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Mars is red because it is rusty. The Martian dust is full of iron oxide
It is, as a tourist brochure would say, a land of dramatic contrasts, with the largest volcano in the solar system, Olympus Mons, 15 miles high , and the longest canyon, Valles Marineris, 2500 miles long and 4 miles deep.
As far as we know, it is inhabited mainly by our own robots, like the rovers and Vikings we sent there, and the wreckage of the lost landers. Some 45 space missions – all of which have not been realized – were launched to Mars by humans. There are five on the record, including the efforts of China and the United Arab Emirates, scheduled for the summer of 2020.
If anyone else was interested, s & # 39; There is something like a foreign iPhone or one of these monoliths: An odyssey of space, "sitting on a rock somewhere, we would not have found it yet."
From all this exploration, a new story emerged, just as haunted. It is a planet once splashed by the oceans and dug by fast-flowing rivers, a world long warmed by an atmosphere. But something happened and Mars lost its sparkling waters and its air.
Now, there are only bare shorelines, empty filaments of tributaries, silent rocks and occasional wet spots on the flanks of the cliffs. If there was life here, history goes away, she died or went into hiding.
Instead of little green men, we look for microbes, which is good for me. I feel lonely and maybe the microbes will be what pbades for the cosmic company.
The Vikings, who landed on Mars in 1976, were famous for seeking life in Martian soil. And scientists are still arguing over whether any of the four experiments actually had a positive outcome.
Since then, any rumor of past or present Martian life has aroused public and perhaps congressional enthusiasm for the space agency's budget. In 1996, scientists said they detected the fossil of a microbe in a meteorite from Mars at a press conference accompanied by a statement by President Bill Clinton. But few scientists have accepted it.
In June, the Curiosity rover confirmed that there are small amounts of methane emitted periodically in the atmosphere in Gale Crater where it spends its time. On Earth, a lot of methane comes from biological activity, like cows that ruminate, but pure geological processes can also do it.
The newly discovered underground lake, it is confirmed by other observations, is only the latest in date There has been a lot of excitement about extraterrestrial life in the outer solar system where many moons of Jupiter, Saturn and the other gaseous giants proved to be oceanic worlds hidden under shells. of ice. Some of them, like Jupiter 's Europa and Saturn' s Enceladus, seem to project salty plumes of water and perhaps even microbes in the space.
NASA is planning a probe for Europa, and many astrobiologists have pushed Enceladus sprays or for a mission to send drones to explore the methane lakes of Titan, Saturn's largest moon. . Nobody really knows what extraterrestrial life would look like or what it would need.
As Jill Tarter of the SETI Institute of Mountain View, California, who has spent her life looking for ET, says, we only know one example of life in the world. # 39; universe. This is the complex network of DNA-based organisms on Earth.
"We are looking for No. 2," she said.
We still do not know how or why life began on Earth or if it prevailed it's in the universe. It is an article of faith among astronomers and astrobiologists full of hope that, in the right conditions, life will find a way.
In the next 50 years we will probably know if Darwin's test tube has produced another result in our own cosmos. , in our own solar system. Mars missions have been running every two years for decades now.
We will not know for sure about Mars until someone walks and does exercises on it. I thought I would never live to see humans even on the moon, but that was before SpaceX started doing things with rockets – coming back and landing in line – that I'd only seen in old sci-fi movies
We could not find monoliths or a wandering extraterrestrial iPhone. We could only find dead microbes, or fossil prints of them. But even that would be exciting, to know that nature had already tried before.
But if they are alive – whatever that may mean – then some kind of spiritual and intellectual calculation will be upon us. Depending on the wild or familiar nature of these extraterrestrial creatures, we might have to decide whether our allegiance is to DNA-based organisms or something even broader.
And we may have to decide whether whole potential microbes or biospheres have rights. If we decide to engage in the ultimate imperialist project, we could try to make Mars habitable for humans by heating the planet to melt the ice caps and release carbon dioxide – a greenhouse gas – and the red soil . The result would be a thick atmosphere that would keep things hot and humid, causing intentional climate change.
This was the subject of an interactive exhibition at the American Museum of Natural History seven years ago, where visitors could choose to bomb on the Martian surface, paint the black ice caps or plant the world with rippling chimneys, which I did jubilantly.
But trying to make Mars habitable for humans would take centuries, if not millennia, and might not work, a report published Monday in Nature Astronomy.
Using data obtained through 20 years of orbiter and rover reconnaissance, Bruce Jakofsky of the University of Colorado, Boulder, and Christopher Edwards of Northern Arizona University in Flagstaff, concluded that he was not an expert in the field. There is not enough carbon dioxide currently on the planet to thicken the atmosphere and warm it more than about 20 degrees Fahrenheit.
Terraforming Mars, they concluded, "will need technologies far beyond our current understanding."
We have centuries, if not millennia, to settle all this, as we must.
All we know about geology and astronomy tells us that the Earth will become an uninhabitable day.
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