Van Allen Radiation Belts

Van Allen Probes Find Storage Ring in Earth’s Outer Radiation Belt

Since their discovery over 50 years ago, the Earth’s Van Allen radiation belts have been considered to consist of two distinct zones of trapped, highly energetic charged particles. Observations from NASA’s Van Allen Probes reveal an isolated third ring in the outer radiation belt.

A cutaway model of the radiation belts with the 2 RBSP satellites flying through them. The radiation belts are two donut-shaped regions encircling Earth, where high-energy particles, mostly electrons and ions, are trapped by Earth’s magnetic field. This radiation is a kind of “weather” in space, analogous to weather on Earth, and can affect the performance and reliability of our technologies, and pose a threat to astronauts and spacecraft. The inner belt extends from about 1,000 to 8,000 miles above Earth’s equator. The outer belt extends from about 12,000 to 25,000 miles. This graphic also shows other satellites near the region of trapped radiation.

A cutaway model of the radiation belts with the 2 RBSP satellites flying through them. The radiation belts are two donut-shaped regions encircling Earth, where high-energy particles, mostly electrons and ions, are trapped by Earth’s magnetic field. This radiation is a kind of “weather” in space, analogous to weather on Earth, and can affect the performance and reliability of our technologies, and pose a threat to astronauts and spacecraft.

The inner belt extends from about 1000 to 8000 miles above Earth’s equator. The outer belt extends from about 12,000 to 25,000 miles. This graphic also shows other satellites near the region of trapped radiation.

Picture Credit: NASA

Available formats at NASA:
320 x 179         PNG     271 KB
7952 x 4449     JPEG       2 MB
160 x 80           PNG       75 KB
80 x 40            PNG       29 KB

NASA’s Van Allen Probes Discover a Surprise Circling Earth

28.02.13

After most NASA science spacecraft launches, researchers wait patiently for months as instruments on board are turned on one at a time, slowly ramped up to full power, and tested to make sure they work at full capacity. It’s a rite of passage for any new satellite in space, and such a schedule was in place for the Van Allen Probes when they launched on Aug. 30, 2012, to study two giant belts of radiation that surround Earth.

Van Allen Belts
But a group of scientists on the mission made a case for changing the plan. They asked that the Relativistic Electron Proton Telescope (REPT) be turned on early – just three days after launch — in order that its observations would overlap with another mission called SAMPEX (Solar, Anomalous, and Magnetospheric Particle Explorer), that was soon going to de-orbit and re-enter Earth’s atmosphere.

It was a lucky decision. Shortly before REPT turned on, solar activity on the sun had sent energy toward Earth that caused the radiation belts to swell. The REPT instrument worked well from the moment it was turned on Sep. 1. It made observations of these new particles trapped in the belts, recording their high energies, and the belts’ increased size.

Van Allen Belts 2
Then something happened no one had ever seen before: the particles settled into a new configuration, showing an extra, third belt extending out into space. Within mere days of launch, the Van Allen Probes showed scientists something that would require rewriting textbooks.

“By the fifth day REPT was on, we could plot out our observations and watch the formation of a third radiation belt,” says Shri Kanekal, the deputy mission scientist for the Van Allen Probes at NASA’s Goddard Space Flight Center in Greenbelt, Md. and a coauthor of a paper on these results. “We started wondering if there was something wrong with our instruments. We checked everything, but there was nothing wrong with them. The third belt persisted beautifully, day after day, week after week, for four weeks.”

The scientists published their results in a paper in the journal Science on Feb. 28, 2013. Incorporating this new configuration into their models of the radiation belts offers scientists new clues to what causes the changing shapes of the belts – a region that can sometimes swell dramatically in response to incoming energy from the sun, impacting satellites and spacecraft or pose potential threats to manned space flight.

VanAllenBelts1

Published on 28 Feb 2013

Since their discovery over 50 years ago, the Earth’s Van Allen radiation belts have been considered to consist of two distinct zones of trapped, highly energetic charged particles. Observations from NASA’s Van Allen Probes reveal an isolated third ring in the outer radiation belt.

