NASA wants to know which among the most popular Hubble photos the internet likes the most, so it's pitting them against each other. To celebrate the telescope's 25th birthday in April, the agency has launched Hubble Mania, which is a space image smackdown of sorts, where the winner's determined by your votes. The space telescope's known for capturing some mighty stunning photos of our universe, so it won't be easy choosing: the 32 contenders include long-time favorites, such as the Pillars of Creation, the sombrero galaxy, crab and apple nebulae, as well as the Rose of Galaxies. Voting for the first round has already begun, with two more rounds to follow, until the grand winner is announced on April 6th. NASA promises new downloadable products featuring the last photo standing, which could include HD wallpapers, among other things.