Astronomers have detected
such icy particles before, Watson says, «but what's new here is that we've seen them as definitely belonging to the proto - planetary system we're looking at.»
It also would be far easier to get a water sample from Enceladus, which has plumes of water vapor, ice and
particles shooting more than 300 miles off its surface, than from other moons,
such as Jupiter's Europa, where a massive ocean is believed to be buried beneath a thick
icy crust.