The Solar Polar Magnetic Field

During its closest approaches of the Sun, Solar Orbiter will travel fast enough to study how magnetically active regions evolve for up to four weeks at a time. Solar Orbiter will return the first images and measurements of the Sun’s polar magnetic field, helping scientists relate the poles to the solar activity cycle.Credit: ESA/ATG Medialab Solar Orbiter orbiting the Sun. Over its seven-year mission, the spacecraft will go as close as 26 million miles from the Sun.Credit: NASA's Goddard Space Flight Center/Conceptual Image Lab/Adriana Manrique Gutierrez This animation of Solar Orbiter and its instruments begins by showing small sliding doors in the heat shield open to allow the internally mounted, remote-sensing instruments to observe the Sun. Special windows block out heat to protect the instruments during operations. The doors are closed when the remote-sensing instruments are not observing. The in situ instruments are in science mode throughout the spacecraft’s orbit.Credit: ESA/ATG Medialab Animation of the solar wind, the stream of charged particles that constantly blows from the Sun. Solar activity shapes space throughout the solar system, and has profound effects on our home planet.Credit: NASA's Goddard Space Flight Center Animation of a spacecraft experience damage from space weather. Sometimes, solar eruptions can disrupt satellites and everyday technology such as GPS and radio. At worst, space weather can also impact astronauts.Credit: NASA’s Goddard Space Flight Center/Conceptual Image Lab/Krystofer Kim A solar eruption bursts from the Sun, as seen by NASA’s Solar Dynamics Observatory. Credit: NASA's Goddard Space Flight Center/SDO This visualization presents a model of the Sun’s magnetic field based on solar observations. Currently, scientists lack measurements of the magnetic field at the Sun’s north and south poles. Solar Orbiter will fly in an inclined orbit in order to study the poles. Credit: NASA's Scientific Visualization Studio/Tom Bridgman Animation showing the deployment of the boom and antennas. Solar Orbiter carries a comprehensive suite of 10 instruments that take both in situ and remote measurements.Credit: ESA/ATG Medialab Animation of a coronal mass ejection impacting Mars, Earth, and Jupiter. Solar Orbiter is equipped to image such eruptions as they burst from the Sun, and measure the eruption directly as it passes the spacecraft.Credit: NASA’s Goddard Space Flight Center/Conceptual Image Lab/Bailee DesRocher Image of NASA’s heliophysics observatory fleet. Credit: NASA Image of the European Space Agency’s solar system explorers. Credit: ESA Animation of the Artemis program’s lunar lander concept. Credit: NASA NASA and the European Space Agency (ESA) will present Solar Orbiter, the ESA/NASA mission to the Sun, during a science press briefing on Friday, Feb. 7. 2020, at 2.30 p.m. EST. Solar Orbiter will observe the Sun with high spatial resolution telescopes and capture observations in the environment directly surrounding the spacecraft to create a one-of-a-kind picture of how the Sun can affect the space environment throughout our solar system. The spacecraft also will provide the first-ever images of the Sun’s poles and the never-before-observed magnetic environment there, which helps drive the Sun’s 11-year solar cycle and its periodic outpouring of solar storms.The teleconference audio will stream live at:https://www.nasa.gov/liveParticipants include:European Space Agency• Daniel Müller, Solar Orbiter Project Scientist• Günther Hasinger, Director of ScienceNASA• Nicky Fox, Heliophysics Division Director, NASA HQ• Thomas Zurbuchen, Associate Administrator for the Science Mission Directorate, NASA HQ For More InformationSee [https://www.nasa.gov/press-release/nasa-to-broadcast-solar-orbiter-launch-prelaunch-activities](https://www.nasa.gov/press-release/nasa-to-broadcast-solar-orbiter-launch-prelaunch-activities) Related pages

VideoWatch this video on the NASA Goddard YouTube channel.Music credits: “Oxide” and “Virtual Tidings” by Andrew Michael Britton [PRS], David Stephen Goldsmith [PRS]; “Progressive Practice” by Emmanuel David Lipszc [SACEM], Franck Lascombes [SACEM], Sebastien Lipszyc [SACEM]; “Political Spectrum” by Laurent Dury [SACEM} from Universal Production MusicComplete transcript available. Still ImageCredit: NASA/CiLab A new spacecraft is journeying to the Sun to snap the first pictures of the Sun’s north and south poles. Solar Orbiter, a collaboration between ESA (the European Space Agency) and NASA will have its first opportunity to launch from Cape Canaveral on Feb. 7, 2020, at 11:15 p.m. EST. Launching on a United Launch Alliance Atlas V rocket, the spacecraft will use Venus’ and Earth’s gravity to swing itself out of the ecliptic plane — the swath of space, roughly aligned with the Sun’s equator, where all planets orbit. From there, Solar Orbiter's bird’s eye view will give it the first-ever look at the Sun's poles.Read more: https://www.nasa.gov/feature/goddard/2020/new-mission-will-take-first-peek-at-sun-s-poles Related pages

