October 13, 2013
Astronomers have found the shattered remains of an asteroid that contained huge amounts of water orbiting an exhausted star, or white dwarf. This suggests that the star GD 61 and its planetary system — located about 150 light years away and at the end of its life — had the potential to contain Earth-like exoplanets, they say. This is the first time that both water and a rocky surface — two “key ingredients” for habitable planets — have been found together beyond our solar system.
Earth is essentially a ‘dry’ planet, with only 0.02% of its mass as surface water, so oceans came long after it had formed; most likely when water-rich asteroids in the solar system crashed into our planet.
The new discovery shows that the same water ‘delivery system’ could have occurred in this distant, dying star’s solar system — as latest evidence points to it containing a similar type of water-rich asteroid that would have first brought water to Earth.