracloud lightning strokes related to, but not created by, the gamma-ray flash.

    Scientists suspect TGFs arise from the strong electric fields near the tops of thunderstorms. Under certain conditions, the field becomes strong enough that it drives a high-speed upward avalanche of electrons, which give off gamma rays when they are deflected by air molecules.

    "What's new here is that the same electron avalanche likely responsible for the gamma-ray emission also produces the VLF radio bursts, and this gives us a new window into understanding this phenomenon," said Joseph Dwyer, a physics professor at the Florida Institute of Technology in Melbourne, Fla., and a member of the study team.

    Because the WWLLN radio positions are far more precise than those based on Fermi's orbit, scientists will develop a much clearer picture of where TGFs occur and perhaps which types of thunderstorms tend to produce them.

    Watch this video on YouTube.

  • Fermi Pulsar Interactive Videos
    2011.11.03
    These videos accompany the Fermi Pulsar Interactive here.
  • Fermi Launch - June 11, 2008
    2010.12.20
    Footage of the Fermi satellite launch from Cape Canaveral Air Station on June 11, 2008.
  • GLAST LAT Integration - B-Roll
    2007.09.17
    In fall of 2006, the LAT was shipped to the General Dynamics facility in Arizona for integration onto the spacecraft bus. The General Dynamics spacecraft bus provides the power, data, and pointing resources that will enable the LAT to perform its survey of the Universe. Subsequent to the mechanical integration, the command, data, and power interfaces between the instrument and the spacecraft were tested rigorously to insure the compatibility of this spaceflight hardware that had been manufactured all around the globe.
  • GLAST LAT Testing - B-Roll
    2007.09.17
    The GLAST LAT (Large Area Telescope) was tested extensively during the summer of 2006 at the U.S. Naval Research Laboratory in Washington, DC. The NRL also contributed to the GLAST project by managing the construction of the LAT Calorimeter.

Presentation Resources

  • Fermi TGF Visualization for Science on a Sphere
    2018.05.18
    Visualization of ten years of Fermi observations of Terrestrial Gamma-ray Flashes (TGFs). This version is optimized for display on normal screens, has labels, and dates for each data pass.
  • Fermi Hyperwall--2016 AAS Technical
    2016.01.04
    3x3 hyperwall-resolution animation of the Fermi spacecraft.

    Credit: NASA's Goddard Space Flight Center/CI Lab

  • Fermi Hyperwall--2016 AAS, A Walk Through Fermi Science
    2016.01.04
    For additional Fermi hyperwall visuals please check the second hyperwall page

  • Fermi Hints at Dark Matter
    2014.04.03
    Using public data from NASA's Fermi Gamma-ray Space Telescope, independent scientists at the Fermi National Accelerator Laboratory, Harvard University, MIT and the University of Chicago have developed new maps showing that the galactic center produces more high-energy gamma rays than can be explained by known sources and that this excess emission is consistent with some forms of dark matter.

    No one knows the true nature of dark matter, but WIMPs, or Weakly Interacting Massive Particles, represent a leading class of candidates. Theorists have envisioned a wide range of WIMP types, some of which may either mutually annihilate or produce an intermediate, quickly decaying particle when they collide. Both of these pathways end with the production of gamma rays — the most energetic form of light — at energies within the detection range of Fermi's Large Area Telescope (LAT).

    The galactic center teems with gamma-ray sources, from interacting binary systems and isolated pulsars to supernova remnants and particles colliding with interstellar gas. It's also where astronomers expect to find the galaxy's highest density of dark matter, which only affects normal matter and radiation through its gravity. Large amounts of dark matter attract normal matter, forming a foundation upon which visible structures, like galaxies, are built.

    When the astronomers carefully subtract all known gamma-ray sources from LAT observations of the galactic center, a patch of leftover emission remains. This excess appears most prominent at energies between 1 and 3 billion electron volts (GeV) — roughly a billion times greater than that of visible light — and extends outward at least 5,000 light-years from the galactic center. The researchers find these features difficult to reconcile with other explanations proposed, such as undiscovered pulsars. The gamma-ray spectrum of the excess, its symmetry around the galactic center and its overall brightness, is, however, consistent with annihilations of dark matter particles in the mass range of 31 and 40 GeV.

