Testing the Waters
Last year, Curiosity found evidence suggesting liquid water flows on the Red Planet. It was a breakthrough, debunking the notion that Mars is a dry, dead planet, and raising the possibility that primitive life may exist there. Having found it, Curiosity is, well curious, and wants to take a look at that water.
NASA revealed that the Curiosity rover will investigate recurring slope lineae (RSL) around Mars' Gale Crater in hopes of finding water.
RSL is a seasonal phenomenon that works as follows: Briny water flows in many mountainous regions of Mars when the surface temperature rises enough, becoming visible on the sandy hillsides as dark stains that appear and then recede. Its these stains that are the RSL.
First, Curiosity will move into a position that will allow the rover to image the nearby hillsides that could contain liquid water. If the rover confirms that the streaks in the images are periodically flowing water and not, say, dust slides, it will go and take samples.
But before Curiosity can go near any potential water site, it will need the go ahead from Catharine Conley, NASA's planetary protection officer. Her job is to ensure that Mars is protected from Earth microorganisms that may hide in the nooks and crannies of the rover.
"Kilometers away -- it's unlikely that it would be an issue. In terms of coming much closer, we need to understand well in advance the potential for Earth organisms to come off the rover, and that will tell us how far away the rover should stay," said Conley.
NASA is extra careful around these dark streaks, since the suspected presence of liquid water means the possibility of life, and contamination may kill any possible lifeforms in the water.
"Not only are these on steep slopes, we need to ensure that planetary protection concerns are met. In other words, how can we search for evidence of life without contaminating the sites with bugs from Earth?" said Jim Green, NASA's director of planetary science.