Nothing fascinates the imagination quite like the search for extraterrestrial life, even if that life is on the smallish side. It is this fascination that governed the creation of NASA’s Curiosity rover.
The primary goal of this mission is to determine whether or not Earth is the only planet in our solar system that is capable (or ever was capable) of sustaining life. We’re not really expecting to find any woolly beasts rambling across the Martian surface, just hoping to find evidence of habitable conditions for microscopic organisms.
In an attempt to find such evidence, the rover was sent to Mars to study geological formations and the Martian atmosphere.
Of course, water is an integral part of habitable conditions. And shortly after landing on the planetary surface, Curiosity found evidence of water—more than that, it found evidence of flowing water (only a small amount, enough to dampen the surface, but it's still an amazing find).
So. That's it? Case closed? Mars could have supported life?
Well, no. Things aren't quite that simple. Evidence of flowing water is not evidence of life, and there are other factors that are required in order for a planet to support life as we know it. Ancient Mars had flowing rivers and impressive lakes and streams; however, that doesn't mean the Red Planet necessarily could have supported life.
Other necessities include a global magnetic field to protect from the Sun's rays, a viable atmosphere, and similar features. The rover has an operating lifespan of a full Martian year (687 Earth days), so what will Curiosity do for the rest of its mission?
It will continue searching for other evidence of water and the conditions conducive to life. The Mars Hand Lens Imager is able to take close-up pictures of rocks and soil. Ultimately, it can reveal details smaller than the width of a human hair. The rover also has a number of instruments that are capable of identifying a wide range of organic (carbon-containing) compounds, and determining the compositions of various Martian rocks.
But unfortunately, Curiosity can't actually investigate any flowing stream or damp water.
Since the rover’s drill bits may be tainted with microbes from Earth, and these microbes could survive upon touching Martian water, it could cause contamination of the Red Planet. The drill bits were sterilized inside a box six months before launch; however, engineers grew concerned that a rough landing could damage the drill mechanism, so they decided to open the box and mount one bit in the drill. Opening the box required the consent of the NASA scientist responsible for guarding Mars against contamination, but Planetary Protection Officer Catharine Conley wasn’t consulted.
Sometime ago, before the most recent announcement regarding water on Mars, John D. Rummel, a professor of biology at East Carolina University and a former NASA Planetary Protection Officer, stated: “It will be a sad day for NASA if they do detect ice or water. That’s because the Curiosity project will most likely be told, ‘Gee, that’s nice. Now turn around.'”
And the search for habitable conditions will continue elsewhere.