Rio Tinta: the "Martian" river on Earth

The unusual surroundings of the mining mines near the Rio Tinta River in the province of Huelva (Spain) are strikingly reminiscent of the Martian landscape. For many years, it was believed that the characteristic "Martian" color of the soil and water was caused by environmental pollution as a result of mining operations.

At the end of the XIX century, the British founded the Río Tinto Mine Company here, which worked for several decades. After the extraction of copper ore proved unprofitable, the mines were closed.

Now scientists believe that the color of the local soil is mainly due to natural causes.

The Rio Tinto basin is rich in metal ores. And although almost the entire periodic table is presented here, iron predominates, the oxides of which give a peculiar reddish hue to the soil and water.

It is home to strange microorganisms called chemolithotrophs that feed on inorganic compounds. They also oxidize iron sulfite, which is found in the local soil in excess, turning it into sulfuric acid and iron chloride.

Three years ago, the Rio Tinto River basin even tested equipment that can be used to study Mars in conditions, so to speak, as close as possible to real conditions — the Eurobot rover and testing new space suits.

"The Rio Tinto basin is almost perfect for such tests. In addition, this area is very close to inhabited areas, which makes it easier to organize expeditions, " Felipe Gomez, a researcher at the Center for Astrobiology, coordinator of the Europlanet project, told El Mundo.