New Asteroid Points to Habitable Exoplanets

Scientists have spotted the remains of a water-rich asteroid, orbiting a dying star about 170 light-years from Earth. It's more than a bit of space waste—the find suggests that this far-off solar system may have once had planets capable of supporting life, the LA Times reports. "The finding of water in a large asteroid means the building blocks of habitable planets existed—and maybe still exist—in the GD 61 system," says Jay Farihi, the lead author of a paper about the discovery, per Space.com. "These water-rich building blocks, and the terrestrial planets they build, may, in fact, be common—a system cannot create things as big as asteroids and avoid building planets."

GD 61 is a white dwarf star which collapsed about 200 million years ago. The scientists analyzed observations of the star and the watery asteroid remains raining down on it made by an instrument on the Hubble Space Telescope. They calculate that the parent body of the asteroid was about 26% water—a similar makeup to the dwarf planet Ceres in our own solar system. "That kind of rock together with water chemistry—like the Earth's surface, basically —that has never been seen before," says Farihi. (More asteroid stories.)