ICON

Beauty pass showing ICON observing the ionosphere. Credit: NASA/GSFC/CIL || The Ionospheric Connection Explorer will study the frontier of space: the dynamic zone high in our atmosphere where terrestrial weather from below meets space weather above. In this region, the tenuous gases are anything but quiet, as a mix of neutral and charged particles travel through in giant winds. These winds can change on a wide variety of time scales -- due to Earth's seasons, the day's heating and cooling, and incoming bursts of radiation from the sun.This region of space and its changes have practical repercussions, given our ever-increasing reliance on technology -- this is the area through which radio communications and GPS signals travel. Variations there can result in distortions or even complete disruption of signals. In order to understand this complicated region of near-Earth space, called the ionosphere, NASA has developed the ICON mission. To understand what drives variability in the ionosphere requires a careful look at a complicated system that is driven by both terrestrial and space weather.ICON will help determine the physics of our space environment and pave the way for mitigating its effects on our technology, communications systems and society. ||

Music credit: Design Principle by Wayne RobertsComplete transcript available. || NASA's Ionospheric Connection Explorer, or ICON launches in fall 2018. It orbits above the upper atmosphere, through the bottom edge of near-Earth space. From this vantage point, ICON observes both the upper atmosphere and a layer of charged particles called the ionosphere, which extends from about 50 to 360 miles above the surface of Earth. Processes in the ionosphere also create bright swaths of color in the sky, known as airglow. ICON will observe how interactions between Earth's weather and the ionosphere create such shimmering airglow as well as other changes in the space environment. Find more views of the ionosphere from the International Space Station at The Crew Earth Observations Video Page ||

ICON orbits Earth at 575 kilometers altitude, measuring the composition and motions of the ionosphere. || The ICON (Ionospheric Connection Explorer) satellite orbits Earth at an altitude of 575 kilometers. In this visualization, we show the ICON spacecraft with the fields-of-view of four instruments for measuring the properties of the ionosphere. ICON has an EUV (Extreme Ultraviolet) and FUV (Far Ultraviolet) imagers (violet colored frustrums directed from spacecraft) pointing perpendicular to the orbit direction for detecting ionospheric emissions. Two Doppler interferometer imagers, MIGHTI (Michelson Interferometer for Global High-resolution Thermospheric Imaging), represented by the blue frustrums, are directed at 45 degrees from the EUV and FUV imagers to measure ionospheric wind velocities.Three reference models important in ionospheric physics are presented in this visualization. One of the goals of ICON is to improve on these models.International Reference Ionosphere (IRI)This model provides parameters such as electron temperature and density, ion temperature and the densities of various ions (O+, H+, He+, NO+, O2+). In this visualization, we display the atomic oxygen positive ion (a single atom ion) density at an altitude of 350 kilometers. On the limb of Earth, we present a vertical cross-section of the model, illustrating how the density varies with altitude and providing an altitude scale for comparison. This dataset exhibits two notable characteristics.Daily variation: The oxygen ion density increases during the day and then decreases after nightfall. This is due to photoionization by solar ultraviolet light, which increases with sunrise to a maximum at local noon, and then decreases towards evening.Appleton Anomaly: One of the more striking features of the ion density is the daytime enhancement is split into two regions, distributed symmetrically above and below the magnetic equator. This feature was discovered by Edward Appleton in 1946. It is now understood to be an effect of the interaction of Earth's geomagnetic field with upper atmosphere electric fields, and often referred to as the 'fountain effect,' explained in 1965. The electric fields lift ions and electrons upward by E-cross-B drift (Plasma Zoo). At higher altitudes, the upward drift decreases and the geomagnetic field and gravity dominate the motion, guiding the charged particles earthward.Horizontal Wind Model (HWM)This model provides speed and direction of horizontal (parallel to Earth's surface) winds constructed from over 70 million ground-based and satellite measurements. Two altitude levels are displayed in this visualization: 350 kilometers (same altitude as the IRI oxygen ion data) in violet glyphs, and 100 kilometers (white glyphs). This model only extends to 60 degrees latitude, so there are gaps around the poles in this visualization.One of the most notable characteristics in this dataset, particularly the 350 kilometer data, is how the winds are driven by the daily solar heating cycle. As the sun rises, the upper atmosphere is heated by solar ultraviolet light. This creates a high-pressure region which drives the atmosphere away from direct sunlight; westward in the morning and eastward in the afternoon. As the sun sets and the atmosphere cools, we see the wind reverse, filling in the now cooler and lower-pressure region.International Geomagnetic Reference Field-12 (IGRF-12)This model provides the structure of Earth's magnetic field which is a dominant influence on the motion of electrons and ions in the ionosphere. The geomagnetic field changes very slowly over decades. For this visualization, we display only a few field lines (golden wire-like structures) near the geomagnetic equator. As we observe the daily variation of the data, particularly the oxygen ions, we see the Appleton anomaly is hedged in by the low-latitude geomagnetic field.ReferencesNOAA/National Geophysical Data Center. International Geomagnetic Reference FieldErwan Thebault, Christopher C. Finlay, et al. International Geomagnetic Reference Field: the 12th generation. Earth, Planets and Space 67:79 (2015)Dieter Bilitza. The International Reference Ionosphere - Status 2013. Advances in Space Research, Volume 55, p. 1914-1927 (2015)Douglas P. Drob, John T. Emmert, et al. An update to the Horizontal Wind Model (HWM): The quiet time thermosphere. Earth and Space Science, vol. 2, issue 7, pp. 301-319Edward V. Appleton. Two Anomalies in the Ionosphere. Nature, Volume 157, pp. 691 (1946)E. N. Bramley and M. Peart. Diffusion and electromagnetic drift in the equatorial F2-region. Journal of Atmospheric and Terrestrial Physics, vol. 27, pp. 1201-1211 (1965)R.J. Moffett & W.B. Hanson. Effect of Ionization Transport on the Equatorial F-Region. Nature 206, pp705-706 (1965) ||