    The scientists note that discoveries in other astronomical objects, such as dwarf galaxies, and experiments on Earth designed to directly detect dark matter particles will be needed to confirm this interpretation.
    For more information: Fermi Data Tantalize With New Clues To Dark Matter

  • Briefing Materials: NASA Missions Explore Record-Setting Cosmic Blast
    2013.11.21
    On Thursday, Nov. 21, 2013, NASA held a media teleconference to discuss new findings related to a brilliant gamma-ray burst detected on April 27. Audio of the teleconference is available for download here.
  • Fermi's Five-year View of the Gamma-ray Sky
    2013.08.21
    This all-sky view shows how the sky appears at energies greater than 1 billion electron volts (GeV) according to five years of data from NASA's Fermi Gamma-ray Space Telescope. (For comparison, the energy of visible light is between 2 and 3 electron volts.) The image contains 60 months of data from Fermi's Large Area Telescope; for better angular resolution, the map shows only gamma rays converted at the front of the instrument's tracker. Brighter colors indicate brighter gamma-ray sources. The map is shown in galactic coordinates, which places the midplane of our galaxy along the center.

    The five-year Fermi map is available in multiple resolutions below, along with additional plots containing reference information and identifying some of the brightest sources.

  • Fermi Discovers Youngest Millisecond Pulsar
    2011.11.03
    An international team of scientists using NASA's Fermi Gamma-ray Space Telescope has discovered a surprisingly powerful millisecond pulsar that challenges existing theories about how these objects form. At the same time, another team has exploited improved analytical techniques to locate nine new gamma-ray pulsars in Fermi data.

    A pulsar, also called a neutron star, is the closest thing to a black hole astronomers can observe directly, crushing half a million times more mass than Earth into a sphere no larger than a city. This matter is so compressed that even a teaspoonful weighs as much as Mount Everest.

    Typically, millisecond pulsars are a billion years or more old, ages commensurate with a stellar lifetime. But in the Nov. 3 issue of Science, the Fermi team reveals a bright, energetic millisecond pulsar only 25 million years old.

    The object, named PSR J1823—3021A, lies within NGC 6624, a spherical assemblage of ancient stars called a globular cluster, one of about 160 similar objects that orbit our galaxy. The cluster is about 10 billion years old and lies about 27,000 light-years away toward the constellation Sagittarius.

    "With this new batch of pulsars, Fermi now has detected more than 100, which is an exciting milestone when you consider that before Fermi's launch only seven of them were known to emit gamma rays," said Pablo Saz Parkinson, an astrophysicist at the Santa Cruz Institute for Particle Physics, University of California Santa Cruz.

  • Fermi Pulsar Interactive Videos
    2011.11.03
    These videos accompany the Fermi Pulsar Interactive here.
  • Fermi discovers giant gamma-ray bubbles in the Milky Way
    2010.11.09
    Using data from NASA's Fermi Gamma-ray Space Telescope, scientists have recently discovered a gigantic, mysterious structure in our galaxy. This never-before-seen feature looks like a pair of bubbles extending above and below our galaxy's center.

    But these enormous gamma-ray emitting lobes aren't immediately visible in the Fermi all-sky map. However, by processing the data, a group of scientists was able to bring these unexpected structures into sharp relief.

    Each lobe is 25,000 light-years tall and the whole structure may be only a few million years old. Within the bubbles, extremely energetic electrons are interacting with lower-energy light to create gamma rays, but right now, no one knows the source of these electrons.

    Are the bubbles remnants of a massive burst of star formation? Leftovers from an eruption by the supermassive black hole at our galaxy's center? Or or did these forces work in tandem to produce them? Scientists aren't sure yet, but the more they learn about this amazing structure, the better we'll understand the Milky Way.

    For an animation that shows the inverse Compton scattering responsible for the gamma rays, go to #10690.

    For an animation that shows an artist's interpretation of the Milky Way galaxy and the lobes, go to#10691.

