October 21, 2008 NASA has launched the Interstellar Boundary Explorer, which will observe the edge of our solar system from a 200,000-mile Earth orbit and determine whether or not we’re, well, doomed. Over the next two years, the 23-inch high octagonal craft will study the area of space where solar wind hits the wider galaxy – hopefully it will also find out why the solar wind, which shields us from harmful cosmic rays, has decreased by 25% in the last ten years.
The solar wind is made up of magnetically charged particles expelled from the sun at one million miles per hour. The particles form a protective shield around our solar system, filtering out 90% of intergalactic radiation. The clashing of the solar wind with external forces was detected by the Voyager crafts, but IBEX was specifically designed to study it.
"No one has seen an image of the interaction at the edge of our solar system where the solar wind collides with interstellar space," said IBEX Principal Investigator David McComas of the Southwest Research Institute in San Antonio. "We know we're going to be surprised. It's a little like getting the first weather satellite images. Prior to that, you had to infer the global weather patterns from a limited number of local weather stations. But with the weather satellite images, you could see the hurricanes forming and the fronts developing and moving across the country."
The Interstellar Boundary Explorer is part of NASA’s Small Explorer Program, a series of low-cost data-gathering missions.