Researchers found out that vast quantities of water were flowing on the Martian surface more than 3 billion years ago. The new study says that the amount of water and the diversity of the environments where it was present are clear signs that it could have supported life. Whether it did or not remains to be seen, since there could have been no sufficient time for life to appear.

The new study found out that large areas of the planet's surface contain clay minerals. These minerals form only in the presence of water, and can be told apart from other minerals because they contain water or hydroxyl in their crystalline structure. The discovery of clay minerals on Mars isn't new. The OMEGA instrument, which stands from Observatoire pour la Mineralogie, l'Eau, les Glaces et l'Activite, with which a previous mission to Mars had been equipped, also found this sort of minerals, but in much smaller quantity.

The findings were made using Mars Reconnaissance Orbiter's new CRISM, or Compact Reconnaissance Imaging Spectrometer for Mars, technology, which analyzes 500 colors reflected by an area of the surface of the planet to determine the structure of its soil. By using this method, scientists were able to discover that up until 3.5-3.7 billion years ago, rivers were flowing on Mars, and many craters were filled with water, forming lakes.

The new discovery will be used to prepare a list of places where future NASA missions to Mars could land in order to have an increased chance of getting some substantial information by analyzing the soil that contains these clay minerals.