
NASA’s Curiosity rover has set its sights for the fertile layers of Mt Sharp. You know the place – it’s that big hump on the horizon seen in many of the rover’s photos. The 3.4-mile-high (5.5 km) mountain has beckoned like a tempting Shangri-la for almost a year. Curiosity will roll across rocky terrain and a swath of potentially perilous sand dunes to reach the mountain’s base in a journey expected to take from 9 months to a year.

After landing in August, rather than heading straight for the mountain, the car-sized rover detoured for more than six months to explore the Glenelg area, a region once braided by ancient streams. Curiosity found sedimentary rocks – desiccated riverbeds – chock full of rounded rocks shaped by waters cascading down the walls of Gale Crater several billion years ago. What a sight that must have been.

Rocks found in neighboring Yellowknife Bay area were found to contain clays that formed in the presence of water that was neither too alkaline nor acidic. Just right for life.
Likewise, detailed analysis by Curiosity’s Sample Analysis at Mars (SAM) and Chemistry and Mineralogy (CheMin) instruments found elements essential for life to thrive and derive energy from its environment. Carbon, nitrogen, hydrogen, oxygen, sulfur and phosphorus all turned up. Those elements cover about 99% of what makes you you and me me.

Indeed, the mission’s main science objective – finding evidence for a wet environment that had the conditions favorable for microbial life – has already been accomplished. But it’s not time to go home yet. After photographing, drilling and laser-zapping near its home turf, on July 4 Curiosity drove 59 feet (18 m) toward its new target; on July 7, a second drive added another 131 feet (40 m).

The many-layered base of Mt. Sharp are like pages of an ancient book to be turned over one at a time and studied for more clues about how Mars, once clearly a wet world friendly to life, turned dry, cold and hostile.