[3] The apparent shape of the very
faint outer belt, if confirmed, would give astronomers a way to estimate the inclination of the Proxima Centauri planetary system.
The team has also considered a different scenario where a hypothetical second dwarf planet suffered a catastrophic collision with Fomalhaut b. Kalas explained, «The collision scenario would provide a solution as to why Fomalhaut (the star) has a
narrow outer belt linked to an extreme planet.
If confirmed, the nature of
an outer belt is intriguing, given its very cold environment far from a star that is cooler and fainter than the Sun.
According to Dan Baker, REPT instrument lead at the Laboratory for Atmospheric and Space Physics (LASP) at the University of Colorado in Boulder, «a powerful electron acceleration event was already in progress, and we clearly saw the new belt and new slot between it and
the outer belt.»
The mission has answered one long - standing question about the nature and behavior of the belts, and revealed that
the outer belt can split into two separate belts.
Fomalhaut's mystery planet (inset) is bound to enter the inner edge of the star's
outer belt of icy debris in 2032.
The scientific successes for the Van Allen Probes began almost immediately after launch, starting with a discovery made when scientists turned on the Relativistic Electron Proton Telescope (REPT) instrument on Sept. 1: a new third radiation belt, formed at the interior of
the outer belt.
Particles can escape
the outer belt in about a week, but the inner belt can hold onto particles for about a year.
Scientists think a shock wave (an energetic disturbance) from the sun disrupted
the outer belt, moving particles lower and forming the temporary belt.
During this interval is when the researchers recorded measurements of the Van Allen radiations belts, and found that
the outer belt was not as calm as expected.
«
The outer belt is somehow feeding material into the inner warm belt,» said Geoff Bryden of JPL, a co-author of the study.
The boundary between the plasmapause and the inner edge of
the outer belt -LSB-...]
According to Furlan, the dust generated from the collision of rocky objects in
the outer belt should eventually migrate toward the inner disk.
The Van Allen belts consist of an inner belt composed primarily of protons and
an outer belt composed mostly of electrons.