Craterização de impacto periódica e eventos de extinção ao longo dos últimos 260 milhões de anos

quinta-feira, outubro 22, 2015

Periodic impact cratering and extinction events over the last 260 million years

Michael R. Rampino 1,2,3,★ and Ken Caldeira 4

1Department of Biology, New York University, New York, NY 10003, USA

2Department of Environmental Studies, New York University, New York, NY 10003, USA

3NASA, Goddard Institute for Space Studies, 2880 Broadway, New York, NY 10025, USA

4Carnegie Institution for Science, Department of Global Ecology, 260 Panama Street, Stanford, CA 94305, USA

↵★E-mail: mrr1{at}

Accepted 2015 September 4. Received 2015 September 4.

In original form 2015 June 15. First published online October 20, 2015.

Source/Fonte: NASA

The claims of periodicity in impact cratering and biological extinction events are controversial. A newly revised record of dated impact craters has been analyzed for periodicity, and compared with the record of extinctions over the past 260 Myr. A digital circular spectral analysis of 37 crater ages (ranging in age from 15 to 254 Myr ago) yielded evidence for a significant 25.8 ± 0.6 Myr cycle. Using the same method, we found a significant 27.0 ± 0.7 Myr cycle in the dates of the eight recognized marine extinction events over the same period. The cycles detected in impacts and extinctions have a similar phase. The impact crater dataset shows 11 apparent peaks in the last 260 Myr, at least 5 of which correlate closely with significant extinction peaks. These results suggest that the hypothesis of periodic impacts and extinction events is still viable.

Key words comets: general – Earth meteorites, meteors, meteoroids planets and satellites: surfaces

© 2015 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society