Venus Rising

Venus rising to enjoy a rare day in the sun


ON Wednesday morning skywatchers will don eclipse glasses, put filters on backyard telescopes and head out to nearby observatories to watch one of the rarest events on the cosmic calendar: the transit of Venus.

While the transit follows close on the heels of a 2004 transit, Venus won't pass across the face of the sun again until December 2117. "Transits of Venus are more rare than Halley's Comet, which appears every 75 to 76 years," said Michael Drinkwater, head of astrophysics at the University of Queensland.

Unlike a total solar eclipse, the sun is not obliterated. Instead Venus will appear as a dot slowly moving across the top of the sun. Australia is one of the best places to witness the transit, as the entire event will be visible from eastern and central parts of the continent.

Only six transits have been observed by Western scientists: 1639, 1761, 1769, 1882 and 2004. The early transits were of great interest to scientists who observed them from different parts of the world in order to triangulate the distance from Earth to the sun.