Comet-Bound Spacecraft Beams Back First Photo of Icy Target

A NASA comet probe has beamed back to Earth its first photo of its quarry, Comet Hartley 2.

NASA's Deep Impact spacecraft is zooming toward the comet, snapping pictures in the lead-up to a planned flyby of the ice ball on Nov. 4. The new photo is the first of 64,000 or so the probe is expected to take of Hartley 2.

"Like any tourist who can't wait to get to a destination, we have already begun taking pictures of our comet, Hartley 2," Tim Larson, the mission's project manager at NASA's Jet Propulsion Laboratory, said in a statement. "We have to wait for Nov. 4 to get the close-up pictures of the cometary nucleus, but these approach images should keep the science team busy for quite some time as well."

Hartley 2, discovered in 1986, is thought to be about 1.5 kilometers (0.9 miles) across. It makes a complete orbit around the sun every 6.5 years or so.

During its two-month approach to Hartley 2, Deep Impact will use all three of its instruments (two telescopes with digital color cameras and an infrared spectrometer) to scrutinize the comet. The observations and measurements Deep Impact collects will give the mission's science team the best-ever extended view of a comet's pass through the inner solar system, NASA officials said.

Deep Impact took its first portrait of the comet Sept. 5, when the probe was 60 million km (37 million miles) from Hartley 2.

With the exception of one six-day break to calibrate instruments and make a trajectory-correction maneuver, Deep Impact will monitor Hartley 2 and its surrounding gas and dust cloud continuously for the next few months.

Recycled, repurposed spacecraft

The Deep Impact spacecraft was originally built as the mother ship for NASA's Deep Impact mission, which intentionally crashed a probe into Comet Tempel 1 in 2005 to study the object's composition.

Now, the Deep Impact probe is being put to other uses. It's tracking and studying various celestial objects in a broad mission NASA calls EPOXI. The name is derived from the mission's dual science investigations — the Extrasolar Planet Observation and Characterization (EPOCh) and Deep Impact Extended Investigations (DIXI).

Among other things, the EPOXI mission hopes to understand more about how comets formed and evolved, NASA officials have said. Because many comets are left over from the solar system's early days, learning about them could also yield clues about the solar system's formation and growth.

This past June, Deep Impact flew past Earth to use our planet's gravity as a slingshot to pick up a speed boost for the trip to Hartley 2. Its Nov. 4 flyby of the comet is scheduled to last one day.

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