Life on Mars? NASA orbiter starts its search.
The orbiter's cameras offer the most detailed images yet of the red planet's surface.
The quest to discover whether Mars ever hosted life is getting a big new boost.
NASA's Mars Reconnaissance Orbiter has begun capturing the most detailed images yet of the red planet. One of the orbiter's cameras has detected a Mars rover – and its shadow. Another of its cameras, whose first images were unveiled Monday, is starting to decipher in unprecedented detail the chemical makeup of minerals on the planet's surface.
The imaging capability is expected to give scientists new insight into whether Mars once might have served as a moist incubator for simple forms of life.
"For understanding big questions like 'In what kinds of environments does life originate?' Mars is still the place to go," says Scott Murchie, lead investigator for the orbiter's mineral-mapping camera, known by its acronym CRISM. The planet and its rocky surface are less exotic and more accessible than other potential targets, such as Jupiter's moon Europa or Saturn's Enceladus. And a decade's worth of missions has uncovered places "where water lingered on the surface, where it ponded," he says. Some of these locations could well have "given life a start" deep in the planet's past.
Monday, Dr. Murchie and his colleagues unveiled the first images from the CRISM, taken last month after the craft reached its operating orbit some 175 miles above the planet. The images focus on one of the youngest and one of the oldest geological formations on the planet.
At the Martian North Pole, CRISM has captured distinct differences in two layers of rock exposed along the steep wall of an ice-draped valley. In the ice cap itself, thought to be less than 200,000 years old, the team is seeing for the first time variations in the contents of dust and ice layers. These results suggest "a complex history of past climate change," Murchie says. Meanwhile, a valley whose rocks are thought to be up to 3.8 billion years old hosts a range of different clays – each bearing a story of the watery environment that gave it its mineral composition. Europe's Mars Express orbiter first spotted the deposits, but the Mars Reconnaissance Orbiter's CRISM has been able to zoom in to detect the types of clays and their distribution down to patches several tens of feet across.