Nasa has found liquid water on Mars

Nasa has announced scientists have found traces of liquid water on the red planet.

FILE: One of the first photos taken by Nasa's Curiosity Rover on Mars' surface. Picture: @NASA.

JOHANNESBURG - Nasa has made what it called a 'major announcement' that has solved a mystery on the planet Mars.

Nasa Planetary Science Director Jim Green announced that scientists have found traces of liquid water on the red planet.

The findings are based on research conducted by Nasa and several US universities on dark, narrow streaks on the surface of the planet.

The dark streaks that helped scientists conclude water does exist on Mars are called recurring slope lineae.

Nasa scientist Mike Myer says they form in late spring, grow through the summer and disappear by autumn.

But scientists aren't saying that this discovery means that life does exist on Mars.

Myer says that remains a mystery for now.

"We have only one example of life and that is us. We don't know how it started and so one of the things we found at Mars is that it could have supported life. But we don't know how life started here so we don't know if it's possible for life to start on Mars."

Nasa astronaut John Grunsfeld says, "Our quest on Mars has been to 'follow the water,' in our search for life in the universe, and now we have convincing science that validates what we've long suspected."

Grunsfeld says this has profound implications for the question of whether Mars might support life.

"The existence of water, even if its super salty and briny water, gives the possibility that if there's life on Mars we have a way to describe how it might survive."

These dark, narrow, 100 meter-long streaks called recurring slope lineae flowing downhill on Mars are inferred to have been formed by contemporary flowing water. Picture: Nasa.

Mars Reconnaissance Orbiter has been examining Mars since 2006 with its six science instruments.

The discovery is the latest of many breakthroughs by Nasa's Mars missions.

Water on Mars means we are now one step closer to solving the red planet's ultimate question: did it, does it or could it ever support life?