This view of Mars's south polar ice cap and the surrounding area was captured by the European Space Agency's Mars Express spacecraft on February 25, 2015. Recent observations from Mars Express have revealed a lake of liquid water lurking beneath the ice cap.

Scientists have always suspected that there could be water on Mars based on traces of rivers that had dried up billions of years ago on the Martian surface, and by the presence ice-caps in the polar regions of the planet. But now comes the tantalising evidence that there is water beneath the surface that could be the size of an ocean spread across the planet.

The inference was based on the seismic data from the American Insight rover collected between 2018 and 2022. It was found that the seismic waves were faster which is due to the subterranean water. Led by Vashan Wright at the University of California’s San Diego’s Scripps Institution of Oceanography, the group of American geophysicists have proclaimed that there is an ocean of water in the mid-crust of the crevices of Mars.

The research paper appears in the Proceedings of the National Academy of Sciences. Michael Manga of the University of California Berkeley and member of the Vashan Wright team is careful enough to draw a cautious line around the discovery of the Martian ocean. He said, “Establishing that there is a big reservoir of liquid water provides some window into what the climate was like or could be like. And water is necessary for life as we know it. I don’t see why [the underground reservoir] is not a habitable environment. It’s certainly true on Earth – deep, deep mines host life, the bottom of the ocean hosts life. We haven’t found any evidence for life on Mars, but at least we have identified a place that should, in principle, be able to sustain life.”

There is the very practical problem that the water is lying seven to 12 kilometres beneath the Martian surface, and there is no technological possibility as of now of tapping something so deep. So, all that the scientists can hope to study is the climate and geological history of Mars.

It is now confirmed that the surface water sources like rivers and lakes on Mars evaporated into space three billion years ago when the Martian atmosphere disappeared. But among all the planets in the solar system, Mars is, apart from Earth, the nearest in promise of water and life. There is as yet no evidence that Mars supported life even all those billions of years ago.

Strangely enough, maverick entrepreneurs like Elon Musk look to Mars as amenable to human colonisation if Earth becomes too hot a place for humans to survive. It is a wild proposition because Mars is an example of what a planet would become if it is denuded of its protective layer – the atmosphere. Planetary scientists believe that Mars would serve as a good base for further space travel and exploration.

Mars is also the nearest to Earth for travel compared to other uninhabitable places like Jupiter, Venus and Saturn. Even Jupiter’s moons are not too friendly in terms of habitation for earthlings. So a devastated Mars seem to be the only possible way-station for human beings, offering them a base camp as it were for space travel into the vast and nearly infinite universe.

There is the dilemma whether human beings are alone in the universe, and whether there is life in other parts. This issue remains in the realm of speculation. While some argue that there could be civilisations in other galaxies which are far superior to that of the human beings on earth, there are others who point to the fact if there are other intelligent beings then we would have come across them, or they would have come across us.

As there has been no signal of life from anywhere else in the universe, it would seem that human beings are the only living, intelligent beings in the universe. And Mars could provide a stepping stone for humans to get out further into the universe.