Halley’s Comet reaches the closest point to earth

Halley's Comet is named after the astronomer Edmund Halley, who in 1705 calculated the orbit of the comet around the sun. Halley was also the first astronomer to suggest that comets are naturally occurring phenomena in the solar system. Traditionally comets are seen as portents or signs that tragic events are about to occur. Halley's Comet has been known since 240 and the last sighting of this comet was in 1986.  The earliest sightings have been mentioned in Chinese documents pertaining to astronomy from this period. On 20 May 1910, the comet passed its closest point to earth, when it passed within 22 million kilometres of earth. References: Halley's Comet (online), available at: http://www.solarviews.com[Accessed 10 May 2010] Halley's Comet (online), available at: http://windows2universe.org[Accessed 10 May 2010] 1P/Halley (online), available at: http://cometography.com[Accessed 10 May 2010] Shoemaker-Levy 9 (online), available at: http://en.wikipedia.org Accessed 10 May 2010]