On 28 September this year, a piece of  news caused a frenzy of excitement in the world. “There is liquid water on Mars!”, NASA announced . Another big piece to add to the space-related trend we can observe today, with the pictures of Pluto released in february and the “active region loops “ on the sun this september. But is water on mars really such a big deal, or is it more like a seek of attention from the NASA?

First of all, there have been clues of water on mars for years now. This water was, however, found in small proportions in vapour state or in ice form. The discovery of liquid water could have at least one important meaning, the possibility of life on Mars. Well, maybe not dinosaurs and such, but microbacterial life. Or, who knows, it could be easier for mankind to adapt to a martian lifestyle with water. This water could indeed be purified for human consumption, turned into oxygen, or even transformed to  create rocket fuel. This, at least, is what the medias have repeated over and over, filling people with hopes and dreams for the future.

Now, what are the actual evidences of water on Mars?

In June 2000, possible evidence of  liquid water flowing at the surface of Mars was discovered in the form of flood-like gullies. The images did not actually show flowing water. Rather, they showed changes in steep crater walls and sediment deposits. Well, it could look like a shabby proof, but well done NASA; you’ve at least got something. Even if there are other  theories about these craters, like erosion due to the strong winds on the surface of the red planet.

In May 2007, the Spirit rover disturbed a patch of ground with its inoperative wheel, uncovering an area extremely rich in silica (90%). The feature is reminiscent of the effect of hot spring water or steam coming into contact with volcanic rocks. Scientists consider this as evidence of a past environment that may have been favorable for microbial life, and theorize that one possible origin for the silica may have been produced by the interaction of soil with acid vapors produced by volcanic activity in the presence of water. Again, this is only an hypothesis.

Then, first identified in 2011, features known as recurring slope lineae (RSL) were confirmed to be signs of salty water running on the surface of the planet today. Scientists also discovered a slab of ice as large as California combined in the region between the equator and north pole of the Red Planet. And in the new reports, NASA declared to have found liquid water. In fact, they could not observe it directly but they are sure that liquid water runs seasonally on the martian surface. But instead of fresh, pure water, it would be water filled with salts and perchlorates, acting as antifreeze. Thanks to that, water can flow even in negative temperatures. But not many species could survive in such an environment.

Furthermore, the world’s space powers are bound by rules agreed to under the 1967 Outer Space Treaty  that forbid anyone from sending a mission, robot or human, close to a water source in the fear of contaminating it with life from Earth. What does that mean? Well, that even if there were water on Mars, it is impossible to study or even come close to it for the moment. If the rover was sterilized, it still carries microbes and bacterias that could alter or kill alien life.

NASA’s hype around the discovery of liquid water on Mars can be explained by its constant need to increase funding for its work. And that attention seems to be helping. But it won’t be eager to tell you that its human mission, currently planned for 2030, will inevitably contaminate Mars with microbes, and break the rules of an international treaty.

So if there certainly is water on Mars, it is maybe not worth all the hype that happened; not for the moment, at least.