Six billion people would die if a massive star exploded, sending ultraviolet light through the earth’s atmosphere and blackening the sky. Scientists from the University of Kansas will explore that possibility tonight in a program on the History Channel.
The show is part of a series called “Mega Disasters” in which scientists consider the effects of large, hypothetical disasters. Tonight’s episode will focus on what might happen if one of these exploding stars, called a gamma-ray burst, hit Earth today. The scientists believe that gamma-ray bursts may have been responsible for past mass extinctions on Earth.
“There would be a flash of light that might be enough to blind some people,” Melott said. “Many people would experience rapid sunburn.”
“There was a sudden, unexplained ice age,” said Adrian Melott, professor of physics and astronomy. “This idea of gamma-ray bursts may explain that.”
Bruce Lieberman, professor of geology senior curator of invertebrate paleontology at the University’s Natural History Museum, will be featured in tonight’s episode. He said a gamma-ray burst could have caused the extinction in the Ordovician Period 450 million years ago that eliminated more than 100 families of marine life.
The program also features Brian Thomas, who earned his doctorate in physics at the University in 2005.
“The chances of another extinction caused by a gamma-ray burst are not high anytime soon,” Thomas said. “We estimate a dangerously close one may occur every billion years or so. If it is the case that a GRB caused the late Ordovician extinction, then we wouldn’t expect one for another 500 million years or so.”
If a gamma-ray burst were to hit Earth today, a narrow jet of radiation would strip the planet of its ozone layer. Chemical smog would block the sun, turning the sky black.
“There would be a flash of light that might be enough to blind some people,” Melott said. “Many people would experience rapid sunburn.”
Melott said the smog would darken the sky for five to ten years. During this time, it would be impossible to grow any crops.
“Basically, the biggest effect would be starvation,” Melott said. “A large fraction of the population would starve.”
The researchers estimate that only five to ten percent of the world’s population would be able to survive the initial effects.
“Technology may provide a way out from that for some of the population, but large numbers of deaths would be inevitable,” Thomas said.
Mikhail Medvedev, associate professor of physics and astronomy, remains optimistic.
“We are protected by the atmosphere, which shields us from gamma-rays,” he said. “Gamma-rays themselves do not penetrate through the atmosphere and, hence, do not affect us. I think we can survive.”
The “Mega Disasters” episode airs at 9 tonight on the History Channel. It will re-air several times this month.
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