If We Ever Find Life on Mars, It Might Look Like These Weird Microbes
Researchers discovered microbial life flourishing in rocky crevices deep beneath the seafloor.
They collected the samples from oceanic crust in the South Pacific in 2010.
These single-celled bacteria may resemble the type of organisms we'd be likely to see on Mars.
Could a new discovery of microbes buried deep in the nether regions of our own planet be the key to finding life on other ones?
Scientists uncovered the single-celled, methane-munching organisms packed tightly in the crevices of the volcanic rock samples harvested from oceanic crust in the South Pacific.
"I thought it was a dream, seeing such rich microbial life in rocks," geoscientist Yohey Suzuki, of the University of Tokyo, said in a statement. Typically, mud pulled from the seafloor might have as many as 100 bacterial cells per cubic centimeter (0.06 cubic inch). But the rocks Suzuki and his team sampled contained more than 10 billion bacterial cells.
In 2010, during an expedition with the Integrated Ocean Drilling Program (IODP), scientists piled on a massive boat and sailed across the Pacific Ocean to collect samples of the ocean floor using a 3.5-mile metal tube. A drill within the tube sliced roughly 400 feet into the oceanic crust to dig up the core samples, the oldest of which dated back 104 million years.
The scientists sterilized the core samples to prevent contamination and sliced thin sections that were later stained with a special dye that illuminates DNA material. Suzuki and his team watched as the stained-green bacteria lit up under the microscope. Whole genome DNA analysis revealed just how many species were trapped in the rock.
The ocean floor is a surprisingly lush ecosystem that's home to wide range of lifeforms. Underwater volcanoes gush lava into the chilly ocean, where it cracks apart and sinks to the seafloor. Clay minerals fill in those cracks, providing the perfect habitat for aerobic bacteria, which thrive on oxygen and organic material. The regions around deep-sea hydrothermal vents are especially lush.
But scientists didn't find these single-celled organisms near a hydrothermal vent. And Suzuki and his colleagues don't believe a current pumped the bacteria into these specific crevices. Evidence suggests the microbes originated there independently, according to the statement.
That's why the organisms and their unlikely habitat just might be the perfect analogue for finding life in other parts of the solar system. The surface of Mars, for example, is covered in basalt, the same type of volcanic rock that makes up the ocean crust. There's ample methane on the red planet, too. Ultimately, the clay minerals are key.
"Minerals are like a fingerprint for what conditions were present when the clay formed. Neutral to slightly alkaline levels, low temperature, moderate salinity, iron-rich environment, basalt rock—all of these conditions are shared between the deep ocean and the surface of Mars," Suzuki said.
Luckily, a new crop of Mars-bound rovers are set to find out whether life lingers on the red planet in the next few years. NASA's Perseverance rover launches for Mars in July, while ESA and Roscosmos' Rosalind Franklin rover will follow in 2022. Both of these rovers will probe Martian soils to find evidence of similar microbial life.
You Might Also Like
