Issue Date: July 11, 2005
With an excited public awaiting details, the team of scientists behind NASA's Fourth of July mission to collide the Deep Impact space probe with the comet Tempel 1 last week revealed what they know so far about the huge divot they created in the heavenly body.
The impact generated a brilliant burst of light that illuminated the comet's surface, captured in images by the Deep Impact probe's mother flyby craft. The pictures show that the gaseous water and CO2 coma that envelops comets, normally visible as a fuzzy cloud from a distance, is transparent up close.
The flyby craft, which carried the impactor probe on its 80 million-mile journey from Earth, kept a safe distance from Tempel 1 after the detonation while it studied the material kicked up by the explosion with a suite of cameras and spectrometers. Scientists hope the data will give them insight into the early conditions that led to planet formation in the outer solar system.
Though the thrown-up dust blocked their view of the impact crater, scientists do know it's "bigger than a house," says Peter H. Schultz, coinvestigator for NASA's Deep Impact mission and a geology professor at Brown University. Now it's just a matter of processing the images they've received from the flyby craft, which should reveal what they expect to be a very large dent.
The Deep Impact team anticipated that the probe would leave a big crater on the comet on the basis of experiments in which they smashed heavy objects into perlite, a "soft and fluffy" silica material that approximates the comet's icy, rocky surface. "This was really dead-on in terms of what we were expecting," Schultz says.
- Chemical & Engineering News
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