| Session Details | |
| Section | PS - Planetary Sciences |
| Session Title | Astrobiology: Quest for Habitable Worlds and Life's Origins |
| Main Convener | Dr. Kensei Kobayashi (Yokohama National University, Japan) |
| Co-convener(s) | Prof. Susan Mckenna-Lawlor (Space Technology Ireland Ltd, Ireland) |
| Session Description | Since the first discovery of a planet orbiting a Sun-type star was announced in 1995 hundreds of planets outside our solar system (exoplanets) are now known. The presence of most of these exoplanets has been inferred either through detecting their parent star's 'wobble', which is caused by the gravitational tug of the planet, or through measuring a dip in the host star's light as the planet passes in front of it (transits). The focus of exoplanet research is now shifting towards finding planets that are the most promising candidates for supporting life, and searching for indicators of biological processes (biomarkers) in their visible and infrared spectra. Habitability can be defined as the set of the necessary conditions for an active life to exist, even if it does not exist. In astronomy, a habitable zone (HZ) is the zone defined around a sun/star, where the temperature conditions allow liquid water to exist on its surface. This habitability concept can be considered from different scientific perspectives and on different spatial and time scales. Characterizing habitability at these various scales requires interdisciplinary research. In this session we have chosen to develop the geophysical, geological, chemical and biological aspects and to insist on the need to integrate them, with a particular focus on our neighboring planets, Mars and Venus together with icy satellites such as Europa, Titan and Enceladus. Important geodynamic processes may affect the habitability conditions of a planet. The concept of habitability is very Earth-centric, as we have only one biological planet to study. However, life elsewhere would most probably be based on organic chemistry and leave traces of its past or recent presence and metabolism by modifying microscopically or macroscopically the physico-chemical characteristics of its environment. The extent to which these modifications occur will determine our ability to detect them in astrobiological exploration. In this view we wish to discuss and review the characteristics of habitable conditions to widen the habitability zone. In addition, chemical evolution processes toward origins of life should be considered to evaluate possibility of generation of life in such worlds. We welcome papers treating any aspects of origins of life on the Earth and elsewhere. |