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Friday, October 31

Grant to Study Terrestrial Impact of Nearby Supernovae

By Carol Best
April 14, 2014
Supernova Icon

Physics professor Andrew Overholt, PhD, learned last week that he and two colleagues will receive a $500,000 NASA Exobiology grant over three years to study the “Terrestrial Impact of Nearby Supernovae.” MNU’s portion of the grant is $150,000 which will be used to support the research, obtain additional computing equipment and fund a student research assistant.

“This is the kind of research we encourage our students to seek out over the summer at other research facilities,” Overholt says. “It is exciting to get to have it here at MNU for a top science student.”

Overholt conducts research with University of Kansas Professor Adrian Melott, PhD, and Brian Thomas, PhD, of Washburn University in a group they have named the KU Astrophysics Biology Working Group. The new research is in a relatively “untouched area” according to Overholt.Overholt-AndrewDr. Overholt

“No one has studied all of the effects there would be on Earth of a nearby supernova,” he says. “Nearby in this instance would be about 10 parsecs or 30 light years.”

A supernova occurs when large stars run out of fuel and collapse, this collapse then leads to a large explosion. Overholt says this happens very frequently because there are hundreds of billions of stars in our galaxy. But statistically they do not happen very close to Earth. A recent study shows that Earth has experienced a nearby supernova in the distant past.

Evidence of “supernova dust” was found in a mud core sample at the bottom of the ocean. Overholt says that a rare iron isotope found in this dust and eaten by bacteria was found in bacteria skeletons which were trapped in the sea floor. Scans of the mud core found the iron deposits proving the supernova dust was there.

Cosmic Rays

Overholt and his colleagues will each study separate aspects of supernova effects. Thomas will focus on atmospheric effects such as ozone depletion. Overholt will study cosmic ray secondaries, high energy pieces of matter that can cause radiation sickness and cancer. Melott will conduct models of the rays from their source before they reach the Earth. All of this research is done through computer modeling requiring data analysis by supercomputers such as the National Science Foundation’s TeraGrid, a cyberinfrastructure of high-performance computers at 11 locations nationwide.  

The colleagues hope to learn how bad a worst case scenario would be, if a nearby supernova is survivable, how close it could be and still be survivable as well as effects on other planets with thinner atmospheres (like Mars).

“This is an unanswered question,” Overholt says. “We know these happen and statistically they should happen near us, but no one really knows what would happen on Earth if there was a nearby supernova.”

The three-year study will be published based on results after peer review.