NASA Unveils Promising Signs of Past Life on Mars

NASA has revealed intriguing findings from its ongoing exploration of Mars, suggesting the planet may have once harboured microbial life. The agency announced the discovery of distinctive patterns in clay-rich rocks located at the edge of the ancient Jezero Crater, an area once filled by Martian river systems. These patterns, resembling “leopard spots,” have sparked excitement among scientists due to their resemblance to traces left by microorganisms on Earth.

While the evidence remains inconclusive, the discovery has reignited discussions about the potential for past life on Mars and whether it might still exist today. According to NASA researchers, a variety of evidence will be necessary to draw firm conclusions about life on the Red Planet. Early Mars and Earth shared similar atmospheric conditions and magnetic fields, which offered protection from harmful solar radiation and allowed for liquid water to exist on their surfaces—conditions thought to be crucial for the emergence of life.

Over time, Mars lost its magnetic field as its core cooled, leading to a thinner atmosphere that left the surface exposed to damaging solar rays. This transition made Mars the cold, dry desert it is today. As a result, many scientists believe that finding living organisms on the Martian surface is unlikely, given its harsh environment. Instead, the search for life may focus on more sheltered locations, such as underground areas or icy regions.

Potential habitats for Martian microbial life might include caves, subglacial environments at the poles, or deep underground. These locations have parallels on Earth that support microbial ecosystems. For instance, Earth’s deep biosphere, found beneath the surface, hosts a significant amount of microbial life. These microorganisms often thrive in rock fractures, supported by lithoautotrophs, which derive energy from the surrounding rocks. Methane, a potential byproduct of these processes, has also been detected on Mars, although non-biological processes could also account for its presence.

The viability of a deep biosphere on Mars depends on several factors, including the availability of liquid water, energy sources, and manageable temperatures. There is ongoing debate over whether liquid water exists beneath Mars’ surface, but its presence could enable chemical reactions that support microbial life. The unique conditions on Mars may mean that rocks are less compressed than those on Earth, allowing for more porous spaces where microbes could reside. Furthermore, Mars’ lower internal heat may allow for life-sustaining temperatures at greater depths compared to Earth.

To understand the possibility of life on Mars, scientists frequently study Earth environments that mimic Martian conditions. The Atacama Desert in South America, sediments at Lake Salda in Turkey, and salt flats in Utah’s Pilot Valley serve as valuable analogues. Researchers are examining these sites to gain insights into how Martian conditions could affect the survival and preservation of life.

In addition to field investigations, scientists conduct controlled laboratory experiments using specialized “Mars chambers” designed to replicate Martian environmental conditions. These experiments aim to simulate the planet’s atmosphere, radiation exposure, and temperature, providing further insights into the potential for life on Mars.

Despite the promising findings of the “leopard spots,” there is currently no definitive evidence of past or present life on Mars. If life exists today, it is likely not as widespread as on Earth; otherwise, NASA’s rovers and probes would have detected it. However, significant opportunities for discovery are on the horizon. The upcoming European Space Agency (ESA) ExoMars Rosalind Franklin rover is set to drill up to two metres below the Martian surface, allowing scientists to investigate the shallow subsurface for living microorganisms.

Although drilling deep into Mars presents substantial scientific and engineering challenges, it is a critical step toward uncovering the mysteries of potential Martian life. As researchers continue to explore, the quest for understanding whether life ever existed on Mars—and whether it could still survive—remains one of the most compelling questions in planetary science.