August 2008

Members of NAI's University of Wisconsin, Madison team have a new paper in Earth and Planetary Science Letters presenting their analyses of 4.35 - 3.36 billion year old detrital zircons from the Jack Hills, Western Australia. Their data reveal relatively high lithium abundances compared to other zircons, as well as lithium isotope ratios that are similar to continental crust weathering products rather than ocean floor basalts. The results support the hypothesis that continental-type crust and oceans existed by 4.3 billion years ago, and suggest that weathering was extensive in the early Archean.

Using data from the CRISM instrument on NASA's Mars Reconnaissance Orbiter, astrobiologists from NAI's SETI Institute and Marine Biological Laboratory teams present findings of silicate mineralogy indicating a wide range of past aqueous activity in the Mawrth Vallis on Mars. This work, published in the August 8 issue of Science, suggests that abundant water was once present on Mars and that hydrothermal activity may have occurred. The Mawrith Vallis could be a landing site for future rover missions to Mars.

NAI's University of Wisconsin team presents a review of iron isotope fingerprints created through biogeochemical cycling in the May, 2008 issue of Annual Review of Earth and Planetary Sciences. This landmark paper brings together for the first time the co-evolution records of photosynthesis, bacterial sulfate reduction, and bacterial iron reduction in the early Earth. They review data on natural systems and experiments, looking at both abiological and biological processes, and conclude that the temporal carbon, sulfur, and iron isotope record reflects the interplay of changing microbial metabolisms over Earth's history.

Tune in for the all new 'Astrobiology Rap', written by Jonathan Chase for the latest Astrobiology Magazine European Edition (AMEE) -- the Nordic Invasion.

Jon is an early career researcher in science communication. Multi-talented, Jon has undergraduate degrees in both Aerospace Engineering, and Science and Science Fiction. As a post-graduate practitioner in communicating science, Jon is actively involved in a number of science communication activities.