Go behind the scenes as we unbox NASA’s Ionospheric Connection Explorer, or ICON, after its arrival at Vandenberg Air Force Base in California. Northrop Grumman engineer Steve Turek and NASA EDGE’s Chris Giersch walk us through the whole process of unboxing a spacecraft – from the instrument that records every tiny bump on its journey to the special crane used to lift the spacecraft to its new home.ICON launches in fall 2018 from NASA's Kennedy Space Center in Florida to study Earth’s interface to space. Read more about the ICON mission: nasa.gov/icon ||

Early in the morning of Nov. 7, 2018, NASA launches the Ionospheric Connection Explorer, or ICON, a spacecraft that will explore the dynamic region where Earth meets space. ICON launches on a Northrop Grumman Pegasus XL rocket, which is carried aloft by the Stargazer L-1011 aircraft.Join NASA on a behind-the-scenes tour of this plane, once a jet airliner and now uniquely retrofitted to boost spacecraft into low-Earth orbit. Learn about ICON’s science and meet the people — including an engineer, technician, and pilot — who will help launch the spacecraft into orbit.Learn more at: nasa.gov/icon ||

Music credit: Foxy Trot by Luis Enriquez Bacalov Complete transcript available.Watch this video on the NASA Goddard YouTube channel. || Learn about the features of the ionosphere! This little-explored region exists between space and Earth. It is home to the aurora, the international space station, a variety of satellites, and radio communication waves. We know it is sensitive to weather from Earth and conditions in space, called space weather. Join us as we venture to this interface to space! ||

What does our planet look like from space? Most are familiar with the beloved images of the blue marble or pale blue dot — Earth from 18,000 and 3.7 billion miles away, respectively. But closer to home, within the nearest region of space, you might encounter an unfamiliar sight. If you peer down on Earth from just 300 miles above the surface, near the orbit of the International Space Station, you can see vibrant swaths of red and green or purple and yellow light emanating from the upper atmosphere. This is airglow. Airglow occurs when atoms and molecules in the upper atmosphere, excited by sunlight, emit light in order to shed their excess energy. Or, it can happen when atoms and molecules that have been ionized by sunlight collide with and capture a free electron. In both cases, they eject a particle of light — called a photon — in order to relax again. The phenomenon is similar to auroras, but where auroras are driven by high-energy particles originating from the solar wind, airglow is energized by day-to-day solar radiation. ||

