[meteorite-list] New Perspectives on the Role Asteroids and Comet Impacts Played in the Evolution and Extinction of Life on Earth

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 10:25:37 2004
Message-ID: <200305082113.OAA16145_at_zagami.jpl.nasa.gov>

http://www.businesswire.com/cgi-bin/cb_headline.cgi?&story_file=bw.050803/231285503

New Perspectives on the Role Asteroids and Comet Impacts Played in the
Evolution and Extinction of Life on Earth

Business Wire
May 8, 2003

    LARCHMONT, N.Y.--Large asteroids and
comets smashing into the Earth are increasingly believed to have
influenced the early evolution of life on our planet and may be directly
linked to mass extinctions, as described in a series of papers published
in the Spring 2003 (Volume 3, Number 1) issue of Astrobiology, a
peer-reviewed journal published by Mary Ann Liebert, Inc.
(www.liebertpub.com <http://www.liebertpub.com>).
    This issue features papers from the Rubey Colloquium, the 10th in a
series of topical colloquia in earth and space sciences hosted by the
University of California, Los Angeles with a focus on impact events and
the origin, evolution, and extinction of life. The entire issue is
available free online at www.liebertpub.com/ast
<http://www.liebertpub.com/ast>.
    "We invited 30 scientists from a broad number of disciplines to
discuss our current understanding of the relationship between impacts
and life on Earth," says Frank Kyte, Ph.D., guest editor of the Spring
issue of Astrobiology and Associate Research Geophysicist at UCLA's
Institute of Geophysics and Planetary Physics. "Throughout this two-day
workshop, the 100 participants, which included a number of
astrobiologists unfamiliar with impact research, engaged in a highly
interactive and instructive dialogue. The papers in this issue are a
good selection of the topics discussed at the colloquium."
    Ongoing debate over the causes of mass extinction events millions of
years ago led to the innovative concept of the impact cratering kill
curve and an understanding of how impact events may affect evolution and
environmental changes on Earth. David A. Kring, Ph.D., Associate
Professor in the Department of Planetary Sciences, University of
Arizona, Tucson, in a paper entitled, "Environmental Consequences of
Impact Cratering Events as a Function of Ambient Conditions on Earth,"
contends that while the size of the impacting object and the energy of
the blast are important in determining the outcome of the impact event,
the environmental conditions and type of ecosystems in existence at the
time of the impact may play an equally important role.
    "Kring's paper represents an important contribution to the field,
presents a valuable review of the environmental effects of impact
cratering events, and provides an outline for future studies that are
essential for applying the impact cratering kill curve theory to past
impact events and for understanding its implications for the future,"
says journal editor, Sherry L. Cady, Ph.D., Assistant Professor in the
Department of Geology at Portland State University.
    Using a climate model to determine the consequences of a meteor
impact on Earth, Elisabetta Pierazzo, Ph.D., Research Scientist at the
Planetary Science Institute and colleagues from the University of
Arizona in Tucson, and the University of California, Santa Cruz,
concluded that although the Chicxulub impact event of 65 million years
ago caused a relatively large disruption to the Earth's atmosphere, it
was not great enough to have a long-term effect on the Earth's climate.
    Donald Lowe, Ph.D., Professor of Geological and Environmental
Sciences at Stanford University, and colleagues from Stanford, Louisiana
State University, and the University of California at Los Angeles, San
Diego, and Berkeley, describe sand-sized particles found in rock beds in
South Africa that were formed as a result of large meteorite impacts
millions of years ago. Exploration of these rock layers will help
researchers understand the effects of impact events on early evolution
of life and on the formation and composition of the Earth's crust, ocean
floor, and atmosphere.
    Astrobiology is an authoritative peer-reviewed journal published
quarterly in print and online. The journal provides a forum for
scientists seeking to advance our understanding of life's origins,
evolution, distribution and destiny in the universe. A complete table of
contents and a full text for this issue may be viewed online at
www.liebertpub.com/AST <http://www.liebertpub.com/AST>.
    Mary Ann Liebert, Inc., is a privately held, fully integrated media
company known for establishing authoritative peer-reviewed journals in
many promising areas of science and biomedical research. Its
biotechnology trade magazine, Genetic Engineering News (GEN), was the
first in its field and is today the industry's most widely read
publication worldwide. A complete list of the firm's 60 journals, books,
and newsletters is available at www.liebertpub.com
<http://www.liebertpub.com>.

    CONTACT: Mary Ann Liebert, Inc., Larchmont
             Vicki Cohn, 914/834-3100 ext. 617
             vcohn_at_liebertpub.com <mailto:vcohn@liebertpub.com>
Received on Thu 08 May 2003 05:13:22 PM PDT