Why do graduate Work in Astrobiology?
Are we alone in the cosmos? This is one of the deepest and most enduring questions in human experience. While generations of thinkers have struggled in trying to answer this question, the frontiers in late 20th and early 21st century science have advanced to the point that this question now drives an enormous scientific effort. The search for life beyond Earth, which is one goal of the emerging new science of astrobiology, is developing very quickly.
Astrobiology is rooted in 4 major scientific revolutions that have, over the last 25 years, lead to the explosive growth of this field.
- First, astronomers discovered the first planet around another star (i.e., an extrasolar planet, or 'exoplanet') in 1995. Since that time, over 700 exoplanets are now known and more than 2300 new candidates have been found by the Kepler observatory. While many of these are gas-giant planets like our own Jupiter and inhospitable to life, an entirely new and abundant class of planets known as SuperEarths -- rocky planets from a few to ten-times the mass of our Earth -- has been detected. The exciting recent discovery of Kepler 22b, an Earth-like planet approximately 2.4 times the radius of the Earth, orbiting within the 'habitable zone' (i.e., region in which water is liquid on a planet surface) around its host, Sun-like star (which is only 600 light years away), suggests that many candidates for habitable terrestrial planets soon will be found.
- Second, microbiologists have, since the mid-1980s, uncovered an entirely new domain of life (archaeans, as well as other groups) containing organisms known as extremophiles, which can exist on the Earth in conditions that are as extreme as we are likely to find on other planets in our solar system and on exoplanets. This discovery suggests that life may have evolved even on planets such as Mars.
- Third, space and planetary scientists have launched spacecraft and rovers to explore planets and moons in our own solar system. The enormous effort to land robotic vehicles on Mars is driven mainly by the questions of whether water exists or existed on that planet and whether we can find 'biosignatures' for life there. The latest in the series of Mars rovers -- the Mars Science Laboratory aboard the rover known as Curiosity -- was launched in 2011 November. It is a well-equipped, robust, car-sized vehicle, that is collecting many rock and soil samples over a large area (20 km radius) to ascertain the habitability of Mars for present or early microbial life.
- Fourth, important advances have occurred in the area of prebiotic chemistry, wherein researchers test hypotheses about how the first cells and earliest genetic code arose (the RNA world hypothesis as an example). This research area is related to the new, practical realm of synthetic biology, which is a top-down approach to create 'minimum' cells that perform specific functions.
All of these subjects currently are 'hot' areas of research that combine a wide range of science, all made possible by several major technological breakthroughs.
Astrobiology, therefore is an intrinsically interdisciplinary, or perhaps more appropriately 'transdisciplinary,' science. Researchers must possess expertise in specific fields such as astrophysics, microbiology, planetary sciences, biochemistry and chemistry, etc. but also must have the training that allows them to work effectively within multidisciplinary teams. Our graduate program provides this kind of training and research opportunities.