Bacteria In Rocks Could Change Views of Life on Mars - Astronomy News with The Cosmic Companion

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In an effort to get news to everyone as quickly as possible, I am trying an experiment for a few weeks, changing the weekly free newsletter from a wrap-up of astronomy and space news, to breaking stories, as they happen. I expect you will see three to four stories per week.

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Bacteria In Rocks Could Change Views of Life on Mars

Primitive lifeforms on Mars, living under now-extinguished seas, may have huddled together in narrow clay tunnels, a new study reveals. Image credit: ESO M Kornmesser

Bacteria in rocks have been discovered hiding inside volcanic rocks from the ocean floor. What could this discovery mean in the search for life on Mars?

By James Maynard

The discovery of bacteria in rocks under the ocean surface suggests life on Mars may be more likely than previously believed. If these microscopic beings could thrive in these conditions on Earth, researchers theorize, lifeforms may have also formed within similar structures on the Red Planet.

The bacteria were found inside thin cracks in rocks recovered from under the ocean floor beneath the Pacific Ocean. The team which made the finding believes the cracks could host collections of bacteria as rich and diverse as the human gut — roughly 10 billion cells per cubic centimeter (0.06 cubic inches). This is 100 million times as dense as the average distribution of bacteria on the ocean floor in the region where samples were collected.

“I am now almost over-expecting that I can find life on Mars. If not, it must be that life relies on some other process that Mars does not have, like plate tectonics,” Yohey Suzuki, Associate Professor at the University of Tokyo, stated.

I Wanna Rock!

Lava erupts from underwater volcanoes at temperatures reaching 1,200 degrees Celsius (2,200 Fahrenheit). This material cools in the chilly water, forming rocks, filled with tiny cracks. Over the course of millions of years, these fissures (up to 1 mm or 1/25 inch across) fill with clay, much like that used to create pottery. Bacteria soon find their way into the clay, where they can multiply, blooming into large colonies.

The samples were collected from the waters of the South Pacific in late 2010 during the Integrated Ocean Drilling Program (IODP). The expedition team collected core samples from three locations between Tahiti and New Zealand.

“The ancestral microbes probably entered with seawater flowing through the fractures in the basalt. The clay formed in place, from alteration of the basalt. Typical oceanic basalt is about 15% fracture when it’s young. Seawater flows continuously through these fractures. As secondary minerals (like clay) grow in the fractures, the fracture volume decreases. Despite this mineral growth, some fractures remain open enough for seawater flow through the basalt to continue for many tens of millions of years (for the entire 100+-million-year lifetime of the basalt in our study),” Dr. Steven D’Hondt of the University of Rhode Island, who headed the Pacific expedition, explained to The Cosmic Companion.

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