Gamma Ray Busrts and Ancient Extinctions

  • Credit

    NASA/Goddard Space Flight Center Scientific Visualization Studio

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.]

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

Metadata

  • Sensor

    No Satellite/ No Data

  • Animation ID

    3149

  • Video ID

    NONE

  • Start Timecode

    00:00:00:00

  • End Timecode

    00:00:00:00

  • Animator

    Greg Shirah

  • Studio

    SVS

  • Visualization Date

    2005/03/30

  • Scientist

    Brian Thomas (Univerisy of Kansas), Daniel Hogan (University of Kansas), Adrian Melott (Univerisy of Kansas), Charles Jackman (NASA/GSFC)

  • Datasets

    Model of DNA damage regions

  • Keywords

    DNA, gamma, burst

  • Data Date

    91 days before burst to 718 days after burst

  • Story URL

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

  • Animation Type

    Regular