The radiation belts, or Van Allen belts, were discovered with the very first launches of satellites in 1958 by James Van Allen. Subsequent missions have observed parts of the belts – including SAMPEX, which observed the belts from below – but what causes such dynamic variation in the belts has remained something of a mystery. Indeed, seemingly similar storms from the sun have at times caused completely different effects in the belts, or have sometimes led to no change at all.

The Van Allen Probes consist of two identical spacecraft with a mission to map out this region with exquisite detail, cataloguing a wide range of energies and particles, and tracking the zoo of magnetic waves that pulse through the area, sometimes kicking particles up to such frenzied speeds that they escape the belts altogether.

Published on 28 Feb 2013

A new radiation belt and storage ring has been discovered above Earth; It is shown here using actual data as the middle arc of orange and red of the three arcs seen on each side of the Earth. The new belt was observed for the first time by Relativistic Electron-Proton Telescopes (REPT) flying on NASA’s twin Van Allen Probes, which launched on Aug. 30 2012. CREDIT: JHUAPL/LASP

“We’ve had a long run of data from missions like SAMPEX,” says Daniel Baker, who is the principal investigator for REPT at the University of Colorado in Boulder and first author on the Science paper. “But we’ve never been in the very throat of the accelerator operating a few hundred miles above our head, speeding these particles up to incredible velocities.”

In its first six months in orbit, the instruments on the Van Allen Probes have worked exceptionally well and scientists are excited about a flood of observations coming in with unprecedented clarity. This is the first time scientists have been able to gather such a complete set of data about the belts, with the added bonus of watching from two separate spacecraft that can better show how events sweep across the area.

Spotting something new in space such as the third radiation belt has more implications than the simple knowledge that a third belt is possible. In a region of space that remains so mysterious, any observations that link certain causes to certain effects adds another piece of information to the puzzle.

Baker likes to compare the radiation belts to the particle storage rings in a particle physics accelerator. In accelerators, magnetic fields are used to hold the particles orbiting in a circle, while energy waves are used to buffet the particles up to ever faster speeds. In such accelerators, everything must be carefully tuned to the size and shape of that ring, and the characteristics of those particles. The Van Allen Belts depend on similar fine-tuning. Given that scientists see the rings only in certain places and at certain times, they can narrow down just which particles and waves must be causing that geometry. Every new set of observations helps narrow the field even further.

“We can offer these new observations to the theorists who model what’s going on in the belts,” says Kanekal. “Nature presents us with this event – it’s there, it’s a fact, you can’t argue with it — and now we have to explain why it’s the case. Why did the third belt persist for four weeks? Why does it change? All of this information teaches us more about space.”

On Aug. 31, 2012, a giant prominence on the sun erupted, sending out particles and a shock wave that traveled near Earth.

› View larger
On Aug. 31, 2012, a giant prominence on the sun erupted, sending out particles and a shock wave that traveled near Earth. This event may have been one of the causes of a third radiation belt that appeared around Earth a few days later, a phenomenon that was observed for the very first time by the newly-launched Van Allen Probes. This image of the prominence before it erupted was captured by NASA’s Solar Dynamics Observatory (SDO). Credit:NASA/SDO/AIA/Goddard Space Flight Center

Scientists already have theories about just what kind of waves sweep out particles in the “slot” region between the first two belts. Now they must devise models to find which waves have the right characteristics to sweep out particles in the new slot region as well. Another tantalizing observation to explore lies in tracking the causes of the slot region back even further: on Aug. 31, 2012, a long filament of solar material that had been hovering in the sun’s atmosphere erupted out into space. Baker says that this might have caused the shock wave that led to the formation of the third ring a few days later. In addition, the new belt was virtually annihilated four weeks after it appeared by another powerful interplanetary shock wave from the sun. Being able to watch such an event in action provides even more material for theories about the Van Allen belts.

Despite the 55 years since the radiation belts were first discovered, there is much left to investigate and explain, and within just a few days of launch the Van Allen Probes showed that the belts are still capable of surprises.

