Feeds

Scientists ID possible Tunguska crater

Was it a bird, a plane or a big sodding rock?

Intelligent flash storage arrays

The largest earth "impact" of recent times, the Tunguska event, might have left a crater after all. The impact levelled more than 2,000 square kilometres of forest in Siberia, but is thought to have been caused by an asteroid or comet exploding in Earth's atmosphere since no crater marking the impact has ever been found. Now researchers at the University of Bologna in Italy think they might have found a scar in the surface of the earth left by the 1908 astro-intrusion.

The team of researchers has identified a lake near the epicentre of the blast whose shape is consistent, they say, with an impact crater. They speculate that a small chunk of debris from the main explosion could have hit the ground, creating the hollow.

Lead researcher professor Giuseppe Longo says he concluded the lake was sitting in a crater by a process of elimination. He told BBC News: "We have no positive proof this is an impact crater, but we were able to exclude some other hypotheses, and this led us to our conclusion."

He says that the lake-bed's geology is unusual. It has a funnel shape that is unlike that of any of its neighbours. After probing the bottom with geophysics equipment, the team also discovered an anomalous feature about 10 metres down. They suggest this could be either compacted lake sediment, or debris left over from a piece of space junk.

But the scientific community is sceptical of professor Longo's hypothesis. Dr Gareth Collins, a research associate at Imperial College London, told the BBC: "The impact-cratering community does not accept structures as craters unless there is evidence of high temperatures and high pressures. That requires evidence of rocks that have been melted or rocks that have been ground up by the impact."

The Tunguska event took place on June 30, 1908. The blast, which had the energy of about 1,000 Hiroshima-sized nukes, was so bright it was even seen in the London skies. No debris from the explosion has ever been found, much less any traces of an impact.

Dr Collins says the lake Longo and his team have studied is not consistent with what we already know about Tunguska. The angle of impact is wrong, any fragments surviving the initial blast would be moving too slowly, and there are trees older than 100 years still standing near the lake, making it unlikely anything from space crashed nearby.

But the Bologna researchers are undeterred. They plan to return to the site and dig into the lake bed to find out whether or not what is buried below the surface once roamed the outer reaches of our solar system. ®

Providing a secure and efficient Helpdesk

More from The Register

next story
SECRET U.S. 'SPACE WARPLANE' set to return from SPY MISSION
Robot minishuttle X-37B returns after almost 2 years in orbit
LOHAN crash lands on CNN
Overflies Die Welt en route to lively US news vid
You can crunch it all you like, but the answer is NOT always in the data
Hear that, 'data journalists'? Our analytics prof holds forth
Experts brand LOHAN's squeaky-clean box
Phytosanitary treatment renders Vulture 2 crate fit for export
No sail: NASA spikes Sunjammer
'Solar sail' demonstrator project binned
Carry On Cosmonaut: Willful Child is a poor taste Star Trek parody
Cringeworthy, crude and crass jokes abound in Steven Erikson’s sci-fi debut
Origins of SEXUAL INTERCOURSE fished out of SCOTTISH LAKE
Fossil find proves it first happened 385 million years ago
Human spacecraft dodge COMET CHUNKS pelting off Mars
Odyssey orbiter yet to report, though - comet's trailing trash poses new threat
prev story

Whitepapers

Forging a new future with identity relationship management
Learn about ForgeRock's next generation IRM platform and how it is designed to empower CEOS's and enterprises to engage with consumers.
Cloud and hybrid-cloud data protection for VMware
Learn how quick and easy it is to configure backups and perform restores for VMware environments.
Three 1TB solid state scorchers up for grabs
Big SSDs can be expensive but think big and think free because you could be the lucky winner of one of three 1TB Samsung SSD 840 EVO drives that we’re giving away worth over £300 apiece.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.
Security for virtualized datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.