The search for life on other planets has captivated humanity for decades.
But the reality could be a little less like Hollywood blockbusters, scientists have revealed.
They say that if there was life on the red planet, it would probably show up as fossilized bacteria, and they have proposed a new way to search for it.
These are the most promising signs of life so far:
Water
When searching for life on Mars, experts agree that water is key.
Although the planet is now rocky and barren with water locked up in the polar ice caps, there could have been water in the past.
In 2000, scientists first detected evidence of the existence of water on Mars.
NASA’s Mars Global Surveyor found gullies that could have been created by flowing water.
Debate is ongoing as to whether these recurring slope lines (RSLs) could have formed from water flow.
meteorites
Earth has been struck by 34 meteorites from Mars, three of which are believed to have the potential to carry evidence of past life on the planet, he writes. space.com.
In 1996, experts found a meteorite in Antarctica known as ALH 84001 that contained formations similar to fossilized bacteria.
However, in 2012, experts concluded that this organic material had been formed by volcanic activity without the participation of life.
Signs of life
The first close-ups of the planet were taken by the 1964 Mariner 4 mission.
These initial images showed that Mars has landforms that could have formed when the climate was much wetter and therefore supported life.
In 1975, the first Viking orbiter was launched and, while inconclusive, paved the way for other landers.
Many rovers, orbiters, and landers have now revealed evidence of water beneath the crust and even occasional precipitation.
Earlier this year, NASA’s Curiosity rover found potential building blocks of life in an ancient Martian lake bed.
Organic molecules preserved in 3.5-billion-year-old bedrock in Gale Crater, which is believed to have once contained a shallow lake the size of Florida’s Lake Okeechobee, suggest that conditions then may have been conducive to formation. life.
Future missions to Mars plan to bring samples back to Earth for further analysis.
Methane
In 2018, Curiosity also confirmed strong seasonal increases in methane in the Martian atmosphere.
The experts said the methane observations provide “one of the most compelling cases” for life today.
Curiosity’s methane measurements occurred over four and a half Earth years, covering parts of three Martian years.
Seasonal peaks were detected in late summer in the northern hemisphere and late winter in the southern hemisphere.
The magnitude of these seasonal spikes, by a factor of three, was much larger than scientists expected.
