Spitzer Space Telescope Finds Planet Smash-Up Sending Vaporized Rock, Hot Lava Flying

NASA's Spitzer Space Telescope has found evidence of a high-speed collision between two burgeoning planets around a young star left vaporized rock and flying lava in the wake. Astronomers say that two rocky bodies, one as least as big as our moon and the other at least as big as Mercury, slammed into each other within the last few thousand years or so -- not long ago by cosmic standards. The impact destroyed the smaller body, vaporizing huge amounts of rock and flinging massive plumes of hot lava into space.

"This collision had to be huge and incredibly high-speed for rock to have been vaporized and melted," said Carey M. Lisse of the Johns Hopkins University Applied Physics Laboratory, Laurel, Md., lead author of a new paper describing the findings in the Aug. 20 issue of the Astrophysical Journal. "This is a really rare and short-lived event, critical in the formation of Earth-like planets and moons. We're lucky to have witnessed one not long after it happened."

Lisse and his colleagues say the cosmic crash is similar to the one that formed our moon more than 4 billion years ago, [vido 9:36], when a body the size of Mars rammed into Earth. More from NASA -