  • NASM 2015: Our Violent Universe
    2015.11.23
    On September 23, 2015, NASA held a special event at the Smithsonian National Air and Space Museum. “Our Violent Universe” put a spotlight on the latest high energy astrophysics research coming out of NASA, highlighting key missions such as Swift, Fermi, Chandra, NuSTAR, and Hubble. NASA scientists who are leaders in this field gave presentations on some of the most exciting events in our universe, including black holes, supernovae, and gamma ray bursts. NASA does an annual presentation at the Smithsonian National Air and Space Museum to share the latest science from the agency.
  • Ten Years of High-Energy Gamma-ray Bursts
    2019.06.13
    For a decade, NASA’s Fermi Gamma-ray Space Telescope has scanned the sky for gamma-ray bursts (GRBs), the universe’s most luminous explosions. A new catalog of the highest-energy blasts provides scientists with fresh insights into how they work. GRBs emit gamma rays, the highest-energy form of light. Most GRBs occurs when some types of massive stars run out of fuel and collapse to create new black holes. Others happen when two neutron stars, superdense remnants of stellar explosions, merge. Both kinds of cataclysmic events create jets of particles that move near the speed of light. The gamma rays are produced in collisions of fast-moving material inside the jets and when the jets interact with the environment around the star. Astronomers can distinguish the two GRB classes by the duration of their lower-energy gamma rays. Short bursts from neutron star mergers last less than 2 seconds, while long bursts typically continue for a minute or more. The new catalog, which includes 17 short and 169 long bursts, describes 186 events seen by Fermi’s Large Area Telescope (LAT) over the last 10 years. The LAT sees about one-fifth of the sky at any time and records gamma rays with energies above 30 million electron volts (MeV) — millions of times the energy of visible light. Fermi’s other instrument, the Gamma-ray Burst Monitor (GBM), sees the entire sky that isn’t blocked by Earth and detects lower-energy emission. All told, the GBM has detected more than 2,300 GRBs so far.
    GRB 130427A set the record for the highest-energy individual gamma ray detected by the LAT instrument. It also holds the record for the most gamma rays — 17 — with energies above 10 billion electron volts. The animation below illustrates the formation of a long GRB and its gamma-ray jets.

    GRB 090510 helped test Einstein’s theory that all forms of light travel through the vacuum of space at the same speed. Learn more about the event in the video below, starting at 0:59.
  • Multimessenger Timeline Resources
    2018.11.08
    The media elements below appear in the multimessenger astronomy video "Luck Favors the Prepared."
  • Pulsar Current Sheets - All Particle Flows
    2018.10.10
    Scientists studying what amounts to a computer-simulated “pulsar in a box” are gaining a more detailed understanding of the complex, high-energy environment around spinning neutron stars, also called pulsars. The model traces the paths of charged particles in magnetic and electric fields near the neutron star, revealing behaviors that may help explain how pulsars emit gamma-ray and radio pulses with ultraprecise timing. A pulsar is the crushed core of a massive star that exploded as a supernova. The core is so compressed that more mass than the Sun's squeezes into a ball no wider than Manhattan Island in New York City. This process also revvs up its rotation and strengthens its magnetic and electric fields. Various physical processes ensure that most of the particles around a pulsar are either electrons or their antimatter counterparts, positrons. To trace the behavior and energies of these particles, the researchers used a comparatively new type of pulsar model called a “particle in cell” (PIC) simulation. The PIC technique lets scientists explore the pulsar from first principles, starting with a spinning, magnetized meutron star. The computer code injects electrons and positrons at the pulsar's surface and tracks how they interact with the electric and magnetic fields. It's computationally intensive because the particle motions affect the fields and the fields affect the particles, and everything is moving near the speed of light. This visualization shows the all the simulation particles, the low speed (bulk) particle flows, and the high energy electrons and positrons, moviing around the pulsar. Darker blue trails represent slow electrons, darker red trails represent slow positrons. White trails indicate high speed (relativisitic) particles.
  • Pulsar Current Sheets - Bulk Particle Trajectories
    2018.10.10
    Scientists studying what amounts to a computer-simulated “pulsar in a box” are gaining a more detailed understanding of the complex, high-energy environment around spinning neutron stars, also called pulsars. The model traces the paths of charged particles in magnetic and electric fields near the neutron star, revealing behaviors that may help explain how pulsars emit gamma-ray and radio pulses with ultraprecise timing. A pulsar is the crushed core of a massive star that exploded as a supernova. The core is so compressed that more mass than the Sun's squeezes into a ball no wider than Manhattan Island in New York City. This process also revvs up its rotation and strengthens its magnetic and electric fields. Various physical processes ensure that most of the particles around a pulsar are either electrons or their antimatter counterparts, positrons. To trace the behavior and energies of these particles, the researchers used a comparatively new type of pulsar model called a “particle in cell” (PIC) simulation. The PIC technique lets scientists explore the pulsar from first principles, starting with a spinning, magnetized meutron star. The computer code injects electrons and positrons at the pulsar's surface and tracks how they interact with the electric and magnetic fields. It's computationally intensive because the particle motions affect the fields and the fields affect the particles, and everything is moving near the speed of light. This visualization shows the bulk particle flows, made up of low-energy electrons and positrons which comprise the majority of the particles. Darker blue trails represent slow electrons, darker red trails represent slow positrons. White trails indicate high speed (relativisitic) particles.
  • Blazar Animations
    2018.07.12
    This animation shows the central supermassive black hole of a blazar. The black hole is surrounded by a bright accretion disk and a darker torus of gas and dust. A bright jet of particles emerges from above and below the black hole. Collisions within the jet produce high-energy photons such as gamma rays. A flare from the blazar results in an additional burst of gamma rays and neutrinos.
  • How to make a gamma ray
    2010.11.09
    A series of animations showing how gamma rays can be created through various particle interactions.
  • How Cosmic-ray Protons Make Gamma rays
    2010.02.13
    In the simplest and most common interaction, a cosmic-ray proton strikes another proton. The protons survive the collision, but their interaction creates an unstable particle — a pion — with only 14 percent the mass of a proton. In 10 millionths of a billionth of a second, the pion decays into a pair of gamma-ray photons. More complex scenarios occur when cosmic-ray protons strike nuclei containing greater numbers of particles.

