Mark Prigg
Scientists have uncovered a mysterious structure that surround the earth rather like a giant zebraprint jacket.
The strange structure has never been seen before, and initially baffled scientists.
Stripes extend through the inner radiation belt, moving as the Earth rotates.
Scientists discovered the new, persistent structure in one of two radiation belts surrounding Earth.
NASA’s twin Van Allen Probes spacecraft spotted the pattern, which that resembles slanted zebra stripes.
The structure is produced by the slow rotation of Earth, previously considered incapable of affecting the motion of radiation belt particles, which have velocities approaching the speed of light.
Scientists had previously believed that increased solar wind activity was the primary force behind any structures in our planet’s radiation belts.
However, these zebra stripes were shown to be visible even during low solar wind activity, which prompted a new search for how they were generated.
‘It is because of the unprecedented resolution of our energetic particle experiment, RBSPICE, that we now understand that the inner belt electrons are, in fact, always organized in zebra patterns,’ said Aleksandr Ukhorskiy, lead author of the paper at The Johns Hopkins Applied Physics Laboratory, or APL, in Laurel.
Because of the tilt in Earth’s magnetic field axis, the planet’s rotation generates an oscillating, weak electric field that permeates through the entire inner radiation belt.
The stretching and folding process results in the striped pattern observed across the entire inner belt, extending from above Earth’s atmosphere, about 500 miles above the planet’s surface up to roughly 8,000 miles.
‘The RBSPICE instrument has remarkably fine resolution and so it was able to bring into focus a phenomena that we previously didn’t even know existed,’ said David Sibeck, the mission scientist for the Van Allen Probes at NASA’s Goddard Space Flight Center in Greenbelt, Md.
‘Better yet, we have a great team of scientists to take advantage of these unprecedented observations: We couldn’t have interpreted this data without analysis from strong theoreticians.’
