The evidence of possible liquid water on Mars announced Thursday has scientists newly excited about the Red Planet's potential to host some form of primitive life, scientists say.
The discovery comes from the Mars Reconnaissance Orbiter (MRO), which spotted slopes carved into the Martian surface that appear to most likely have been created by the flow of liquid saltwater, NASA announced. The slopes appear to change over the course of different seasons on Mars, suggesting that liquid water, if it exists at all, is only present in the Martian spring.
In recent years, evidence has been mounting that Mars has icecaps of frozen water at its poles, but the new discovery is the strongest hint yet that liquid water may also exist on the Martian surface, scientists said.
"It hasn't been a question for some time now that there's ice on Mars," geophysicist Philip Christensen of Arizona State University in Tempe said Thursday during a NASA news conference. "What makes these new observations so interesting is that they occur at much lower latitudes where temperatures are much warmer and where it's actually possible for liquid water to exist."
Liquid water is the Holy Grail for scientists hunting for life beyond Earth. All life on this planet relies on liquid water, and experts think extraterrestrials likely do, too. And Mars, as the planet next in line after Earth from the sun, is one of the top potential habitats for ET.
"I think this is an eye-opening discovery that will really help us begin the planning process for future missions specifically looking for signs of the presence of life on Mars," biogeochemist Lisa Pratt of Indiana University at Bloomington said.