NASA's tease: 'Mars mystery solved'

Evidence of moving water would be the best indication researchers have had of life on the Red Planet. Photo / Getty Images

There is growing speculation that Nasa is about to announce it has discovered liquid water on Mars after the space agency called a press conference for tomorrow entitled "Mars mystery solved".

At the centre of the rumours is Lujendra Ojha, a graduate student at Georgia Tech in the US, who has been announced as one of the speakers alongside two of Nasa's most senior scientists.

Ojha is credited with "accidentally" discovering the first major evidence that moving water existed on Mars after studying images of the planet's surface in 2011 while at the University of Arizona.

With Alfred McEwen, who is also tabled to speak at the Nasa press conference, Ojha decided to study images of gullies on the surface of Mars taken by a fellow researcher, Colin Dundas.

Ojha edited the images to remove blemishes such as shadows and light interference and discovered dark finger-like markings that moved through the gullies over time, in a pattern consistent with flowing water.

Ojha called the discovery a "lucky accident", saying he had no idea what the shapes were at first, but once the potential significance of the shapes was realised he committed to "years of research" trying to prove that the markings were created by flowing water.

Since Ojha's discovery, observations of similar sites on Mars have revealed that the finger-like patterns seem to emerge in warmer seasons and die away during cooler seasons. This could mean there is flowing water under the surface of the Red Planet that rises to ground level during warmer weather.

If scientists have found definitive evidence of liquid water on Mars then the implications could be huge, as evidence of flowing water is still the best indication researchers have that life may once have existed, or may yet come into existence, on an alien world.

Evidence of water on Mars is nothing new. Polar ice caps were discovered there nearly four decades ago, and erosion patterns on the surface suggest rivers and oceans may have existed there in its early years.

But with low gravity and a thin atmosphere, it is thought that this water largely evaporated out into space instead of falling back down, as it would have done on Earth.

Concrete evidence of liquid water on another planet would be the first discovery of its kind. While scientists strongly suspect that liquid water could exist on moons such as Ceres and Europa, this hypothesis has not yet been proven.