2002 Annual Science Report
Arizona State University Reporting | JUL 2001 – JUN 2002
Impacts and the Origin, Distribution, and Evolution of Life
We (PI and my student) continued our examination of impact-generated hydrothermal systems. We have finished a simple model of the thermal evolution of these systems for craters ranging in diameter from 20 to 200 km. A more complicated (three-dimensional (3-D)) computer simulation of the thermal evolution of these systems is now being developed, so that we can define the habitable zones in these systems for thermophilic and hyperthermophilic life.
The PI published the results of a study of an intense period of impact cratering that affected the Earth neary 4 billion years ago, which may have been linked to the origin and early evolution of life on the planet. Over 20,000 impact craters with diameters ranging from 20 km to perhaps 5000 km were produced in a brief flurry of activity, resurfacing much of the planet. The study also concluded that asteroids, not comets, were the likely culprit and that the bombardment affected planets throughout the inner solar system, including Mars.
The PI finished a study of impact-generated wildfires, the results of which are currently in press. Impact-generated wildfires may be one of the most severe ecosystem perturbations following an impact event (at least after the evolution of land plants).
PROJECT MEMBERS:David Kring
RELATED OBJECTIVES:Objective 5.0
Describe the sequences of causes and effects associated with the development of Earth's early biosphere and the global environment.
Define climatological and geological effects upon the limits of habitable zones around the Sun and other stars to help define the frequency of habitable planets in the universe.
Determine the resilience of local and global ecosystems through their response to natural and human-induced disturbances.