NASA's Curiosity Mars rover is celebrating its Martian year (687 Earth days) anniversary this week while traversing ground once covered with massive ancient glaciers, according to a recent analysis of geological images.

A study published in the journal Planetary and Space Science, details this discovery, which provides more details about the massive ocean that likely once covered the Red Planet.

Previous imagery of the Mars surface has revealed that the Red Planet is covered in geological formations that could have once been the sites of raging rivers and towering glaciers.

However, only the most advanced of observational satellites and Mars rovers can get a close enough look to find the truth about what the Martian surface was once like.

Nature World News reported last month that a recent study found evidence that it was lava, not rushing water, that most likely formed some of the planet's most impressive canyons, throwing a wrench into the theory that Mars was covered primarily by water and ice.

However a recent analysis of past images of Martian terrain has revealed striking evidence that at least the impressive Martian crater known as Gale was once covered in thick sheets of frozen water.

"This crater was covered by glaciers approximately 3,500 million years ago, which were particularly extensive on its central mound, Aeolis Mons" lead investigator of the study Alberto Fairén said in a Spanish Foundation for Science and Technology (FECYT) release, via Red Orbit.

According to Fairén, there is also a significant amount of geological evidence indicating that low-lying portions of the crater were also once home to extremely cold lakes of liquid water.

Fairén and his team determined this after analyzing imaged captured the by NASA's Mars Reconnaissance Orbiter and the European Space Agency's (ESA) Mars Express probe. Unfortunately, the study started before Curiosity first rolled into the Gale crater.

The team searched the crater for known geological markers of ancient glacial activity as seen on Earth.

"For example, there is a glacier on Iceland - known as Breiðamerkurjökull - which shows evident resemblances to what we see on Gale crater, and we suppose that is very similar to those which covered Gale's central mound in the past," says Fairén.

Now that the Curiosity rover is "seeing" Gale for itself, the researchers hope that more close-at-hand evidence will be observed that supports their findings.