Michael Meyer, lead scientist for the Mars Exploration program, has been quoted as saying, "We have found repeated and predictable evidence suggesting water flowing on Mars." He added that the Mars Reconnaissance Orbiter, has found more than one instance of what appears to flowing water during the Martian spring and summer.
Alfred McEwen of the University of Arizona's Lunar and Planetary Laboratory, was quoted as saying, "The best explanation we have for these observations so far is flow of briny water, although this study does not prove that. It's a mystery now, but I think it's a solvable mystery with further observations and experiments."
However, there still is no surety about whether the flowing liquid that is seen as water or not. Mars Reconnaissance Orbiter project scientist Richard Zurek of NASA's Jet Propulsion Laboratory, said, "By comparison with Earth, it's hard to imagine they are formed by anything other than fluid seeping down slopes."
And added, "The question is whether this is happening on Mars and, if so, why just in these particular places."
Mars, which is almost identical to Earth, has long been hoped to be able to have living beings on it and that is why it is NASA has placed a renewed focus on it. There are now efforts under way to build a spacecraft capable of carrying humans to Mars by 2030.