This visualization presents data on the concentration of the singly-ionized oxygen atom (rainbow color table, red is highest concentration), the low-latitude geomagnetic field (gold field lines) and the ionospheric winds at two altitude levels, 100km (white) and 350 km (violet). || This visualization presents several 'Reference models' for studying Earth's ionosphere. It presents a close-up view of Earth's limb and ionospheric data-driven models, over a fixed geographic location - off the Atlantic coast of South America.Reference models are used to define well-established knowledge and facilitate mapping out areas for future exploration. The models might be described as semi-empirical, in that they are generated using many measurements at a varietly of locations, and those measurements are used to constrain a theoretical model which is used to estimate measurements at locations where an actual measurement is not available.Three models important in ionospheric physics are presented in this visualization.International Reference Ionosphere (IRI)This model provides parameters such as electron temperature and density, ion temperature and the densities of various ions (O+, H+, He+, NO+, O2+). In this visualization, we display the atomic oxygen positive ion (a single atom ion) density at an altitude of 350 kilometers. On the limb of Earth, we present a vertical cross-section of the model, illustrating how the density varies with altitude and providing an altitude scale for comparison. This dataset exhibits two notable characteristics.Daily variation: The oxygen ion density increases during the day and then decreases after nightfall. This is due to photoionization by solar ultraviolet light, which increases with sunrise to a maximum at local noon, and then decreases towards evening.Appleton Anomaly: One of the more striking features of the ion density is the daytime enhancement is split into two regions, distributed symmetrically above and below the magnetic equator. This feature was discovered by Edward Appleton in 1946. It is now understood to be an effect of the interaction of Earth's geomagnetic field with upper atmosphere electric fields, and often referred to as the 'fountain effect,' explained in 1965. The electric fields lift ions and electrons upward by E-cross-B drift (Plasma Zoo). At higher altitudes, the upward drift decreases and the geomagnetic field and gravity dominate the motion, guiding the charged particles earthward.Horizontal Wind Model (HWM)This model provides speed and direction of horizontal (parallel to Earth's surface) winds constructed from over 70 million ground-based and satellite measurements. Two altitude levels are displayed in this visualization: 350 kilometers (same altitude as the IRI oxygen ion data) in violet glyphs, and 100 kilometers (white glyphs). This model only extends to 60 degrees latitude, so there are gaps around the poles in this visualization.One of the most notable characteristics in this dataset, particularly the 350 kilometer data, is how the winds are driven by the daily solar heating cycle. As the sun rises, the upper atmosphere is heated by solar ultraviolet light. This creates a high-pressure region which drives the atmosphere away from direct sunlight; westward in the morning and eastward in the afternoon. As the sun sets and the atmosphere cools, we see the wind reverse, filling in the now cooler and lower-pressure region.International Geomagnetic Reference Field-12 (IGRF-12)This model provides the structure of Earth's magnetic field which is a dominant influence on the motion of electrons and ions in the ionosphere. The geomagnetic field changes very slowly over decades. For this visualization, we display only a few field lines (golden wire-like structures) near the geomagnetic equator. As we observe the daily variation of the data, particularly the oxygen ions, we see the Appleton anomaly is hedged in by the low-latitude geomagnetic field.ReferencesNOAA/National Geophysical Data Center. International Geomagnetic Reference FieldErwan Thebault, Christopher C. Finlay, et al. International Geomagnetic Reference Field: the 12th generation. Earth, Planets and Space 67:79 (2015)Dieter Bilitza. The International Reference Ionosphere - Status 2013. Advances in Space Research, Volume 55, p. 1914-1927 (2015)Douglas P. Drob, John T. Emmert, et al. An update to the Horizontal Wind Model (HWM): The quiet time thermosphere. Earth and Space Science, vol. 2, issue 7, pp. 301-319Edward V. Appleton. Two Anomalies in the Ionosphere. Nature, Volume 157, pp. 691 (1946)E. N. Bramley and M. Peart. Diffusion and electromagnetic drift in the equatorial F2-region. Journal of Atmospheric and Terrestrial Physics, vol. 27, pp. 1201-1211 (1965)R.J. Moffett & W.B. Hanson. Effect of Ionization Transport on the Equatorial F-Region. Nature 206, pp705-706 (1965) ||

