PASADENA,
Calif. – A NASA spacecraft circling the red planet caught a stunning snapshot of
the Phoenix Mars Lander and its deployed parachute as it plummeted through the
Martian atmosphere for a successful Sunday landing, NASA scientists announced Monday.
It marks the first time that one spacecraft has imaged another's final descent
onto another planet.
"The
picture is awesome," said Phoenix principal investigator Peter Smith of the
University of Arizona at a briefing here at NASA's Jet Propulsion Laboratory
(JPL) today.
Phoenix project
manager Barry Goldstein of JPL said he had been skeptical about the ability of
the Mars Reconnaissance Orbiter's (MRO) HiRISE camera to catch a glimpse of the
falling Phoenix spacecraft during the brief,
seven-minute descent.
The
black-and-white image reveals Phoenix's 30-foot-wide (10-meter) parachute fully
inflated, with the spacecraft itself dangling below. The MRO spacecraft took
the image while flying about 472 miles (760 km) above the Martian surface.
"This was
quite an engineering feat," Goldstein said, hailing the MRO mission team's
success.
The $420 million
Phoenix mission, which launched in August, is designed to dig into the rock-hard
layers of water ice thought to lie beneath the surface in the planet's arctic
north. It will test the soil and ice for signs that the water was once liquid,
and to see if it could have created a habitable zone for microbial life at some
point in the past.
Mission
scientists here at JPL received
the signal that Phoenix had landed at around 7:53 p.m. EDT (2353 GMT) on
Sunday, though it currently takes signals about 15 minutes to cross the 171
million-mile (275 million-km) gulf between Mars and Earth.
Phoenix deployed
its parachute while at an altitude of about 7.8 miles (12.6 km) above its
Vastitas Borealis landing site. The spacecraft was traveling at about 1.7 times
the speed of sound during the process. Mission scientists will use the image
and other data taken during the craft's fiery descent to reconstruct Phoenix's
landing. They are especially interested since Phoenix's parachute unfurled
about 6.5 seconds later than expected, pushing the probe's descent near the
edge of its target drop zone.
Phoenix sent
its first images a few hours after landing, bouncing them off NASA's Mars
Odyssey orbiter to relay them to eager scientists back on Earth. The first
image the lander took was of its solar arrays, both of which appear to have
deployed properly and are providing the spacecraft with energy.
The lander
also sent back its first images of its landing site - the first that have ever
been taken of the Martian arctic terrain from the surface. The images showed a
flat, cracked landscape with just a few pebbles strewn about. The cracks in the
surface had the same polygonal shape, caused by the expansion and contraction of
the water ice below, that had previously been seen in images from the MRO
spacecraft.
These
polygons were a bit smaller than expected though, said Smith, though he
cautioned that this is just a fraction of the terrain that Phoenix will image
and that polygons on the other side of the spacecraft could be larger.
"This is
our first look at the surface, we've only looked at one tiny little slit,"
Smith said. "Over the next few days we'll be filling in the rest of it."
The troughs
seen in surface images point to still-active arctic soils, otherwise the dents
would have been filled by dust blowing across the surface long ago, Smith
said. This bodes well for the science mission, as ice layers still seem to be
active under the surface, he added.
Overnight
Sunday, the science team at the University of Arizona in Tucson sent Phoenix
its instructions for today, which include checking out some of the lander's instruments.
They are expecting to get another set of images from the spacecraft this
evening.
NASA's
next Phoenix mission briefing will be broadcast live on NASA TV at 2:00 p.m.
EDT (1600 GMT) on Tuesday, May 27. Click
here for SPACE.com's
Phoenix mission coverage and a link
to NASA TV.
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