Team makes Tunguska crater claim

[Rick]

Scientists have identified a possible crater left by the biggest space impact in modern times - the Tunguska event.

The blast levelled more than 2,000 sq km of forest near the Tunguska River in Siberia on 30 June 1908.

A comet or asteroid is thought to have exploded in the Earth's atmosphere with a force equal to 1,000 Hiroshima bombs.

More: http://news.bbc.co.uk/2/hi/science/nature/6239334.stm

[Rick]

At 7:17am on 30 June 1908, an immense explosion tore through the forest of central Siberia.

Some 80 million trees were flattened over an area of 2,000 square km (800 square miles) near the Tunguska River.

The blast was 1,000 times more powerful than the atomic bombs dropped on Hiroshima and Nagasaki and generated a shock wave that knocked people to the ground 60km from the epicentre.

The cause was an asteroid or comet just a few tens of metres across which detonated 5-10km above the ground, 100 years ago today.

More: http://news.bbc.co.uk/2/hi/science/nature/7470283.stm

[Rick]

There is new evidence in the debate regarding the 1908 Tunguska event that destroyed 80 million trees in Siberia.

Researchers say that clouds that form at the poles after shuttle launches are due to the turbulent transport of water from shuttle exhaust.

Similar clouds were visible at night long after the Tunguska event.

More: http://news.bbc.co.uk/1/hi/sci/tech/8119097.stm