A new study released this morning featured tantalizing indicators that liquid water exists under the surface of Mars. That leads to the next questions: Could that environment harbor life, and what would it be like?
This question has absorbed more than just science fiction writers. Scientists have been plucking away at the question for years, using direct and indirect measurements the conditions on Mars to figure out what life there would be life—if it exists, or every did.
In 2009, for example, the Phoenix Lander directly confirmed there to be water ice on the Martian surface, Washington State University researcher Dirk Schulze-Makuch told Popular Mechanics then, “I’d be puzzled if Mars were completely sterile. Once life got entrenched, there would be some way for life to sustain itself in ecological niches.”
Thanks to the new study, one such niche has now been found in the form an underground aquifer filled with briny water. The water is at least twice as salty as seawater. In some ways, that’s good for life—saltwater doesn’t freeze as easily as freshwater, which is important because the water under Mars would be between negative 10 and negative 30 degrees Celsius. But there’s also bad news for life. The Mars water would be full of perchlorate salt, which chemically toxic to most Earth lifeforms.