According to NASA, the frost that covers the surface of Mars is “dirty” and mixed with specks of dust

How important is the presence of liquid water?

It is now widely believed that Mars contains a reasonably large volume of water.

However, the planet’s surface is so cold that this water exists only as ice.

For life to exist on a planet, many scientists believe it is essential that the world possess liquid water.

Ever since technology allowed humanity to observe Mars in detail, humans have been looking for indications that there was water on the red planet.

Was the water flowing on the surface of Mars?

Mission Mariner 9 revealed clues to water erosion in river beds and canyons, as well as evidence of weather fronts and fogs on Mars in 1971.

Subsequent missions by Viking orbiters, first launched in 1975, revealed further details about how the water flowed to the surface and carved valleys.

Several studies have studied the presence of liquid water for decades. In 2000, the first evidence of liquid water was discovered on Mars.

It has been claimed that the ravines seen on the planet’s surface must have been formed by flowing water.

Scientists cited the debris and mud deposits left behind as evidence of water movement existing at some point in the red planet’s history.

However, the formation of these ravines has been the subject of heated debate in the following years.

Ice test in geological samples from Mars

Spirit and Opportunity, the twin rovers, found evidence of rock-enclosed water in 2007, when one of Spirit’s wheels broke and gorged on a piece of stone.

Analysis of the silica-rich layer discovered in the scratch suggested that it formed in the presence of liquid water.

In 2008, the Phoenix lander was collecting geological samples, which disappeared after a few days.

Scientists thought they were pieces of ice. This assessment was confirmed when the lander subsequently detected water vapor in a sample.

In 2012, Curiosity was snaking across an ancient Martian seabed when it examined a series of rocks that were exposed to liquid water billions of years ago.

In 2012, Curiosity (pictured) was snaking across an ancient Martian seabed when it examined a series of rocks exposed to liquid water billions of years ago.

In 2012, Curiosity (pictured) was snaking across an ancient Martian seabed when it examined a series of rocks exposed to liquid water billions of years ago.

It is caused by recurring slope lines and debates

Features known as Recurring Slope Lines (RSL) were first identified in 2011.

These dark streaks populate areas of Mars with a steep slope.

The researchers speculated that these may have been caused by the intermittent flow of liquid water along the planet’s steep banks.

In June 2013, Curiosity found compelling evidence that water good enough to drink once flowed on Mars. In September of the same year, the first soil scoop analyzed by Curiosity revealed that the fine materials on the planet’s surface contain two percent water by weight.

In 2015, NASA claimed to have discovered the first evidence of liquid water on Mars to the present day.

The space agency said its Mars Reconnaissance Orbiter (MRO) has provided the strongest evidence that liquid water flows intermittently over present-day Mars.

In 2017, NASA released another statement scolding its initial findings.

Features known as Recurring Slope Lineae (RSL) were first identified in 2011 (pictured). These dark streaks populate areas of Mars with a steep slope. The researchers speculated that these may have been caused by the intermittent flow of liquid water

He said the dark features running down the steep slopes of the red planet were actually granular streams, where grains of sand and dust slide downstream to create dark streaks, rather than the ground being obscured by water infiltration.

Images from the MRO revealed that the streaks only exist on slopes steep enough to allow dry grains to descend as they do on the walls of active dunes.

Also in 2017, scientists provided their best estimates for water on Mars, stating that it once had more liquid H2O than the Arctic Ocean, and the planet has maintained these oceans for over 1.5 billion years.

The findings suggest there was enough time and water for life on Mars to thrive, but in the past 3.7 billion years, the red planet has lost 87% of its water, leaving the surface barren and dry.

An underground lake

In a study published in the journal Science, ESO researchers have now discovered the first concrete evidence of liquid water on Mars.

Using radar images from the Mars Express probe, ESO’s team found a 12-mile-long underground lake filled with liquid water.