NASA's IBEX Ready to Measure the Edges of Our Solar SystemA NASA mission to measure and study the mysterious edge of the solar system is underway this week. The Interstellar Boundary Explorer (IBEX) is one of the low-cost "Small Explorers" missions - it can study the termination shock area of our solar system without even leaving Earth's orbit. How will it manage that? By acting as a target for particles that have traveled hundreds of millions of miles.The termination shock is where the solar wind runs into the interstellar medium, which is astronomy jargon for "whatever is in space beyond our solar system." We learned a lot about this region of space when Voyager II passed through it last year, but IBEX will be able to study the interactions happening out there in far greater detail. Particles called energetic neutral atoms are ejected from the termination shock at high speed. IBEX will measure these particles as they strike it, and piece together an image of what's going on as the solar wind slows and ripples. NASA likes to compare it to an Impressionist painting in their IBEX press releases, but it's really more like...well, science. IBEX has been in orbit for more than a month, but it needed time to push itelf into a very high-altitude orbit and run some tests. Now it's ready to rock. So what will IBEX find out there? It's such an unexplored region of space that scientists really have no idea. They believe that the termination sock filters out cosmic rays that would otherwise bombard the solar system, and they have some rough ideas of the heliosphere's irregular dimensions, thanks to the Voyagers, but beyond that, it's an unknown frontier. Image by: NASA. NASA Launches IBEX Mission to Outer Solar System. [NASA]