Spacecraft-Riding Microbes Could Colonize Mars
NASA/Rachael Lussos, The Tauri Group
NASA is eyeing future expeditions to Mars, relying on efficient transportation technology. This artist's illustration of a NASA photo shows how the view of Mars might look like to future astronauts.
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.
Microorganisms from Earth could hitch a ride on spacecraft and end up colonizing the Red Planet and other celestial bodies in the solar system, recent research suggests.
The new research has implications for the search for life in the solar system: If Earth's microbes can survive the perilous journey to other planets and moons, it may be difficult to determine whether any microbial life discovered on those bodies originated there or was introduced from Earth, scientists say.
To ensure space missions don't accidentally transfer microbes to other cosmic bodies, spacecraft are currently allowed to harbor only a certain level of microbial life. This level, called the "bioburden," is based on studies that tested how resistant different microbes are to intense radiation and other dangers associated with space travel. [5 Bold Claims of Alien Life]
However, research detailed in three studies published in the journal Astrobiology in 2012 suggest that the current bioburden standard isn't set high enough, because some microbes are far hardier than expected.
In two of the studies, scientists tested the ability of the spore-forming bacterium Bacillus pumilus SAFR-032 — which has a high resistance to the ultraviolet (UV) radiation and peroxide used to clean spacecraft — to survive in space. (One study also looked at another spore-forming bacterium, B. subtilis 168).
Using the European Technology Exposure Facility (EuTEF) mounted on the International Space Station, scientists exposed the bacteria to a simulated Mars atmosphere. They also subjected the bacteria to various space parameters, including space vacuum, solar radiation and intense temperature fluctuations.
"To our surprise, some of the spores survived for 18 months," Kasthuri Venkateswaran, a researcher with NASA's Jet Propulsion Laboratory in Pasadena, Calif., and a co-author on all three papers, said in a statement. A mission to Mars would take less than half that time, spaceflight experts have said.
Surviving B. pumilus SAFR-032 spores also demonstrated elevated levels of proteins associated with UV resistance, the researchers said. Given that UV radiation is a big threat to space-living bacteria, the researchers believe that spores sheltered from solar radiation, such as those living under spacecraft structures, or mutant subpopulations with heightened UV protection, could possibly survive a trip to Mars.
In the third study, Venkateswaran and his colleagues tested the survivability of rock-colonizing cellular organisms on the EuTEF. Some of the organisms lasted the full 18 months in space. The results suggest that rocks ejected from a planet due to a meteor impact could possibly carry rock-colonizing organisms to other planets (though it would take thousands to millions of years for the rocks to reach another planet).
More From LiveScience:
The Search for Life on Mars (A Photo Timeline)
The 10 Strangest Places Where Life Is Found on Earth
7 Biggest Mysteries of Mars
This story originally appeared on LiveScience.com.
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