Gamma Ray Bursts May Have Caused Ancient Extinctions (2005)
2005 · Short film
Synopsis
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. Note: Regions of Earth susceptible to DNA damage are shown in red. Data Collected: 91 days before burst to 718 days after burst. Animator: Greg Shirah (NASA/GSFC). Scientist: Brian Thomas (Univerisy of Kansas), Daniel Hogan (University of Kansas), Adrian Melott…
Uploader's description on archive.org
Details
- Collection
- NASA
Subjects on the Internet Archive
- Gamma Ray, DNA, Gamma Ray Burst