Asteroids In the News ...

Asteroid In the News ...

Meteorite hunters 'strike gold' in Nubian Desert Sudan New Scientist - March 26, 2009
Meteorites in Africa Traced to Asteroid "Parent" National Geographic - March 25, 2009 Almahata Sitta 15 NASA - March 28, 2009
... the first material recovered from a known asteroid.

Tunguska-sized space rock buzzes Earth New Scientist - March 2, 2009
Surprise Asteroid Buzzed Earth National Geographic - March 2, 2009

Strange Asteroid Shapes Explained Live Science - July 3, 2008

Record spin for newfound asteroid BBC - May 30, 2008

Sumerian Cuneiform Clay tablet translated - holds clue to asteroid impacts PhysOrg - March 31, 2008

The giant landslide centred at Köfels in Austria is 500m thick and five kilometres in diameter and has long been a mystery since geologists first looked at it in the 19th century. The conclusion drawn by research in the middle 20th century was that it must be due to a very large meteor impact because of the evidence of crushing pressures and explosions. But this view lost favour as a much better understanding of impact sites developed in the late 20th century. In the case of Köfels there is no crater, so to modern eyes it does not look as an impact site should look. However, the evidence that puzzled the earlier researchers remains unexplained by the view that it is just another landslide.

This new research by Alan Bond, Managing Director of Reaction Engines Ltd and Mark Hempsell, Senior Lecturer in Astronautics at Bristol University, brings the impact theory back into play. It centres on another 19th century mystery, a Cuneiform tablet in the British Museum collection No K8538 (known as "the Planisphere").

It was found by Henry Layard in the remains of the library in the Royal Place at Nineveh, and was made by an Assyrian scribe around 700 BC. It is an astronomical work as it has drawings of constellations on it and the text has known constellation names. It has attracted a lot of attention but in over a hundred years nobody has come up with a convincing explanation as to what it is.

With modern computer programmes that can simulate trajectories and reconstruct the night sky thousands of years ago the researchers have established what the Planisphere tablet refers to. It is a copy of the night notebook of a Sumerian astronomer as he records the events in the sky before dawn on the 29 June 3123 BC (Julian calendar). Half the tablet records planet positions and cloud cover, the same as any other night, but the other half of the tablet records an object large enough for its shape to be noted even though it is still in space. The astronomers made an accurate note of its trajectory relative to the stars, which to an error better than one degree is consistent with an impact at Köfels.

The observation suggests the asteroid is over a kilometre in diameter and the original orbit about the Sun was an Aten type, a class of asteroid that orbit close to the earth, that is resonant with the Earth's orbit. This trajectory explains why there is no crater at Köfels. The in coming angle was very low (six degrees) and means the asteroid clipped a mountain called Gamskogel above the town of Längenfeld, 11 kilometres from Köfels, and this caused the asteroid to explode before it reached its final impact point. As it travelled down the valley it became a fireball, around five kilometres in diameter (the size of the landslide). When it hit Köfels it created enormous pressures that pulverised the rock and caused the landslide but because it was no longer a solid object it did not create a classic impact crater.

Mark Hempsell, discussing the Köfels event, said: "Another conclusion can be made from the trajectory. The back plume from the explosion (the mushroom cloud) would be bent over the Mediterranean Sea re-entering the atmosphere over the Levant, Sinai, and Northern Egypt. "The ground heating though very short would be enough to ignite any flammable material - including human hair and clothes. It is probable more people died under the plume than in the Alps due to the impact blast."

The Enduring Mysteries of Comets Live Science - December 26, 2007

Asteroid Itokawa Jiggles Like a Jar of Mixed Nuts Space.com - April 20, 2007

Astronomers have caught their first glimpse of the innards of an icy asteroid ... New Scientist - March 15, 2007

Asteroids Spin Faster Due to Solar Power, Studies Show National Geographic - March 7, 2007

Corkscrew Asteroid NASA - June 13, 2006

Asteroid Probe Offers New Views of Near-Earth Object National Geographic - June 2, 2006
Unique asteroid's a ball of rubble News in Science - June 2, 2006

The Itokawa asteroid is made up of loosely packed bits of sand and boulders
25143 Itokawa Wikipedia

Relic of ancient asteroid found BBC - May 10, 2006

A large fragment of an asteroid that punched 160km-wide (100 miles) hole in the Earth's surface has been found.

Japanese Craft Takes Close-up Photos of Asteroid Space.com - September 16, 2005

Solar system's first triple asteroid system found New Scientist - August 10, 2005

Magma oceans sloshed across early asteroids New Scientist - June 15, 2005

Asteroid Belt Discovered Around Our Sun's "Twin" National Geographic - April 2005

How Collisions Shaped an Asteroid Space.com - December 2004

Pushing asteroids away from the Earth Astrobiology Magazine - November 2004

View video of Asteroid Toutatis closest approach to Earth Space.com - September 29, 2004

Ancient Impact Turned Part of Earth Inside-Out Space.com - June 2004

A space rock the size of a large mountain hit 1.8 billion years ago and dredged up part of Earth's lower crust, essentially turning a bit of the planet inside out.

New Object is 2nd Rock from the Sun Space.com - May 2004

Discovered - the second known asteroid whose orbit is completely inside that of Earth. It supplants Venus as the second rock from the Sun.

Space rock caused 'great dying' BBC - November 2003
Scientists have found new evidence that the greatest extinction in the Earth's history was triggered by an asteroid. About 250 million years ago, something unknown wiped out most of the life on the planet. It was far more devastating than the impact that ended the rule of the dinosaurs 65 million years ago.

Hermes: Asteroid found after 66 years lost in space BBC - October 2003

Astronomers have seen a large asteroid that they first found 66 years ago and then lost in the depths of space. It is called Hermes and it entered the record books by making a close approach to the Earth, just beyond the Moon.