More 60-Second Space Back in 1958, at the dawn of the space age,
physicist James Van Allen discovered that the Earth is ringed by
high-energy charged particles. Held in place by the planet’s
magnetic field, these bands of radiation were named the inner
and outer Van Allen Belts. They’re of particular interest to
NASA as they pose a potential danger to spacecraft. Now a NASA
mission also named for Van Allen has found something new about
his belts. By looping through them repeatedly, the twin Van
Allen Probes discovered a third band of radiation. Or at least
there were three. The two spacecraft uncovered the previously
unknown structure in September. It consisted of fast-moving
electrons, situated between the two previously known Van Allen
Belts. The discovery was reported in the journal Science.
[Daniel N. Baker et al., A Long-Lived Relativistic Electron
Storage Ring Embedded in Earth's Outer Van Allen Belt] But the
new structure is no longer. Four weeks after the probes found
it, the third ring was wiped out