Humans have been captivated by fictional images of Martian life since the 19th century. In 1877, Giovanni Schiaparelli, an Italian astronomer, observed canali–channels, then mistranslated as canals–on the planet, unintentionally sparking a movement of Martian conspiracists enchanted by the possibility of extraterrestrial life.
Since then, we’ve been inching closer and closer to finding the real thing. This quest was most recently advanced by the Perseverance rover’s recent detection of organic matter, which has taken the media by storm in the past few days.
The Perseverance rover was launched in July 2020, as part of NASA’s Mars 2020 mission. Astrobiology has served as a major motivating objective of the mission, as scientists hope for signs of microbial life. As a result, Perseverance has spent much of its journey lolling about the Jezero Crater, which once housed a river delta–an ideal spot for Martian life to flourish.
A recent sample collected by Perseverance–from a rock dubbed “Wildcat Ridge”–suggested the presence of sulfate minerals, as well as signs of carbon-containing organic molecules.
“On Earth, sulfate deposits are known to preserve organics and often harbor signs of life,” said Sunanda Sharma, a JPL astrobiologist involved with the project.
This is not the first discovery of Martian organic material: NASA’s Curiosity rover found organic matter in 2014. However, the context in which it was discovered is especially compelling.
Ken Farley, a Mars 2020 Project Scientist, said, “In the distant past, the sand, mud, and salts that now make up the Wildcat Ridge sample were deposited under conditions where life could potentially have thrived… The fact the organic matter was found in such a sedimentary rock – known for preserving fossils of ancient life here on Earth – is important.”
The Wildcat Ridge sample, and up to 37 others, will be further analyzed back on Earth through the Mars Sample Return Mission.
While this is exciting progress on the journey to alien discovery, it is not a definite sign Mars once harbored life. Extraterrestrial organic matter is not definitive proof that life exists, or once existed, outside of Earth. It is merely a sign that it could.
However, with this recent finding and a continual stream of new exoplanet discoveries, we’re closer to finding extraterrestrial life than we’ve ever been.
“I personally find these results so moving because it feels like we’ve in the right place, with the right tools, at a very pivotal moment,” said Sharma.