Universe  ID: 3149

Gamma Ray Bursts May Have Caused Ancient Extinctions

Scientists at NASA the University of Kansas say that a mass extinction on Earth hundreds of millions of years ago could have been triggered by a star explosion called a gamma-ray burst. The scientists do not have direct evidence that such a burst activated the ancient extinction. The strength of their work is their atmospheric modeling — essentially a 'what if' scenario.

The scientists calculated that gamma-ray radiation from a relatively nearby star explosion, hitting the Earth for only ten seconds, could deplete up to half of the atmosphere's protective ozone layer. Recovery could take at least five years. With the ozone layer damaged, ultraviolet radiation from the Sun could kill much of the life on land and near the surface of oceans and lakes, and disrupt the food chain.

These scientists calculated the potential effect of ultraviolet radiation on life. Deep-sea creatures living several feet below water would be protected. Surface-dwelling plankton and other life near the surface, however, would not survive. Plankton is the foundation of the marine food chain.

This visualization shows the regions of the planet most susceptible to DNA damage (shown in red) if a large gamma ray burst were to occur close to Earth.

[This text is from the NASA web story on the subject. See the Story URL below.]


For More Information

http://www.nasa.gov/vision/universe/starsgalaxies/gammaray_extinction.html


Visualization Credits

Greg Shirah (NASA/GSFC): Lead Animator
Brian Thomas (Univerisy of Kansas): Scientist
Daniel Hogan (University of Kansas): Scientist
Adrian Melott (Univerisy of Kansas): Scientist
Charles Jackman (NASA/GSFC): Scientist
Please give credit for this item to:
NASA/Goddard Space Flight Center Scientific Visualization Studio

Short URL to share this page:
http://svs.gsfc.nasa.gov/3149

Data Used:
DNA damage model/DNA damage 91 days before burst to 718 days after burst
Airborne Topographic Mapper
Note: While we identify the data sets used in these visualizations, we do not store any further details nor the data sets themselves on our site.

This item is part of this series:
Astrophysics Stills

Keywords:
GCMD >> Earth Science >> Spectral/Engineering >> Gamma Ray
SVS >> DNA
SVS >> Gamma Ray Burst
NASA Science >> Universe

GCMD keywords can be found on the Internet with the following citation: Olsen, L.M., G. Major, K. Shein, J. Scialdone, S. Ritz, T. Stevens, M. Morahan, A. Aleman, R. Vogel, S. Leicester, H. Weir, M. Meaux, S. Grebas, C.Solomon, M. Holland, T. Northcutt, R. A. Restrepo, R. Bilodeau, 2013. NASA/Global Change Master Directory (GCMD) Earth Science Keywords. Version 8.0.0.0.0