The collision of a NASA space probe and a potato-shaped comet hurled a bright cloud of debris into space at the speed of a jetliner, scientists said.
The Hubble Space Tele- findings were among observations pouring in from telescopes in space and on the ground. For example, an infrared camera on the Very Large Telescope in Chile detected a colour change in the plume, suggesting different size dust particles were sprayed from the comet and were traveling at different speeds through space.
The impact suggests the probe struck a surface that was soft and powdery before penetrating trapped gas and ice beneath, said Pete Schultz, a Deep Impact co-investigator.
But other researchers scope took pictures of the July 4 impact that initially showed comet Tempel 1 as a fuzzy dot that grew four times brighter 15 minutes after the collision.
This is pretty dramatic, said Paul Feldman, a professor at Johns Hopkins University, who observed the impact with the Hubble telescope.He also said that the initial ultraviolet readings taken by NASAs Swift satellite detected a dramatic rise in UV light, indicating the surface was hard or there was solid material underneath. The debris cloud has prevented scientists from peering into the impact crater.
Scientists said it could take at least a week for the cosmic dust to settle before they get to look at the inside of a comet.
Studying the debris hurled from the interior of Tempel 1 and the crater left behind could yield clues to how the sun and planets formed 4.5 billion years ago.