While Earth spins around the sun at around 67,000 mph, the sun rotates around the Milky Way galaxy at a zippy 140 miles per second. With such a massive force moving through space, there's bound to be a trail of cosmic dust following behind, but it's always been a mystery -- until now. For the first time, scientists have combined the observations of NASA's Interstellar Boundary Explorer (IBEX) satellite and mapped the solar system's tail, but the length remains unclear.
Capturing the tail, which is composed of solar wind plasma and magnetic field, required three years of observation based upon data from IBEX's powerful energetic neutral atom imaging system. As neutral atoms (and other particles) from other parts of the galaxy flow through our solar system, those atoms eventually collide with faster charged particles -- usually carried by solar winds -- and exchange an electron.… Read more