Mt. Sharp in Gale Crater looms five miles in the distance in this photo taken on July 8. Credit: NASA/JPL-Caltech
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.
The photo at left is a closeup of chunk of ancient, pebble-riddled streambed on Mars with a particularly round pebble highlighted. It’s just under 1/2 inch (1 cm)across. At right, rocks are rounded into pebbles by the action of water in Amity Creek in Duluth, Minn. Credit: Bob King
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.
A rock in Yellowknife Bay is made of fine-grained sediments likely deposited under water. The rock was then fractured. Neutral pH waters deposited calcium sulfate, a form of gypsum, filling the crack. Credit: NASA/ JPL-Caltech
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.
The many layers of Mt. Sharp as seen from orbit. The 3.4-mile-high (5.5 km)mountain is really a huge deposit of materials similar to the layers in the walls of the Grand Canyon. Some are probably sedimentary, laid down by rivers or deposited in shallow seas; others possibly volcanic ash. Credit: NASA/JPL-Caltech
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).
Mars Rover Curiosity looks back at wheel tracks (right foreground) made during the first drive into the “Glenelg” area 7 months ago. It’s now headed to Mount Sharp. Credit: NASA/JPL-Caltech
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.
