With plumes of matter rising up to 186 miles (300 km) above the surface, Io is considered a prime candidate as a hotspot for extreme extraterrestrial life.
“Everyone right away tends to categorically exclude the possibility of life on Io,” said astrobiologist Dirk Schulze-Makuch at Washington State University. Conditions on Io might have made it a friendlier habitat in the distant past. If life did ever develop on Io, there is a chance it might have survived to the present day, Schulze-Makuch suggested.