Venus about to put on a show

By David Momphard  /  STAFF REPORTER

Fri, Jun 04, 2004 - Page 18

The planets will align next Tuesday, treating stargazers to a rare spectacle when Venus passes across the face of the sun, a planetary phenomenon known as a Venus transit. While visible in roughly half the world, it will be seen in Taiwan only during the early hours of the evening.

Venus transits occur at intervals of 105.5 years, eight years, 121.5 years and eight years again. The last transit was on Dec. 6, 1882 and inspired governments around the world to dispatch expeditions bent on answering the most pressing scientific question of the day: What is the exact distance between the sun and Earth?

While the expeditions failed to arrive at the exact distance between earth and sun, scientists eventually used radar signals in the 1960s to arrive at the figure now taught to schoolchildren everywhere: 149,597,954km.

Meanwhile, those of us peering west between 5pm and sunset on Tuesday will see Venus as a black dot moving slowly left to right across the sun's southern hemisphere. Despite the fact that Venus will be much closer to the Earth than it is to the sun, its diameter will be only one thirty-second of the sun's.

Looking at the sun without protecting your eyes is, of course, idiotic. Scientists suggest the safest method is to project an image of the sun onto a piece of white paper using a telescope or binoculars.

If you miss the transit this year for whatever reason (cloudy weather?), don't despair; you'll have another chance come June 6, 2012. Mark your calendars.