Early Fermi

  • Fermi Launch - June 11, 2008
    2010.12.20
    Footage of the Fermi satellite launch from Cape Canaveral Air Station on June 11, 2008.
  • GLAST Promo Video
    2007.09.17
    NASA's Gamma-ray Large Area Space Telescope (GLAST) is a powerful space observatory that will open a wide window on the universe. Gamma rays are the highest-energy form of light and the gamma-ray sky is spectacularly different from the one we perceive with our own eyes. With a huge leap in all key capabilities, GLAST data will enable scientists to answer persistent questions across a broad range of topics, including supermassive black-hole systems, pulsars, the origina of cosmic rays, and searches for signals new physics. NASA's GLAST mission is an astrophysics and particle physics partnership, developed in collaboration with the U.S. Department of Energy, along with important contributions from academic institutions and partners in France, Germany, Italy, Japan, Sweden, and the U.S.
  • GLASTcast Episode 1: What is GLAST?
    2008.05.29
    NASA's GLAST mission is an astrophysics and particle physics partnership, developed in collaboration with the U.S. Department of Energy, along with important contributions from academic institutions and partners in France, Germany, Italy, Japan, Sweden, and the U.S.

    The Universe is home to numerous exotic and beautiful phenomena, some of which can generate inconceivable amounts of energy. GLAST will open a new window on this high-energy world. With GLAST, astronomers will have a superior tool to study how black holes, notorious for pulling matter in, can accelerate jets of gas outward at fantastic speeds. Physicists will be able to search for signals of new fundamental processes that are inaccessible in ground-based accelerators and observatories. GLAST's spectacular high-energy gamma-ray "eyeglasses" will reveal hidden wonders, opening our minds to new possibilities and discoveries, expanding our understanding of the Universe and our place in it.

    Interviews with (in order of appearance):

    Steve Ritz - GLAST Project Scientist, NASA Goddard

    Peter Michaelson - Large Area Telescope (LAT) Principal Investigator, Stanford University

    Diego Torres - Large Area Telescope (LAT) Scientist, University of Barcelona

    Neil Gehrels - GLAST Deputy Project Scientist, NASA Goddard

    David Thompson - GLAST Deputy Project Scientist, NASA Goddard

    Luke Drury - Professor of Astronomy, Dublin Institute for Advanced Studies

    Valerie Connaughton - GLAST Burst Monitor (GBM) Team, NASA Marshall/University of Alabama

    Martin Pohl - GLAST Interdisciplinary Scientist, Iowa State University

    Per Carlson - Professor of Elementary Particle Physics, Manne Siegbahn Laboratory

    Charles "Chip" Meegan - GLAST Burst Monitor (GBM) Principal Investigator, NASA Marshall

    Alan Marscher - Professor of Astronomy, Boston University

    Julie McEnery - GLAST Deputy Project Scientist, NASA Goddard

  • GLASTcast Episode 2: What are Gamma Rays?
    2008.05.23
    NASA's GLAST mission is an astrophysics and particle physics partnership, developed in collaboration with the U.S. Department of Energy, along with important contributions from academic institutions and partners in France, Germany, Italy, Japan, Sweden, and the U.S.

