Turns out in searching for life on Mars, NASA actively avoids the regions where the probability to find life is highest. What's that all about?
NASA tries to avoid as much as possible to contaminate Mars with life from Earth. They even have a Planetary Protection Officer, Catharine A. Conley, and the New York Times has an article about her and her policies. She appears to have the authority to forbid a Mars rover to go to a particular place. For instance, recently NASA announced that on some locations on Mars water flows occasionally. Some of those places are withing reach of the Curiosity rover but it may well be that it's not going to take a look because it could be paradise for hitch-hiking microbes from Earth. Several more regions on Mars have been proclaimed Special Regions where bacteria from Earth might thrive. Mars rovers cannot go there.
This shows the magnitude of the dilemma of physically searching for alien life. Mars landers have always been sterilized as much as possible. But it is impossible to completely sterilize a complicated machine like a lander or a rover. There will always be some microbes who survive first the sterilizing process, then the cold, the vacuum and the radiation during the space journey, and finally the harsh Mars environment. Catharine Conley estimates that at launch there may still be millions of microbes sticking to a spacecraft. How many there are left on Curiosity now is difficult to determine, but her calculations will decide where Curiosity is going.
On the one hand it's understandable. If there is life on Mars you want it to stay undisturbed. You'd want to find out how it works, what species there are, how it evolved and whatnot. Life forms from Earth could compete with Mars life, poison it or even consume it. Probably any Mars life is having a hard time surviving without all of that. If they survive despite contamination from Earth, you don't want to be a scientist who, after the fact, has to find out which microbes belong on Mars and which are illegal immigrants. It will be a mess.
But wait. Isn't it a scientifically established fact that rocks fly back and forth between Earth and Mars? Suppose you find life on Mars now, how can you be sure it's not from Earth already? Heck, many people speculate that life on Earth came from outer space, why not Mars?
Furthermore, NASA's and many other organization's long term goal is to bring people to Mars. How can you expect Mars to stay uncontaminated with people on it? There's really no way. On Earth we know that where people travel, other life forms travel with them. On Mars initially the scale will be small, but it will happen there as well.
Since any life on Mars could have come from someplace else, since microbes from Earth must already be there, let's let it go. Let's not study supposedly original Mars life. Let's study what kind of organisms can survive on Mars and how people on Mars can benefit from them. Then NASA's Planetary Protection Officer can worry about littering and other kinds of pollution, which also follow Man everywhere he goes.
Herbert Blankesteijn is a technology journalist from the Netherlands who has written for many prominent Dutch newspapers. He presented and directed television and radio programmes and has 10 books to his name. Herbert is interested in nascent fields such as 3D printing, drones, robotics and the private space business.