WASHINGTON — It's official: NASA's next Mars rover has a landing site, and it's a giant crater called Gale.
NASA's $2.5 billion Mars Science Laboratory (MSL) mission is slated to launch in late November, and will drop a car-size rover named Curiosity at the Gale crater.
"We are going to the mountain at Gale crater," Michael Watkins, project engineer for the Mars Science Laboratory at the Jet Propulsion Laboratory (JPL) in Pasadena, Calif., revealed in a press conference today (July 22). "It exhibits three different kinds of environmental settings, perhaps the trilogy of Mars history. It's a worthy goal, a worthy challenge for such a capable rover."
Gale crater is about 96 miles (154 kilometers) wide and has a mountain at its center that rises higher, from the crater floor up, than Mount Rainer near Seattle. The crater, which is named after Australian astronomer Walter F. Gale, is so large that the U.S. states of Connecticut and Rhode Island could fit inside it, NASA officials said. [Video: Fly Over Gale Crater on Mars]
"Mars is firmly in our sights," NASA Administrator Charles Bolden said in a statement. "Curiosity not only will return a wealth of important science data, but it will serve as a precursor mission for human exploration to the Red Planet."
Gale crater is also thought to harbor clues of ancient water activity on the Martian surface, and one of Curiosity's primary tasks will be to root around for evidence that Mars is, or was, capable of supporting microbial life. [Gale Crater FAQ: Mars Landing Spot for Next Rover Explained]
"Scientists identified Gale as their top choice to pursue the ambitious goals of this new rover mission," said Jim Green, director for the planetary science division at NASA Headquarters in Washington, in a statement. "The site offers a visually dramatic landscape and also great potential for significant science findings."
The agency revealed the landing site today (July 22) in a briefing hosted by the Smithsonian National Air and Space Museum in Washington. The announcement coincides with the museum's celebration of Mars Day, which commemorates the 35th anniversary of NASA's Viking 1 Mars landing on July 20, 1976.
The next Mars landing
During a series of worldwide workshops, members of the science community proposed 60 potential landing sites, said John Grant, a geologist at the National Air and Space Museum in Washington, D.C. [Best (And Worst) Mars Landings in History]
In 2008, four primary candidates were selected, and eventually two finalists were identified: Eberswalde crater and Gale crater.
Eberswalde is largely considered one of the best deltas on Mars, and at some point, the crater was likely filled with water, Grant said. Each of the candidate sites "represent an incredible opportunity for MSL. It was a very difficult decision to arrive at a final one," he said.
Targeted images from the Mars Reconnaissance Orbiter, which has been circling the Red Planet since 2006, provided detailed imagery of the potential landing sites that enabled scientists and engineers to evaluate safety concerns and the scientific benefits of each candidate location.
A team of senior NASA officials, principal investigators and co-investigators then conducted a thorough review and unanimously selected Gale crater as the official landing site.
"All four of the final sites were really great candidates," Grant told SPACE.com. "Early on in the process, I had a favorite. I can honestly say that that went away. They're really different. With Gale crater, there're still questions about how this mountain of material is in place. All of them have very attractive attributes and some unknowns, so you really have to say, 'Which one offers us the broadest benefits to the objectives of MSL?'"