01 June 2012
KOKOMO, Ind. — The last chance for just about everybody living today to see a transit of Venus across the sun is Tuesday, June 5.
The next occurrence of this once-in-a-century event is 105 years away, so Indiana University Kokomo's Observatory wants to be sure nobody in north central Indiana misses it.
The Observatory, 105 E. Rebecca Lane, opens at 5 p.m. for solar viewing, with the transit expected to begin just after 6 p.m.
During this rare alignment, the planet Venus passes directly between the earth and sun, and is visible as a small dot gliding slowly across the sun's face. The entire event lasts about seven hours.
Patrick Motl, assistant professor of physics, will keep the observatory open until 10 p.m., so visitors may also view Saturn through the telescopes.
"We'll be able to watch the transit up to sunset, which will be close to mid-transit, with Venus halfway across the disc of the sun," Motl said.
A transit of Venus is rare, coming in pairs eight years apart, separated by 100 years. The last transit was in 2004. Motl said the next one isn't expected until 2117.
"I'm not so optimistic to plan on seeing that one," he said.
Astronomer and mathematician Johannes Kepler in 1627 was the first to predict that Venus would pass between Earth and the sun. In 1716, Edmund Halley, of Halley's Comet fame, determined it was possible to compute the distance of the earth from the sun during the transit.
By the time of the 1761 and 1769 transits, scientists calculated that distance at 95 million miles. In 1896, the international scientific community adopted Simon Newcomb's value, a distance from earth to sun of 92,702,000, plus or minus 53,700 miles.
Those who want to see the transit should take the usual precautions for viewing solar events. Viewers should never look directly at the sun, and never look at the sun with binoculars. Simple pinhole projectors may be created at home using instructions on the web. Instructions are available at solar.center.stanford.edu/observe/
Those who cannot attend can watch live feed of the transit of Venus from the Mauna Kea Observatory in Hawaii, at venustransit.nasa.gov/2012/transit/webcast.php
For more information about the transit of Venus, go to www.astro.indiana.edu/transit.shtml
The event is free and open to the public. Free parking is available.
Indiana University Kokomo serves north central Indiana.