Sunday, February 25, 2018

Insights from mud volcanoes and Pitch Lake of Trinidad

Understanding the mystery of life


natural formation: Atop a mud volcano.

Mark Fraser

Astronomy is often seen as a big science. Meaningful research in astronomy appears in the media to be associated with multimillion-dollar telescopes and billion-dollar space missions—all presumably out of the reach of the expertise and priorities of the Caribbean islands.

However, at The University of the West Indies (UWI), St Augustine campus, important questions about the mystery of life in the universe are being answered by studying our own natural habitat in the mud volcanoes and the Pitch Lake in Trinidad. Moreover, these efforts have gained the attention of international media titans like the BBC and the Discovery Channel.

The astrobiology at the Pitch Lake project is being conducted by a multidisciplinary UWI-led team, along with their international collaborators from Canada, USA, Finland and Germany. The UWI team currently comprises Dr Shirin Haque and Dr Denise Beckles from the Physics and Chemistry departments, respectively, of the Faculty of Science and Technology, with PhD student Mr Riad Hosein. Notably, some of the research findings from this project are also in the press in the prestigious journal Science.

The interdisciplinary field of astrobio­logy refers broadly to the study of the origin, evolution, distribution and future of life in the universe. Until a decade ago, the term astrobiology was barely used and, in fact, persons who dared to study extra-terrestrial life were not taken seriously in the scientific community. That is certainly not the case today.

When astrobiologists talk about life in the universe, it is not of the alien type seen in Star Trek or Star Wars—but the presence of microorganisms on a planet. There are two ways to explore life in the universe—one is to look outwards, by searching space for other planetary systems that could possibly have planets in the “habitable zone” where the temperatures and pressures are such that liquid water can pool on the surface of the planet. The discovery of the first such earth-like planet was announced in April 2014 by the US National Aeronau­tics and Space Administration (NASA). The limitations of existing technology however prevent humans from visiting and studying such habitats.

The second approach is to study environ-ments that may serve as an

analogue of extra-terrestrial environments on another planet or moon. Additionally, because it is unlikely conditions are going to be the same, the limits of tolerance for life are also explored, using the presence of microbial life that can survive in extreme conditions, also called extremophiles, as a proxy. This is where the mud volcanoes and pitch lake in Trinidad come in.

The primary motivation for the study at the Pitch Lake and mud volcanoes is the presence of me­thane being emitted at both these sites. The presence of methane on a planet is a key element in the study of the origin and proliferation of life.

Haque explained: “Methane gas is a respiration by-product of some microorganisms. Therefore, if methane is detected on a planet or moon, it is a clue to astronomers that its origin could possibly be biogenic, hence our excitement about detecting methane on a planet in our search for life in the universe. The other thing is that methane is quickly destroyed by sunlight. Therefore, its presence indicates that it is being replenished, which is also an indication of living microorga­nisms.”

Besides serving as an analogue site with respect to methane pro­­-

duction, the project team also sees the Pitch Lake and the mud volcanoes as serving as analogue sites for particular planets. Haque elaborated: “There are features on Mars which resemble the mud volcanoes. Thus, the mud volcanoes can act as an analogue for Mars. Furthermore, liquid hydrocarbon lakes have been found on the surface of Saturn’s largest moon, Titan. Well, right here in Trinidad, we have a gigantic hydrocarbon lake, more popularly known as the Pitch Lake. The Pitch Lake therefore acts as an analogue for Titan.”

Both the Pitch Lake and

the mud volcanoes are harsh environments for the proliferation of microorganisms. Light, oxygen and nutrients cannot penetrate beneath the surface of these geolo­gical formations. These are extreme and adverse conditions for sustaining life. Could there be microbial colonies of extremophiles here?

Chemical profiling of 11 mud volcanoes in Trinidad has been carried out, with a view to compa­ring these profiles to the soil conditions on Mars and its ability to harbour extremophiles. The team has been able to successfully culture microbial colonies from subsurface samples collected from our mud volcanoes. Samples of the pitch have also been

tested extensively by the research team for extremophiles, yielding positive results and the identification of microorganisms not seen before. These discoveries lend credence to the idea there may be microbial life on Mars and Titan.

Dr William P Schonberg, faculty research fellow at NASA’s Jet Propulsion Laboratory, California Institute of Technology, in California, USA, commented on the reputational impact of this project: “In addition to having the potential for ground-breaking discoveries regarding the origins of life on earth, Dr Haque’s Pitch Lake Project brings international recognition to UWI, as well as Trinidad and Tobago. There are very few workable natural extreme environments on earth, and the accessibility of Trinidad’s Pitch Lake makes it the perfect place for scientists from around the world to probe the secrets of the universe.