“I consider ourselves very fortunate,” says Baker. “By turning on our instruments when we did, taking great pride in our engineers and having confidence that the instruments would work immediately and having the cooperation of the sun to drive the system the way it did – it was an extraordinary opportunity. It validates the importance of this mission and how important it is to revisit the Van Allen Belts with new eyes.”

The Johns Hopkins University Applied Physics Laboratory (APL) built and operates the twin Van Allen Probes. The Van Allen Probes comprise the second mission in NASA’s Living With a Star (LWS) program to explore aspects of the connected sun-Earth system that directly affect life and society. The program is managed by NASA Goddard.

› View NASA Press Release
› View briefing materials from the February 28, 2013 news conference

A playlist of 4 Video’s on the Radiation Belt Storm Probe (RBSP) mission will explore Earth’s Van Allen Radiation Belts. The protons, ions, and electrons in these belts can be hazardous to both spacecraft and astronauts.

Published on 28 Sep 2012

the twin Radiation Belt Storm Probes (RBSP) have recorded the “music” of the Van Allen Radiation Belts -actually radio waves at acoustic frequencies. These frequencies may play a role in speeding up electrons in the belts. Video From you tube user  ‘Coconut  Science Lab’ his website: Jungle Joel
Credit: NASA

More on:

Van Allen Probes Find Storage Ring in Earth’s Outer Radiation Belt

NASA's Living With a Star (LWS) program is a space-weather focused and applications driven research program. Its goal is to develop the scientific understanding necessary to effectively address those aspects of the connected sun–Earth system that directly affect life and society.  The program is implemented by a series of inter-related science missions, space environment testbeds, and a targeted theory, modeling, and data analysis program.  The Van Allen Probes are the second mission in the LWS program.  Credit: NASA
 NASA’s Living With a Star (LWS) program is a space-weather focused and applications driven research program. Its goal is to develop the scientific understanding necessary to effectively address those aspects of the connected sun–Earth system that directly affect life and society. The program is implemented by a series of inter-related science missions, space environment testbeds, and a targeted theory, modeling, and data analysis program. The Van Allen Probes are the second mission in the LWS program.Credit: NASA

Available formats:
3225 x 4725     JPEG       1 MB
319 x 468         JPEG     81 KB
320 x 468         PNG     549 KB
160 x 80           PNG       72 KB
80 x 40             PNG       36 KBThis two part movie shows an Aug. 31 coronal mass ejection (CME) from the sun , the same event that caused depletion and refilling of the radiation belts just after the Relativistic Electron-Proton Telescope (REPT) instruments on the Van Allen Probes were turned on. The first movie shows the CME as captured by NASA’s Solar Dynamics Observatory (SDO); the second shows several views of the same CME from the Solar and Heliospheric Observatory (SOHO). Credit: NASA

This two part movie shows an Aug. 31 coronal mass ejection (CME) from the sun , the same event that caused depletion and refilling of the radiation belts just after the Relativistic Electron-Proton Telescope (REPT) instruments on the Van Allen Probes were turned on. The first movie shows the CME as captured by NASA’s Solar Dynamics Observatory (SDO); the second shows several views of the same CME from the Solar and Heliospheric Observatory (SOHO).

Credit: NASA
Duration: 19.1 seconds
Available formats:
1280×720   MPEG-4   5 MB
320×180     PNG           138 KB
160×80       PNG           33 KB
80×40         PNG           9 KB
This graph shows energetic electron data gathered by the Relativistic Electron-Proton Telescope (REPT) instruments, on the twin Van Allen Probes satellites in eccentric orbits around the Earth, from Sept. 1, 2012 to Oct. 4, 2012 (horizontal axis). It shows three discrete energy channels (measured in megaelectron volts, or MeV). The third belt region (in yellow) and second slot (in green) are highlighted, and exist up until a coronal mass ejection (CME) destroys them on Oct. 1. The vertical axis in each is L*, effectively the distance in Earth radii at which a magnetic field line crosses the magnetic equatorial plane. Credit: LASP

