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 found.
They say that if there was life on the red planet, it would probably present itself as fossilized bacteria – and suggested a new way of finding it.
Here are the most promising signs of life so far –
Water
In the search for life on Mars, experts agree that water is the key to success.
Although the planet is now rocky and barren, and the water is trapped in polar ice caps, it may have been in the past.
In 2000, scientists first discovered evidence for the existence of water on Mars.
NASA’s Mars Global Surveyor has discovered gullies that could have been formed by flowing water.
There is an ongoing debate as to whether these Repetitive Slope Lines (RSLs) could have formed from water flow.
Meteorites
34 meteorites from Mars fell to Earth, three of which are believed to carry evidence of past life on the planet. Space.com…
In 1996, experts discovered a meteorite in Antarctica known as ALH 84001, which contained fossilized formations similar to bacteria.
However, in 2012, experts concluded that this organic material was formed as a result of volcanic activity without the participation of life.
Signs of life
The first close-ups of the planet were made by the 1964 Mariner 4 mission.
These initial images showed that Mars has landforms that could have formed in wetter climates and thus become home to life.
In 1975, the first Viking orbiter was launched, which, albeit to no avail, opened the way for other lander.
Many rovers, orbiters and lander have now found evidence of water under the earth’s crust and even accidental precipitation.
Earlier this year, NASA’s Curiosity rover discovered the potential building blocks of life at the bottom of an ancient Martian lake.
Organic molecules preserved in the 3.5 billion-year-old rock in Gale Crater, which is believed to have once contained a shallow lake the size of Lake Okeechobee in Florida, suggest that conditions at the time could have been favorable for life.
In future missions to Mars, it is planned to deliver samples to Earth for more thorough testing.
Methane
In 2018, Curiosity also confirmed a sharp seasonal increase in methane in the Martian atmosphere.
According to experts, methane observations are “one of the most compelling” examples for modern life.
Curiosity’s methane measurements were taken over four and a half Earth years, which is a fraction of three Martian years.
Seasonal peaks were found in late summer in the northern hemisphere and late winter in the southern hemisphere.
The magnitude of these seasonal peaks – three times – was much larger than scientists expected.
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