For NASA it was a long journey of finding water on Mars for sure and finally it was proved beyond doubt that there is liquid water on the red planet suggesting the possibility of alien life forms on it.
Going back to past, it was a suspense thriller for space enthusiasts since 1965 whether there is water on Mars or not. The first successful Mars flyby in 1965 by Mariner 4 gave the first instance of the presence of liquid water on the planet’s surface in the form of periodic variations in light and dark patches in the polar latitudes, which were construed to seas and continents.
The first finding gave fillip to wild speculation that there were irrigation channels for liquid water,while some brushed it aside as mere optical illusions. Others held that Mars once had large-scale water coverage on its surface at some earlier stage of its life.
The next breakthrough came in 2005 when radar data showed traces of water ice at the poles and at mid-latitudes. Next, the Mars rover Spirit sampled chemical compounds containing water molecules in March 2007 and the Phoenix lander collected samples of water ice in shallow Martian soil on July 31, 2008, breaking the myth into reality.
Mars has currently 5 orbiting spacecraft — 2001 Mars Odyssey, Mars Express, Mars Reconnaissance Orbiter, MAVEN and Mars Orbiter Mission (Mangalyaan of India) amd twp rovers on its surface — Opportunity and Curiosity.
In 2013, NASA’s Curiosity rover discovered that Mars’s soil contains between 1.5% and 3% water by mass, mixed with other compounds.
Finally on sept. 28, 2015, based on new findings from NASA’s Mars Reconnaissance Orbiter (MRO), scientists provided the strongest evidence that liquid water flows intermittently on present-day Mars. NASA "revealed" the mystery of water on Mars with images taken by MRO’s spectrometer of hydrated minerals on slopes with mysterious streaks.
These darkish streaks appear to flow down steep slopes during warm seasons, and then fade in cooler seasons and they appear in several locations on Mars whenever temperatures are above minus 10 degrees Fahrenheit (minus 23 Celsius), and disappear at colder times.
"Our quest on Mars has been to ‘follow the water,’ in our search for life in the universe, and now we have convincing science that validates what we’ve long suspected," said John Grunsfeld, associate administrator of NASA. "This is a significant development, as it appears to confirm that water — albeit briny — is flowing today on the surface of Mars," he declared putting the so-called mystery to rest forever.
Images credit: NASA