Wow! Most of those dots are not stars: they are actual snowballs, frozen matter that has been ejected by the comet itself! They range in size from a few centimeters to a few dozen across, so they really are about the size of snowballs you’d use in a snowball fight… or to make a snowman. But I wouldn’t recommend it: a lot of that material is not frozen water, it’s actually frozen carbon dioxide, or dry ice.
Find out what else we’ve learned about Hartley 2 and see more photos at Bad Astronomy.
Bad Astronomy: Amazing Close-Ups of Comet Hartley 2!
80beats: Holy Hartley 2! What to Know About NASA’s Comet Flyby
80beats: Video: Comet Caught Crashing into the Sun
80beats: Spacecraft-Collected Comet Dust Reveals Surprises From the Solar System’s Boondocks
Bad Astronomy: Ten Things You Don’t Know About Comets
Image: NASA / JPL-Caltech / UMD