21 -- The Habitable Galaxy: Variation in Space and Time
TUESDAY, April 15, 2008: MORNING
Adrian Melott
University of Kansas
Lawrence, KS, USA
Description
The concept of a galactic habitable zone has recently been broadened, and may also include dynamical considerations which will be relevant to the Terrestrial Planet Finder. There should be differences in the suitability of planetary life with time and position dependence in the galaxy. Examples include sufficient element abundance for rocky planet formation, the rate of supernovae which can damage biospheres, exposure to extragalactic cosmic rays, and sufficient time for evolution of life. These processes can cause extinctions or possibly stimulate biodiversification--a fundamental research topic in paleontology and evolutionary biology--and so have bearing on the probability that life has emerged elsewhere and the broader context for life. On Earth, evidence is emerging that there are large and correlated fluctuations in origination and extinction rates on timescales ranging from 10-100 My. These periodicities may be related to galactic forcing. Research on the galactic habitable zone is interdisciplinary, integrating paleontology with broader geophysical and astrophysical inputs, and has only begun to be integrated with astrobiology. This session invites contributions on such topics with the goal of developing an integrated picture of "habitable galactic phase space".
ORAL SESSION
9:45 21-04-O. The Galactic Habitable Zone and the Age Distribution of Complex Life
in the Milky Way [invited] C. Lineweaver
10:15 21-08-O. Cycles of Fossil Diversity [invited] R.A. Muller
10:45 BREAK
11:00 21-06-O. Distribution of Cosmic Rays in the Galaxy–a Link to Biodiversity Cycles
[invited] M. Medvedev
11:30 21-07-O. Further Aspects of Periodicity in Terrestrial Biodiversity A. Melott
11:45 21-01-O. Using Climate Models to Investigate the Cause of Mass Extinction Events G. Feulner
POSTERS
21-02-P. Dynamics of Populations Subjected to Fast Depletions D. Galante, J.E. Horvath
21-03-P. Dynamics of Planetary Systems in Different Galactic Environments
J.J. Jimenez-Torres, B. Pichardo
21-05-P. Astroecology, Directed Panspermia, and the Cosmological Future of Life
M. Mautner
21-09-P. Were Galactic Cosmic Rays Responsible for Global Cooling Associated with
Three Major Paleozoic Mass Extinction Events? D. Petrizzo, P. Jogi, B. Runnegar