Far out in space, a violent boundary zone marks the point where our solar system ends and outer space begins. NASA's Voyager 2 has now confirmed what its sister ship indicated: that this region is squashed and uneven, Space.com reports. This shock wave "sloshes back and forth like surf on a beach," says a scientist. "There's something outside pushing in."
This interstellar crest doesn't behave like a normal shock wave, however. Instead of heating up as it encounters obstacles, the wave seems to be transmitting its energy to cosmic ray particles, shooting them off in all directions. The Voyager spacecraft, both launched in 1977 and still chugging away, will soon exit our solar system entirely. (More solar system stories.)