NASA's rover has found evidence of liquid water on Mars' surface (see photo).

The NASA Curiosity rover has been exploring Mars since August 2012 and recently discovered evidence of a lake of liquid water that existed on the surface of the Red Planet in the distant past. The rover identified small ripples similar to those seen in lake beds on Earth. These ripples may have been formed by wind moving water. This discovery suggests that 3.7 billion years ago, water on the surface of Mars was not frozen. The study was published in the journal Science Advances, according to ScienceAlert.

Mars is the fourth planet from the Sun and is known for its bright red color, which is caused by the presence of iron oxide in the rocks on the planet's surface.

Mars is a rocky planet of the terrestrial group and resembles Earth in that it has features like Earth-like volcanoes, plains, mountains, and dry riverbeds. However, this is where Mars's similarity to our planet ends. The polar caps on Mars are made of frozen carbon dioxide, the planet has an atmosphere that is not breathable, and it also has very low temperatures and a desert-like surface.

Scientists believe that microbial life may have existed on Mars in the distant past, but signs of it have not yet been found. The Curiosity rover, which has been studying the surface and atmosphere of Mars in Gale Crater for nearly 13 years, is among those searching for these signs.

The primary mission of the Curiosity rover is to study the climate and geology of Mars and how they have changed over time. The spacecraft is also tasked with assessing whether conditions on Mars could have supported microbial life in the distant past. To achieve its goals, the rover is equipped with specialized instruments and cameras that allow it to study the local rocks and atmosphere.

Now, scientists have reported that Curiosity has made a very important discovery on Mars. It has found what appears to be ancient wave ripples on the Martian surface, formed in a location where a lake of liquid water existed billions of years ago.

These ripples consist of tiny undulations and are commonly observed on beaches and in lake beds on Earth when wind moves water across shallow areas. According to scientists, this discovery indicates that water on Mars was not frozen 3.7 billion years ago.

The ripples discovered in Gale Crater provide the most convincing evidence that there were bodies of liquid water in the history of the Red Planet. Researchers say that the climate on Mars at that time was much warmer and the atmosphere denser. This means that liquid water could have existed on the surface without being covered by ice.

The authors of the study created computer models to estimate the size of the ancient lake based on the data collected. It is believed that the lake was small and shallow, with a depth of up to 2 meters.