Gamma Ray Bursts May Have Caused Ancient Extinctions

  • Released Wednesday, May 4, 2005
  • Updated Friday, January 16, 2015 at 12:46PM
  • ID: 3149
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.]

Regions of Earth susceptible to DNA damage are shown in red.

Regions susceptible to DNA damage before a Gamma Ray Burst

Regions susceptible to DNA damage before a Gamma Ray Burst

Regions susceptible to DNA damage just after a Gamma Ray Burst

Regions susceptible to DNA damage just after a Gamma Ray Burst

Regions susceptible to DNA damage about 9 months after a Gamma Ray Burst

Regions susceptible to DNA damage about 9 months after a Gamma Ray Burst

Color bar showing blue (0) to dark red (16.5) DNA Damage index

Color bar showing blue (0) to dark red (16.5) DNA Damage index

Color bar showing blue (0) to dark red (16.5) with alpha (transparent colorbar from 0 to 1)

Color bar showing blue (0) to dark red (16.5) with alpha (transparent colorbar from 0 to 1)

For More Information

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

Credits

Please give credit for this item to:
NASA/Goddard Space Flight Center Scientific Visualization Studio

Series

This visualization can be found in the following series:

Datasets used in this visualization

(Collected with the Airborne Topographic Mapper sensor)
See more visualizations using this data set
DNA damage (Collected with the DNA damage model sensor)
Model91 days before burst to 718 days after burst
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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.

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