    Somewhere out in the vast depths of space, a giant star explodes with the power of millions of suns. As the star blows up, a black hole forms at its center. The black hole blows two blowtorches in opposite directions, in narrow jets of gamma rays. NASA's Gamma-ray Large Area Space Telescope, or GLAST, will catch about 200 of these explosions, known as gamma-ray bursts, each year. GLAST's detailed observations may give astronomers the clues they need to unravel the mystery of what exactly produces these gamma-ray bursts, which are the brightest explosions in the universe since the Big Bang.

    Interviews with (in order of appearance):

    Phil Plait - Astronomer, Bad Astronomy

    David Thompson - GLAST Deputy Project Scientist, NASA Goddard

    Valerie Connaughton - GLAST Burst Monitor (GBM) Team, NASA Marshall/University of Alabama

    Neil Gehrels - GLAST Deputy Project Scientist, NASA Goddard

    Isabelle Grenier - Principal Investigator of the GLAST French contribution, French Atomic Energy Commission

    Peter Michaelson - Large Area Telescope (LAT) Principal Investigator, Stanford University

    Charles "Chip" Meegan - GLAST Burst Monitor (GBM) Principal Investigator, NASA Marshall

    Martin Pohl - GLAST Interdisciplinary Scientist, Iowa State University

    Steve Ritz - GLAST Project Scientist, NASA Goddard

  • GLASTCast Episode 3 - Swift and GLAST
    2008.08.05
    NASA's GLAST mission is an astrophysics and particle physics partnership, developed in collaboration with the U.S. Department of Energy, along with important contributions from academic institutions and partners in France, Germany, Italy, Japan, Sweden, and the U.S.

    What's the difference between the Swift and GLAST satellites? Both missions look at gamma-ray bursts (GRBs), but in different ways. Swift can rapidly and precisely determine the locations of GRBs and observe their afterglows at X-ray, ultraviolet, and optical wavelengths. GLAST will provide exquisite observations of the burst over the gamma ray spectrum, giving scientists their first complete view of the total energy released in these extraordinary events. Beyond GRB science, GLAST is a multipurpose observatory that will study a broad range of cosmic phenomena. Swift is also a multipurpose observatory, but was built primarily to study GRBs.

    Interviews with (in order of appearance):

    David Thompson - GLAST Deputy Project Scientist, NASA Goddard

    Charles "Chip" Meegan - GLAST Burst Monitor (GBM) Principal Investigator, NASA Marshall

    Lynn Cominsky - GLAST Astrophysicist and Education and Public Outreach Lead, Sonoma State University

    Neil Gehrels - GLAST Deputy Project Scientist, NASA Goddard

    Steve Ritz - GLAST Project Scientist, NASA Goddard

    Alan Marscher - Professor of Astronomy, Boston University

  • GLASTcast Episode 4: Launching a Spacecraft
    2008.08.05
    NASA's GLAST mission is an astrophysics and particle physics partnership, developed in collaboration with the U.S. Department of Energy, along with important contributions from academic institutions and partners in France, Germany, Italy, Japan, Sweden, and the U.S.

    The GLAST satellite will launch in 2008 from Cape Canaveral Air Station, on Florida's east coast. GLAST will be carried on a Delta II Heavy launch vehicle, with 9 solid rocket boosters. GLAST is the first imaging gamma-ray observatory to survey the entire sky every day and with high sensitivity. It will give scientists a unique opportunity to learn about the ever-changing Universe at extreme energies.

