Comet crystals found in a nearby planetary system

Comet crystals found in a nearby planetary system Pristine material that matches comets in our own Solar System have been found in a dust belt around the young star Beta Pictoris by ESA's Herschel space observatory. Twelve-million-year-old Beta Pictoris resides just 63 light-years from Earth and hosts a gas giant planet along with a dusty debris disc that could, in time, evolve into a torus of icy bodies much like the Kuiper Belt found outside the orbit of Neptune in our Solar System. Thanks to the unique observing capabilities of Herschel, the composition of the dust in the cold outskirts of the Beta Pictoris system has been determined for the first time. Of particular interest was the mineral olivine, which crystallises out of the protoplanetary disc material close to newborn stars and is eventually incorporated into asteroids, comets and planets. "As far as olivine is concerned, it comes in different 'flavours'," explains Ben de Vries from KU Leuven and lead author of - "A magnesium-rich variety is found in small and primitive icy bodies like comets, whereas iron-rich olivine is typically found in large asteroids that have undergone more heating, or 'processing'." Herschel detected the pristine magnesium-rich variety in the Beta Pictoris system at 15-45 astronomical units (AUs) from the star, where temperatures are around -190ºC. For comparison, Earth lies at 1 AU from our Sun and the Solar System's Kuiper Belt extends from the orbit of Neptune at about 30 AU out to 50 AU from the Sun.