A view of the singly-ionizing oxygen atom on the dayside of Earth. This represents the variation of the enhancments due to variation in the geomagnetic field. This version interpolates the IRI model to a higher time cadence for a smoother animation. || The colors over Earth represent model data from the IRI (International Reference Ionosphere) model of the density of the singly-ionized oxygen atom at an altitude of 350 kilometers. Red represents high density. The ion density is enhanced above and below the geomagnetic equator (not perfectly aligned with the geographic equator) on the dayside due to the ionizing effects of solar ultraviolet radiation combined with the effects of high-altitude winds and the geomagnetic field. This ion density decreases at night as the ions recombine with free electrons. ||

Oxygen ion enhancements at 350km altitude, ionospheric winds at altitudes of 100 km (white) and 350 km (violet) and the low-latitude geomagnetic field. || This visualization presents several 'reference models' for studying Earth's ionosphere. It opens with a full-disk view of Earth, then zooms-in to a close-up view of Earth's limb and ionospheric data-driven models, over a fixed geographic location - off the Atlantic coast of South America.Reference models are used to define well-established knowledge and facilitate mapping out areas for future exploration. The models might be described as semi-empirical, in that they are generated using many measurements at a varietly of locations, and those measurements are used to constrain a theoretical model which is used to estimate measurements at locations where an actual measurement is not available.Three models important in ionospheric physics are presented in this visualization.International Reference Ionosphere (IRI)This model provides parameters such as electron temperature and density, ion temperature and the densities of various ions (O+, H+, He+, NO+, O2+). In this visualization, we display the atomic oxygen positive ion (a single atom ion) density at an altitude of 350 kilometers. On the limb of Earth, we present a vertical cross-section of the model, illustrating how the density varies with altitude and providing an altitude scale for comparison. This dataset exhibits two notable characteristics.Daily variation: The oxygen ion density increases during the day and then decreases after nightfall. This is due to photoionization by solar ultraviolet light, which increases with sunrise to a maximum at local noon, and then decreases towards evening.Appleton Anomaly: One of the more striking features of the ion density is the daytime enhancement is split into two regions, distributed symmetrically above and below the magnetic equator. This feature was discovered by Edward Appleton in 1946. It is now understood to be an effect of the interaction of Earth's geomagnetic field with upper atmosphere electric fields, and often referred to as the 'fountain effect,' explained in 1965. The electric fields lift ions and electrons upward by E-cross-B drift (Plasma Zoo). At higher altitudes, the upward drift decreases and the geomagnetic field and gravity dominate the motion, guiding the charged particles earthward.Horizontal Wind Model (HWM)This model provides speed and direction of horizontal (parallel to Earth's surface) winds constructed from over 70 million ground-based and satellite measurements. Two altitude levels are displayed in this visualization: 350 kilometers (same altitude as the IRI oxygen ion data) in violet glyphs, and 100 kilometers (white glyphs). This model only extends to 60 degrees latitude, so there are gaps around the poles in this visualization.One of the most notable characteristics in this dataset, particularly the 350 kilometer data, is how the winds are driven by the daily solar heating cycle. As the sun rises, the upper atmosphere is heated by solar ultraviolet light. This creates a high-pressure region which drives the atmosphere away from direct sunlight; westward in the morning and eastward in the afternoon. As the sun sets and the atmosphere cools, we see the wind reverse, filling in the now cooler and lower-pressure region.International Geomagnetic Reference Field-12 (IGRF-12)This model provides the structure of Earth's magnetic field which is a dominant influence on the motion of electrons and ions in the ionosphere. The geomagnetic field changes very slowly over decades. For this visualization, we display only a few field lines (golden wire-like structures) near the geomagnetic equator. As we observe the daily variation of the data, particularly the oxygen ions, we see the Appleton anomaly is hedged in by the low-latitude geomagnetic field.ReferencesNOAA/National Geophysical Data Center. International Geomagnetic Reference FieldErwan Thebault, Christopher C. Finlay, et al. International Geomagnetic Reference Field: the 12th generation. Earth, Planets and Space 67:79 (2015)Dieter Bilitza. The International Reference Ionosphere - Status 2013. Advances in Space Research, Volume 55, p. 1914-1927 (2015)Douglas P. Drob, John T. Emmert, et al. An update to the Horizontal Wind Model (HWM): The quiet time thermosphere. Earth and Space Science, vol. 2, issue 7, pp. 301-319Edward V. Appleton. Two Anomalies in the Ionosphere. Nature, Volume 157, pp. 691 (1946)E. N. Bramley and M. Peart. Diffusion and electromagnetic drift in the equatorial F2-region. Journal of Atmospheric and Terrestrial Physics, vol. 27, pp. 1201-1211 (1965)R.J. Moffett & W.B. Hanson. Effect of Ionization Transport on the Equatorial F-Region. Nature 206, pp705-706 (1965) ||

