Thursday, scientists reported that an orbiting spacecraft had found a mineral on the planet Mars’ surface that suggested the latter might have been a hospitable environment to life in the past.

The Mars Reconnaissance Orbiter discovered carbonate mineral in rock outcrops in the Nili Fossae region comprising valleys that have thrust themselves into Mars’ surface, which led scientists to believe that the area was less rugged than the rest of the planet.

The 3.6 billion-year-old carbonate was discovered in bedrock at the edge of a 930-mile-wide crater. 

The mineral detected is one that forms in the presence of water and traces of it have been spotted before in Martian dust and soil samples that were provided by the Phoenix Mars Lander.

Nevertheless, the fact that it was also found in bedrock goes to prove that the water in the region had not been as acidic as previously thought, which means the environment could have been hospitable to life at one point.

Since carbonate is formed when water and carbon dioxide mix with calcium, iron or magnesium, but dissolves rapidly in acid, the discovery of the mineral on the planet’s surface suggests that not all water on Mars was at one point acidic, which has been a widely spread theory so far.

Even though the deposits are fairly limited at this time, Scott Murchie, a scientist at Johns Hopkins University in Baltimore, stated that the watery environment could have been larger in the past.

The scientists’ findings were revealed Thursday at an American Geophysical Union meeting in San Francisco and published Friday in the journal Science.