NASA announced today that Mars, which scientists once thought of as a dry, dusty planet, is home to liquid water. That makes Mars an even better candidate for supporting alien—or, one day, human—life.
The findings were discussed in a study published in Nature Geoscience on Friday, and announced in a press conference soon after.
The team of scientists found briny flows at four different locations on Mars’ surface, all at dark streaks, called recurring slope lineae (R.S.L.) that have long intrigued planetary scientists… When they analyzed these Martian formations, scientists found some evidence of several different types of salts. And the salts were hydrated, meaning they had water around them.
The news marks a significant change in how we think about Mars. Jim Green, director of NASA's planetary science division, said during the announcement that "Today we’re revolutionizing our understanding of this planet."
NASA’s Mars Exploration Program's Michael Meyer added, "it seems that the more we study Mars, the more we learn how life could be supported and where there are resources to support life in the future.”
In a statement, Meyer said that the discovery could not have been made without NASA's advanced technology. “It took multiple spacecraft over several years to solve this mystery, and now we know there is liquid water on the surface of this cold, desert planet,” Meyer said.
The discovery brings us that much closer to finding life on Mars, if it's there. Green explained that NASA can now target specific places on the red planet that are most likely to harbor life. NASA's John Grunsfeld added that the discovery also gives further credence to the search for life. "Now that question is not an abstract, scientific question. It's a concrete one."
Speakers said during the press conference that they’re hoping samples from the Mars mission in 2020 will bring us closer to finding Martian life, though it's not clear what exactly it would look like.
Water is an important resource for any future Mars missions—even though the water itself is not drinkable. The water, for instance, could be used to help grow crops on a colonized Mars, if scientists learn how to purify it. Researchers are holding out hope for a well of fresh water.
Scientists are also taking steps to make sure they don't bring stowaway microbes to Mars from Earth aboard NASA's rovers. The New York Times points out that it's unlikely that NASA probes will be able to make contact with the water without contaminating it with microbes from Earth (as Green pointed out, we've already brought bacterial life to Mars.) Per the Times:
R.S.L.s are treated as special regions that NASA’s current robotic explorers are barred from because the rovers were not thoroughly sterilized, and NASA worries that they might be carrying microbial hitchhikers from Earth that could contaminate Mars. Of the spacecraft NASA has sent to Mars, only the two Viking landers in 1976 were baked to temperatures hot enough to kill Earth microbes.
Either way, space enthusiasts are psyched.
Danielle Wiener-Bronner is a news reporter.