Comet Tempel 1 is a big dust ball.
When the “impactor” from the Deep Impact spacecraft hit Tempel 1 on July 3, it kicked up dust and icy water, revealing that the 5-mile-long comet was as fragile as snow drift, as porous as a sponge.
It also was laden with the sort of chemicals that may have helped start life on Earth, according to Deep Impact data.
“If you touched it, it (would) just crumble,” Horst Uwe Keller of the Max Planck Institute for Astronomy in Germany said at a news conference Tuesday.
Inside the dusty comet are water and organic chemicals.
Similar comets probably smashed into the Earth billions of years ago, delivering the same compounds and helping start life, scientists said.
Science magazine will publish several papers on Deep Impact results in Thursday’s issue.
Engineers at Ball Aerospace and Technologies Corp. in Boulder built Deep Impact for the National Aeronautics and Space Administration in two parts: a fly-by spacecraft with sophisticated cameras and an 820-pound copper “impactor,” with its own engines, camera and steering software.
The two flew together for most of their 268 million-mile journey and separated 24 hours before impact.
From the shower of dust and ice that followed the impact, scientists calculate Deep Impact carved a crater about the diameter of Denver’s Invesco Field and 30 to 90 feet deep, said chief mission scientist Michael A’Hearn, who is a professor at the University of Maryland.
Some of that dust sprayed 1,000 miles into space, but more than half of it drifted back down into the comet’s crater, making it difficult for scientists to find the hole, A’Hearn said.
A problem with moisture in one of Deep Impact’s cameras also has plagued the search to pinpoint the crater’s size, A’Hearn said. Still, scientists have captured clear images of what appear to be impact craters on the surface of the comet.
The mission also has sent Europeans scrambling to understand the strength of the surface of Comet Tempel 1 because the European Space Agency craft Rosetta, launched last year, is supposed to land on the comet in 2014.
Keller said he hoped preliminary calculations of surface strength were wrong.
“Otherwise, the spacecraft is just going to sink into the comet,” he said.
Monte Henderson, deputy project manager of the mission with Ball Aerospace, said he and his colleagues were proud of their spacecraft, which still has enough fuel for another mission.
“Not only did it do its job perfectly,” Henderson said, “it’s out there waiting to do something else.”
Staff writer Katy Human can be reached at 303-820-1910 or khuman@denverpost.com.