This graph shows energetic electron data gathered by the Relativistic Electron-Proton Telescope (REPT) instruments, on the twin Van Allen Probes satellites in eccentric orbits around the Earth, from Sept. 1, 2012 to Oct. 4, 2012 (horizontal axis). It shows three discrete energy channels (measured in megaelectron volts, or MeV). The third belt region (in yellow) and second slot (in green) are highlighted, and exist up until a coronal mass ejection (CME) destroys them on Oct. 1. The vertical axis in each is L*, effectively the distance in Earth radii at which a magnetic field line crosses the magnetic equatorial plane.Credit: LASP

Available formats:
1280 x 720       JPEG   544 KB
80 x 40             PNG       21 KB
320 x 180         PNG     116 KB
160 x 80           PNG       42 KBGraphic with annotations.

Graphic with annotations.

Available formats:
1280 x 720       JPEG   555 KB
80 x 40             PNG       21 KB
320 x 180         JPEG     66 KB
320 x 180         PNG     119 KB
160 x 80           PNG       43 KBOne of the two Relativistic Electron-Proton Telescope (REPT) instruments for the Van Allen Probes is shown prior to and then during integration into the spacecraft in 2012. Each Van Allen Probe carries an identical suite of five instruments; REPT is part of the Energetic Particle, Composition, and Thermal Plasma Suite (ECT) aboard the Van Allen Probes. Credit: JHUAPL

One of the two Relativistic Electron-Proton Telescope (REPT) instruments for the Van Allen Probes is shown prior to and then during integration into the spacecraft in 2012. Each Van Allen Probe carries an identical suite of five instruments; REPT is part of the Energetic Particle, Composition, and Thermal Plasma Suite (ECT) aboard the Van Allen Probes.Credit: JHUAPL
Duration: 18.6 seconds
Available formats:
1280×720   MPEG-4   5 MB
320×180     PNG           229 KB
160×80       PNG           63 KB
80×40         PNG           17 KB
How to play NASA’s moviesThis long-term plot (approximately 12 years) from NASA’s Solar Anomalous and Magnetospheric Particle Explorer (SAMPEX) spacecraft shows the established two-belt structure of the Van Allen radiation belts above the Earth. The L value is distance above the Earth. New, more advanced instrumentation on the Van Allen Probes has revealed a third belt. Credit: NASA

This long-term plot (approximately 12 years) from NASA’s Solar Anomalous and Magnetospheric Particle Explorer (SAMPEX) spacecraft shows the established two-belt structure of the Van Allen radiation belts above the Earth. The L value is distance above the Earth. New, more advanced instrumentation on the Van Allen Probes has revealed a third belt.

Credit: NASA

Available formats:
1280 x 720       JPEG   429 KB
320 x 180         PNG     107 KB
160 x 80           PNG       38 KB
80 x 40             PNG       19 KB

This animation shows meridional (from north-south) plane projections of the REPT-A and REPT-B electron flux values. The animation first shows the expected two-belt Van Allen zone structure; from Sept. 3 through Sept. 6 only an intense belt of electrons remains and the inner zone and traditional slot region have not changed; next, the third ‘storage ring’ belt feature persists while a new slot region is seen and a completely new outer zone population has formed. Then, around Oct. 1, the storage ring feature remains while the outer zone decays away. Credit: LASP

This animation shows meridional (from north-south) plane projections of the REPT-A and REPT-B electron flux values. The animation first shows the expected two-belt Van Allen zone structure; from Sept. 3 through Sept. 6 only an intense belt of electrons remains and the inner zone and traditional slot region have not changed; next, the third ‘storage ring’ belt feature persists while a new slot region is seen and a completely new outer zone population has formed. Then, around Oct. 1, the storage ring feature remains while the outer zone decays away.Credit: LASP
Duration: 30.2 seconds
Available formats:
1280×720   MPEG-4   6 MB
320×180     PNG           122 KB
160×80       PNG           34 KB
80×40         PNG           10 KB
This visualization, created using actual data from the Relativistic Electron-Proton Telescopes (REPT) on NASA’s Van Allen Probes, clearly shows the emergence of new third belt and second slot regions. The new belt is seen as the middle orange and red arc of the three seen on each side of the Earth. The twin Van Allen Probes launched on Aug. 30 2012. Credit: JHU/APL, from REPT data/LASP

