Where there is moisture and heat, life thrives — at least on Earth. Applying the same to logic to their study of our next-door neighbor, scientists have long hunted for regions on Mars that may once have harbored microbial life and may still do so.
New evidence gathered using NASA's Mars Reconnaissance Orbiter (MRO) has now provided scientists more information about Mars’ past, when its environment may have provided favorable conditions for microbial life. The data show that the surface of Mars was once covered by extensive sheets of ice, which, combined with volcanoes located below the ice sheets, may have set the stage for life to appear and thrive on Mars.
“Rocks tell stories. Studying the rocks can show how the volcano formed or how it was changed over time,” Sheridan Ackiss from Purdue University — one of the researchers who investigated surface composition of an oddly textured region known as “Sisyphi Montes,” located in Mars’ southern hemisphere — said in a statement. "I wanted to learn what story the rocks on these volcanoes were telling.”
The Sisyphi Montes region extends from about 55 degrees to 75 degrees south latitude, far from any extant ice sheet on Mars. Researchers had previously noted that the shape of the flat-topped mountains in the region resembled volcanoes on Earth that erupted underneath ice.
In order to confirm these suspicions, scientists examined the Sisyphi Montes region using the MRO’s Compact Reconnaissance Imaging Spectrometer for Mars, which is capable of capturing high-resolution images.
“Some of the sites that have shapes and compositions consistent with volcanic eruptions beneath an ice sheet are about 1,000 miles from the current south polar ice cap of Mars. The cap now has a diameter of about 220 miles,” NASA said in the statement. “Characteristic minerals resulting from such subglacial volcanism on Earth include zeolites, sulfates and clays. Those are just what the new research has detected at some flat-topped mountains.”
The discovery not only paves the way for choosing landing sites for manned mission to Mars, it also adds to what we already know about the presence of liquid water on the planet — an idea that has been at the forefront of humanity’s collective imagination since the late 19th century, when Italian astronomer Giovanni Schiaparelli first observed “canals” on Mars' surface.