BEIJING, Jan. 2 (Xinhuanet) -- On schedule for a 2010
meeting with Hartley 2 comet while searching for Earth-sized planets around a
cluster of stars, NASA's Deep Impact probe took a swing past Earth Monday
on the first of three flybys to generate the speed needed to complete its
1.6-billion-mile mission.
Last week, engineers calibrated the instruments
aboard the spacecraft using the moon as a target in advance of the flyby, which
occurred as planned, said William Blume of NASA's Jet Propulsion Laboratory. At
closest approach the spacecraft was 10,000 miles (16,092 km) above
Australia.
"We're taking laps around the sun until the comet
comes," he said.
Deep Impact -- named after the movie
-- became the first spacecraft to bust a comet by releasing a copper
impactor that smashed into Tempel 1 in 2005, giving scientists their first
glimpse of the interior. The mothership survived and was placed in safe mode
before it was tapped for an encore.
The new mission, known as Epoxi, calls for Deep
Impact to reach Hartley 2, which will be about 12 million miles (19.31
million km) from Earth at the time of the encounter. Deep Impact will hover
550 miles (885.1 km) from the half mile-wide surface and use its two telescopes
and infrared spectrometer to map features and record gas outbursts.
On its way to the comet, Deep Impact will spend six
months using one of its telescopes to search for Earth-sized planets around five
nearby stars, which are known to have Jupiter-like planets orbiting them.
The extended mission, managed by JPL in Pasadena,
cost 40 million U.S. dollars compared to the 333 million dollars it took to
collide with Tempel 1.
NASA initially wanted Deep Impact's second act to be
an exploration of comet 85P/Boethin in 2008. But to scientists' surprise, a bevy
of ground and space telescopes were unable to spot it this fall. Astronomers
believe the comet may have shattered into specks too small to be seen from
Earth.
(Agencies)