Nasa scientists find evidence of flowing water on Mars
The evidence comes from dark streaks that appear on the surface of the Red Planet. These have been known about for many years because the landscape has been seen to change on successive images taken by spacecraft orbiting Mars. Although flowing water has always been a possibility for their creation, other ideas such as the movement of dry ice (carbon dioxide) or the action of the wind, could not be ruled out.
Now, however, strong evidence for them being driven by water has been collected by an instrument called CRISM on board Nasa’s Mars Reconnaissance Orbiter. It has seen the signature of salts known as perchlorates in the dark streaks. These indicate that flowing salty water is responsible for the markings.
This new discovery is likely to change the focus of future Mars exploration by influencing decision makers to focus on how to safely land near areas where liquid water may be close to the surface.
Mars has long been the subject of human fascination. Early telescopic observations revealed color changes on the surface that were originally attributed to seasonal vegetation as well as apparent linear features that were ascribed to intelligent design. These early and erroneous interpretations led to widespread public interest in Mars. Further telescopic observations found Mars’ two moons, Phobos and Deimos, the polar ice caps, and the feature now known as Olympus Mons, the solar system’s tallest mountain.These discoveries piqued further interest in the study and exploration of the red planet. Mars is a rocky planet, like Earth, that formed around the same time, yet with only half the diameter of Earth, and a far thinner atmosphere, it has a cold and desert-like surface. It is notable, however, that although the planet has only one quarter of the surface area of the Earth, it has about the same land area, since only one quarter of the surface area of the Earth is land.