For the past few days, the big buzz on the Internet has been the news that NASA has a Mars announcement about a mystery solved. Today it is official, NASA says that there are signs of flowing, liquid water on the present Martian surface. Many scientists have claimed, with good reason, that flowing water had existed on Mars in the distant past. But images from the Mars Reconnaissance Orbiter appear to confirm that there is still flowing, liquid water on Mars now! So says the principal investigator of those images, Professor Alfred S. McEwen, a planetary geologist at the University of Arizona.
McEwen published his findings in the journal Nature Geoscience. It seems that it all comes down to the presence a type of salt known as perchlorates, which have been identified by instruments on the Mars orbiter. These ″water-logged molecules″ were detected ″recently″, according to McEwen. In some cases, within days. Billions of years ago, Mars had plenty of flowing, liquid water. But few people expected to find any today. Actually, the first signs of such were noticed by scientists reviewing the orbiter′s imagery back in 2011.
Signs of these hydrated salt molecules were found in at least four separate sites on Mars. Scientists saw what appeared to be streaks which formed along slopes of craters, mountains and such. As the seasons changed on Mars, the streaks would disappear, then reappear later. The streaks were named ′Recurrent Slope Linae′, or R.S.L. and since first seen, thousands have been noticed on satellite imagery. The streaks are caused by water flowing over rocks and such, making them wet, and therefore changing the color of the rocks and soil to a darker shade. As the rocks and soil dry out, they revert back to a lighter shade.
When the spectrometer on board the Mars Reconnaissance Orbiter was activated and focused on the streaks, the chemical nature of the streaks was determined. Once it was identified as being hydrated salts, the assumption became quite clear that there is still flowing, liquid water on the surface of Mars. So this is the big news from NASA as it made its Mars announcement today. Is there enough water to support a human colony? Well, that remains to be seen. Some scientists are already thinking that the RLS streaks may just be mostly caused by humidity. That there is very little actual flowing, liquid water from melting ice, or even frost. But it opens the door and demands further study.