Comets - 1

Most comets originate from the Kuiper belt, having been nudged out of their orbits by collisions or the gravity of a passing star. Would there be life on Earth without comets? There is increasing evidence that water and organic molecules, both needed for life to form, were partially delivered to the early Earth by comets. Comets are enriched with water ice. Studies of comet Halley in 1986 revealed it to be some of the most organic-rich material ever measured in the solar system, NASA’s 2004 Stardust Mission to Comet Wild 2 found a range of complex hydrocarbon molecules, and NASA’s 2005 Deep Impact mission to Comet Tempel 1 discovered a mixture of organic and clay particles. Scientists think comet impacts and deliveries were a common occurrence in the early solar system, but still question if Earth’s water was incorporated as it formed or was a result of cometary impacts after formation was complete