1. NASA's Van Allen Probes Discover a
Surprise Circling Earth

2. 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.

3. The Van Allen Probes
Launched on Aug. 30, 2012,
To study two giant belts of radiation that
surround Earth.

4. Van Allen belts, were discovered with the first
launches of satellites in 1958 by James Van
Allen.

5. Relativistic Electron Proton Telescope (REPT)

6. Changing the plan
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.

7. SAMPEX

8. NASA's Goddard Space Flight Center in
Greenbelt
"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."

9. 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

10. 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.

11. The Van Allen Belts
In 1958, discovered Two giant swaths of
radiation surrounding Earth.
But In 2012, observations a 3rd belt appears.

12. The radiation is shown here in
Yellow
Green
Credit: NASA/Van Allen
Probes/Goddard Space Flight Center

13. Two giant belts of radiation

15. 3rd giant Radiation Belt
On Aug. 31, 2012
A giant prominence on the sun erupted,
sending out particles and a shock wave
that traveled near Earth.

16. 3rd radiation belt

18. 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

19. NASA solar dynamics observatory (SDO)