An alien asteroid belt may have been spotted circling a mature star nearby. The observations, made by NASA’s Spitzer Space Telescope, reveal a dense ring of dust around the star that might arise from rocks colliding and smashing each other apart.
Alternatively, the dust could come from a âsupercometâ? almost the size of Pluto, said Charles Beichman of the California Institute of Technology in Pasadena, US, at a NASA news conference on Wednesday.
Beichman and his colleagues used Spitzer to observe more than 80 Sun-like stars, including one called HD69830, which lies 41 light years away. Its infrared spectrum suggested it has a thick disc of warm dust grains surrounding it. The dust could be produced in a busy asteroid belt if large rocks are colliding every 1000 years or so, replenishing the ring.