One way, anyway. An astrophysicist from my alma mater, researching on the Spitzer Space Telescope, has found that ice particles are impacting on a disk of dust circling the star NCG 1333-IRAS 4B.
“For the first time, we are seeing water being delivered to the region where planets will most likely form,” said Dan Watson, an astrophysicist at the University of Rochester.
“On Earth, water arrived in the form of icy asteroids and comets,” Watson said. “Water also exists mostly as ice in the dense clouds that form stars.”
The dust forms along the plane of the orbits of future planets, and the ice hovers around the star as a cloud.
It’s thought a more likely method of watering the planets is deposit by comets. Twenty-nine other star systems surveyed by Watson and his colleagues seemed to be bone dry.