An article published in the journal “Nature Communications” describes the discovery of evidence of the existence of very ancient hydrothermal deposits on a seabed in the Eridania region on Mars. A team of researchers studied data collected by NASA’s Mars Reconnaissance Orbiter (MRO) space probe to reconstruct the presence of massive deposits in a basin in the red planet’s southern hemisphere. It’s a type of environment favorable to the birth of life forms, similar to that in which scientists think life on Earth was born.
The Eridania region is part of a quadrangle with the same name and borders the regions of Terra Cimmeria and Terra Sirenum. It’s a large basin formed by some smaller quasi-circular basins connected to each other, probably formed by the impacts of huge meteorites that occurred when Mars was very young. The subsequent volcanic activity in the area and the erosion probably created an ancient sea.
The great Eridania basing contains a massive amount of deposits whose age is estimated at 3.7 billion years. That was the end of the Noachian period, an era in which the area was filled by a sea that contained a mass of water estimated to be nearly three times that of the Caspian Sea on Earth. The top image shows the basin with the estimated depth at its various points.
The collected data consist of photos of the region but also of detections carried out using the Compact Reconnaissance Spectrometer for Mars (CRISM) instrument, useful to identify the minerals contained in the basin’s deposits. According to the researchers, those data indicate that the deposits were formed by water heated by an active volcano that was part of the planetary crust that entered that ancient sea’s bottom. The bottom image shows the origin of the deposits including the chloride deposition and the water evaporation.
That hydrothermal activity created conditions favorable to the birth of life forms at the time when they were probably just born on Earth, possibly in a similar environment. It must be said that there’s no evidence that in the then Eridania sea life forms were actually born but it’s undeniable that there was a potential.
It’s not the first place on Mars that shows traces of an ancient environment that had that kind of potential, for example, an article published in the magazine “Icarus” described the new evidence of the presence of ancient hydrothermal activities in the Auki crater. However, in this case the characteristics combined with similarities with environments existing on Earth make the Eridania basin extremely interesting from an astrobiological point of view.
The geological activity existing on Earth radically altered the environments where life is likely to have been born, while on Mars there are still direct traces of those ancient hydrothermal activities. Those in the Eridania basin can offer new clues about the birth of life that might also be useful in understanding the chances that it might exist in the underground oceans Jupiter’s moon Europa, and Saturn’s moon Enceladus.