Scientists are intrigued by a new discovery that may suggest life on Mars had existed several billion years ago. And while the life forms believed to have thrived in the lake that eventually became the Gale crater were likely microbial, the findings offer an interesting look at how the Red Planet may have once had the key ingredients of life, at around the same time Earth first did.
In a study published Friday in the journal Science, researchers described how they analyzed rocks found in Mars’ Gale crater, which measures 96 miles wide and once was home to a lake where life may have been found between 3.8 billion and 3.1 billion years ago. This was because of changes in the planet’s climate, as it evolved from a frigid planet to one with a warmer temperature that could have allowed life on Mars to exist.
In an interview with Newsweek, study co-author and Stony Brook University geochemist/planetary scientist Joel Hurowitz explained why Gale crater is a good place for scientists to analyze Mars’ climate as it was billions of years ago — NASA’s Curiosity rover can be found there and is sending back more data on how conditions in ancient Martian history may have been conducive to life.
“One of the things we’re really learning from Gale crater is that Mars—in its ancient geological history — really was home to environments that were very Earth-like in their quality. We’re talking about a lake that was being fed by freshwater rivers, it was a standing body of water that was there for a long period of time that had lake chemistry very similar to what we see on Earth.”
Although the findings do not suggest that it is possible for life on Mars to thrive in today’s conditions, Hurowitz added that his team’s study is proof that the Red Planet was very Earth-like in its early days, just as previous studies had once theorized.
“We can place ourselves onto the surface of another planet and imagine what it would be like at one time in its history—and it would’ve looked quite similar to what Earth looks like.”
For purposes of the study, Hurowitz’s team analyzed rocks gathered by the Curiosity rover over the three-plus years it has been on the Martian surface. The rocks came from a variety of depths, and this allowed the researchers to see how changes took place in the rocks’ chemical and mineral features over the years.
With the scientists able to simulate the conditions in the lake that dried up and became Gale crater, they discovered that Martian climate was initially very cold, but had warmed up and become temperate enough to sustain life. But Mars’ exact climate during that 700,000-year window in which it may have been habitable is still a mystery, according to Hurowitz.
“We don’t understand rock chemistry quite as well as (we do) on Earth, so it’s difficult to ascribe a specific climate condition,” said Hurowitz.
The researchers are firm in their belief that Mars’ Gale crater was one of the areas of the Red Planet that had the ingredients for the recipe of life. According to the Verge, the lake that was once in the crater had some parts that were rich in oxygen and others that weren’t and could have potentially sustained some forms of microbial life, depending on how much oxygen they needed to survive. As oxygen could react when mixed with other chemicals to provide the energy necessary to help microbes feed, experts believe that it is indeed possible that life on Mars was once a possibility.
“Liquid water is important for habitability, but providing an energy source is also important,” said SETI Institute chemist and planetary scientist Janice Bishop, who was not involved in the study.
While most other outside researchers were impressed with Hurowitz’s findings, there are some limitations to the study that cast some doubt as to whether Martian life was possible 3.8 billion to 3.1 billion years ago. But as the Verge wrote, Curiosity is still going up Mount Sharp inside Gale crater and collecting more sediment samples, and these samples may allow researchers to find out more conclusively whether there was life on Mars in its ancient history.
[Featured Image by NASA]