News Print Email Font ResizeCU-Boulder researchers contribute to revelations about third radiation belt encircling Earth Local scientists pivotal in new discoveries about the Van Allen beltsBy Charlie Brennan, Camera Staff WriterPosted:
02/28/2013 12:00:00 PM MSTA little pushiness on the part of a University of Colorado scientist has triggered a discovery about the nature of the radiation belts encircling Earth, which were initially detected by the first U.S. space mission. For about 50 years, it has been thought that the Van Allen belts consisted of two doughnut-shaped rings around our planet, between 8,000 and 36,000 miles above the Earth's surface, made up of ions and electrons trapped by Earth's magnetic field. The belts, which can be dramatically affected by space weather and solar storms, take their name from James Van Allen, the University of Iowa space scientist who designed the instrument on board the first American satellite, Explorer I, which launched Jan. 31, 1958. Subsequent data that same year from NASA's Explorer IV and Pioneer 3 established there were two rings, the outer ring rich in so-called "killer electrons" that could prove dangerous to astronauts, spacecraft and even technologies on the ground. Now, however, NASA's Radiation Belt Storm Probes mission, launched Aug. 30, has found that the structure of the Van Allen belts might be far more volatile than previously believed. That's because Dan Baker, director of CU's Laboratory for Atmospheric and Space Physics, pushed to turn on the Relativistic Electron-Proton Telescope (REPT) that flies on the twin NASA space probes about a month sooner than scheduled. When the REPT instruments were activated just a few days following the August launch, scientists were astounded to see the formation of a third "storage ring" radiation belt. "For the better part of four weeks, we first foolishly thought the instruments were not working properly," so odd-looking were the results the instruments showed, Baker said. Baker is the REPT lead investigator and lead author of the study published online Thursday in the journal Science. A new radiation belt and storage ring has been discovered above Earth. It is shown here as the middle arc of orange and red on each side of the Earth. (JHUAPL/LASP )
"But we saw things identically on each of the spacecraft. We had to come to the conclusion that this was real." Invoking Yogi Berra, Baker said Thursday at a news conference, "You can observe a lot, just by looking." Initial data fed back to Earth during September showed the two Van Allen belts as expected. But after a few days, the outer ring seemed to compress into a tightly packed electron band, while a third, less compact belt of electrons formed farther out, creating a third ring. The center so-called storage ring persisted, as the third, outer belt began to erode in the third week of September, when a powerful interplanetary shockwave from the sun appeared to destroy the storage ring and the remnants of the outer belt. Since that event, the Van Allen belts have reformed into the historically presumed two-belt structure. "We have no idea how often this sort of thing happens," Baker said. "This may occur fairly frequently, but we didn't have the tools to see it." As originally scheduled, the REPT instruments had not been programmed to be commissioned -- turned on, tested and calibrated -- until about a month following the launch. However, Baker was concerned that the only other NASA instruments collecting similar data were on a separate mission, launched in 1992 and then in its final months of service. "We went on a campaign," Baker said, urging that the REPT instruments be pushed to the front of the commissioning schedule. "Had we not done so, we would have missed this" event, Baker said. "It's good to be in the right place at the right time." Joe Kunches, a space scientist at the National Oceanic and Atmospheric Administration's Space Weather Prediction Center in Boulder, pointed out about $177 billion in revenue was generated in 2011 by the roughly 300 satellites in 24-hour Earth-orbit. "This is a very important customer base which needs the best space information it can get," Kunches said. Contact Camera Staff Writer Charlie Brennan at 303-473-1327 or .Print Email Font ResizeReturn to Top RELATED