The photographs used to make this video were taken on September 17, 2011 from 17:22:27 to 17:37:21 GMT from the International Space Station (ISS). This image sequence begins over the Indian Ocean halfway between Madagascar and Antarctica. Aurora Australis is present for the first 2/3rds of the video, then Australis comes into view. Yellow lights near the coast show the presence of cities, while interior oragne lights indicate brush fires.http://eol.jsc.nasa.gov || Time lapse photos of Aurora Australis ||

Visualization illustrating the Fountain Effect of ions in the near-Earth electric and magnetic fields. || This is a visualization of the Equatorial Fountain process in the ionosphere, whereby ions are driven away from the equator forming ion density enhancements to the north and south of the equator. This visualization is depicted near 50 degrees west longitude, where the magnetic equator crosses the geographic equator. Magnetic field lines near Earth are represented by the gold lines. Particles appear in a blue-white flash, representing the point where atoms are ionized, becoming positively charged and releasing an electron. Now these charged particles can 'feel' the near-Earth electric and magnetic fields. Their motion becomes a combination of circular gyromotion (see Plasma Zoo: Gyromotion in Three Dimensions) due to the magnetic field and E-cross-B drift (see Plasma Zoo: E-cross-B Drift). At higher altitudes, the electric field is weaker, reducing the vertical motion, and the ion motion becomes dominated by the magnetic field and gravity, allowing the ion to 'slide' down the magnetic field line back to Earth. At lower altitudes, the ions combine with free electrons in a process called recombination, represented by a red flash and fading of the particle trail. A slice of data from the IRI (International Reference Ionosphere) model represents the density of singly-ionized oxygen atoms is faded-in to compare to the particle motion. Red represents high ion density, green represents low ion density. The camera finally pulls out from Earth, providing an overview of the enhanced ion density (red) above and below the magnetic equator on the dayside of Earth. This enhancement was discovered by Edward Appleton in 1946.The Fountain effect is just one of the many of complex processes which occur in the layer of thinning atmosphere that forms Earth's interface to the space environment. A conceptual inventory of some of these processes are presented in the graphic at Terrestrial Atmosphere ITM Processes.What creates the dayside near-Earth electric field? As the sun warms Earth's atmosphere during the day, the temperature and pressure differences create wind flows. In the upper atmosphere, where the solar ultraviolet photons also break atoms into negative-charged electrons and positive-charged ions, these winds carry the charges creating currents and electric fields. The major current from this process is called the equatorial electrojet and travels along the magnetic equator (not quite aligned with the geographic equator). This motion of charges also creates a west-to-east directed electric field.Are the particles in this visualization at a realistic scale? The particles in this visualization are generated to be representative of the motion in the fountain effect to the appropriate altitudes and latitudes, but items such as the size of the gyromotion, and the particle size, are not to be regarded as physically accurate. ||

The northern lights were seen over Alaska the night of Feb. 16, 2017 at the the Poker Flat Research Range north of Fairbanks. Credit: NASA/Terry Zaperach || The northern lights were dancing across the sky over Alaska the night of Feb. 16 as seen from the Poker Flat Research Range north of Fairbanks. While skies were clear at Poker and the auroras were active, cloudy skies over downrange viewing sites prevented the launch of NASA sounding rockets carrying instruments to explore the Earth's magnetic environment and its impact on Earth’s upper atmosphere and ionosphere. Special ground-based instruments are located at the downrange sites for observing the aurora into which the rockets fly. The launch window for the four sounding rockets runs through March 3. Credit: NASA/Terry Zaperach ||

Airglow occurs when atoms and molecules in the upper atmosphere, excited by sunlight, emit light in order to shed their excess energy. The phenomenon is similar to auroras, but where auroras are driven by high-energy particles originating from the solar wind, airglow is sparked by day-to-day solar radiation. Airglow carries information on the upper atmosphere’s temperature, density, and composition, but it also helps us trace how particles move through the region itself. Vast, high-altitude winds sweep through the ionosphere, pushing its contents around the globe — and airglow’s subtle dance follows their lead, highlighting global patterns. ||

