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HMB Endeavour Teacher

Edmond Halley pointed out the feasibility of using transits for measuring the distance from the Earth to the

A of is observation party and the equipment. Telescope will be aimed at the moon one of the rarest of all Cook and his crew were set to to detect dips in brightness” during astronomical events. observe Venus gliding across the face the Transit. “We’ll get an idea what It occurs when the of the sun, and by so doing measure earth-size will look like …and we’d ‘Never perhaps in orbit of the planet the size of the solar system, one of actually be able to measure the Venus takes it between the Earth the chief puzzles of 18th century atmosphere of Venus …” the world’s history and the Sun. Transits occur in pairs science. If they failed every (www.transitofvenus.org/education/ne did morning dawn separated by 8 years, and then astronomer on earth would be dead w-discoveries) a gap of over 100 years. Only 7 before the next opportunity in 1874. Australia is one of the best places to on so many waiting transits have occurred since the On 3 June, 1769 they succeeded observe the 2012 Transit. In Sydney astronomers as it invention of the telescope around however, including documenting the it should be visible from 8.16am until th 1609. This generation is one of the ‘black drop’ effect for the first time 2.44pm EST. did on the 9 of few to witness two Transits of Venus, (see definition below). They then went When observing the Transit do not Fort Venus, Tahiti, from Journal of a Voyage December 1874.’ 2004 and 2012. The next will on to ‘discover’ Australia. look directly at the sun or through the to the South Seas, Sydney Parkinson, 1784 not occur until December 2117. telescope or finderscope. Instead use ANMM Collection NSW Government astronomer Black drop is “an optical effect that the telescope or binoculars to project Henry Chamberlain Russell Young English astronomer Rev disturbed many 18th- and 19th-century an image of the sun onto a white Jeremiah Horrocks was the first to astronomers trying to time the surface. Viewing the projected image predict and observe a Transit on 24 instants that Venus touched the edge is quite safe. November 1639. In his “Venus in sole of the Sun during a transit. A common visa” he notes “The chance of a manifestation was as a dark thread Some believe it is possible that clouded atmosphere caused me much joining the edges of the planet and somewhere out in distant space anxiety, for Jupiter and were the Sun.” ‘someone’ or ‘something’ may be in conjunction with the Sun almost at From Lomb, Nick 2011 : looking toward our star detecting two the same time as Venus… When the 1631 to the present, p.216 planets, Venus and Earth, passing in time of the observation approached… front of the sun. What do you think? I directed my telescope … the Sun’s In 1874 the British mounted yet image exactly filled the circle, and another expedition to the Pacific to I watched carefully and unceasingly observe the Transit – this time to for any dark body that might enter Hawaii –while astronomers in Australia upon the disk of light.” were on the lookout at the Venus Veneris, in pursuit Observatories in both Sydney and followed her source from the In 1716 Edmond Halley pointed out Melbourne. NSW Government sea. Translucent in the The Transit of Venus – operating with the feasibility of using transits for astronomer Henry Chamberlain protoplasmic light, she touched the photo-heliograph at the Melbourne Cook’s and Green’s drawings of the 1769 transit from Philosophical Transactions measuring the distance from the Russell wrote: “Never perhaps in the a limb of the sun, pressed, Observatory, December 1874 of the Royal Society, 61 : 410 , 1771 Earth to the Sun, and suggested world’s history did morning dawn on And entering her crescent within Courtesy State Library of Victoria a method of observation. Sadly so many waiting astronomers as it did the yolk-sac, was visible. Her th he did not live to be part of it himself. on the 9 of December 1874.” In mirror-back Appeared like she addition to Sydney Observatory, seed in the plexus of reciprocal Further References The next recorded observation was in Russell organised three observing radiance until After noon when www.transitofvenus.org 1761 during the Seven Years War, stations at Woodford in the Blue centred in fluid ectoplasm of http://science.nasa.gov/science- and was one of the first times the Mountains, Eden and Goulburn, all solar light, Face to face made a news international community cooperated staffed by leading scientists. Used in conjugation. Objectively, the www.venus- to try and answer one of the leading conjunction with other Commonwealth spectacle conveyed itself along transit.de/1639/horrox.htm scientific questions of the day. observations a modern value for the a line of sight Until expelled by www.sydneyobservatory.com.au/e Unfortunately the weather did not Sun’s distance from earth was the descending sun. The ducation/transit-of-venus cooperate as well. determined. By the 1882 transit witnesses engaged an www.astronomy.org.au interest had waned, and bad weather intellectual passion Moving like www.exploratorium.edu./venus Eight years later came the most also hampered observations. verse (the turn of a plough; a www.transitofvenus.com.au celebrated historical viewing – that by line of words) In the infinite Lomb, Nick 2011 Transit of Captain James Cook and astronomer On June 8, 2004, Venus crossed the aspect of perspective…” Venus : 1631 to the present

Charles Green, who travelled to Tahiti face of the Sun again. The event was From ‘A Transit of Venus: poems of ANMM Signals Magazine, aboard HMB Endeavour, sponsored by recorded as a web cast, broadcast Courtesy NASA website passage’ by Alex Galloway (p.5) Number 66, March- May 2004, England’s Royal Academy. Arriving six live, and targeted by innumerable pp12-13 (http://eclipse.gsfc.nasa.gov/OH/tran/TOV2012-Fig01.pdf) weeks ahead of the expected date, telescopes and organisations around Cook set up Fort Venus to house the the globe. In 2012 “the Hubble Space © National Maritime Museum 2012