    Interviews with (in order of appearance):

    Peter Michaelson - Large Area Telescope (LAT) Principal Investigator, Stanford University

    Lynn Cominsky - GLAST Astrophysicist and Education and Public Outreach Lead, Sonoma State University

    David Thompson - GLAST Deputy Project Scientist, NASA Goddard

    Kevin Grady - GLAST Project Manager, NASA Goddard

    Neil Johnson - Large Area Telescope (LAT) Deputy Principal Investigator, US Naval Research Lab

    Jonathan Ormes - Large Area Telescope (LAT) Senior Scientist Advisory Committee, University of Denver

    Charles "Chip" Meegan - GLAST Burst Monitor (GBM) Principal Investigator, NASA Marshall

    Luke Drury - Professor of Astronomy, Dublin Institute for Advanced Studies

    Per Carlson - Professor of Elementary Particle Physics, Manne Siegbahn Laboratory

    Isabelle Grenier - Principal Investigator of the GLAST French contribution, French Atomic Energy Commission

  • GLASTcast Episode 5: Meet the U.S. Team
    2008.08.05
    NASA's GLAST mission is an astrophysics and particle physics partnership, developed in collaboration with the U.S. Department of Energy, along with important contributions from academic institutions and partners in France, Germany, Italy, Japan, Sweden, and the U.S.

    This video introduces only a small fraction of the hundreds of U.S. and international GLAST team members. To meet more of the team go to: www.nasa.gov/glast.

    Interviews with (in order of appearance):

    Bill Atwood - GLAST Co-Creator, Santa Cruz Institute of Particle Physics, University of California, Santa Cruz

    David Thompson - GLAST Deputy Project Scientist, NASA Goddard

    Julie McEnery - GLAST Deputy Project Scientist, NASA Goddard

    Steve Ritz - GLAST Project Scientist, NASA Goddard

    Neil Gehrels - GLAST Deputy Project Scientist, NASA Goddard

    Peter Michaelson - Large Area Telescope (LAT) Principal Investigator, Stanford University

    Kevin Grady - GLAST Project Manager, NASA Goddard

    Charles "Chip" Meegan - GLAST Burst Monitor (GBM) Principal Investigator, NASA Marshall

  • GLASTcast Episode 6: 2008 Mission Update
    2008.12.21
    The GLAST mission launched on June 11, 2008 and has been returning remarkable and revolutionary discoveries ever since. Recently renamed to the Fermi Space Telescope, after Nobel Prize winner Enrico Fermi, the mission is expected to discover dozens of new pulsars within its first year alone. The telescope is also giving us new insights into gamma-ray bursts and the massive jets that erupt from distant galaxies. Stay tuned — the mission of NASA's Fermi telescope is just getting started.
  • GLASTcast in HD for Apple TV and iTunes
    2008.08.25
    The Universe is home to numerous exotic and beautiful phenomena, some of which can generate inconceivable amounts of energy. GLAST will open a new window on this high-energy world. With GLAST, astronomers will have a superior tool to study how black holes, notorious for pulling matter in, can accelerate jets of gas outward at fantastic speeds. Physicists will be able to search for signals of new fundamental processes that are inaccessible in ground-based accelerators and observatories. GLAST's spectacular high-energy gamma-ray 'eyeglasses' will reveal hidden wonders, opening our minds to new possibilities and discoveries, expanding our understanding of the Universe and our place in it.
  • GLASTcast for iTunes
    2008.06.03
    The GLAST mission launched on June 11, 2008 and has been returning remarkable and revolutionary discoveries ever since. Recently renamed to the Fermi Space Telescope, after Nobel Prize winner Enrico Fermi, the mission is expected to discover dozens of new pulsars within the first year alone. The telescope is also giving us new insights into gamma-ray bursts and the massive jets that erupt from distant galaxies. Stay tuned — the mission of NASA's Fermi telescope is just getting started.
  • GLAST LAT Integration - B-Roll
    2007.09.17
    In fall of 2006, the LAT was shipped to the General Dynamics facility in Arizona for integration onto the spacecraft bus. The General Dynamics spacecraft bus provides the power, data, and pointing resources that will enable the LAT to perform its survey of the Universe. Subsequent to the mechanical integration, the command, data, and power interfaces between the instrument and the spacecraft were tested rigorously to insure the compatibility of this spaceflight hardware that had been manufactured all around the globe.
  • GLAST LAT Testing - B-Roll
    2007.09.17
    The GLAST LAT (Large Area Telescope) was tested extensively during the summer of 2006 at the U.S. Naval Research Laboratory in Washington, DC. The NRL also contributed to the GLAST project by managing the construction of the LAT Calorimeter.
  • GLAST Prelude, for Brass Quintet, Op.12
    2008.05.31
    NASA's GLAST mission is an astrophysics and particle physics partnership, developed in collaboration with the U.S. Department of Energy, along with important contributions from academic institiutions and partners in France, Germany, Italy, Japan, Sweden, and the U.S. Music composed by Nolan Gasser, © 2008 Music performed by the American Brass Quintet
  • GLAST Soundbites
    2008.07.30
    Selected soundbites with Steve Ritz, GLAST Project Scientist; Peter Michelson, LAT Principal Investigator; Charles 'Chip' Meegan, GBM Principal Investigator. NASA's GLAST mission is an astrophysics partnership, developed in collaboration with the U.S. Department of Energy along with important contributions from academic institutions and partners in France, Germany, Italy, Japan, Sweden, and the U.S.
  • Highlights of Fermi's First Five Years
    2013.08.21
    This compilation summarizes the wide range of science from the first five years of NASA's Fermi Gamma-ray Space Telescope. Fermi is a NASA observatory designed to reveal the high-energy universe in never-before-seen detail. Launched in 2008, Fermi continues to give astronomers a unique tool for exploring high-energy processes associated with solar flares, spinning neutron stars, outbursts from black holes, exploding stars, supernova remnants and energetic particles to gain insight into how the universe works.

