How essential is the presence of liquid water?
It’s now widely believed that Mars holds a pretty big volume of water.
Nonetheless, the surface of the planet is so cold, this water exists only as ice.
To ensure that life to exist on a planet, many scientists consider it is crucial for the world to own liquid water.
Ever since technology has enabled mankind to stare upon Mars intimately, humans have been searching for indications that there was water on the red planet.
Did water used to flow on the surface of Mars?
The Mariner 9 mission revealed clues of water erosion in river beds and canyons, in addition to evidence of weather fronts and fogs on Mars in 1971.
Later missions from the Viking orbiters, which first launched in 1975, revealed yet more details about how water flowed on the surface and carved valleys.
Several studies investigated the presence of liquid water for a long time. In 2000, the primary proof of liquid water on Mars was discovered.
It was claimed the gullies seen on the surface of the planet needed to have been formed by flowing water.
Scientists cited the debris and dust deposits left behind as evidence for moving water existing sooner or later within the history of the red planet.
Nonetheless, the formation of those gullies has been hotly debated throughout the following years.
Proof of ice in geological samples from Mars
Spirit and Opportunity, the dual rovers, found evidence of the presence of water enclosed in rock in 2007, when one in every of Spirit’s wheels broke and gorged a bit of stone.
Evaluation of the silica-rich layer discovered within the scratch suggested it formed within the presence of liquid water.
In 2008, the Phoenix lander was gathering geological samples, and so they disappeared after just a few days.
Scientists thought these were pieces of ice. This assessment was confirmed when the lander later detected water vapour in a sample.
In 2012, Curiosity was meandering over an ancient martian seabed when it examined quite a lot of rocks that were exposed to liquid water billions of years ago.
In 2012, Curiosity (pictured) was meandering over an ancient martian seabed when it examined quite a lot of rocks that were exposed to liquid water billions of years ago
Recurring slope lineae and debate causes it
Features referred to as recurring slope lineae (RSL) were first identified in 2011.
These dark streaks populate the areas of Mars with a pointy incline.
Researchers speculated that these can have been brought on by the intermittent flow of liquid water down steep banks on the planet.
In June 2013, Curiosity found powerful evidence that water adequate to drink once flowed on Mars. In September of the identical 12 months, the primary scoop of soil analysed by Curiosity revealed that high-quality materials on the surface of the planet contain two per cent water by weight.
In 2015, Nasa claimed to have discovered the primary evidence of liquid water on Mars in the current day.
The space agency said that its Mars Reconnaissance Orbiter (MRO) provided the strongest evidence yet that liquid water flows intermittently on present-day Mars.
In 2017, Nasa issued one other statement rebuking its initial findings.
Features referred to as recurring slope lineae (RSL) were first identified in 2011 (pictured). These dark streaks populate the areas of Mars with a pointy incline. Researchers speculated that these can have been brought on by the intermittent flow of liquid water
It said the dark features that run down steep inclines on the red planet were actually granular flows, where grains of sand and dirt slip downhill to make dark streaks, slightly than the bottom being darkened by seeping water.
Images from the MRO revealed the streaks only exist on slopes steep enough for dry grains to descend the best way they do on faces of lively dunes.
Also in 2017, scientists provided one of the best estimates for water on Mars, claiming it once had more liquid H2O than the Arctic Ocean – and the planet kept these oceans for greater than 1.5 billion years.
The findings suggest there was ample time and water for all times on Mars to thrive, but over the past 3.7 billion years the red planet has lost 87 per cent of its water – leaving the surface barren and dry.
A subterranean lake
In a study published within the journal Science, ESO researchers have now discovered the primary concrete evidence for liquid water on Mars.
Using radar imagery from the Mars Express probe, the ESO team have found a 12-mile long underground lake full of liquid water.