May 16, 2011

4 Possible Landing Sites Chosen For Next Mars Rover

What locations would you go see if you had a chance to visit the surface of Mars? This is the question that researchers have been pondering for several years and now the landing sites have been narrowed down to four choices from an original list of 60 sites, according to several sources.

After a two-year delay, the next robotic rover to roam the surface of Mars is set to launch in November, The rover Curiosity, part of the Mars Science Laboratory Program, is the size of a small car and will study whether the area near the landing site area will have environmental conditions suitable for life or if extraterrestrial microbial life previously existed.

The Mars research community at the Jet Propulsion Laboratory (JPL) gets one last chance to make their case this week when they gather before a panel of NASA "judges" in finding a suitable landing location for the $2.5 billion mission, the Associated Press (AP) reports.

"All four of these places are compelling places on Mars to study. There's not a loser among them," landing site scientist Matt Golombek of the NASA Jet Propulsion Laboratory, one of the meeting's leaders, told the AP.

The short list of sites include:

  • Gale crater located near the Martian equator possesses a 3-mile-high mound of layered mineral deposits.
  • Mawrth Vallis is an ancient flood channel in the Martian northern highlands that is rich in clay minerals.
  • Eberswalde crater in the southern hemisphere contains remnant of a river delta.
  • Holden crater, close to Eberswalde, is the site of water-carved gullies and sediment deposits.

Being nuclear-powered, the rover cannot go to a location that has either water or ice within one meter of the surface.

In a process that began in 2006, scientists broke up into teams to pour over close-up images snapped from the eagle-eyed Mars Reconnaissance Orbiter for the various locations and presented their findings at meetings. Research scientist Steve Ruff of Arizona State University stayed on the sidelines for much of the debate. No longer.

According to the AP, Ruff is campaigning for Mawrth Vallis, the only spot where Curiosity can conduct science experiments as soon as it lands. For the other three sites, the rover would need to drive outside its landing zone to reach interesting targets. Mawrth is the sole locale "that contains the scientific goodies."

There are great reasons for the other landing sites as well but they will require the rover to travel longer distances to get to them from their landing areas. "You could eat up a substantial portion of your mission just driving where you want to go," said Ruff, who called the other sites an unnecessary risk.

Astronomer Jim Bell of Arizona State University, favors both Gale and Eberswalde craters, agreed it was chancy, but thinks it's worth it. "We won't be putting on blinders and heading east or west without stopping," Bell, who is part of the mission's camera team, told AP's Alicia Chang. "There's a clear pot of gold at the end of the rainbow, but there are also some neat things to do along the way."

Planetary geologist John Mustard of Brown University was disappointed when the site he was rooting for, the Nili Fossae region, a series of deep fractures in the Martian crust, was rejected as too dangerous to attempt a landing.

He now supports the diversity of the Mawrth site. "It's not a one-trick pony. You've got more than enough compelling outcrops that one can test," he said.

After the research community input, the team will meet in private to debate each site and eventually recommend one to NASA. The space agency has the last say, but it usually follows the advice of its researchers and a final decision is expected early this summer.

Smithsonian geologist John Grant, who is co-chairing the meeting, said he hopes there's more clarity about the strengths and weaknesses of the final four. "There's a big investment in this rover. We want to make sure that it goes to the best possible site."


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