Exploding Stars May Have Caused Mass Extinction on Earth

By UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN, NEWS BUREAU

Re-Blogged From WUWT

CHAMPAIGN, Ill. — Imagine reading by the light of an exploded star, brighter than a full moon – it might be fun to think about, but this scene is the prelude to a disaster when the radiation devastates life as we know it. Killer cosmic rays from nearby supernovae could be the culprit behind at least one mass extinction event, researchers said, and finding certain radioactive isotopes in Earth’s rock record could confirm this scenario.

A new study led by University of Illinois, Urbana-Champaign astronomy and physics professor Brian Fields explores the possibility that astronomical events were responsible for an extinction event 359 million years ago, at the boundary between the Devonian and Carboniferous periods.

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IMAGE: A TEAM OF RESEARCHERS LED BY PROFESSOR BRIAN FIELDS HYPOTHESIZES THAT A SUPERNOVA ABOUT 65 LIGHT-YEARS AWAY MAY HAVE CONTRIBUTED TO THE OZONE DEPLETION AND SUBSEQUENT MASS EXTINCTION OF THE… view more CREDIT: GRAPHIC COURTESY JESSE MILLER

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405 Thousand Year Climate Cycle Discovered Related to Earth’s Orbit Around the Sun

By Anthony Watts – Re-Blogged From http://www.WattsUpWithThat.com

In ancient rocks, scientists see a climate cycle working across deep time.

A repeating shift in Earth’s orbit spans hundreds of millions of years

From THE EARTH INSTITUTE AT COLUMBIA UNIVERSITY

Scientists drilling deep into ancient rocks in the Arizona desert say they have documented a gradual shift in Earth’s orbit that repeats regularly every 405,000 years, playing a role in natural climate swings. Astrophysicists have long hypothesized that the cycle exists based on calculations of celestial mechanics, but the authors of the new research have found the first verifiable physical evidence. They showed that the cycle has been stable for hundreds of millions of years, from before the rise of dinosaurs, and is still active today. The research may have implications not only for climate studies, but our understanding of the evolution of life on Earth, and the evolution of the Solar System. It appears this week in the Proceedings of the National Academy of Sciences.

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