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theweaselkingA nearby star system thought of as a candidate for harbouring life has 10 times the number of asteroids and comets as found in our Solar System. The sheer number of bodies raging around the Sun-like star may mean that any potential life is choked off, say UK researchers.
The star, Tau Ceti, lies just 12 light-years away and has been eyed as a possible oasis for life because of its similarity to the Sun and the inference of a surrounding debris disk that may harbour planets.
Imaging the disk has now identified the 10-billion-year-old Tau Ceti as the oldest of about a dozen stars with confirmed disks. Its span is similar to our Solar System's Kuiper Belt.
This shadowy belt consists of a ring of comets and asteroids reaching just past Pluto's orbit. But the amount of dust around Tau Ceti suggests it is circled by more than 10 times as many of the objects.
If there are planets around the star, says lead researcher Jane Greaves, an astronomer at the University of St Andrews, UK, this means "it is likely that they will experience constant bombardment from asteroids of the kind believed to have wiped out the dinosaurs".
"It is likely that with so many large impacts life would not have the opportunity to evolve," says Greaves, whose team imaged Tau Ceti for the first time.
But other astronomers say the implications for life are not so clear. "You could argue the other way as well," says Glenn Schneider of the University of Arizona in Tucson, US. He says the key factor is whether the impacts would occur in the habitable zone - the region around the star where liquid water can exist.
Scott Kenyon, an astronomer at the Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, US, agrees. He says a giant planet could orbit the star, gravitationally deflecting comets and asteroids away from planets that may support life in the same way that Jupiter protects Earth.
The star, Tau Ceti, lies just 12 light-years away and has been eyed as a possible oasis for life because of its similarity to the Sun and the inference of a surrounding debris disk that may harbour planets.
Imaging the disk has now identified the 10-billion-year-old Tau Ceti as the oldest of about a dozen stars with confirmed disks. Its span is similar to our Solar System's Kuiper Belt.
This shadowy belt consists of a ring of comets and asteroids reaching just past Pluto's orbit. But the amount of dust around Tau Ceti suggests it is circled by more than 10 times as many of the objects.
If there are planets around the star, says lead researcher Jane Greaves, an astronomer at the University of St Andrews, UK, this means "it is likely that they will experience constant bombardment from asteroids of the kind believed to have wiped out the dinosaurs".
"It is likely that with so many large impacts life would not have the opportunity to evolve," says Greaves, whose team imaged Tau Ceti for the first time.
But other astronomers say the implications for life are not so clear. "You could argue the other way as well," says Glenn Schneider of the University of Arizona in Tucson, US. He says the key factor is whether the impacts would occur in the habitable zone - the region around the star where liquid water can exist.
Scott Kenyon, an astronomer at the Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, US, agrees. He says a giant planet could orbit the star, gravitationally deflecting comets and asteroids away from planets that may support life in the same way that Jupiter protects Earth.