If I remember correctly, one of the asteroids actually IS a potato (although its one of the smaller background ones I believe.)
"You're not actually going INTO a potato field?!"
That being said, the appearance of the asteroids looks great to me, it just needs color correcting like the rest of the movie does.
And as for Boba Fett, he's not the guy with the Hummer H2 who's all talk and shiny things, he's a bloody Mad Max with the beat up jalopy that gets the job done!