This aerial picture shows the Gossan reservoir at the Rio Tinto mines on June 6, 2023 in Minas de Riotinto, Huelva Province, Spain. The extremely acidic environment around southern Spain’s Rio Tinto river has proven ideal for astrobiology research, including scientists who tested prototype drilling systems for future Mars exploration as part of NASA’s MARTE campaign (Mars Astrobiology Rio Tinto Experiment. (Photo by Octavio Passos/Getty Images)
