One year ago NASA's Mars Science Laboratory spacecraft and its unprecedented sky crane landing system placed the Curiosity rover -- about the size of a car -- on Mars
"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."
The rover has already satisfied its mission objective, having found key chemical ingredients for life in rock samples. Carbon, hydrogen, oxygen, phosphorous and sulfur were found, along with clay mineral deposits formed by water.
Evidence of a knee-deep stream bed also supports the case for water on ancient Mars.
Though the Red Planet may once have supported life, Curiosity has so far found no methane, which is produced by living organisms, in the air. The Curiosity mission also found evidence Mars lost most of its original atmosphere through processes that occurred at the top of the atmosphere.
Curiosity has experienced radiation levels exceeding NASA's career limit for astronauts -- data that scientists will use to plan future human missions.
"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 targets; collected and analyzed sample material from two rocks; and driven more than one mile."
"We now know Mars offered favorable conditions for microbial life billions of years ago," said project scientist, John Grotzinger of the California Institute of Technology.
Curiosity is now on its way to investigate Mount Sharp. "We hope those enticing layers at Mount Sharp will preserve a broad diversity of other environmental conditions that could have affected habitability," Grotzinger said.