The Ionospheric Connection Explorer, or ICON, will study the frontier of space: the dynamic zone high in our atmosphere where Earth weather and space weather meet. In fall 2018, the mission launches on an Northrop Grumman (formerly Orbital ATK) Pegasus XL rocket from NASA's Kennedy Space Center in Florida. || Animated depiction of ICON's launch from a Northrop Grumman (formerly Orbital ATK) Pegasus XL rocketCredit: NASA GSFC/CIL/Josh Masters ||

The Ionospheric Connection Explorer, or ICON, will study the frontier of space: the dynamic zone high in our atmosphere where Earth weather and space weather meet. In fall 2018, the mission launches on an Northrop Grumman (formerly Orbital ATK) Pegasus XL rocket from NASA's Kennedy Space Center in Florida. || An animation zooming into ICON's launch site at NASA's Kennedy Space Center in Cap Canaveral, Florida with no location labels. || An animation zooming into ICON's launch site at NASA's Kennedy Space Center in Cap Canaveral, Florida with location labels. ||

The Global-scale Observations of the Limb and Disk, or GOLD, instrument launches aboard a commercial communications satellite in January 2018 to inspect the dynamic intermingling of space and Earth’s uppermost atmosphere. Together, GOLD and another NASA mission, Ionospheric Connection Explorer spacecraft, or ICON, will provide the most comprehensive of Earth’s upper atmosphere we’ve ever had.Above the ozone layer, the ionosphere is a part of Earth’s atmosphere where particles have been cooked into a sea of electrically-charged electrons and ions by the Sun’s radiation. The ionosphere is co-mingled with the very highest — and quite thin — layers of Earth’s neutral upper atmosphere, making this region an area that is constantly in flux undergoing the push-and-pull between Earth’s conditions and those in space. Increasingly, these layers of near-Earth space are part of the human domain, as it’s home not only to astronauts, but to radio signals used to guide airplanes and ships, and satellites that provide our communications and GPS systems. Understanding the fundamental processes that govern our upper atmosphere and ionosphere is crucial to improve situational awareness that helps protect astronauts, spacecraft and humans on the ground.GOLD, in geostationary orbit over the Western Hemisphere, will build up a full-disk view of the ionosphere and upper atmosphere every half hour, providing detailed large-scale measurements of related processes — a cadence which makes it the first mission to be able to monitor the true weather of the upper atmosphere. GOLD is also able to focus in on a tighter region and scan more quickly, to complement additional research plans as needed. ||

Visualization of ICON and GOLD orbiting Earth with image scanning. This version presents several geospace models, including the singly-ionized oxygen density, the low-latitude geomagnetic field, and the high-altitude winds (100km and 350km altitudes). || A basic view of the orbits for ICON (Ionospheric Connections Explorer) and GOLD (Global-scale Observations of the Limb and Disk). These missions will conduct measurements of ionospheric composition, ionization, and winds to better understand the connection between space weather and its terrestrial impacts.In this visualization, we present GOLD (in geostationary orbit around Earth) and ICON (in low Earth orbit). The colors over Earth represent model data from the IRI (International Reference Ionosphere) model of the density of the singly-ionized oxygen atom at an altitude of 350 kilometers. Red represents high density. The ion density is enhanced above and below the geomagnetic equator (not perfectly aligned with the geographic equator) on the dayside due to the ionizing effects of solar ultraviolet radiation combined with the effects of high-altitude winds and the geomagnetic field.In the latter half of the visualization, the viewing fields of the various instruments are displayed. ICON has an EUV (Extreme Ultraviolet) and FUV (Far Ultraviolet) cameras (violet colored frustrums directed from spacecraft) pointing perpendicular to the orbit direction for detecting ionospheric emissions. Two Doppler interferometer cameras (blue) are directed at 45 degrees from this camera to detect ionospheric wind velocities.GOLD has an imaging spectrometer (green) that periodically scans the disk of Earth with additional higher-resolution scans of the dayside limb. ||

