History/Background

Here we focus on life moving beyond its planet of origin, a question of evolutionary interest and because the human exploration of space is the movement of life from Earth. Today, our research effort provides a home within NAI for an integrated research program relating to this major area of Astrobiology. With this renewal, we propose a focused research plan as a nucleus for an expanded emphasis on this area of interplanetary travel of life as the field of Astrobiology matures.

Moving beyond the planet of origin requires a vehicle for transport, the ability to withstand transport, and the ability to colonize, thrive and ultimately evolve in the new environment. The core of this study will be to identify organisms and ecosystems that are likely to withstand the rigors of space, using as a guiding principle the hypothesis that desiccation resistance and natural exposure to high levels of radiation are good predictors of radiation resistance. Once this work - collecting, testing in the lab and in a space simulator, looking at mechanisms underlying the results - has been established, we will expand to include a flight component and to bring in workers from related fields to study other aspects of natural transport.

As a means of transport the work proposed focuses on natural transport, such as on a meteorite, where the primary factors determining success are finding a suitable vehicle for transport, and the ability of the organisms to withstand space radiation, space vacuum, desiccation, time in transit, and the physical rigors of leaving the parent body and landing on a new one. The product of the probabilities of each factor provides an estimate of the likelihood of success. As a result of this proposed effort we will increase our understanding of several of these parameters.

Objectives and Significance of Research

• To identify terrestrial organisms and ecosystems that will survive space radiation and vacuum. To assess the mechanisms underlying survival.
• To expand this nucleus to other aspects of transport beyond the planet of origin, focusing on the suitability of meteorites as a vehicle of transport.
• To provide a conceptual framework and collaboration for this new field.
• To use this knowledge to inform related fields such as evolutionary biology, global change, the search for life elsewhere, and planetary protection.

What Are We Doing Now?

Identify and collect samples likely to withstand space flight. Field trips have been conducted by Rothschild to the following sites since this project began in 2004.

• Cargill Salt Company, San Francisco Bay (multiple trips; Dana Rogoff, lead)
• Lassen Volcanic National Park (Rothschild and Mancinelli, July 2005)
• Yellowstone National Park (Rothschild, October 2004)
• Bolivian Altiplano (Rothschild, fall 2004; Rothschild & Rogoff, November 2005. In conjunction with the High Lakes team from the SETI NAI group, Nathalie Cabral Co-I.
• Paralana Springs, Australia (team member Roberto Anitori, lead Rothschild and Anitori, February 2005)

Screen for survival after exposure to a solar simulator in Mancinelli's lab, NASA/ARC.

• Bolivian Altiplano

Expose most promising samples to space simulators at the DLR e.V. , Koln, Germany.

Look for mechanistic explanations for radiation or desiccation resistance.

• Currently measuring naturally-occurring DNA damage in collected samples, and naked DNA

Prepare for flight experiments as part of ROSE consortium. Fly most promising samples when the external platform is built on the International Space Station.

• Mancinelli attended planning meeting, Germany, January 2006. Flight likely within year.

Use these results to determine if these organisms are likely to survive in Earth orbit, and thus would make a good future candidate for long-term space flight.

• Pending above.

Assess meteorites as environment for microbes. Study survival of the most promising organisms during simulated meteoritic impact.

• Preliminary studies begun with team members Consolmagno and Rogoff.
• Planning for impact studies underway with team member Shultz.

Model potential for such life forms elsewhere.

Results and Accomplishments

Field work to new sites in extreme environments. This consisted of field trips to the Bolivian Andes as part of the SETI NAI team led by Nathalie Cabrol of the SETI Institute. The idea was that at the altitudes where we sampled (near about 15,000 feet), the ozone column was substantially reduced, resulting in high levels of UV radiation flux. Additionally, many lagoons exist in the Altiplano with unusual chemistries. As we suspected, organisms new to science, and possibly highly radiation resistant, appear to grow there. The work on one of the lagoons, Laguna Colorado, was presented at the annual NAI meeting in Boulder. The second field site was a radioactive hotspring, Paralana Springs, in the Flinders Ranges in central Australia. Currently collaborator Anitori is working on getting samples into culture and identifying the organisms through DNA sequencing prior to testing for radiation resistance.

