NASA snaps closeup pics of comet Hartley 2
A closeup of the comet Hartley 2, photographed from 435 miles away, taken and released today by NASA. The comet's nucleus, or main body, is approximately 2 kilometers (1.2 miles) long and .4 kilometers (.25 miles) at the "neck," or most narrow portion. Jets can be seen streaming out of the nucleus.
HUNTSVILLE, AL - Running a "bargain" mission under a program managed by Huntsville's Marshall Space Flight Center, scientists Thursday made only the fifth photographic fly-by of a comet.
Why should anyone on Earth care beyond a moment's "hmmm" reaction to the new and detailed images?
We should care, scientists say, because flights like these bring us closer to "the ultimate origins question."
"How did we get here? What material came to Earth 4.5 billion years ago that enable life to exist here?" asked mission principal investigator Dr. Michael A'hearn.
A'hearn is one of the astronomers looking for answers in comets, the icy solar bodies that orbit the Sun and form the core of Jupiter and other planets.
Scientists know comets bombarded the early Solar System, and some theorize they were the space taxis that brought the building blocks of life to Earth.
A'hearn's team got to take a close look at the comet Hartley 2 after engineers realized there was life left in a spacecraft that had already delivered the Deep Impact probe to its comet target in 2005.
Aiming the spacecraft at Hartley 2 cost NASA less than $50 million, engineers said, which basically meant NASA got two high-yield missions for the price of one. The fly-by mission is called EXPOXI, a smash-up of the names of the flight's main components.
At their briefing Thursday at NASA's Jet Propulsion Laboratory, scientists and engineers wore broad smiles and used words like "amazing" to describe what they had seen.
The black and white photographs showed a roughly 1.25-mile-long comet nucleus described variously as potato- or peanut-shaped. The comet was photographed from only 435 miles away after a journey by the spacecraft of 23 million miles.
Emitting from the nucleus were jets of dust fueled by carbon dioxide from dry ice within the core, scientists said.
"It's been an exciting day," Marshall Discovery program manager Dennon Clardy said from California.
Clardy said the Discovery program funds smaller space missions, often in collaboration with industry or educational institutions.
Clardy and mission manager Brian Key were in California for the fly-by and in the room when the first images returned.
"Every now and then we get a day like this," Key said. "It went off without a hitch. It has given us a lot of science and a great return on investment."
Also at JPL Thursday was Michael Hartley, the Australian astronomer who discovered the comet in 1986.