This narrated visualization transitions from a view of the Sun in visible light, to a view in ultraviolet light showing the plasma flowing along solar magnetic structures, to the underlying magnetic field of the solar photosphere, to a model construction of magnetic fieldlines above the photosphere.This video is also available on our YouTube channel. This visualization transitions from a view of the Sun in visible light, to a view in ultraviolet light showing the plasma flowing along solar magnetic structures, to the underlying magnetic field of the solar photosphere, to a model construction of magnetic fieldlines above the photosphere.Coming soon to our YouTube channel. A view of the Sun in visible light, showing a few sunspots. A view of the Sun in ultraviolet light at a wavelength of 171 Ångstroms. A photospheric magnetogram, showing regions of strong magnetic fields. The PFSS magnetic field model, one of the possible configurations for the magnetic field near the Sun based on the photospheric magnetogram. While the sun is well known as the overwhelming source of visible light in our solar system, a substantial part of its influence is driven by some aspects less visible to human perception - the magnetic field.In this visualization we start a view of the Sun in visible light (similiar to what you would see from the ground on Earth), to a view in extreme ultraviolet wavelengths (only visible to space-based instruments) which shows hot plasma streaming along magnetic field lines, to a magnetogram (derived from the visible light data) and finally to a three-dimensional magnetic field model built from that data. The sphere represents the solar photosphere, with neutral grey indicating a magnetic field of near zero intensity, black representing a magnetic field pointing INTO the sun (south or negative polarity) and white representing a magnetic field pointing OUT of the sun (north or positive polarity). We see that these magnetic regions often appear in nearby pairs of opposite polarities - which in visible light would often correspond to a pair of sunspots.Most of the solar photosphere has a magnetic field intensity of a few gauss while the active regions which form around sunspots can have magnetic fields of a few thousand gauss. Modern space-based instruments such as HMI (Helioseismic and Magnetic Imager) on the Solar Dynamics Observatory (SDO) enable us to measure the intensity of the magnetic field at the visible surface of the sun.Using this measured magnetic field on the photosphere, combined with mathematical models based on Maxwell's equations and plasma physics, we can construct how the magnetic field would look above the photosphere. Here, the white magnetic field lines are considered 'closed'. They move up, and then return to the solar surface. We often see these closed lines associated with pairs of active regions on the sun. The green and violet lines represent field lines that are considered 'open'. Green represents positive magnetic polarity, and violet represents negative polarity. These field lines do not connect back to the sun but with more distant magnetic fields in space.Here we build one of the simpler magnetic field models, called Potential Field Source Surface or PFSS, to construct how the magnetic 'lines of force' might look above the sun. The PFSS model represents the simplest and most steady magnetic field possible, though here we sample the field each day to illustrate the slow changes of the magnetic structure over time, in this case between January 1, 2011 through December 30, 2014.This camera view is fixed in Carrington Heliographic coordinates, so it moves with an 'average' solar rotation value with a period of 25.38 days. The solar equator moves faster than this, and high latitudes move slower. This makes active regions near the equator appear to move to the right (on average) while higher latitude regions move leftward.Some might note that this model looks rather different than an earlier version The Sun's Magnetic Field. In the earlier version, we were interested in the magnetic field structure significantly above the solar surface and so the model is examined favoring the field lines that reach high above the photosphere. In the model presented here, we are more interested in the magnetic field around the solar active regions, so we examine the model much closer to the photosphere, which favors magnetic field lines clustered around the active regions.An artifact in this visualization is a 'jump' of change that sweeps through the magnetic loops about once per month based on the timestamp in the lower left corner. This is an artifact of the fact that these types of magnetic field measurements can only be done on one side of the sun at a time. As the sun rotates, the features disappear over the limb and new ones appear on the opposite limb. While on the far-side of the sun from Earth, we have no direct measurements. However, we do have models that can simulate the slow changes in the field while not visible from Earth (described in the science paper Photospheric and heliospheric magnetic fields by Carolus J. Schrijver and Marc L. De Rosa). The 'jump' is created at the seam where the less accurate model gets overwritten by newer data. Related pages

