Curiosity rover examines third potential drill spot

NASA's Curiosity Mars rover has driven within robotic-arm's reach of the sandstone slab at the center of this April 23 view from the rover's Mast Camera. The rover team plans to have Curiosity examine a target patch on the rock, called "Windjana," to aid a decision about whether to drill there.

Last Updated Apr 28, 2014 5:10 PM EDT

NASA's Mars Curiosity rover explored a sandstone slab over the weekend to determine if the area, known as Windjana, is a good spot to drill deeper into the red planet. The researchers are continuing to examine images of the samples collected, but it looks like they will go ahead with drilling.

"Over the weekend, Curiosity used its Dust Removal Tool (DRT) to brush the surface of Windjana, and also performed a pre-load test with the rover arm to see if the rock would be a suitable target for drilling. Both of these activities were successful, and nothing so far has ruled out Windjana as our next drill target," team member Melissa Rice told CBS News in an email.

"In the brushed spot we can see that the rock is fine-grained, its true color is much grayer than the surface dust, and some portions of the rock are harder than others, creating the interesting bumpy textures. All of these traits reinforce our interest in drilling here in order understand the chemistry of the fluids that bound these grains together to form the rock."

If the team decides to drill, it will be examining the cements that hold the sandstone together.

"We want to learn more about the wet process that turned sand deposits into sandstone here," said Curiosity Project Scientist John Grotzinger, of the California Institute of Technology in Pasadena, in a press release. "What was the composition of the fluids that bound the grains together? That aqueous chemistry is part of the habitability story we're investigating."

Understanding how the sandstone formed would help the scientists understand how various formations came together in the area, which is known as Gale Crater. They are especially interested in how Mount Sharp, a large layered mountain, formed in the center of the crater.

Several tools, including camera and X-ray spectrometry, were used during the inspection. The rover also used a brush to remove dust from a patch of the rock, and took composition readings using a laser. During the actual drilling, the rover's hammering drill will collect powdered samples from the interior of the rock. An onboard laboratory will inspect the samples.

This would be the mission's third drilled rock. The first two were mudstone and located about 2.5 miles away from Curiosity's current location. The two mudstone rocks "yielded evidence of an ancient lakebed environment with key chemical elements and a chemical energy source that provided conditions billions of years ago favorable for microbial life," according to the release.