A basic view of the orbits for ICON (Ionospheric Connections Explorer) and GOLD (Global-scale Observations of the Limb and Disk). These missions will conduct measurements of ionospheric composition, ionization, and winds to better understand the connection between space weather and its terrestrial impacts.In this visualization, we present GOLD (in geostationary orbit around Earth) and ICON (in low Earth orbit). The colors over Earth represent model data from the IRI (International Reference Ionosphere) model of the density of the singly-ionized oxygen atom at an altitude of 350 kilometers. Red represents high density. The ion density is enhanced above and below the geomagnetic equator (not perfectly aligned with the geographic equator) on the dayside due to the ionizing effects of solar ultraviolet radiation combined with the effects of high-altitude winds and the geomagnetic field. ||

The Global-scale Observations of the Limb and Disk, or GOLD, mission is designed to explore the nearest reaches of space. Capturing never-before-seen images of Earth’s upper atmosphere, GOLD explores in unprecedented detail our space environment — which is home to astronauts, radio signals used to guide airplanes and ships, as well as satellites that provide communications and GPS systems. The more we know about the fundamental physics of this region of space, the more we can protect our assets there. Gathering observations from geostationary orbit above the Western Hemisphere, GOLD measures the temperature and composition of neutral gases in Earth’s thermosphere. This part of the atmosphere co-mingles with the ionosphere, which is made up of charged particles. Both the Sun from above and terrestrial weather from below can change the types, numbers, and characteristics of the particles found here — and GOLD helps track those changes. Activity in this region is responsible for a variety of key space weather events. GOLD scientists are particularly interested in the cause of dense, unpredictable bubbles of charged gas that appear over the equator and tropics, sometimes causing communication problems. As we discover the very nature of the Sun-Earth interaction in this region, the mission could ultimately lead to ways to improve forecasts of such space weather and mitigate its effects. Download the GOLD beauty pass: https://svs.gsfc.nasa.gov/20275 Download other GOLD resources: https://svs.gsfc.nasa.gov/GOLDresources

The Ionospheric Connection Explorer, or ICON, is a low-Earth orbiting satellite that will give us new information about how Earth’s atmosphere interacts with near-Earth space — a give-and-take that plays a major role in the safety of our satellites and reliability of communications signals. Specifically, ICON investigates the connections between the neutral atmosphere — which extends from here near the surface to far above us, at the edge of space — and the electrically charged part of the atmosphere, called the ionosphere. The particles of the ionosphere carry electrical charge that can disrupt communications signals, cause satellites in low-Earth orbit to become electrically charged, and, in extreme cases, cause power outages on the ground. ||

Stretching from roughly 50 to 400 miles above Earth’s surface, the ionosphere is an electrified layer of the upper atmosphere, generated by extreme ultraviolet radiation from the Sun. It’s neither fully Earth nor space, and instead, reacts to both terrestrial weather below and solar energy streaming in from above, forming a complex space weather system of its own. The particles of the ionosphere carry electrical charge that can disrupt communications signals, cause satellites in low-Earth orbit to become electrically charged, and, in extreme cases, cause power outages on the ground. Positioned on the edge of space and intermingled with the neutral atmosphere, the ionosphere’s response to conditions on Earth and in space is difficult to pin down. ||

Heliophysics encompasses science that improves our un­derstanding of fundamental physical processes throughout the solar system, and enables us to understand how the Sun, as the major driver of the energy throughout the solar system, impacts our technological society. The scope of heliophysics is vast, spanning from the Sun’s interior to Earth’s upper atmosphere, throughout interplanetary space, to the edges of the heliosphere, where the solar wind interacts with the local interstellar medium. Heliophysics incorporates studies of the interconnected elements in a single system that produces dynamic space weather and that evolves in response to solar, planetary, and interstellar conditions. ||

The Ionospheric Connection Explorer, or ICON, is a low-Earth orbiting satellite that will give us new information about how Earth’s atmosphere interacts with near-Earth space — a give-and-take that plays a major role in the safety of our satellites and reliability of communications signals.Specifically, ICON investigates the connections between the neutral atmosphere — which extends from here near the surface to far above us, at the edge of space — and the electrically charged part of the atmosphere, called the ionosphere. The particles of the ionosphere carry electrical charge that can disrupt communications signals, cause satellites in low-Earth orbit to become electrically charged, and, in extreme cases, cause power outages on the ground. ||