Nav: Home

Proof that ancient supernovae zapped Earth sparks hunt for after effects

April 06, 2016

LAWRENCE -- Two new papers appearing in the journal Nature this week are "slam-dunk" evidence that energies from supernovae have buffeted our planet, according to astrophysicist Adrian Melott of the University of Kansas.

Melott offers his judgment of these studies in an associated letter, entitled "Supernovae in the neighborhood," also appearing this week in Nature.

One paper, authored by Anton Wallner and colleagues, proves the existence of ancient seabed deposits of iron-60 isotopes, tracing their source to supernovae occurring about 325 light years from Earth. The second paper, by a team headed by Deiter Breitschwerdt, estimates explosion times of these supernovae, isolating two events: one 1.7 to 3.2 million years ago, and the other 6.5 to 8.7 million years ago.

"This research essentially proves that certain events happened in the not-too-distant past," said Melott, a KU professor of physics and astronomy. "They make it clear approximately when they happened and how far away they were. Knowing that, we can consider what the effect may have been with definite numbers. Then we can look for events in the history of the Earth that might be connected to them."

Melott said both supernovae events were beyond the "kill zone" of roughly 30 light years, but they might have had other impacts -- including influence on human evolution.

"Our local research group is working on figuring out what the effects were likely to have been," he said. "We really don't know. The events weren't close enough to cause a big mass extinction or severe effects, but not so far away that we can ignore them either. We're trying to decide if we should expect to have seen any effects on the ground on the Earth."

A major colloquium, entitled "When Stars Attack! Near-Earth Supernovae Explosions Threat and Evidence," is intended to further discussion of the new evidence. A free public lecture by astrophysicist Brian Fields of the University of Illinois will take place at 7:30 p.m. April 18 at Woodruff Auditorium in the Kansas Union.

Melott said Fields originally conceived of using iron-60 as a telltale isotope to expose historical episodes of neighborhood supernovae.

"In the 1990s he did the calculations and carried it forward," stated Melott. "He said, 'Hey, look for iron-60. This is a way to find out if there have been supernova near the Earth.' Five years later came the first indications of supernovae using iron-60. Now, 20 years later, we've got a slam-dunk. So Fields is the one that really got all this going, and it's just a really nice coincidence that's he's coming to KU just as these papers are coming out."
-end-


University of Kansas

Related Supernovae Articles:

Scientists observe year-long plateaus in decline of type Ia supernova light curves
A team of scientists, including a researcher from Queen's University Belfast, have discovered that the fading of infrared light following Type Ia supernovae explosions can be interrupted, with brightness staying the same for up to a year.
Hubble sets sights on an explosive galaxy
When massive stars die at the end of their short lives, they light up the cosmos with bright, explosive bursts of light and material known as supernovae.
Subaru Telescope captures 1800 exploding stars
The Subaru Telescope has captured images of more than 1800 exploding stars in the Universe, some located 8 billion light years from Earth.
Researchers wonder if ancient supernovae prompted human ancestors to walk upright
Supernovae bombarded Earth with cosmic energy starting as many as 8 million years ago, with a peak some 2.6 million years ago, initiating an avalanche of electrons in the lower atmosphere and setting off a chain of events that feasibly ended with bipedal hominins.
Stars exploding as supernovae lose their mass to companion stars during their lives
Stars over eight times more massive than the sun end their lives in supernovae explosions.
More Supernovae News and Supernovae Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Erasing The Stigma
Many of us either cope with mental illness or know someone who does. But we still have a hard time talking about it. This hour, TED speakers explore ways to push past — and even erase — the stigma. Guests include musician and comedian Jordan Raskopoulos, neuroscientist and psychiatrist Thomas Insel, psychiatrist Dixon Chibanda, anxiety and depression researcher Olivia Remes, and entrepreneur Sangu Delle.
Now Playing: Science for the People

#537 Science Journalism, Hold the Hype
Everyone's seen a piece of science getting over-exaggerated in the media. Most people would be quick to blame journalists and big media for getting in wrong. In many cases, you'd be right. But there's other sources of hype in science journalism. and one of them can be found in the humble, and little-known press release. We're talking with Chris Chambers about doing science about science journalism, and where the hype creeps in. Related links: The association between exaggeration in health related science news and academic press releases: retrospective observational study Claims of causality in health news: a randomised trial This...