Mars Orbiter Catches Snapshot of Phoenix Probe's Landing

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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