For decades, mankind has been fascinated by the search for life elsewhere on Earth.

Scientists have shown that the truth could not be as glamorous and blockbuster-like as it seems.

According to them, if there is life on the red earth, then it will likely present itself in the form of fossilized bacteria.

These are some of the most hopeful signs of life that we have seen so far.

Water 

Experts agree water is the key to life on Mars.

Although Earth is now barren and rocky, it could still have water trapped in its polar ice cap.

The first evidence that Mars had water was found by scientists in 2000.

According to the Nasa Mars Global Surveyor, there were gullies which could have been caused by water flowing.

It is currently being debated whether these recurring lineae (RSLs), could have formed from water flow.

Meteorites 

According to Space.com, Earth was hit by 34 Mars meteorites. Three of these are thought to be evidence of Earth’s past life, Space.com reports.

Experts discovered a meteorite from Antarctica named ALH 84001 in 1996. It contained fossilised bacteria-like forms.

In 2012 however, scientists concluded that the formation of this organic material was due to volcanic activity and not life.

The Signs of Life 

1964 Mariner 4 was the first to take close-ups.

These first images indicated that Mars may have landforms formed in a climate warmer than today.

1975 saw the launch of the Viking orbiter. It was inconclusive but it was a step forward for future landers.

Numerous rovers, orbiters, and landers now show evidence that water is beneath the crust.

In an old Martian lakebed, Nasa’s Curiosity Rover discovered potential life-building blocks earlier this year.

The organic molecules preserved in 3.5 billion-year-old bedrock in Gale Crater — believed to have once contained a shallow lake the size of Florida’s Lake Okeechobee — suggest conditions back then may have been conducive to life.

Future Mars missions will be able to bring back samples from Mars for further testing.

Methane 

Curiosity confirmed that methane was increasing in Martian atmosphere during 2018 as well.

Experts believe that methane observations are a compelling case for modern-day living.

Curiosity took methane measurements over four and a half Earth-years, which covered parts of three Martian-years.

In the late summer of the northern hemisphere, and in the late winter of the southern hemisphere, seasonal peaks could be seen. 

The magnitude of these seasonal peaks – by a factor of three – was far more than scientists expected.