Water Discovery Is Good News for Mars Colonists
Artist's impression of humans exploring the Martian surface -- perhaps the soil beneath their feet can be processed as a water resource.
Since NASA's Mars Science Laboratory (MSL) rover Curiosity landed on the red planet, each sol (a Martian "day") of the mission sees a flood of new photographs from Aeolis Palus -- the plain inside Gale Crater where Curiosity landed on Aug. 5. In September 2012, mission controllers sent the command for Curiosity to flip open the dust cap in front of the robotic arm-mounted Mars Hand Lens Imager (MAHLI). Until that point, the semi-transparent dust cap only allowed MAHLI to make out fuzzy shapes -- although it did a great job imaging Curiosity's "head" and it is also famous for capturing Curiosity's first color photograph. But since the true clarity of MAHLI has been unleashed, we've been treated to some of the most high-resolution views of the rover, Martian landscape and, most importantly, we've seen exactly what MAHLI was designed to do: Look closely at Mars rocks and dirt, assembling geological evidence of potential past habitability of Mars.
The Business End
Curiosity is armed with 17 cameras and MAHLI is designed to capture close-up photos of geological samples and formations as the rover explores. MAHLI was designed and built by Malin Space Science Systems and is analogous to a geologist's hand lens -- only a lot more sophisticated. Its high-resolution system can focus and magnify objects as small as 12.5 micrometers (that's smaller than the width of a human hair!). This photograph captured by the rover's Mastcam shows the MAHLI lens (with dust cap in place) in the center of the end of Curiosity's instrument-laden robotic arm.
To aid its studies, MAHLI is equipped with four LEDs to light up the imager's samples.
The first photograph to be returned from MAHLI without the dust cover in place was received on Sol 33 (Sept. 8) of Curiosity's mission. Shown here is a view of the ground immediately in front of the rover. Although this photo was a test, mission scientists were able to do a very preliminary study of the large "pebble" at the bottom of the picture: "Notice that the ground immediately around that pebble has less dust visible (more gravel exposed) than in other parts of the image. The presence of the pebble may have affected the wind in a way that preferentially removes dust from the surface around it," they wrote.
How Did Lincoln Help MAHLI?
On Sol 34 (Sept. 9), MAHLI was aimed at Curiosity's calibration target. This target is intended to color balance the instrument and provide a "standard" for mission scientists to refer to. The 1909 Lincoln penny was provided by MAHLI's principal investigatory Ken Edgett. Using a penny as a calibration target is a nod to geologists' tradition of placing a coin or some other object of known scale as a size reference in close-up photographs of rocks, says the MSL mission site.
Although MAHLI will be used to examine microscopic scales, it is showing its prowess at generating some spectacular high-definition views of the rover. Shown here is a mosaic of Curiosity's three left-side dusty wheels.
Hazard Avoidance Cameras
Hazard Avoidance Cameras, or Hazcams, have become "standard issue" for the last three rovers to land on Mars. Mounted on the front and back of rovers Opportunity, Spirit and Curiosity, these small cameras provide invaluable information about the terrain and potential hazards surrounding the rovers. These cameras are not scientific cameras -- they are engineering cameras. Shown here, MAHLI has imaged the four front Hazcams on Curiosity. Interestingly, it was these cameras who returned Curiosity's first dusty image after touch down in August.
Using the flexibility of the robotic arm, MAHLI was able to check the underside of Curiosity. As the camera can focus on objects from 0.8 inch (2.1 centimeters) to infinity, MAHLI has incredible versatility allowing mission controllers to focus on the very small features of Mars to checking the health of the rover to viewing the impressive vistas beyond.
In October 2012, the Internet was abuzz with speculation about a "mystery object" lying beneath the rover during digging operations at "Rocknest." Sadly, after studying the translucent object, mission scientists deduced that it wasn't anything native to the alien environment, it was actually a piece of plastic that had fallen from Curiosity. Yes, Curiosity is littering the red planet.
The MAHLI camera was very attentive while Curiosity dug trenches in the Mars soil at "Rocknest."
In early 2013, MAHLI snapped another curious photo. This time, after driving to a rocky outcrop at a location dubbed "Yellowknife," the camera picked out what appeared to be some kind of organic-looking object embedded in the rock. Nope, it's not a Mars "flower" -- more likely it's a concentration of minerals.
In what has become an iconic photo of Curiosity, MAHLI was commanded to capture dozens of high-resolution pictures of the rover. Like an "arms length" shot you may have in your Facebook profile, Curiosity did the same, composing a mosaic of pics taken with its outstretched robotic arm.
Curiosity Cleans Up!
The Mars rover isn't only a scientific superstar, it also has a talent for cleaning. This circular pattern on a Mars rock was brushed aside by Curiosity's Dust Removal Tool (DRT), helping the rover carry out analysis of the rock surface beneath the layer of dirt.
The discovery of water in the soils of Mars bodes well for potential future settlers, but don't pack your bags quite yet.
The results come from NASA's Mars rover Curiosity, which landed inside a giant impact basin in August 2012 to assess if the planet most like Earth in the solar system has or ever had the chemical ingredients and environments for life.
Its first analysis of fine-grained sand scooped up from the planet’s surface revealed between 1.5 percent and 3 percent of water by weight.
"If you take a cubic foot of that soil you can basically get two pints of water out it -- a couple of water bottles like you'd take to the gym, worth of water," Curiosity scientist Laurie Leshin, of Rensselaer Polytechnic Institute, N.Y., told Discovery News.
"It was kind of a surprise to me," she added.
Leshin and colleagues found the water -- along with sulfur dioxide, carbon dioxide, water and other gases -- by heating tiny bits of the soil inside Curiosity’s onboard laboratory and analyzing released gases with science instruments.
The way the water was released indicates it likely was absorbed into the soil from the atmosphere, a telltale clue that water-laced soil is globally spread.
"The water is not very well bound at all. You still have to sort of gently heat this stuff, but it comes off pretty easily," Leshin said.
"It’s good news from the point of view of future of human space missions," added Curiosity lead scientist John Grotzinger, with the California Institute of Technology.
"It’s also good news from the point of the view of microbes. If there’s a chance for modern life on Mars, if there was a way that these fine materials could have been exploited to produce water, it might have helped in that sense," Grotzinger told Discovery News.
The analysis, however, also revealed a potential hazard in the soil -- perchlorates, which are known to impact human thyroid production of hormones.
"We would need to think about how we would mitigate any hazard from that," Leshin said.
As a first step in developing technology to live off the Martian land, NASA is planning to include an experiment on its next rover that would pull carbon dioxide out of the atmosphere and purify it. Ultimately, the gas could be converted into oxygen for breathing and for propellant. The rover, which will be a copy of the Curiosity chassis and landing system, but with different science instruments, is targeted for launch in 2020.
Curiosity’s analysis also showed no clear indigenous source for organic carbon found on Mars, though it did not rule out that possibility either.
The research appears in special report in this week’s Science on the first 100 days of the Mars Curiosity mission.