Life on Mars? The Red Planet’s Gale Lake Might Have Harboured Life

A study on the findings of NASA’s Curiosity rover has shown the possibility of life existing on Mars in the past. In 2014, the rover found Gale Crater’s former long-lasting lakebed, which existed over 3 million years ago. The findings show the lake could have provided stable conditions for the development of a number of alien life forms.

Curiosity rover takes a selfie. Image Courtesy: nasa.gov

Currently, the 4WD droid rover explores the planet and takes surface samples to find any signs of alien life. The lake had significantly differing environmental conditions in each part shown in the study, which analysed the first 3.5 years of the rover’s mission findings. “Different conditions favourable for different types of microbes existed simultaneously in the same lake,” said NASA’s spokesperson. “I know microbes were not what many of you were hoping for, however, it is a major astronomical discovery.

Stimulated view of what Gale Lake would have looked like. Image Courtesy: nasa.gov

The study determined the chemical conditions that existed in the lake as well as the fact that the lake was stratified. This type of water body, like those on Earth, exhibits distinct chemical and physical differences in deep and shallow water, with Gale Lake’s shallow side being richer in oxidants. Stony Brook’s Assistant Professor and the study report’s lead author Joel Hurowitz said, “These were very different, co-existing environments in the same lake.” He explained that multiple survival opportunities would have been provided for different types of microbes to thrive in the rich and poor oxidant conditions as well as the interface between the two in the Martian lake. These are significant findings but unfortunately, it’s still unknown if life existed on Mars.

We’re learning that in parts of the lake and at certain times, the water carried more oxygen,” said Roger Wiens, a planetary scientist at Los Alamos National Laboratory and co-author of the study. This discovery is critical because oxygen is important for life. Yet, during the time of Gale Lake, life on Earth hadn’t yet adapted to using oxygen because photosynthesis wasn’t invented yet. Wiens believes the oxidation state, controlled by the water’s dissolved oxygen content, of elements like manganese or iron, might have been more important for life on Mars if it existed.

The back layers on the Ancient Martian Lake shown on images taken by the Curiosity rover. Image courtesy: nasa.gov

Since then, Curiosity is driving to a base of a Martian layered mountain called Mount Sharp inside the Gale Crater to inspect the rock layers. As the rover gains elevation on the mountain, the layers are progressively younger. The information on the minerals and bedding-thickness mapped out perfectly onto each other, similar to Earth’s stratified lakes, and this explained why iron minerals differed between parts of the lake.

Additionally, the study’s authors also documented the planet’s ancient climate fluctuations. A change occurred between the deposition of crater-floor rocks and the time of the rocks making up Mount Sharp’s base. Curiosity Project Scientist Ashwin Vasavada said: “These results give us unprecedented detail in answering questions about ancient environmental conditions on Mars.

In mid-2017, Curiosity will continue to reach Mount Sharp’s higher and younger layers to find out the evolution of the ancient lake environment to a drier one in modern Mars.

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