While the existence of Martian microbes remains unconfirmed, the search for these tiny lifeforms is one of the most exciting frontiers in astrobiology. Our understanding of potential Martian life is constantly evolving, thanks to ongoing research and the tireless efforts of rovers and orbiters like Curiosity and Perseverance.
Here's a glimpse into what we're learning:
Evidence suggests that Mars, billions of years ago, was a very different planet. Liquid water flowed freely on its surface, carving valleys and filling vast lakes. This ancient Martian water, along with a thicker atmosphere and possibly even geothermal activity, could have provided a suitable environment for microbial life to flourish.
Scientists are searching for biosignatures, indirect evidence of past or present life, in Martian rocks and the atmosphere. Curiosity rover, for example, detected organic molecules, the building blocks of life, in drilled Martian rock samples.
Perseverance rover is specifically equipped to search for biosignatures, with instruments that can analyze the chemical composition of rocks and soil with unprecedented precision. The rover recently found intriguing rock textures that could be the result of microbial activity, though further investigation is needed.
One of the most intriguing puzzles is the presence of methane in the Martian atmosphere. Methane is a short-lived gas on Mars, and its ongoing presence suggests a source of replenishment. While geological processes could be responsible, some scientists believe biological activity, such as methanogenic microbes living underground, could be the culprit.
The harsh Martian surface is not friendly to life as we know it. However, subsurface environments, with potential liquid water and protection from radiation, could offer a haven for microbes. Future missions aim to explore these underground realms, using methods like ground-penetrating radar and drilling to peer into the Martian crust.
Guest:
Dr. Kennda Lynch is a scientist at the Lunar and Planetary Institute.
Her research focuses on using these extreme environments as models for characterizing habitable environments on other planets and moons and searching for biosignatures – signs of past or present life – on celestial bodies in our solar system and beyond.
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This interview will air on Tuesday, January 30, 2024.
