The first sample of dust and soil analysed by NASA’s Curiosity Mars Rover in August 2012 was found to contain a substantial amount of water . This discovery provided new hope that a manned mission to Mars would be able to succeed.

Scientists have confirmed that the soil sample contained about two percent water, a fairly remarkable figure for an apparently cold, lifeless world.

“If you are a human explorer, this is really good news because you can quite easily extract water from almost anywhere,” said Dr. Laurie Leshin, a mission researcher affiliated with Rensselaer Polytechnic Institute in New York.

“If you take about a cubic foot of this dirt and just heat it a little bit—a few hundred degrees—you’ll actually get off about two pints of water,” Dr. Leshin explained. This would be about half the amount required to meet the needs of the average person in a single day, and this level of soil saturation is believed to be typical for the red planet.

Based on this discovery, it seems that human explorers visiting Mars could bake enough water out of the soil to meet a significant portion of their needs. But this wouldn’t be their only option. They could also obtain water in the form of ice.

Finding Ice

In 2002, the NASA Odyssey mission scanned the planet’s surface from orbit, and detected sings indicating the presence of ground ice at high (cold) latitudes. In 2008, the NASA’s Mars lander Phoenix actually dug up samples of ice near the planet’s North Pole. And in 2016, the Mars Reconnaissance Orbiter took an extraordinary series of photographs that revealed the presence of a massive ice sheet buried at lower latitudes. This sheet contains more than 12,000 cubic kilometers of water, which if harvested and melted would create enough liquid water to flood an area of Mars’s surface equivalent to the size of the North and South American continents combined.

Following the discovery of this huge ice sheet, further analysis of Mars Reconnaissance Orbiter (MRO) imagery turned up even more signs of frozen ice deposits . Cut banks or cliffs exposed to heavy erosion revealed layers of rock and ice intermixed, with the top bands of ice found just 1-2 meters below the Martian surface. This finding is especially significant, because it means that at more hospitable latitudes where humans visitors might encamp, water could be obtained from ice found at a reasonable depth, without the use of super-sized drilling equipment.

Martian astronauts (or long-term settlers) could bake water out of the soil, or acquire it my melting the ice. The water could be used for drinking, bathing, washing or sanitation, or it could be broken down into oxygen and hydrogen to create breathable air and methane fuel for power spacecraft.

Of course, the existence of frozen water or soil saturated with water raises another intriguing question: could there be pools or lakes of liquid water somewhere farther beneath the surface, where temperatures are more moderate? For a long time scientists speculated that there could be, and radar images acquired by the European Space Agency’s Mars Express spacecraft confirmed these assumptions.

These images were collected several years ago. But they only revealed their hidden secrets recently, when improvements in data processing techniques allowed scientists to properly interpret them.

Results of this analysis were published in July 2018 in the journal Science. In this article, it was revealed that a 19-kilometer-wide lake of liquid water had been found nearly two kilometers beneath the surface of the planet’s southern ice cap, which is comprised of frozen carbon dioxide. At this depth the water would be difficult to reach, however, meaning it probably wouldn’t be accessible to human explorers.

Was there Once Life on Mars? Don’t Bet Against It

It seems that wherever an intrepid human explorer on Mars might tread, there would be enough water beneath his or her feet to make a long-term stay feasible.

However, the implications of these discoveries are far greater than having a resource available for future Mars missions. These findings also provide evidence that Mars was once habitable and had conditions favorable for life. In fact, most recent research suggests life as we know it actually originated on Mars and was carried to Earth on a meteorite .

There is now no question that water once flowed freely on the surface of Mars . The Curiosity Mars Rover collected small, smooth rocks that were identified as pebbles formed by the actions of a rapidly running river. Later, the Curiosity found proof that an area it explored called the Gale Crater had once been the site of a lake fed by multiple rivers . Significantly, the discovery of clay deposits inside a crater by another Mars Rover called Opportunity proved that at least some of the surface water on Mars had a neutral pH value , and therefore was fully safe to drink.

All of this data confirmed the truth about the presence of liquid water on the surface of Mars. Curiously, however, the implication of what water on Mars means for its ancient past is strangely absent from most mainstream media reporting on these discoveries.

It is now believed that liquid water could be found on the Martian surface approximately four billion years ago , when the planet was much younger and its atmosphere much thicker. Over time circumstances obviously changed, but how long it took for the planet to dry out and lose its surface warmth is unknown. Even the mechanisms responsible for these changes remain a mystery.

Evolution of Life in the Solar System

If indeed the climate on Mars was hospitable to life in the ancient past, as the presence of liquid water on the surface suggests it must have been, then physical evidence to prove life existed should be obtainable. This could be in the form of fossils, which presumably could be discovered by a Mars Rover at some point in the future. It could also be in the form of actual living microbes, if such life is present in one of the planet’s underground seas.

Or, if life had enough time to evolve, it could have reached much higher levels of intelligence and complexity than mainstream scientists are currently prepared to admit. This raises the possibility that artifacts created by an advanced civilization could someday be discovered, which would revolutionize our understanding of how life evolved in the solar system. If the theory about a Martian meteorite bringing life to Earth is true, and intelligent life evolved in both locations from the same initial seeds, it even raises the possibility that lifeforms on Mars could have closely resembled life forms on Earth.

As of now this is only conjecture, and will remain so until future Mars rovers, orbiters or manned missions bring back actual proof of life, intelligent or otherwise.

Top image: Curiosity rover on Mars looks for water. Credit: Sasa Kadrjevic / Adobe Stock

By Nathan Falde