NASA's Curiosity rover touched down on Mars last night at 10:31 PDT, or approximately 3 p.m. local time on the Red Planet.
The one-ton rover, hanging by ropes from a rocket backpack, was gently lowered to the surface of Mars, ending a 36-week flight and kicking off a two-year investigation of the fourth planet from the Sun.
"Today, the wheels of Curiosity have begun to blaze the trail for human footprints on Mars. Curiosity, the most sophisticated rover ever built, is now on the surface of the Red Planet, where it will seek to answer age-old questions about whether life ever existed on Mars - or if the planet can sustain life in the future," said NASA Administrator Charles Bolden.
"This is an amazing achievement, made possible by a team of scientists and engineers from around the world and led by the extraordinary men and women of NASA and our Jet Propulsion Laboratory. President Obama has laid out a bold vision for sending humans to Mars in the mid-2030's, and today's landing marks a significant step toward achieving this goal."
Curiosity is currently active near the foot of a mountain three miles tall and 96 miles in diameter inside Gale Crater. During a nearly two-year prime mission, the rover will investigate whether the region ever offered conditions favorable for microbial life. The rover has already beamed back its first images, snapped by one of the vehicle's lower-fidelity, black-and-white Hazard Avoidance Cameras - or Hazcams.
"Curiosity's landing site is beginning to come into focus," explained John Grotzinger, project manager of NASA's Mars Science Laboratory mission, at the California Institute of Technology in Pasadena.
"In the image, we are looking to the northwest. What you see on the horizon is the rim of Gale Crater. In the foreground, you can see a gravel field. The question is, where does this gravel come from? It is the first of what will be many scientific questions to come from our new home on Mars."
Curiosity is equipped with 10 science instruments, giving it a total mass 15 times as large as the science payloads on previous Mars rovers Spirit and Opportunity. Some of the tools are the first of their kind on Mars, such as a laser-firing instrument for checking elemental composition of rocks from a distance.
The rover will also use a drill and scoop at the end of its robotic arm to gather soil and powdered samples of rock interiors, then sieve and parcel out these samples into analytical laboratory instruments inside the rover.
To handle its elaborate science toolkit, Curiosity is twice as long and five times as heavy as Spirit or Opportunity.
As noted above, the Gale Crater landing site places the rover within driving distance of layers of the crater's interior mountain. Observations from orbit have identified clay and sulfate minerals in the lower layers, indicating a wet history.