Development of high-throughput assays to detect DNA damage. Previously our lab used an HPLC method that while accurate, required highly purified DNA and was expensive and slow. Through work conducted by Erin Lashnits, formerly an undergraduate and now a graduate student at Stanford, a quicker, high throughput method for detection of direct and indirect DNA damage is available in our lab.

Survival of microbes in meteorites. Collaborator Consolmagno obtained breccia that functions as an analog of meteorites, and is determining crack dimensions in collaboration with the Natural History Museum, London. In our lab, Technician Rogoff has begun to test whether we can easily get microbes in and out of the breccia. This work is being conducted in preparation for tests of radiation resistance of the organisms once inside meteorites, and to have enough data to request actual meteorite samples.

Astrobiology Roadmap Goals that Relate to this Investigation

Astrobiology addresses three major questions:

1. How does life begin and evolve?
2. Does life exist elsewhere in the universe?
3. What is the future of life on Earth and beyond?

The research conducted in this project has implication for all three in that it helps to understand how life may have arisen in a high radiation regime, what are the limits to life on earth and thus an understanding of the envelope for life in the universe, and the potential for terrestrial organisms to travel and survive beyond earth using a meteorite as a vehicle.

More specifically, this research addresses the following goals in the current Astrobiology Roadmap (2003; http://astrobiology.arc.nasa.gov/roadmap/)

Goal 4. Understand how past life on Earth interacted with its changing planetary and Solar System environment. Investigate the historical relationship between Earth and its biota by integrating evidence from both the geologic and biomolecular records of ancient life and its environments. Objective 4.1 is particularly relevant as we are investigating key biological properties: the ability to cope with damaging radiation, high salinity and desiccation. In the case of halophiles, the three processes may be linked.

Goal 5. Understand the evolutionary mechanisms and environmental limits of life. Determine the molecular, genetic, and biochemical mechanisms that control and limit evolution, metabolic diversity, and acclimatization of life. Objective 5.2, understanding the biochemical adaptation of organisms is particularly relevant as we study the survival tactics of organisms that should be particular radiation and desiccation resistance.

Goal 6. Understand the principles that will shape the future of life, both on Earth and beyond. Elucidate the drivers and effects of ecosystem change as a basis for projecting likely future changes on time scales ranging from decades to millions of years, and explore the potential for microbial life to adapt and evolve in environments beyond its planet of origin. As the ultimate goal of this project is to understand how terrestrial organisms could survive interplanetary transfer, objective 6.2 is especially pertinent.

Ames Team Members Participating in this Investigation:

NAME	ROLE	ORGANIZATION	EMAIL
Rothschild, Lynn	Lead Co-Investigator	NASA Ames Research Center	Lynn.J.Rothschild@nasa.gov
Anitori, Roberto	Collaborator	Macquarie University, Australia	ranitori@rna.bio.mq.edu.au
Consolmagno, Guy	Collaborator	Vatican Observatory/ University of Arizona	gjc@as.arizona.edu
Horneck, Gerda	Collaborator	German Aerospace Center DLR	gerda.horneck@dlr.de
Lashnits, Erin	Undergraduate	Stanford University	lashnits@stanford.edu
Mancinelli, Rocco	Co-Investigator	SETI Institute	rmancinelli@mail.arc.nasa.gov
Purcell, Diane	Collaborator	SETI Institute/NASA	dpurcell@mail.arc.nasa.gov
Rettberg, Petra	Collaborator	German Aerospace Center DLR	Petra.Rettberg@dlr.de
Rogoff, Dana	Collaborator	SETI Institute/NASA	drogoff@mail.arc.nasa.gov
Shultz, Peter	Collaborator	Brown University	peter_schultz@brown.edu

See the following Ames Team research pages:

Formation and Evolution of Habitable Planets
Prebiotic Organics from Space
Origin and Early Evolution of Proteins and Metabolism
Biosignatures in Chemosynthetic and Photosynthetic Systems
Modeling Ecosystems and Biospheres
Hind-Casting Past Environments
Interplanetary Pioneers