A dust cloud surrounding a nearby star 300 light-years from Earth may be all that remains from the collision of two rocky planets, researchers say.
The planets may have been similar to Earth in size, age, and distance from their sun. The bodies circled a binary star, or a pair of stars locked in tight rotation, known as BD +20 307.
Until now, no other binary stars close to our solar system have shown evidence of having planets.
Using optical and x-ray telescopes to estimate the volume and temperature of BD +20 307's dust cloud, researchers concluded that it must have been produced by the violent collision of two planet-size bodies.
Such planets would have been prime locations for the possible evolution of extraterrestrial life, experts say.
"They were certainly old enough for full-fledged biology [to have developed]," said lead study author Benjamin Zuckerman, an astronomer at the University of California, Los Angeles.
Inhabited or not, both planets would have been obliterated when their two worlds collided.
The resulting dust will dissipate over the course of a few thousand years, leaving no lasting trace of the planets, Zuckerman said.
The study, currently published on Cornell University's arXiv.org academic online archive, will appear in the December issue of Astrophysical Journal.
Dust to Dust
Our own solar system contains significant amounts of dust, which is produced by colliding asteroids and dragged here by wandering comets.
In a 2005 study Zuckerman and his colleagues estimated that BD +20 307 contains about a million times more dust.
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