Carbon monoxide cloud may mark extrasolar planetary collision

Los Angeles Times : Beta Pictoris is 63 light years away and is an extremely young star system—only about 20 million years old. It is still surrounded by a cloud of gas and dust, so studying the system may provide clues about the formation of such systems. Beta Pictoris is known to have one planet, several times the mass of Jupiter. Observations of the system using the Atacama Large Millimeter/Submillimeter Array telescope reveal an extremely large cloud of carbon monoxide roughly 8 million miles (12.9 million km) from the star. Carbon monoxide has a short life in space due to radiation breaking the molecule apart, so unless the observations caught a rare event, something must be maintaining the cloud. Because of its size—more than 200 trillion tons—the two options the astronomers suggest are the rapid collision of comets or the more likely explanation, the collision of two Mars-sized planets.