Curiosity Data Suggests Ancient Martian Lake Could Have Harbored Life

Curiosity has been exploring Mars since 2012, and has already traveled further than any other rover in history. Curiosity isn’t done providing fascinating insights into the red planet, either. A new analysis of data from the rover indicates that its landing site in Gale Crater was once a lake that would have had the capacity to support a wide variety of life.

NASA has previously released data from Curiosity that supports the idea that liquid water once flowed in Gale Crater (above). It has been drilling into rocks to study the chemical composition as it moves ever higher up Mount Sharp in the center of the crater. It has discovered all the elements essential to life as we know it, including carbon, nitrogen, oxygen, and phosphorous.

The new study is based on a detailed analysis of data from three and a half years of drill samples from Curiosity. This has allowed scientists to understand the chemical environment of a lake that hasn’t existed for billions of years. Mount Sharp is an ideal place to conduct this testing, as NASA believes it’s the result of rock and sediment being carried there over time by rivers and streams.

Researchers now say that Curiosity’s data shows evidence of varying exposure to oxygen in the past. Some sediment samples were near the surface of the lake, and were more oxygenated. Meanwhile, other samples show lower oxygen exposure, indicating they were buried more deeply. Some microorganisms on Earth live in low-oxygen environments, but most need oxygen in the environment (and the chemical reactions that come with it) to survive. So, there’s good evidence at this point that Gale Crater would have had everything necessary for life in its past. The varying chemical environments could have provided a home to a many different types of microorganisms.

A drill hole made by Curiosity on Mars.

The review of Curiosity’s data also offered more insights into the climate of Mars. It’s long been understood that Mars was warmer and wetter in the distant past, but there may have been another cold and dry period before that. The older sediments scanned by the rover showed less evidence of alteration than younger samples. That suggests that they were formed in an environment more like the current Mars than the “wet” version.

As Curiosity continues to climb upward, it will have the opportunity to analyze more layers of ancient sediment. This data, along with more detailed analysis from the upcoming Mars 2020 rover could make the Martian past much clearer.