Nasa has discovered that liquid water "almost certainly" exists on the surface of Mars.
"Under certain circumstances, liquid water has been found on Mars" - Jim Green, NASA Planetary Science Director https://t.co/MvErxberG3
It's not known where the extremely salty water comes from, with theories including the melting of 'near-surface ice', seasonal discharges from layers of water-bearing rock or absorption from the Martian atmosphere.
"It is conceivable that RSL are forming in different parts of Mars through different formation mechanisms," said the scientists.
Nasa have announced that liquid water "almost certainly" exists on Mars.
In a press conference, the space exploration agency said it has discovered that seasonal changes to the Martian landscape are caused by flowing water on the surface of the planet.
"Under certain circumstances, liquid water has been found on Mars" - Nasa Planetary Science Director Jim Green, said in the briefing.
Liquid water on the surface of Mars could support life and "may affect future human exploration," according to Nasa.
The live announcement has now ended.
Mysterious features on Mars that change with the seasons are almost certainly created by flowing liquid water, scientists at Nasa believe.
Latest satellite images have identified narrow streaks, typically less than five metres (16.4 ft) wide, that appear on slopes during warm seasons, lengthen, and then fade when conditions become cooler.
Experts have speculated that water might be involved in the formation of the gully-like features, known as recurring slope lineae, but only now has evidence supporting the theory come to light.
Liquid water could suggest that the surface of Mars is able to support life.
Nasa wrote: "Water is essential to life as we know it. The presence of liquid water on Mars today has astrobiological, geologic and hydrologic implications and may affect future human exploration."
As Nasa prepares to reveal the Mars mystery, ITV News looks back at the previous missions to Mars and what they revealed.Read the full story ›
Nasa is due to reveal details of a "major science finding" resulting from the space agency's ongoing exploration of Mars.Read the full story ›
Stargazers will be able to watch a once in 30 years phenomenon when a giant 'supermoon' turns red when it combines with a lunar eclipse.Read the full story ›
Six people have begun living in a dome in Hawaii to simulate what life would be like on Mars.Read the full story ›
Nasa has been forced to deny claims that a devastating asteroid will strike Earth next month.Read the full story ›
New close-up images of Pluto have been released by NASA.Read the full story ›
A Nasa mission has discovered Kepler 452b - a "bigger, older cousin" to Earth and a possible host of life in space.Read the full story ›