Strongest evidence of life on Mars found: What did they look like?

Last year, the Perseverance rover discovered rusty circular tracks called "leopard spots" in a dried-up riverbed north of the Martian equator.

NASA administrator Sean Duffy explained that these markings could be left over from microscopic creatures that lived billions of years ago.

Within these traces, located in the "Bright Angel" region of Jezero Crater, researchers identified two critical minerals: Vivianite, found in decaying organic matter, and Greigite, produced by microbes on Earth.

Dr. Keyron Hickman-Lewis from Birkbeck University said: "It's very encouraging that mineral-organic assemblages produced by microbial life on Earth are also observed on Mars. It could be the strongest evidence for life found to date."

WHAT WOULD LIFE ON MARS LOOK LIKE?

According to the British newspaper Daily Mail, the Jezero Crater, which is barren today, was a lake bed filled with water billions of years ago.

According to the researchers, the life forms that could have existed in this environment were limited to simple microorganisms.

It's thought this life could be similar to bacteria that thrive in extreme environments on Earth—like the microbial layers in salt lakes or the microbes found miles underground.

IS A MORE COMPLEX LIFE POSSIBLE?

If these "leopard spots" are indeed biomarkers, the researchers suggest, life may not have been confined to a single region. However, the likelihood of complex animal-like life forms evolving on Mars is extremely low.

It is estimated that microbes may have emerged at the same time as life on Earth, but that evolution stopped early because the climate rapidly cooled and dried out as Mars lost its atmosphere.

These harsh conditions limited body size and complexity. It would take another 3 billion years for complex life to evolve on Earth.