Hubble's Top 10.

This article presents Hubble's most riveting contributions to astronomy, according to the author, in light of its sixteen-year anniversary. From a human perspective, the impact of Comet Shoemaker-Levy 9 into Jupiter was a once-in-a-lifetime event: on average a comet plows into a planet only once every 1,000 years. Hubble has followed up on the ground-based discovery of extrasolar planets by focusing on these planets when they are aligned with our line of sight. Hubble's observation of a planet around the star HD 209458 have given the most detailed information about any planet outside our solar system.