Images taken from Mars show a long, deep canyon and the remains of beaches, which suggest the existence of a lake on the planet, reports say. Acco

A reconstruction of the lake on the Shalbatana Vallis river valley on Mars as it looked around 3.4 billion of year ago.

Images taken from Mars show a long, deep canyon and the remains of beaches, which suggest the existence of a lake on the planet, reports say.

According to the reports released by the University of Colorado at Boulder, the pictures indicate water carved a 50-kilometer-long canyon, Reuters reported.

Taken by the High Resolution Imaging Science Experiment aboard the Mars Reconnaissance Orbiter, the images show that the canyon would have covered an area of 200 square kilometers and been up to 450 meters deep.

Scientists have also identified formations that could belong to the shores of giant rivers and seas, but some of them could also have been created by dry landslides.

"This is the first unambiguous evidence of shorelines on the surface of Mars," says research associate and leader of the study Gaetano Di Achille.

"The identification of the shorelines and accompanying geological evidence allows us to calculate the size and volume of the lake, which appears to have formed about 3.4 billion years ago."

The Mars Phoenix mission found frozen water on the Red Planet last year. There is also evidence suggesting that water might still seep to the surface from underground.