Extraterrestrial liquid water
The Gliese 581 planetary system contains multiple planets that may be candidates for surface water, including Gliese 581c, Gliese 581d, might be warm enough for oceans if a greenhouse effect was operating, and Gliese 581e.
Galán
The caldera contains a lake in its southwestern corner, which is known as Laguna Diamante. Laguna Diamante has gained attention among scientists for the extreme environmental conditions that life within the lake has to withstand, including high arsenic contents of the waters and high insolation with ultraviolet radiation. The water is hyper-alkaline and five times as salty as the sea but supports microorganisms which form microbial mats and provide food for a colony of flamingos. A smaller lake known as Laguna Pabellon lies just south of Laguna Diamante. North of the resurgent dome, the Rio Aguas Calientes drains the caldera northward, while east of it the Rio Leon Muerto runs eastward out of the caldera. Rivers in the caldera and neighbourhood display river terraces which may reflect pre-caldera formation uplift of the terrain and uplift associated with the resurgent dome. These drainages eventually converge in the Rio de Los Patos and end into the Salar del Hombre Muerto north of Galán. The western flanks of the caldera drain into the Antofagasta de la Sierra valley through a number of drainages such as Rio Punilla, Rio Toconquis, Rio Miriguaca, Rio Las Pitas; the waters eventually end into the Laguna Antofagasta south of Antofagasta de la Sierra. Two hot springs are found within the caldera, the first close to its northern end and the second on the southwestern foot of the resurgent dome, both emitting water with temperatures of about . The first one is known as the Aguas Calientes hydrothermal spring and features deposits of tufa and boiling water. Another geothermal system is known as La Colcha and includes fumaroles as well as boiling water and sinter deposits; it has been prospected for the possibility of geothermal power generation.