By Charlene Porter
One year since landing on Mars, the rover Curiosity and the Mars Science Laboratory (MSL) on board have answered the big question the craft was sent there to investigate: Have Martian environmental conditions ever been conducive to life? Yes, is Curiosity’s answer. What is now a dry, cold planet was once a warm and wet place, with water probably pure enough to drink.
NASA and partnering scientific organizations celebrated the anniversary of the historic August 6 landing of the spacecraft, looking back on the exuberant moments of the touchdown in mission control, the engineering achievements that made it happen, and the astonishing science that the craft is conducting and will continue to pursue in the future.
Curiosity, the size of a car, carries a camera array able to provide close-up views of the surface, which allowed scientists to make the conclusions about the past environment. MSL captured photos of what looks like a dry streambed, similar to those on Earth, with geologic features revealing what NASA calls “a vigorous ancient stream flow.” For the first time, scientists had a close-up view of pebble deposits on Mars, as if rushing water had just dropped them.
“We now know Mars offered favorable conditions for microbial life billions of years ago,” said the mission’s project scientist, John Grotzinger of the California Institute of Technology in Pasadena. “It has been gratifying to succeed, but that has also whetted our appetites to learn more.”
The rover is now making its way to the base of Mount Sharp, a carefully chosen landing target. Observations made by earlier orbital craft have shown that the mountain has exposed geological layers, including ones originating in a wet environment, Grotzinger said. “We hope those enticing layers at Mount Sharp will preserve a broad diversity of other environmental conditions that could have affected habitability.”
Ken Edgett, a principal scientific investigator of the mission, had his first view of Mount Sharp in photographs taken from hundreds of kilometers above the surface more than a decade ago. He was involved in identifying the mountain as a primary scientific target of Curiosity’s mission.
“Every layer is a page in a history book,” Edgett said. He was one of the mission scientists and engineers discussing Curiosity’s first year on NASA TV programming August 6. “We can go there and see: Not only are there habitable environments recorded in there, but how do environments change over time?”
Curiosity will reach Mount Sharp soon and begin photographing and sampling the layers that provide different data on successive periods in planetary history.
All the data, photos and information Curiosity has already provided — and the discoveries still to come — form the foundation of expanded planetary exploration of the future. “Successes of our Curiosity — that dramatic touchdown a year ago and the science findings since then — advance us toward further exploration, including sending humans to an asteroid and Mars,” said NASA Administrator Charles Bolden. “Wheel tracks now will lead to boot prints later.”
Curiosity has provided more than 190 gigabits of data; returned more than 36,700 full images and 35,000 thumbnail images; fired more than 75,000 laser shots to investigate the composition of targeted planetary features; and driven about 1.6 kilometers.
The Curiosity team at the Jet Propulsion Laboratory, where the mission is managed, is anticipating the rover will be transmitting data and photos back to eager scientists for years to come. Meantime, another Mars mission is preparing for launch. The Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft is being tested and tweaked for November liftoff.
MAVEN will be dedicated to surveying the upper atmosphere of Mars, the first ever mission to do so. The climate changes that have occurred on the planet are thought to be caused in part by the loss of atmospheric gas, blown away by the solar wind. MAVEN is expected to collect data allowing scientists to better understand the processes at work.
Scientists from all over the world have been studying the data returned by Curiosity. National space agencies from Canada, Russia and Spain provided key operational systems of the spacecraft or MSL and continue to be involved in their operation.