Is there life on Mars? A NASA scientist explains it in a new video
The search for life beyond Earth is one of the core motivations behind many missions to explore the Red Planet, and in this new video, a NASA scientist takes a look at the question that drives it all: Is there life on Mars ?
NASA has a number of missions running on the surface of March that are intensely dedicated to the search for traces of life. The main ones of these missions are the rovers curiositythat landed on Mars in 2012, and Perseverance which settled on the Martian surface in 2021. The latest of these has been collecting rock cores from Jezero Crater where they might have trapped tiny traces of life.
“Now we’re putting instruments on the Martian surface that can help us understand these potentially habitable sites, and we can ask deeper questions about the potential for habitability in these rock cores,” said Heather Graham, an astrobiologist at the Goddard Space Flight Center in NASA. Greenbelt, Md., said in the 1-minute video premiered on December 28 (opens in a new tab). “We’ve been looking for life on Mars for a long time.”
Related: How microbes on Mars could survive the salty puddles of the red planet
NASA scientist Heather Graham is an organic geochemist and research associate based at the agency’s Goddard Space Flight Center in Greenbelt, Maryland, who studies the connections between biotic and abiotic systems. His research focuses on “agnostic biosignatures,” which NASA describes as evidence of living systems that may not share commonalities with life on Earth.
Graham’s research has focused on developing tools and techniques that can help us identify evidence of living systems that may have a different biochemistry than life on Earth, also known as “agnostic biosignatures.”
While investigating Mars and intending to study others planets of the solar system for traces of life, scientists need detection methods that assume a common heritage with life on Earth. These methods could also help scientists understand life deep within the Earth, where life could be very different from that on the planet’s surface as a result of following different evolutionary lines over billions of years.
“And while NASA hasn’t found any evidence of life now, we’ve found plenty of evidence that Mars could have supported life in the past,” Graham explained. “There is a lot of evidence that says Once upon a time there was a huge ocean on Mars and an atmosphere that could have supported life.”
One of the most important lines of evidence suggesting that Mars could have supported life is the fact that the now dry and barren planet once harbored an abundance of water, a key ingredient for life.
The fact that the 45 kilometers wide (28 miles wide) The Jezero crater was flooded with water and it was home to an ancient river delta is why NASA chose it as the landing area for the Perseverance rover.
About 4 billion years ago, Jezero’s river channels spilled over the crater walls creating a lake, which also filled it with clay minerals from the surrounding area. If there was microbial life on Jezero during these wetter Martians, signs of that life might remain in the lake bed or coastal sediments. Thus, signs of this past life could exist in samples of Martian rock and soil collected by Perseverance.
Turned on land, our magnetic field prevents harmful radiation from stripping the atmosphere and protects life on the planet’s surface. Mars is believed to have it lost water when it lost its magnetic field about 4 billion years ago. With no atmosphere, there was nothing to prevent Martian water from evaporating and then being lost to space. This radiation also made the existence of life on the surface of Mars unviable.
However, there is a possibility that there is still liquid water under the surface of the planet, and so Graham thinks that if there was still life on Mars, it would also be under the outer layers of the planet. The advantage of an underground dwelling would be that the layers of rock and soil provide protection from harmful solar radiation once delivered by the Red Planet’s magnetic field.
“There are places that are potentially habitable, like deep underground. There are places underground that could have fluids or that could have organisms living in them, and they would be protected from the radiation that’s so damaging on the surface,” Graham explained. “So, is there life on Mars? We haven’t found it yet, but there’s still a lot of Mars left to explore.”
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