    Fermi detects gamma rays, the most powerful form of light, with energies thousands to billions of times greater than the visible spectrum.

    The mission has discovered pulsars, proved that supernova remnants can accelerate particles to near the speed of light, monitored eruptions of black holes in distant galaxies, and found giant bubbles linked to the central black hole in our own galaxy.

    From blazars to thunderstorms, from dark matter to supernova remnants, catch the highlights of NASA Fermi’s first five years in space.

    View all the Fermi-related media from the last 5 years in the Fermi Gallery.

    For more information about Fermi, visit NASA's Fermi webpage.

  • Fermi All-Sky First Year Progress
    2009.10.28
    This view of the gamma-ray sky constructed from one year of Fermi LAT observations is the best view of the extreme universe to date. The map shows the rate at which the LAT detects gamma rays with energies above 300 million electron volts — about 120 million times the energy of visible light — from different sky directions. Brighter colors equal higher rates.
  • GLAST First Light All Sky Map
    2008.08.26
    NASA's newest observatory, the Gamma-Ray Large Area Space Telescope (GLAST), has begun its mission of exploring the universe in high-energy gamma rays. The spacecraft and its revolutionary instruments passed their orbital checkout with flying colors. NASA announced today that GLAST has been renamed the Fermi Gamma-ray Space Telescope. The new name honors Prof. Enrico Fermi (1901 - 1954), a pioneer in high-energy physics. Scientists expect Fermi will discover many new pulsars in our own galaxy, reveal powerful processes near supermassive black holes at the cores of thousands of active galaxies across, and enable a search for signs of new physical laws.
  • Simulations of the Gamma-Ray Sky
    2007.09.13
    The Gamma-Ray Large Area Space Telescope (GLAST) will observe the sky in gamma-rays with energies between 10 million electron volts (MeV) to 300 billion electron volts (GeV) (a photon of visible light is roughly 2 electron volts). At these energies, the detectors will receive roughly 2 photons every second. At these energies, the objects visible will be active galaxies, quasars, pulsars, and gamma-ray bursts. This visualization is generated from one year of simulated photon event-lists using known sources. These event lists are used for testing the various data analysis software being developed for the project. Due to the extremely low event rate, it takes about one week of event accumulation to see structure in the sky. To generate the 600+ frames of this visualization, the event lists were box-car averaged for a duration of one week for each frame, and each frame shifted 50,000 seconds in time from the previous frame. The low angular resolution of gamma-ray detectors makes point sources appear spread out in the sky. In these maps, the color of each pixel represents the number of photons accumulated in that pixel (over an energy range of 10MeV-300GeV). Horizontally, across the center of the map, is the diffuse emission from the plane of our own Milky Way galaxy. The images are projected in galactic coordinates with a plate carrée projection so there is significant distortion with increasing latitude above the galactic disk. This emission in the galactic plane is created by pulsars and supernova remnants. Located away from this plane is emission from active galaxies and high-velocity pulsars. Occasionally, a bright spot appears which can be a gamma-ray burst or quasar in an active state.