This visualization, created using actual data from the Relativistic Electron-Proton Telescopes (REPT) on NASA’s Van Allen Probes, clearly shows the emergence of new third belt and second slot regions. The new belt is seen as the middle orange and red arc of the three seen on each side of the Earth. The twin Van Allen Probes launched on Aug. 30 2012.Credit: JHU/APL, from REPT data/LASP
Duration: 1.1 minutes
Available formats:
1280×720   MPEG-4   20 MB
320×180     PNG           159 KB
160×80       PNG           50 KB
80×40         PNG           16 KB
Radiation regions like the belts are found throughout our solar system and the universe. We are fortunate that we have this region of interest just a few thousand kilometers above the planet – it is like having our very own particle accelerator in the backyard. Here are four objects with radiation regions: The sun, Earth, Jupiter, and the Crab Nebula. Credit: NASA/JHUAPL

Radiation regions like the belts are found throughout our solar system and the universe. We are fortunate that we have this region of interest just a few thousand kilometers above the planet – it is like having our very own particle accelerator in the backyard. Here are four objects with radiation regions: The sun, Earth, Jupiter, and the Crab Nebula.Credit: NASA/JHUAPL

Available formats:
1280 x 720       JPEG   287 KB
320 x 180         PNG     172 KBThis Sept. 28 coronal mass ejection (CME) from the sun, captured by NASA’s Solar Dynamics Observatory (SDO), is the event which caused the near total annihilation of the new radiation belt and slot region on Oct. 1. Credit: NASA

This Sept. 28 coronal mass ejection (CME) from the sun, captured by NASA’s Solar Dynamics Observatory (SDO), is the event which caused the near total annihilation of the new radiation belt and slot region on Oct. 1.Credit: NASA
Duration: 10.3 seconds
Available formats:
1000×1034 QT         8 MB
320×330     PNG           511 KB
160×80       PNG           67 KB
80×40         PNG           17 KB
This movie shows NASA’s Earth-orbiting heliophysics fleet as of 2013, from near Earth orbit out to the orbit of the moon. These missions study the thermosphere, ionosphere, and mesosphere; geospace and the magnetosphere; the heliosphere; and take solar observations and imagery. The Van Allen Probes (marked here as RBSP-A and RBSP-B) are in a highly elliptical orbit, shown in blue, around the Earth. Working as a team, these spacecraft provide the most comprehensive picture ever provided of how our sun interacts with our world. Credit: NASATo download the video, click here.

This movie shows NASA’s Earth-orbiting heliophysics fleet as of 2013, from near Earth orbit out to the orbit of the moon. These missions study the thermosphere, ionosphere, and mesosphere; geospace and the magnetosphere; the heliosphere; and take solar observations and imagery. The Van Allen Probes (marked here as RBSP-A and RBSP-B) are in a highly elliptical orbit, shown in blue, around the Earth. Working as a team, these spacecraft provide the most comprehensive picture ever provided of how our sun interacts with our world.Credit: NASA

To download the video, click here.

Available formats:
320 x 180         PNG     293 KBThe Forecast Office of NOAA's Space Weather Prediction Center is the nation's official source of alerts, warnings, and watches. The office, staffed 24/7, is always vigilant for solar activity that can affect critical infrastructure. Credit: NOAA.

 The Forecast Office of NOAA’s Space Weather Prediction Center is the nation’s official source of alerts, warnings, and watches. The office, staffed 24/7, is always vigilant for solar activity that can affect critical infrastructure.

Credit: NOAA.

