Mars can now be viewed as a barren, icy desert, but did Earth’s closest neighbor once hosted life?
Scientists have been asking this question for centuries and have triggered science fiction ideas.
Now three space research projects are preparing to launch some of the most ambitious deals to find an answer.
Scientists believe that both planets had the potential to feed life four billion years ago ̵
The new Mars probes from the United States, the United Arab Emirates and China will be launched this summer.
Their goal is not to find life on Mars – scientists believe that nothing would survive there now – but to look for possible traces of past life forms.
These extensive and costly programs could prove futile. But astrobiologists say that the red planet is still our best hope of finding a record of life on other planets.
Mars is “the only planet with a real chance of finding traces of extraterrestrial life because we know it was habitable billions of years ago,” said Jean-Yves Le Gall, president of the French space agency CNES, during a conference call with journalists in this week.
Le Gall is one of the architects for NASA’s Mars 2020 exploration probe, which is slated to launch in late July when Earth and Mars will be closest for more than two years.
The more than $ 2.5 billion project is the latest – and technologically most advanced – attempt to uncover Mars’ deeply buried secrets.
But it is not alone because enthusiasm for space exploration has increased again.
“News from Mars”
The scientific study of the red planet started seriously in the 17th century.
In 1609, the Italian Galileo Galilei observed Mars with a primitive telescope and was the first to use the new technology for astronomical purposes.
Fifty years later, Dutch astronomer Christiaan Huygens used a more advanced telescope of his own design to create the planet’s first topographic drawing.
Mars – compared to the “desolate, empty” moon – has long been promising for a possible habitability by microorganisms, wrote the astrophysicist Francis Rocard in his latest article “Latest News from Mars”.
However, the 20th century brought setbacks.
In the 1960s, as the race for a man to the moon accelerated towards his dazzling “giant leap”, Dian Hitchcock and James Lovelock dampened hopes of finding life on Mars.
Her research analyzed the planet’s atmosphere for a chemical imbalance, with gases reacting with each other, which would indicate life.
“If there is no response, there is likely to be no life there,” Lovelock told AFP.
“And that was the case – Mars has an atmosphere that is completely inactive in terms of chemistry.”
Their conclusion was confirmed a decade later when the Viking countries took atmospheric and soil samples that showed that the planet was no longer habitable.
This discovery was a “real tanker” for Mars research, Rocard told AFP.
Mars programs have been essentially interrupted for 20 years.
Then, in 2000, scientists made a groundbreaking discovery: They discovered that water had once flowed over its surface.
Follow the water
This tempting finding helped to revive the latent interest in the exploration of Mars.
Scientists scanned images of canyons and gorges and searched for evidence of liquid water on the surface of Mars.
More than 10 years later, in 2011, they definitely found it.
Rocard said the strategy “follow the water, follow the carbon, follow the light” has paid off.
Every mission since the discovery of the water has “brought to light more and more evidence that Mars is not quite as dead as we thought,” said Michel Viso, astrobiologist at CNES, to AFP.
The latest US rover to take the trip – aptly called Perseverance – is scheduled to land in February next year after a six-month trip from the start.
The probe is perhaps the most anticipated so far. Its landing site, the Jezero crater, was once a wide, 45 km long river delta.
Jezero is rich in sedimentary rocks such as clay and carbonates – the same types of rock that contain fossil traces on Earth – and could be a treasure trove.
Or maybe not.
“We know that water once flowed, but the question remains: how long?” Rocard asked. “We don’t even know how long it took for life to appear on Earth.”
If the mission could bring these stones back to Earth, they could provide answers to questions that have long confused scientists.
However, you must wait at least 10 years for the analysis to be available.
Viso said the results would likely be “a bundle of clues” rather than a clear answer.
At the beginning
Scientists may also consider an even deeper question.
If there was never life on Mars, why not?
The answer to this could enrich our understanding of the evolution of life on our own planet, said Jorge Vago, spokesman for the European Space Agency.
Due to the shift of plate tectonics below the earth’s core, it is extremely difficult to find traces of life here 3.5 billion years ago.
Mars has no tectonic plates and therefore there is a possibility that four billion year old signs of life “that could never be found on Earth” remain, said Vago.
And if the latest Mars programs find no sign of old Mars life, there are always more boundaries to explore.
Encelade and Europa, two of Saturn’s and Jupiter’s moons, are promising competitors.
Although achieving these goals is more science fiction than reality.
A trio of Mars missions on the starting blocks
© 2020 AFP
Quote: The search for signs of ancient life on Mars (2020, July 11) was accessed on July 12, 2020 from https://phys.org/news/2020-07-quest-ancient-life-mars.html
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