By Blaine P. Friedlander Jr. Special to The Washington Post
Wednesday, June 2, 2004; Page B08
There's a little black spot on the sun June 8.
From our earthly perspective, the planet Venus crosses the sun for the first time since 1882, and the event will be visible at sunrise in the Washington area. This solar crossing, or transit, is among the rarest of astronomical events.
The eastern half of North America gets to see the final portion of the transit, while Europe, Asia and Africa get a longer, better view.
Washingtonians can see the transit after sunrise, which is at 5:43 a.m., according to the U.S. Naval Observatory. Venus will be in the latter stage of the transit by that time. By 7:06 a.m., Venus will be exiting the sun's edge, and the event will be over by 7:26 a.m.
Because Venusian transits happen in pairs because of celestial mechanics -- albeit eight years apart -- the second transit in this set will be June 6, 2012. If you miss it, the next set will be Dec. 11, 2117, and Dec. 8, 2125.
Never look at the sun directly with the naked eye, or do something foolish such as use smoked glass or sunglasses -- you could go blind. Instead, for safety's sake, project the image through a telescope or binoculars onto white paper or poster board. (Never view the sun directly through the lens of a telescope or the lenses of binoculars, as this will increase the sun's intensity and blind you.) The pinhole-in-cardboard technique, popular for viewing solar eclipses, works for transits as well.
Through his research, astronomer Sten Odenwald of NASA's Sun-Earth Connection Education Forum has discovered that John Philip Sousa wrote the "Transit of Venus March" after the 1882 event. The Smithsonian Institution commissioned Sousa to write a march for the dedication of the Joseph Henry statue. (Henry, a scientist, was the institution's first director.) It was first performed April 19, 1883, and a modern recording by the Virginia Grand Military Band can be heard at a Library of Congress Web site, lcweb2.loc.gov/cocoon/ihas/html/venus/venus-home.html.
What happens when you mix astronomy and entomology? You get another rare event. Even more infrequent than the transit of Venus is a simultaneous visit by Brood X (17-year) cicadas. Odenwald calculated that the last time these cicadas emerged concurrently with a Venus transit was May 22, 797, and the time before that was May 23, 921 BC.
If you want to get up early and watch safely, the local events for June 8 transit will include: