The Curiosity rover hit the science “jackpot” and discovered widespread evidence of multiple episodes of liquid water flowing over ancient Mars billions of years ago when the planet was warmer and wetter, scientists announced on Saturday. The watery evidence comes in the form of water-bearing mineral veins and cross-bedded layering.
Any day now the robot will be instructed to drill directly into veined rocks where water once flowed, the team announced at a media briefing.
Delighted researchers said Curiosity surprisingly found lots of evidence for light-toned chains of linear mineral veins inside fractured rocks littering the diverse Martian terrain. Veins form when liquid water circulates through fractures and deposit minerals, gradually filling the insides of the fractured rocks over time.
Sometime in the next two weeks, NASA’s car-sized rover will carry out history’s first drilling inside a Martian rock that was “percolated” by liquid water – an essential prerequisite for life as we know it. A powdered sample will then be delivered to the robots duo of analytical chemistry labs to determine its composition and see whether organic molecules are present.
“We identified a potential drill target and are preparing to do drill activities in the next two weeks. We are ready to go,” said Richard Cook, the project manager of NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, Calif.
“Drilling [into a rock] is the most significant engineering activity since landing. It is the most difficult aspect of the surface mission, interacting with an unknown surface terrain, and has never been done on Mars. We will go slowly. It will take some time.”
“The scientists have been let into the candy store,” said Cook referring to the unexpected wealth of science targets surrounding the rover.
“There is a high diversity of rocks types here to characterize,” added Mike Malin, principal investigator of Malin Space Science Systems (MSSS). “We see layering, veins and concretions. The area is still undergoing some changes.”
White colored veins were discovered over the past few weeks -- using high- resolution mast-mounted imaging cameras -- precisely where Curiosity is currently investigating, a shallow basin called Yellowknife Bay roughly a half mile from the landing site inside Gale Crater.
“(It) turns out to be kind of the ‘jackpot’ unit,” said John Grotzinger, the mission’s chief scientist of the California Institute of Technology. “It is literally shot through with these fractures and vein fills.”
Mineral veins are probably comprised of calcium sulfate – which exists in several hydrated (water bearing) forms.
Water percolated through rocks
“These veins are likely composed of hydrated calcium sulfate,” said team member Nicolas Mangold of the Laboratoire de Planétologie et Géodynamique de Nantes in France. “On Earth, forming veins like these requires water circulating in fractures and occur at low to moderate temperatures.”
The newly found veins appear quite similar to analogous veins discovered in late 2011 by NASA’s Opportunity rover – Curiosity’s older sister – inside Endeavour crater and nearly on the opposite side of Mars.
“What these vein fills tell us is water moved and percolated through these rocks,” Grotzinger explained.
“So this is the first time in this mission that we have seen something that is not just an aqueous environment, but one that also results in precipitation of minerals, which is very attractive to us.”
“This has been really exciting and we can’t wait to start drilling,” Grotzinger emphasized.
Curiosity can drill about 2 inches into rocks. Ultimately a powdered sample about half an aspirin tablet in size will be delivered after a few weeks. All rover systems and instruments are healthy, said Cook.
How long the episodes of water flowed is not yet known and it’s a complex history. But the water was at least hip to ankle deep at times and able to transport and round gravel.
Drilling goes to the heart of the mission and will mark a historic feat in planetary exploration –the first time that an indigenous sample has been cored from the interior of a rock on another planet and subsequently analyzed by chemical spectrometers to determine its composition and whether organic molecules are present .
Curiosity landed on the Red Planet five months ago inside Gale Crater to investigate whether Mars ever offered an environment favorable for microbial life, past or present and is now nearly a quarter of the way through her two year prime mission.
Used with permission of Universe Today.