Gamma-ray burst blasted Earth - study

2013-01-21 09:10
(Nasa, AP)

(Nasa, AP)

Multimedia   ·   User Galleries   ·   News in Pictures Send us your pictures  ·  Send us your stories

kalahari.com

Paris - A mystery wave of cosmic radiation that smashed into Earth in the eighth century may have come from two black holes that collided, a study published on Monday says.

Clues for the strange event were unearthed last year by Japanese astrophysicist Fusa Miyake, who discovered a surge in carbon-14 - an isotope that derives from high-energy radiation - in the rings of ancient cedar trees.

Dating of the trees showed that the burst struck the Earth in either 774 or 775 AD.

But what was the nature of the radiation, and what caused it?

Space scientists lined up the usual suspects only to let them go. There was no evidence that an exploding star, also called a supernova, occurred at that time, they found.

The Anglo-Saxon Chronicle, a record in Old English, makes a dramatic reference to the appearance of a "red crucifix" seen in the skies after sunset. But that happened in 776 AD, which was too late to tally with the event marked by the tree rings.

Also ruled out was a tantrum by the Sun, which can throw out sizzling cosmic rays or gouts of energy called solar flares.

Black holes

Writing in Monthly Notices, a journal of Britain's Royal Astronomical Society, German-based scientists Valeri Hambaryan and Ralph Neuhaeuser have come up with a new explanation.

The pair suggest that two black holes collided and then merged, releasing an intense but extremely brief burst of gamma rays.

A collision of neutron stars or "white dwarf" stars (tiny, compact stars near the end of their lives) may also have been the cause, say Hambaryan and Neuhaeuser of the University of Jena's Astrophysics Institute.

Mergers of this kind are often spotted in galaxies other than our own Milky Way, and do not generate visible light.

The event in 774 or 775 AD could only have taken place at least 3 000 light years from here, otherwise the planet would have fried, says the paper.

If their theory is right, this would explain why there is no record of some ultra-brilliant event in the sky, or evidence of any extinction event in Earth's biodiversity at that time.

Future risk

Astronomers should scour the skies because invisible remnants of the event could well exist today, the paper suggests.

And estimating the risk from a future collision of this kind could be vital.

"If the gamma ray burst had been much closer to the Earth it would have caused significant harm to the biosphere," explains Neuhaeuser.

"But even thousands of light years away, a similar event today could cause havoc with the sensitive electronic systems that advanced societies have come to depend on. The challenge now is to establish how rare such carbon-14 spikes are, or rather how often such radiation bursts hit the Earth.

"In the last 3 000 years, the maximum age of trees alive today, only one such event appears to have taken place."

Read more on:    space  |  research
NEXT ON NEWS24X

Read News24’s Comments Policy

24.com publishes all comments posted on articles provided that they adhere to our Comments Policy. Should you wish to report a comment for editorial review, please do so by clicking the 'Report Comment' button to the right of each comment.

Comment on this story
18 comments
Add your comment
Comment 0 characters remaining
 

Inside News24

 
 
Traffic
Lottery
 
  • Wednesday Salt River - 16:45 PM
    Road name: Victoria Road
    TRAFFIC LIGHTS not working at Durham Avenue
  • Wednesday Cape Town - 16:36 PM
    Road name: De Waal Drive Outbound
    DELAYS between Roeland Street and Hospital Bend
 
More traffic reports...
 

Jobs in Cape Town [change area]

Property [change area]

Travel - Look, Book, Go!

Escape winter, head to Mauritius

Escape winter by spending 7 nights in Mauritius' tropical bliss from R13 215 per person sharing. Includes return flights, airport transfers and accommodation. Book now!

Kalahari.com - shop online today

Get many eggs in one basket!

Gaming bundles: 2 Super Hits games for R99, 3 Disney games for R99 and more + exclusive accessory bundles only available on kalahari.com. While stocks last. Shop now!

25% off bestselling books!

The Real Meal Revolution by Tim Noakes, Jeffrey Archer’s Be Careful What You Wish for, Man’s Search for Meaning by Victor E. Frank and many more titles. Shop now!

Up to 25% off electronics

Buy top electronics and save up to 25%. Such as kalahari.com’s 1# selling product the gobii eReader, Patriot X Porter flash drive, Asus Nexus 7” 3G tablet, Samsung Galaxy SIII, Lenovo G580 Notebook and many more. Shop now!

DStv HD PVR Decoder now R949

The DStv HD PVR Decoder has further revolutionised the television experience with lifelike viewing, sharper images, more vibrant colours and precision picture quality. Now R949, save R550. Offer valid while stocks last. Shop now!

Up to 30% off appliances & homeware

Save up to 30% on appliances and homeware this Easter! Offer valid while stocks last. Shop now.

OLX Free Classifieds [change area]

Samsung Galaxy s4

Mobile, Cell Phones in South Africa, Western Cape, Cape Town. Date October 24

Best bargain in big bay

Real Estate, Houses - Apartments for Sale in South Africa, Western Cape, Cape Town. Date October 25

VW Golf 6, 1.6 Trendline (Excellent condition)

Vehicles, Cars in South Africa, Western Cape, Cape Town. Date October 25

BlackBerry Curve 9360

The BlackBerry Curve 9360 smartphone comes preloaded with Blackberry OS7...

From R1595.00

I'm shopping for:

Horoscopes
Aquarius
Aquarius

You may find yourself fascinated by something which could draw you in to obsessively exploring this subject in depth....read more

There are new stories on the homepage. Click here to see them.
 
English
Afrikaans
isiZulu

Hello 

Create Profile

Creating your profile will enable you to submit photos and stories to get published on News24.


Please provide a username for your profile page:

This username must be unique, cannot be edited and will be used in the URL to your profile page across the entire 24.com network.

Settings

Location Settings

News24 allows you to edit the display of certain components based on a location. If you wish to personalise the page based on your preferences, please select a location for each component and click "Submit" in order for the changes to take affect.








Facebook Sign-In

Hi News addict,

Join the News24 Community to be involved in breaking the news.

Log in with Facebook to comment and personalise news, weather and listings.