Space agency Nasa has just announced at a US press conference that it has found evidence of flowing water on Mars.

The exciting discovery means that the planet could potentially support life-forms.

Mars is the fourth planet from the Sun in the Solar System and is located 225million km from Earth.

Scientists have long speculated that the dark patches on Mars were made up of briny water, but the new findings prove that those patches are actually caused by liquid water.

This water runs down canyons and crater walls over the summer months on Mars (when temperature rise to about minus 23C) – water which then dries up in the autumn as the planet's surface cools.

“There is liquid water today on the surface of Mars,” Michael Meyer, the lead scientist on Nasa’s Mars exploration programme, told The Guardian this evening.

“Because of this, we suspect that it is at least possible to have a habitable environment today.”

Researchers will now focus on finding out where the water comes from: porous rocks under the Martian surface may hold frozen water that melts in the summer and seeps up to the surface.

We already know that a few billion years ago, the planet was inundated by rivers, lakes and maybe even an ocean.

#NASA is already the No.1 trending topic on Twitter in Ireland this evening.