Comet Halley in the 5th century BC

10 Sep 2010

At www.decodingtheheavens.com/blog/post/2010/09/08/Halley-and-the-ancient-Greeks/ (see also BBC News September 10th) ... in 466BC a large meteortie, described as the size of a wagon load, fell in northern Greece. Plutarch later said that for 75 days previous to the fall a huge fiery body was visible in the sky - like a reddened cloud that moved with complex and branching motions so that fiery fragments from it flowed in various directions and they flashed like shooting stars. It is now being suggested this was an account of Comet Halley - an earlier sighting than the Chinese one of 240BC. They used a model to reconstruct the exact path Halley might take and then compared that with other ancient records - for example that the comet was in the western sky when the meteorite fell. The comet would have been visible for 82 days in 466 and in July/ August the earth was moving in a position under the tail of the comet so the shooting stars could be debris from that zone. However, the origin of the meteorite itself is less sure. The comet might have nudged a Near Earth Object from its course and sent it on a collision course with the earth.

At www.physorg.com/print203177148.html NASAs Deep Impact spacecraft is now taking pictures of its next quarry, Comet Hartley 2. It will reach the comet in early November and will spend two months looking at it with digital colour cameras and an infrared spectrometer.