Tim O’Brien, Professor of astrophysics at The University of Manchester, explains why finding liquid water on Mars is such an important discovery and what it means.
“This is a truly exciting discovery. We have known there are features on the planet which suggest flowing material. What we were not sure about was whether this was water.
“NASA has now studied the signature of this material and they can see that it looks like briny water.
“What they don’t know is where the water is coming from. Is it seeping up to mix with salts on the surface to make the briny water? Or it this water coming from the atmosphere, as it sometimes does on Earth?
“The really interesting thing is what this means for life on Mars. Billions of years ago conditions on Mars were similar to what we have on Earth now. So life may have evolved on Mars billions of years ago. Whether it did or whether any of that life exists to the present day is still an open question.
“The presence of liquid water increases the possibility that there could be some microbial life forms still on the planet. But this in itself it is not evidence for life.
“As we understand it life needs liquid water. So they have found a key prerequisite for life on Mars but as yet not life itself.”