In recent months, we have learned of new evidence that complex organic molecules – presumably the most important ingredients for life – have been preserved in Martian stones. that Mars's atmosphere exhibits seasonal variations of methane, a potential chemical signature of life; and that a large reservoir of liquid water is below the surface of the planet itself.
Each of these discoveries enriches the plot in the search for extraterrestrial organisms and prompts us to believe that we can soon find the first evidence ever that life is elsewhere.
And while signs of foreign life that lived long ago would be groundbreaking
" If life ever started on Mars, it's probably still there. "
–  Nathalie Cabrol, NASA Astrobiologist
Life on Mars would be a wonderful thing to witness. However, it would be a mistake to assume that this summer's news means that we are likely to see something of this scale being developed.
These reasons begin with the March 4.6 billion story being a complicated and tragic story.
Ancient Mars was a very different planet from its present form. The fact is that it resembled the earth. It was full of a thick atmosphere that kept things warmer and protected by a magnetic field that could stop cosmic radiation and UV rays from sterilizing the surface and almost flowing with large bodies of liquid water on the planet's surface that could support life as we know it .
"There is no agreement, but there is a general expectation [ancient] Mars must have been like a good summer on the Arctic day," Nathalie Cabrol, an astrobiologist from NASA who is widely involved in the search for signs of extraterrestrials on Mars, told The Daily Beast.
For life to exist, "you need energy, you need water, you need nutrients, and you need protection, and you have all these at an early March. If you want a time where life could have begun, early March would have been time. "
It is far from what Mars looks like today. Even under the most ideal conditions, like a summer day, Mars temperatures can attach up to almost 70 degrees Fahrenheit.
But at night the temperature drops to -100 degrees. It does not even matter how much cooler things are near the poles or during the winter months. There is no strong atmosphere for keeping the climate warm and temperate for humans. And Mars lost its magnetic field long ago, which means that radiation would zap everything that hangs on the surface anyway.
"I always compare this to the kitchen," said Cabrol. "You have ingredients on the table. Two people can take these ingredients and get the same results. But if you are a good cook and you do not know anything about cooking, you will end up with two very different things."
These two sets of hands The kitchen is respective soil and march. And while the earth showed a dish of biological delights, Mars could hardly have done anything edible, if it ever succeeded.
Three months ago, the rover of Curiosity stumbled upon a three-mile high mountain – the Gale Crater near the Mars Equator with a valley that seemed to contain methane, a sign of primitive organic life.
But researchers prevented their excitement, due to the structure of the body itself.
"The chemical structure [of the molecules] as far as we understand is quite random," says Roger Everett Summons, an MIT scholar of planet science and a member of the team who made the Gale crater discovery.
They are chemically the buildings of life, but they lack the kind of organization that actually allows them to be built into life. It's a bit like seeing concrete cliffs in fine blocks, as opposed to concrete that has just been cut into some kind of odd shape that you can think of.
"That [these organics are] still exists after millions of years of radiation cosmic rays and UV-says something about the stability of these materials," summons said. "But it does not matter about the origins."
Claims believe that the organic molecules, due to their structure, were not formed on Mars, but instead came to the red planet aboard meteorites.
Dirk Schulze-Makuch, a German astrobiologist and professor at Berlin University of Technology, interprets the structure of the body in different ways, and believes that they can be signs of the former extraterrestrial life.
" The fact that [these organics are] remains there after millions of years of radiation cosmic rays and UV-says something about the stability of these materials. "
– Roger Everett Summons, MIT scientist for planet science
But He also notes that they show signs of degradation. "It does not go in the opposite direction, the direction of life," he said. "It's about decaying to be destroyed. It would be more important that the molecules once were a part of organisms, or less likely, from space meteorites. But they will not develop into life."
Even if conditions on Mars would change to something more favorable-say, people come down and terraform the red planet to the planet 2.0-Schulze-Makuch still doubt the molecules have chemistry to get together and create biology.
"Even in current soil conditions, I do not think we could see any origins in life," he said. "Acids should immediately oxidize organic molecules. In Mars, it's the same way – the radiation would easily oxidize molecules, so we would not get the correct synthesis reaction. I see no realistic scenario on Mars, where this may happen."
Caroline Freissinet, a researchers with the Atmospheres Laboratory (LATMOS) for the French National Center for Scientific Research and another member of the Gale Crater team, also pointed out that although all of the above problems did not exist, there is still an important reason why these molecules would not work in the creation of the new march life. There are not enough them on the planet.
"You could touch the ground on Earth's surface and find more organic material on your finger than is currently on Mars as we have discovered," she said.
Ultimately, the best chance of future life on Mars is the fact that it has already survived the last several billions of years on earth.
"We know from the earth that life is like a disease," said Cabrol. "It's really really hard to get rid of it! It would not have been too difficult for life to continue to survive on Mars. If life ever started on Mars, it's probably still there."
So how would life see out today on mars? Cabrol has spent a lot of research on the field exploring some of the hardest coldest places on earth to study the sharp microbes, called extremophiles, who have managed to live in these places. These environments are the closest analogues we must have on Mars.
" When you think you've figured it out, life finds a way to surprise you and be in places you would not expect to be.
– Nathalie Cabrol, NASA astrobiologist
She thinks that endolites, extremophiles living in clay in porous rocks are the most we can find on Mars if there is still something there.
The subglacial fluid reservoir near the South Pole is a potential habitat where we can trip Martial life, but there is reason to be skeptical. The water has probably escaped a frozen fate by interacting with hyperchlorates, the water is extremely salty. Some extremophiles could have learned to adapt to these conditions, but Freissinet pointed out that "life remains Surprisingly. "
According to Cabrol, if there is an energy source near the water that can maintain potential life, like volcanic heat, there is hope of finding something down there.
"Life 1.5 kilometers below the surface does not really care what's happening on the surface," she said. "Climate change on the surface does not matter."
If exists on Mars, we would almost need to dig hundreds or thousands of feet deep into all the red stones to find it. Striking it from the surface seems quite unlikely, and even less likely is the thought that life, regardless of what we did on the planet, could resurrect.
But improbability does not mean it's wise to write it as an opportunity. We could see that Martian life is developing one day.
"At this time, there is no way of saying that life can or may not develop on Mars, says Cabrol." When you think you've figured it out, life finds a way to surprise you and be in places you would not expect to be ".