NASA Now: Extremophiles

Summary

NASA researchers study extreme environments on Earth as analogues for Mars, whose present-day surface is extremely cold and dry. By observing how microbes survive in Earth’s harshest places, scientists can better understand the conditions under which life might persist—or may once have existed—on Mars.

Examples of Extreme Environments

• Atacama Desert, Chile: One of Earth’s driest regions, where rain may be absent for years. Microbes have been found living inside salt deposits, which can provide access to moisture drawn from the surrounding air.
• Antarctica: Microorganisms can use the boundaries of ice as a source of liquid water, even at freezing temperatures. Some also live inside sandstone, where spaces between grains offer shelter, warmth, and moisture.
• Mars: The planet was wetter early in its history but is now extremely dry. A satellite-observed deposit containing chloride—a component of halite, or ordinary salt—has been proposed as the remains of an ancient lake, with evaporated salts left at the surface.

Researchers’ Approach

Researchers:

1. Study Earth environments that resemble Mars.
2. Examine where microbes live and how they cope with extreme dryness and cold.
3. Measure environmental chemistry and available moisture, including water vapor.
4. Use those measurements to estimate the limits of microbial survival and apply that knowledge to Mars.

The segment also notes that NASA’s Spirit rover landed on Mars in January 2004 and began sending back images within hours.

Researchers and Sources Featured

• Dr. Margarita Marinova — NASA Ames Research Center
• Dr. Alfonso Davila — NASA Ames Research Center
• NASA Explorer Schools Virtual Campus — Home of the Fingerprints of Life education module
• NASA’s Spirit Mars Exploration Rover — Referenced in the segment’s mission history