Just a comparison between 1980 and 2004's graphics. At least the asteroid in 2004 looks like an asteroid, instead of the potato (yes, they did use a potato in 1980).
http://www.starwars.com/episode-v/r.../pictureviewer.html?imgNum=71&world=episode-v
http://www.starwars.com/episode-v/r.../pictureviewer.html?imgNum=71&world=episode-v