2002 Annual Science Report
NASA Ames Research Center Reporting | JUL 2001 – JUN 2002
Life Beyond the Planet of Origin
During this funding period work continued on several fronts. Several team members (Warren-Rhodes, Rettberg, and Lloret y Sanchez) have isolated halophiles from nature, and testing has begun to determine radiation resistance. Kelly joined the team and has begun his master’s thesis with Rothschild on the DNA damage resistance of Dunaliella salina, an extremely halophilic eukaryotic alga. He has tested a dozen strains for resistance to oxidative damage. Rothschild’s lab has focused on developing new techniques to assess damage resistance. Additionally, a student in Rothschild’s lab began work on two animals that should be particularly resistant to the space environment, tardigrades and brine shrimp.
Previous experiments have shown that halophilic organisms isolated from salterns and the intertidal can survive a two-week exposure to the space environment. Using the space simulation facility at the DLR in Cologne, Germany, Mancinelli, Rettberg and Horneck have completed a series of ground simulation experiments using a halophilic cyanobacterium from the genus Synechococcus spp., and Deinococcus radiodurans, as well as a number of Archaeael halophiles. Using these facilities they have exposed this organism to vacuum desiccation and ultraviolet (UV) radiation. These experiments reveal that the cyanobacterium and the Archaeael halophiles are more UV and desiccation resistant then Deinococcus radiodurans. In addition, we have shown that halophilic Archaea and Synechococcus can survive exposure to UV radiation and vacuum desiccation for at least six months, and probably longer. The simulation facilities were used in January 2002 in support of this work.
With the death of one team member, David Wynn-Williams, work on Antarctic samples has been halted for the moment.
PROJECT MEMBERS:Lynn Rothschild
Oliver de Peyer
RELATED OBJECTIVES:Objective 5.0
Describe the sequences of causes and effects associated with the development of Earth's early biosphere and the global environment.
Define how ecophysiological processes structure microbial communities, influence their adaptation and evolution, and affect their detection on other planets.
Identify the environmental limits for life by examining biological adaptations to extremes in environmental conditions.
Search for evidence of ancient climates, extinct life and potential habitats for extant life on Mars.
Understand the natural processes by which life can migrate from one world to another. Are we alone in the Universe?
Define climatological and geological effects upon the limits of habitable zones around the Sun and other stars to help define the frequency of habitable planets in the universe.
Determine the resilience of local and global ecosystems through their response to natural and human-induced disturbances.
Model the future habitability of Earth by examining the interactions between the biosphere and the chemistry and radiation balance of the atmosphere.
Understand the human-directed processes by which life can migrate from one world to another.
Refine planetary protection guidelines and develop protection technology for human and robotic missions.