Duration: 44.0 seconds
Available formats:
1280×720   MPEG-4   13 MB
320×180     PNG           192 KB
160×80       PNG           60 KB
80×40         PNG           17 KB
How to play our movies

The Space Weather Prediction Center has offered an email subscription service to customers both nationally and internationally since 2005. Now numbering over 32,000 subscribers, the satellite community accounts for about 9,500. Credit:NOAA.

The Space Weather Prediction Center has offered an email subscription service to customers both nationally and internationally since 2005. Now numbering over 32,000 subscribers, the satellite community accounts for about 9,500. Credit:NOAA.

Available formats:
1280 x 720       JPEG   500 KB
160 x 80           PNG       65 KB
320 x 180         PNG     226 KB
80 x 40             PNG       26 KBSatellite industry revenues globally have grown at about nine percent on average since 2006. In 2011, the last year for which data are available, the revenue was more than $177B (USD). Credit: Satellite Industry Association.

Satellite industry revenues globally have grown at about nine percent on average since 2006. In 2011, the last year for which data are available, the revenue was more than $177B (USD).Credit: Satellite Industry Association.
Available formats:
864 x 648         JPEG   295 KB
320 x 240         PNG     257 KB
160 x 80           PNG       55 KB
80 x 40             PNG       27 KBSatellite anomalies of various types are the result of high levels of charged particles. The Van Allen Probes offer unique measurements of these populations for the benefit of satellite builders and operators. Credit: JHUAPL

Satellite anomalies of various types are the result of high levels of charged particles. The Van Allen Probes offer unique measurements of these populations for the benefit of satellite builders and operators.Credit: JHUAPL

Available formats:
1280 x 720       JPEG   503 KB
320 x 180         PNG     191 KB
160 x 80           PNG       65 KB
80 x 40             PNG       28 KB

for the Following Picture/ Video:

A narrated short video featuring visualizations of the Van Allen Belt’s three ring structure. This video was not part of the news briefing, but is included in the associated feature story.

For complete transcript, click here.

Duration: 1.0 minutes
Available formats:
1280×720 (59.94 fps) QT         1 GB
1280×720 (29.97 fps) QT         37 MB
1280×720 (29.97 fps) WMV         34 MB
720×480 (29.97 fps) WMV         27 MB
640×360 (29.97 fps) QT         28 MB
640×360 (29.97 fps) MPEG-4   11 MB
320×240 (29.97 fps) MPEG-4   6 MB
1263×707   PNG           821 KB
320×179     PNG           244 KB
160×80       PNG           64 KB
80×40         PNG           18 KB
How to play our movies

A narrated short video featuring visualizations of the Van Allen Belt's three ring structure.  This video was not part of the news briefing, but is included in the associated feature story. For complete transcript, click here.

Short URL to This Page: http://svs.gsfc.nasa.gov/goto?11212
Animation Number: 11212
Completed: 2013-02-27
Animator: Tom Bridgman (GST) (Lead)
Video Editor: Genna Duberstein (USRA)
Narrator: Karen Fox (ASI)
Producer: Genna Duberstein (USRA)
Scientists: Shrikanth G. Kanekal (NASA/GSFC)
Dan Baker (University of Colorado)
Nicola Fox (NASA/GSFC)
Writer: Karen Fox (ASI)
Goddard TV Tape: G2013-024 — Van Allen Probes Find Storage Ring in Earth’s Outer Radiation Belt
Keywords:
SVS >> CME
SVS >> Coronal Mass Ejection
SVS >> Magnetosphere
SVS >> Solar Flare
SVS >> Solar Ultraviolet
SVS >> Solar Wind
SVS >> Sun
SVS >> Radiation Belts
SVS >> Space Weather
SVS >> SDO
SVS >> Solar Dynamics Observatory
SVS >> Heliophysics
SVS >> Sun-Earth interactions
SVS >> Corona
SVS >> RBSP
SVS >> Van Allen Belts
SVS >> Van Allen Probes

Please give Credit for this item to:

NASA’s Goddard Space Flight Center. However, individual items should be credited as indicated above.