Holy interplanetary snowstorm! This image, a focused (“deconvolved”) view of comet Hartley 2 which was approached by NASA’s EPOXI spacecraft on November 4, shows a swarm of specks surrounding an ice-spraying, boulder-crusted nucleus. Those specks aren’t stars, they’re golfball- to basketball-sized balls of loosely-packed ice particles… a.k.a snowballs! And comet Hartley-2 is literally surrounded by them as it travels through the inner solar system, the Sun’s heat causing it to spew out sublimated carbon dioxide gas (think dry ice) mixed with water ice and dust.
There’s enough frozen particles around the comet’s nucleus that it casts a shadow through the cloud! (And check out a Quicktime animation of the particles, which gives a bit of a 3D perspective of the scene.)
Now that they’ve had some time to pore through the image data, EPOXI mission scientists are really discovering a lot of information about this mile-and-a-half-long mobile member of our solar system. Read more on the mission site here, or in this article by astronomer Phil Plait on Discover’s Bad Astronomy blog.