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On February 18, NASA’s Tenacity spacecraft will parachute into the thin airs of Mars, ushering in a new era of exploration of the Red Planet. Landing on the crater of the lake, which lies north of the Martian equator, will not be an easy task. According to NASA, only about 40% of missions sent to Mars are successful. If so, then persistence could radically change the way we think about life beyond Earth. Indeed, scientists believe that Jezero, a 28-mile-wide crater that was once a lake, is a great place to look for evidence of ancient microbial life on Mars.
Once there, it will gather persistence and store rock and soil samples from Mars, which will eventually be sent back to Earth. This is called a “sample return mission”, a rare type of space exploration mission due to its calculation. (In fact, there was no mission to return a sample from another planet.) Once Martian soil returns to Earth in a decade, scientists will begin to study materials to determine the existence of life. ancient on Mars.
However, some scientists believe these samples could answer a bigger question: Did life on Earth originate on Mars?
While the idea that life began on Mars before migrating to Earth seems like a crazy science fiction hypothesis, many prominent scientists take this theory seriously. The general idea of life that begins elsewhere in space before migrating here also has a name: panspermia. It is a hypothesis that life exists elsewhere in the universe and that it is distributed by asteroids and other space debris.
To be clear, the idea of life on Earth coming from Mars is not a popular theory in the scientific community, but rather seems to be spreading. Scientists like Gary Rufcon, professor of genetics at Harvard Medical School, say it sounds “pretty straightforward.”
The guide begins with how space debris moved around the young solar system. In fact, we have evidence of rock exchange from Mars to Earth. Martian meteorites have been discovered in Antarctica and around the world – around 159, according to the International Meteorite Collector’s Association.
“You could attribute them to Mars based on their gaseous impurities, which are somehow equivalent to the gases that the Viking spacecraft showed” in the Martian atmosphere, Rovkon said. In other words, the tiny air bubbles in these rocks reveal that they formed in the air of Mars. “So there is an exchange between Mars and Earth – perhaps more often from Mars to Earth as it is heading downward, going to Mars ‘upward’, in terms of gravity.
But for Ruvkun, whose area of expertise is genomics, this is the moment in cellular life that he says demonstrates that life on Earth comes from elsewhere – perhaps from Mars, or perhaps from Mars facing another planet.
Rufcon notes that our genomes reveal the history of life and provide clues to ancestors who came millions, if not billions of years before us. “In our genomes you can kind of see the story, right?” He said. “There is a world of RNA which predates the world of DNA and which is well supported by all kinds of current biology; So we know what steps evolution has taken to get to where we are.
Thanks to advances in genomics, the understanding of LUCA (the last universal common ancestor) – that is, the organism from which all life on Earth evolved – has advanced tremendously. By studying the genetics of all living things on Earth, scientists get a really good idea of what the one-celled ancestor of all living things (on Earth) looked like. They also know the timeline: all modern life descends from a one-celled creature that lived about 3.9 billion years ago, that is, only 200 million years after the appearance of the liquid water. In the grand scheme of the universe, it is not long.
And the last universal common ancestor was very complex when it comes to living things. Rovcon says that leaves two possibilities. “Either the evolution to the modern full genome is really easy, or the reason you see it so quickly is that we just ‘took’ life, and it didn’t really start here. “I like the idea that we just had it and that’s why it’s so fast, but I’m weird.”
If so, Erik Asphaug, professor of planetary science at the University of Arizona, is also an exception. Asfog said what we know about Earth’s oldest rocks – which have chemical evidence for carbon isotopes, dating back almost 4 billion years – tells us that life is “starting to form.” On the ground almost as soon as possible. ‘
If so, it sets an interesting precedent. “Suppose you expected life to flourish when the planet cools down to the point where liquid water can start,” Asfog said. “But once you look at our solar system, which planet is likely to be habitable first?
Asfugh said it’s because Mars formed before Earth. Early in Mars’ history, when Mars was cooling, Mars had a “hospitable” environment before Earth.
“If life starts anywhere, it can start on Mars first,” Asfog said. “We don’t know what the condition is – you know, if it required something special like the presence of the moon or something unique to Earth – but just as to where the liquid water has been. first found, it would have been Mars.
There is interesting and compelling evidence for how matter moves between the two neighboring planets. In fact, the further back in time one goes, the greater the magnitude of the rock collision between Mars and Earth, said Asfog. These collisions could be “Mars mountain-sized rocks” being launched into space. These massive asteroids could be the habitat of a powerful microorganism.
“When it collides with a planet, some of that mountain-sized mass will remain debris on the surface,” he said. “It took a while for the modeling to show that you can survive relatively healthily what we call ‘ballistic panspermia’ – shooting at one planet, throwing pieces of it and landing it on another planet.” But it is possible, we believe, and the path tends to be from Mars to Earth, much more likely than from Earth to Mars. ‘
Asfuj added that surviving the theft, given the car’s mass of microorganisms, wouldn’t be a problem – and she wouldn’t live on a new hospitable planet, either.
“Any early life form would be resistant to what happens at the end of the planet’s formation,” he said. “Every living creature present in the horrible influence bombardment, even outside of it, must be used from planet to planet.”
In other words, early microbial life was good in harsh environments and long periods of dormancy.
Harvard University professor Avi Loeb told Salon via email that one of the Martian rocks found on Earth, ALH 84001, “had not heated its entire flight above 40 degrees Celsius and could have withstood to the life. ‘
All three believe that persistence may be able to add credence to the theory of panspermia.
“If you were to go looking for the remains of life on Mars, which we hope to do with Perseverance Rach and other adventures on Mars, I would be personally surprised if it was not related to life on Earth,” he said. declared Asfog.
Rufcon said he hopes to be one of the scientists looking for DNA when the Mars sample finally returns.
“Launching something from Mars is very difficult,” he says.
But what does this mean for humans and our existential understanding of who we are and where we come from?
“In that case, we could all be Martians,” Loeb said. He joked that the self-help book “Men are from Mars, Women are from Venus” might be healthier than you think.
Or maybe, as Rovcon believes, we are from a different solar system and life is spreading throughout the universe.
“To me, the idea that it all started on Earth, and that each solar system has its own little life evolution going on, and that they’re all independent – that sounds a little silly,” Rufcon said. He added: “It is more explanatory to say, ‘No, it’s spreading, it’s spreading throughout the universe, and we also found out, it didn’t start here.’ And at this point in the pandemic – what a wonderful time to pitch the idea. Maybe people will believe it eventually.
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