The discovery of ancient hydrothermal deposits on an ancient seabed on Mars has revealed an area of the planet that may provide clues about the origin of life on Earth.
A recent international report examined observations by the Mars Reconnaissance orbiter, which recorded huge deposits of minerals in a depression in the south of Mars. The authors interpret this data as evidence that these deposits were formed by the heated water of the volcanically active part of the planet's crust, which was once the bottom of a large sea.
Photo of the region called Eridania. & copy; NASA
“Even if we never find evidence that life existed on Mars, this place can tell us about the conditions under which life began on Earth,” says Paul Niles of NASA's Johnson Space Center in Houston.
"Volcanic activity, together with stagnant water, provided conditions that were very similar to those that existed on Earth around the same time as the first life forms appeared."
There is no standing water or volcanic activity on Mars today. Researchers estimate the age of Martian sediments associated with hydrothermal activity on the seabed at about 3.7 billion years. The underwater hydrothermal environment on Earth at almost the same time is one of the most obvious candidates for the place where life originated.
There are still corners on Earth where many life forms thrive on chemical energy extracted from rocks, without sunlight. But because of the active crust of the Earth, our planet contains little direct geological evidence that has survived from the time when life began.
The likelihood of underwater hydrothermal activity within icy moons such as Jupiter's Europa and Saturnian Enceladus makes them promising for the search for extraterrestrial life.
Promotional video:
The Mars Reconnaissance spectrometer observations of the Red Planet have provided data for the determination of minerals in huge deposits in the Eridania Basin, which is located in the region with the most ancient exposed crust of the Red Planet. “This place shows us the history of the sea and deep sea hydrothermal environment,” says Niles. “It's reminiscent of deep sea hydrothermal conditions on Earth, which are similar to conditions that could potentially contain life on other worlds. We are talking about life, which does not need an atmosphere, but only rocks, heat and water."
Researchers estimate that the ancient Eridanian Sea contained about 210 cubic kilometers of water. This is the same as in all other lakes and seas of ancient Mars combined and almost 9 times more than the total volume of all the Great Lakes of North America. A mixture of serpentine, talc and carbonate minerals identified from spectrometer data, the shape and structure of the dense rock layers of the bed led to the discovery of possible hydrothermal deposits on the seabed.
There are lava flows in this region that date from a later date than the disappearance of the sea. The researchers cite this argument as evidence that this region of the Martian crust was characterized by active volcanism when the sea still existed.
“Ancient deep-sea hydrothermal deposits in the Eridania Basin are a new astrobiological target on Mars,” the report says.