A visualization of the slow changes of the solar magnetic field over the course of four years. A visualization of the slow changes of the solar magnetic field over the course of four years. This version has the color thresholds of the magnetogram adjusted to better illustrate the active regions.This video is also available on our YouTube channel. High-resolution still image of the solar magnetic field via PFSS - January 1, 2011. High-resolution still image of the solar magnetic field via PFSS - October 28, 2011. High-resolution still image of the solar magnetic field via PFSS - August 23, 2012. High-resolution still image of the solar magnetic field via PFSS - June 19, 2013. A visualization of the slow changes of the solar magnetic field over the course of four years. This version has the color thresholds of the magnetogram adjusted to better illustrate the active regions. High-resolution still image of the solar magnetic field via PFSS - April 15, 2014. While the sun is well known as the overwhelming source of visible light in our solar system, a substantial part of its influence is driven by some aspects less visible to human perception - the magnetic field.Most of the solar photosphere has a magnetic field intensity of a few gauss while the active regions which form around sunspots can have magnetic fields of a few thousand gauss. Modern space-based instruments such as HMI (Helioseismic and Magnetic Imager) on the Solar Dynamics Observatory (SDO) enable us to measure the intensity of the magnetic field at the visible surface of the sun. In this visualization, the sphere represents the solar photosphere, with neutral grey indicating a magnetic field of near zero intensity, black representing a magnetic field pointing INTO the sun (south or negative polarity) and white representing a magnetic field pointing OUT of the sun (north or positive polarity). We see that these magnetic regions often appear in nearby pairs of opposite polarities - which in visible light would often correspond to a pair of sunspots.Using this measured magnetic field on the photosphere, combined with mathematical models based on Maxwell's equations and plasma physics, we can construct how the magnetic field would look above the photosphere. Here, the white magnetic field lines are considered 'closed'. They move up, and then return to the solar surface. We often see these closed lines associated with pairs of active regions on the sun. The green and violet lines represent field lines that are considered 'open'. Green represents positive magnetic polarity, and violet represents negative polarity. These field lines do not connect back to the sun but with more distant magnetic fields in space.Here we build one of the simpler magnetic field models, called Potential Field Source Surface or PFSS, to construct how the magnetic 'lines of force' might look above the sun. The PFSS model represents the simplest and most steady magnetic field possible, though here we sample the field each day to illustrate the slow changes of the magnetic structure over time, in this case between January 1, 2011 through December 30, 2014.This camera view is fixed in Carrington Heliographic coordinates, so it moves with an 'average' solar rotation value with a period of 25.38 days. The solar equator moves faster than this, and high latitudes move slower. This makes active regions near the equator appear to move to the right (on average) while higher latitude regions move leftward.Some might note that this model looks rather different than an earlier version The Sun's Magnetic Field. In the earlier version, we were interested in the magnetic field structure significantly above the solar surface and so the model is examined favoring the field lines that reach high above the photosphere. In the model presented here, we are more interested in the magnetic field around the solar active regions, so we examine the model much closer to the photosphere, which favors magnetic field lines clustered around the active regions.An artifact in this visualization is a 'jump' of change that sweeps through the magnetic loops about once per month based on the timestamp in the lower left corner. This is an artifact of the fact that these types of magnetic field measurements can only be done on one side of the sun at a time. As the sun rotates, the features disappear over the limb and new ones appear on the opposite limb. While on the far-side of the sun from Earth, we have no direct measurements. However, we do have models that can simulate the slow changes in the field while not visible from Earth (described in the science paper Photospheric and heliospheric magnetic fields by Carolus J. Schrijver and Marc L. De Rosa). The 'jump' is created at the seam where the less accurate model gets overwritten by newer data. Related pages

Holly Gilbert, NASA GSFC solar scientist, explains a model of magnetic fields on the sun. In this video NASA solar physicist Holly Gilbert narrates a visualization of the slow changes in the sun's magnetic field over the course of four years.Grasping what drives that magnetic system is crucial for understanding the nature of space throughout the solar system: The sun's invisible magnetic field is responsible for everything from the solar explosions that cause space weather on Earth – such as auroras – to the interplanetary magnetic field and radiation through which our spacecraft journeying around the solar system must travel. We can observe the shape of the magnetic fields above the sun's surface because they guide the motion of that plasma – the loops and towers of material in the corona glow brightly in EUV images. Additionally, the footpoints on the sun’s surface, or photosphere, of these magnetic loops can be more precisely measured using an instrument called a magnetograph, which measures the strength and direction of magnetic fields. Scientists also turn to models. They combine their observations – measurements of the magnetic field strength and direction on the solar surface – with an understanding of how solar material moves and magnetism to fill in the gaps. Simulations such as the Potential Field Source Surface, or PFSS, model – shown in the accompanying video – can help illustrate exactly how magnetic fields undulate around the sun. Models like PFSS can give us a good idea of what the solar magnetic field looks like in the sun’s corona and even on the sun’s far side. Related pages