Water on the Red Planet – It’s a scientific fact
RECENT IMAGING using the Mars Reconnaissance Orbiter (MRO) detected signatures of hydrated minerals on slopes where mysterious streaks are seen.
These darkish streaks appear to ebb and flow over time. They darken and appear to flow down steep slopes during warm seasons, and then fade in cooler seasons. They appear in several locations on Mars when temperatures are above -10 degrees Fahrenheit (-23o Celsius), and disappear at colder times.
“It took multiple spacecraft over several years to solve this mystery, and now we know there is liquid water on the surface of this cold, desert planet,” said Michael Meyer, lead scientist for NASA’s Mars Exploration Programme at the agency’s headquarters in Washington. “It seems that the more we study Mars, the more we learn how life could be supported and where there are resources to support life in the future.”
Dark, narrow streaks on Martian slopes such as these at Hale Crater are inferred to be formed by seasonal flow of water on contemporary Mars. The streaks are roughly the length of a football field. These dark features on the slopes are called “recurring slope lineae” or RSL. Planetary scientists detected hydrated salts on these slopes at Hale Crater, corroborating the hypothesis that the streaks are formed by briny liquid water. (Image: NASA/JPL-Caltech/Univ. of Arizona)
“Our quest on Mars has been to ‘follow the water,’” said John Grunsfeld, astronaut, and associate administrator of NASA’s Science Mission Directorate, in Washington. “Scientists are searching for life in the universe, and now we have convincing science that validates what we’ve long suspected. This is a significant development, as it appears to confirm that water, albeit briny, is flowing today on the surface of Mars.”
Some of the earliest missions to Mars revealed a planet with a watery past. Pictures beamed back to Earth from the Viking Project in the 1970s showed a surface crossed by dried-up rivers and plains once submerged beneath vast ancient lakes. Earlier this year, NASA unveiled evidence of an ocean that might have covered half of the planet’s northern hemisphere in the distant past.
HYDRATED SALTS A CLUE
The new findings of hydrated salts on the slopes point to what that relationship may be to these dark features. The hydrated salts would lower the freezing point of a liquid brine, just as salt on roads here on Earth causes ice and snow to melt. Scientists say it is likely there is a shallow subsurface flow, with enough water leaking to the surface to explain the darkening.
But occasionally, Mars probes have found hints that the planet might still be wet. Nearly a decade ago, NASA’s Mars Global Surveyor took pictures of what appeared to be water bursting through a gully wall and flowing around boulders and rocky debris. In 2011, the high-resolution camera on NASA’s Mars Reconnaissance Orbiter captured what looked like little streams flowing down crater walls from late spring to early autumn. Not wanting to assume too much, mission scientists named the flows “recurring slope lineae” (RSL). According to researchers, liquid water runs down canyons and crater walls over the summer months on Mars. This discovery raises the possibility of Mars being home to some form of life.
The trickles leave long, dark stains on the Martian terrain that can reach hundreds of metres downhill in the warmer months, before they dry up in the autumn as surface temperatures drop. Images taken from the MRO show cliffs, and the steep walls of valleys and craters, streaked with summertime flows that, in the most active spots, combine to form intricate fan-like patterns.
Scientists are unsure from where the water comes. Speculation is it may rise up from underground ice or salty aquifers, or condense out of the thin Martian atmosphere.
“There is liquid water today on the surface of Mars,” Meyer said. “Because of this, we suspect that it is at least possible to have a habitable environment today.”................................... For the FULL ARTICLE please subscribe to our digital edition.