Comet Tempel 1, which created a flamboyant Fourth of July fireworks display in space last year, is covered with a small amount of water ice. These results, reported by members of NASA’s Deep Impact team in an advanced online edition of Science, offer the first definitive evidence of surface ice on any comet.
“We have known for a long time that water ice exists in comets, but this is the first evidence of water ice on comets,” said Jessica Sunshine, Deep Impact co-investigator and lead author of the Science article. Tempel I A chief scientist with Science Applications International Corporation who holds three Brown University degrees, Sunshine said the discovery offers important insight into the composition of comets – small, Sun-orbiting space travelers that are believed to be leftovers from the formation of the solar system.
“Understanding a comet’s water cycle and supply is critical to understanding these bodies as a system and as a possible source that delivered water to Earth,” she said. “Add the large organic component in comets and you have two of the key ingredients for life.”