One of the core questions that the Curiosity Mars rover was sent to answer is whether or not there was life of any kind on Mars. To that end, it has been exploring the Gale Crater, a vast and dry ancient lake bed with a 16,404-foot Mount Sharp at the center. This bed once likely held water and scientists wanted to find out if the area held microbial life. The clay in the river was an ideal breeding ground for microbial life and bacteria. Both Mars and Earth have similar basaltic crust that formed four billion years ago, and scientists have recently found methane and water under the crust.
"These cracks are a very friendly place for life. Clay minerals are like a magic material on Earth; if you can find clay minerals, you can almost always find microbes living in them," Yohey Suzuki, an associate professor in the University of Tokyo's Department of Earth and Planetary Science, said.
Suzuki and his team studied samples of basaltic lava found 328 feet below the ocean floor between Tahiti and New Zealand that ranged from 33 to 104 million years old. They found an estimated 10 billion bacterial cells live per cubic centimeter in the iron and clay deposits in the cracks in the crust. The study published in the journal Communications Biology.
"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," said Suzuki.
"I thought it was a dream, seeing such rich microbial life in rocks," Suzuki said, "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."