Wednesday, September 07, 2005
What’s soft as a pillow, cold as hell and just got smacked in the face?—Earlier this summer, when things were sunnier and merrier—give or take a war or two—NASA chased down a comet, Tempel 1, and blasted it to see what flew out. The answer was a lot of the stuff that created the early solar system, which is just what everyone seemed to expect. But that’s good; it’s nice when things work out that way.
The dust contained soot-like hydrocarbons, the stuff you find in limestone and crystalline silicates, scientists at the Johns Hopkins Applied Physics Lab told reporters prior to publication in Science. They also found aluminum sulfides and iron sulfides, the stuff of the earth's crust. The comet also contained a lot of carbon, the building block of carbon-based life forms like us. That also fits the theory, which holds that comets contain the material of the solar system’s beginnings frozen in time and place. It is from that mix that the sun and its planets accreted. While the solar system’s bodies were being formed, the comets were sailing around in the Oort Cloud, untouched. “It’s a missing link between what we’ve seen around these younger, baby stars and solar systems and what we now see around our own,” said Carey Lisse, a member of the Deep Impact team at Hopkins.
The outer layer of Tempel 1 is soft as a pillow, consisting of very fine, grainy material, very fragile in nature, and marked with craters.
NASA launched the project, Deep Impact, in January, sending it 268-million miles to intercept the comet on the Fourth of July. A copper bullet, weighing about 820 pounds, was shot off to intercept the comet while something like 80 observatories watched to see what blew out. Now we know.