by The search for life beyond Earth is at the heart of many exploration missions to the Red Planet and in this new video, a NASA scientist takes a close look at the question driving it all: is there- there life on Mars?
NASA has a number of ongoing missions to the surface of Mars that are intensely engaged in searching for traces of life. Foremost among these missions are the Curiosity rovers, which landed on Mars in 2012, and Perseverance, which touched down on the Martian surface in 2021. The latter collected rock cores from the Jezero crater where tiny traces of life may have been found. trap.
“We’ve just installed instruments on the Martian surface that can help us understand these potentially habitable places and we can ask deeper questions about the habitability potential of these rocky cores,” said astrobiologist Heather Graham. at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, said in the one-minute video released Dec. 28 (opens in a new tab). “We have been searching for life on Mars for a long time.”
Related: How microbes from Mars could survive in salty puddles on 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 different biochemistry from life on Earth, also known as “agnostic biosignatures.”
As they investigate Mars and aim to study other planets in the solar system for signs 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 look very different from that on the planet’s surface due to different lines of evolution being followed for billions of years.
“And although NASA found no evidence of life now, we found plenty of evidence that Mars could have supported life in the past,” Graham explained. “There is a lot of evidence that says there was once a huge ocean on Mars and an atmosphere that could have supported life.”
One of the most important pieces of evidence to suggest that Mars may have once supported life is the fact that the now dry and arid planet was once home to an abundance of water, a key ingredient for life.
The fact that the 45-kilometer-wide (28-mile-wide) Jezero Crater was once flooded with water and housed an ancient river delta is why NASA chose it as the landing zone for the Perseverance rover. .
About 4 billion years ago, the channels of the Jezero River poured down the walls of the crater, creating a lake, also filling it with clay minerals from the surrounding region. If microbial life existed at Jezero during these wetter Martians, signs of that life could remain in lakebed or shoreline sediments. Thus, signs of this past life could exist in samples of Martian rock and soil collected by Perseverance.
On Earth, our magnetic field prevents harmful radiation from stripping the atmosphere and protects life on the planet’s surface. Mars is thought to have lost its water when it lost its magnetic field about 4 billion years ago. Without an atmosphere, nothing prevented the water on Mars from evaporating and then being lost in space. This radiation also made it impossible for life to exist on the surface of Mars.
Still, there’s a chance liquid water could still exist beneath the planet’s surface, so Graham believes that if life still exists on Mars, it would also be found beneath the planet’s outer layers. The benefit of an underground dwelling would be layers of rock and soil providing 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 hold fluids or organisms could live, and they would be shielded from the radiation that is so harmful on the surface,” explained Graham. “So is there life on Mars? Not that we’ve found it yet, but there’s still a lot of Mars to explore.”
Follow us on twitter @Spacedotcom Or on Facebook.
