Martian Equator Had Water 2 Million Years Ago

After carefully assessing a large number of landscape features on the surface of Mars, astronomers and geologists have concluded that the recent past of our neighboring planet was a lot more wetter than it is now. Admittedly, there is currently no liquid water to be found, but billions of years ago, rivers and deltas adorned the planet, and fell inside craters, or created long rift valleys, where lakes also formed. The finds belong to Matthew Balme, an expert at the Open University in the United Kingdom, who analyzed images sent back by the High Resolution Imaging Science Experiment (HiRISE) instrument aboard the Mars Reconnaissance Orbiter (MRO), currently in orbit around the Red Planet.

Most of the images that the NASA space probe took were of the Martian equatorial regions, where Balme argues that the greatest part of the landscape features were created by water flows. But his research is important because it joins growing numbers of others that say water not only existed on Mars billions of years ago, shortly after the planet was formed, but also as recent as a few million years ago. In a recent find, geologists proved that a system of gullies found on the planet was as recent as 1.25 millions years ago, which, in geological terms, is like it happened earlier today.

“The features of this terrain were previously interpreted to be the result of volcanic processes. The amazingly detailed images from HiRISE show that the features are instead caused by the expansion and contraction of ice, and by thawing of ice-rich ground. This all suggests a very different climate to what we see today,” Balme explains. He also says that the cone/mound-shaped structures that can be observed on the planet, along with polygonally patterned surfaces, debris accumulations, and branched channels, all point at a melting of Martian permafrost.

“These observations demonstrate not only that there was ice near the Martian equator in the last few million years, but also that the ice melted to form liquid water and then refroze. And this probably happened for many cycles,” the scientist adds. His study regarding the landscape formations will appear in an upcoming issue of the journal Earth and Planetary Science Letters. “Given that liquid water seems to be essential for life, these kinds of environments could be a great place to look for evidence of past life on Mars,” he concludes, quoted by Space.