Introducing OAST

This post has been a long time in coming!  I’m happy to announce that our Oceans Across Space and Time (OAST) proposal to the NASA Astrobiology Program has been funded, launching a 5 year, 8+ institution effort to improve life detection strategies for key extraterrestrial environments.  We submitted this proposal in response to the NASA Astrobiology Institute call (NAI; a key funding opportunity within the Astrobiology Program), however, OAST was ultimately funded under a new research coordination network titled Network for Life Detection (NfoLD).  Research coordination networks are a relatively new construct for NASA and provide a better framework for exchanging information between teams than the old “node” based NAI model.  NfoLD will eventually encompass a number of NASA projects looking at various aspects of life detection and funded through a variety of different opportunities (Exobiology, PSTAR, Habitable Worlds, etc).

OAST is led by my colleague Britney Schmidt, a planetary scientist at Georgia Tech (click here for the GT press release).  Joining us from SIO is Doug Bartlett, a deep sea microbial ecologist.  Other institutions with a major role include Stanford, MIT, Louisiana State University, Kansas University, University of Texas at Austin, and Blue Marble Space Institute of Science.

The OAST science objectives are structured around the concept of contemporary, remnant, and relict ocean worlds, and predicated on the idea that the distribution of biomass and biomarkers is controlled by different factors for each of these ocean “states”.  Understanding the distribution of biomass, and the persistence of biomarkers, will lead us to better strategies for detecting life on Mars, Europa, Enceledus, and other past or present ocean worlds.

Earth is unique among the planets in our solar system for having contemporary, remnant, and relict ocean environments.  This is convenient for us as it provides an opportunity to study these environments without all the cost and bother of traveling to other planets just to try unproven techniques.  For OAST, we’ve identified a suite of ocean environments that we think best represent these ocean states.  For contemporary oceans worlds (such as Europa and Enceledus) we’re studying deep hypersaline anoxic basins (DHABs – I might have hit the acronym limit for a single post…) which may be one of the most bizarre microbial habitats on Earth.  These highly stratified ecosystems are energetically very limited and contain an extreme amount of environmental stress through pressure and high salinity.  These are very much like the conditions we’d expect on a place like Europa.  The below video from the BBC’s latest Blue Planet series provides some idea of what these environments are like.

For remnant ocean worlds we will study a number of hypersaline lake systems, such as were likely present on Mars as it transitioned from a wet to a dry world.  Unlike the contemporary Europan ocean, the remnant Martian ocean would have had lots of energy to support life, a condition shared by many saline lake environments on Earth.  This is illustrated by this photo of me holding a biomass-rich filter at the Great Salt Lake in Utah, way back in my undergraduate days.

Relict ocean worlds are a smaller component of OAST.  This isn’t for lack of relevance – Mars is a relict ocean world after all – but you can’t do everything, even in five years and with an awesome team.  Nonetheless we will carry out work on what’s known as the Permian mid-continental deposits, to search for unambiguous biomarkers persisting from when the region was a remnant ocean.  OAST will be a big part of what we’re up to for the next five years, so stay tuned!