NASA's Mars Research at Mono Lake
Click here for some info and links on October 2010 Mars rover tests at Mono Lake, and a NASA press release on the 2010 discovery of bacteria that can grow using arsenic in place of phosphorus. The following article was written in 1996 and updated in 2003, with a photo added in 2010.
Click on footnotes -- 1 -- to see the notes at the bottom of the profiles. Click on words in italics to see the definition in the glossary.
In 1976, Viking landers sent to Mars analyzed soil samples and found no conclusive evidence that life had existed there. However, water once flowed freely on Mars, it might have had a thicker atmosphere, and the temperatures that occurred there didn't rule out life.1
In order to figure out where the next Mars probe should look for evidence of life, NASA scientists looked at where they could find evidence of life on Earth. Fossils of 3.5-billion-year-old microbes have been found on Earth, but they are rare. On Mars, however, fossils would not have been destroyed by the heat and pressure of plate tectonics, therefore probes looking in the right spot might have a better chance of finding them, if they do exist.2
Calcium carbonate precipitating out of water often traps microbes, a process which occurs at Mono Lake, and might have occurred on Mars.3 Mars also has basins which likely held lakes like Mono Lake, which contains hydrothermal vents. Upwellings like these of volcanically heated water from the ocean floor are thought by scientists to be a possible place where bacteria developed.4
"There is strong evidence that all life on Earth evolved from such bacteria and that life's origins trace back to hydrothermal vents," stated Carol Stoker, the project director.5
In August 1995, researchers from the Monterey Bay Aquarium Research Institute, the Navy Postgraduate School (involved because of Navy research on improving underwater minefield surveillance), Stanford University, and project director Carol Stoker from NASA Ames Research Center all converged on Mono Lake. From a houseboat they operated a Telepresence Controlled Remotely Operated Vehicle (TROV) equipped with 1000 feet of cable, a state of the art high frequency sonar system, stereoscopic cameras, an acoustic positioning system, and a sample grabbing arm. Something like TROV will travel to Mars perhaps as early as 2003, so bugs were being worked out first here on earth.6
Visibility was only about one foot, the murkiest the researchers had ever seen, and the chemical quality of the water reduced the sonar range from 30 meters to 2 meters. Tufa samples were taken from the bases of tufa towers, and were analyzed over the next few months to see how well they preserved microbes.7
A three step strategy to recover fossils from Mars, developed by paleontologist Jack Farmer, also with NASA Ames Research Center, is to (1) identify likely sites from an orbiting spacecraft, (2) drop a lander at these sites to find fossil-bearing rocks, and (3) send a probe to retrieve rock samples for firsthand studies on Earth. To assist in the first step, in 1996 an aircraft was flown at high altitude above Yellowstone National Park and other hot spring sites to determine how well infrared cameras could pick out silica, iron, and carbonate deposits formed by the springs.8
Also helping with step one was the Mars Observer, which was going to map the surface of Mars, but went mute in August 1993 when it was about to enter into Mars orbit. The next mission to Mars, the beginning of step 2, launched in December 1996, and parachuted to Mars' surface on July 4, 1997. This $170 million Mars Pathfinder mission landed on giant airbags and released a 2-foot-long rover to explore the surface in a 30-foot radius. It landed on Ares Vallis, an expansive plain with different rock types funneled over it by ancient floods.9
The Mars Surveyor program is NASA's plan to send a low-cost orbital probe and lander to Mars every 2 years until 2006. NASA's Mars rover Spirit will land in the Gusev Crater on Mars in 2004. It's unlikely that any microbes are alive in Gusev Crater now, but their fossils might be there. A good place to look would be inside evaporated mineral deposits or tufa towers, if the crater has any.
Scientists recently have grown bacteria that were trapped in 200 million year-old Miocene salt crystals--another way to look for evidence of past life on Mars. This was first done with Cambrian and Devonian salt crystals in 1962, but was not widely accepted and the author of the paper was fired.
Richard B. Hoover, NASA microbiologist, has discovered bacteria fossils inside meteorites. He has been looking at varnishes on rocks as well. In his search for life in extreme environments, Hoover found 3 new species of bacteria in Mono Lake from mud and water samples he collected in September 2000: Spirochaeta americana (also in Owens Lake), Tindallia californiensis, and Desulfonatronum thiodismutans. The last is responsible for the sulfur smell in Mono Lake's mud. Hoover wanted to name it paiutaeum (after the Mono Lake Kutzadika'a Paiute Indians), however in the peer review it was pointed out that you can't name a species after a group of people--hence thiodismutans.
(1)Cole, Richard, Associated Press, NASA
Probes Mono Lake to Find Clues to Life on Mars, Los
Angeles Times, October 8, 1995
Copyright © 1999-2015, Mono Lake Committee.
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