Today's transit of Venus is the last one any currently living human will see.
The Sun is involved - DO NOT VIEW DIRECTLY WITH THE NAKED EYE!
A transit of Venus is when, from our perspective, Venus appears to cross the disk of the sun. For a demonstration see the Venus Transit Simulator on the South Plains Astronomy Club's web site here: http://southplainsastronomy.org/
First contact (when it all begins) is at 5 PM. The transit will be in progress at sunset, 8:55 PM in Lubbock.
Transits of Venus are rare - on average one happens every 80 years or so. That is, however, only an average. Venus transits occur in a 'pair of pairs' pattern that repeats every 243 years. First, two transits take place in December, eight years apart. After 121.5 years two June transits occur, again eight years apart. Today's transit is the second of the June pair - the first was June 8, 2004. The prior December pair was in 1876 and 1882! The pattern repeats after 105.5 years.
Venus, Earth and the Sun actually line up about every 584 days, but the alignment is not perfect. Usually Venus is above or below the sun from Earth's vantage point; just as the Moon doesn't block out (eclipse) the sun every month, even when the Earth, Moon and Sun are roughly aligned (new moon). The perfect alignment of the Earth, Venus and the Sun (transit of Venus) has only occurred seven times since the telescope was invented in 1610!
It's never safe to look at the sun. You must use a device or indirect viewing method to observe the transit. Venus is large enough to be visible as a dot to someone with normal eyesight, without the help of binoculars or a telescope. For safe viewing the same rules apply as those for observing the recent eclipse of the Sun. Eclipse viewing glasses can be used, as long as they are undamaged and observing is limited to a few minutes at a time, but they must NOT be used with binoculars or a telescope. For an enlarged view an image of the Sun can be projected onto a screen by a small telescope. Pinhole projection, which works well for solar eclipses, will not produce a sharp enough image to show Venus clearly. But there is an easier way...
The South Plains Astronomy Club and the TTU Museum are sponsoring a viewing event at the front of the TTU Museum (4th and Indiana in Lubbock) from 5 pm to sunset. They will provide safe viewing of the transit as well as information about the transit, Sun, and Venus. If Lubbock's skies are cloudy - a distinct possibility - the event will be streamed from other locations.
You can also watch a LIVE stream of the Transit of Venus online at the University of Arizona's Mt. Lemmon SkyCenter web site.
Copyright 2012 KCBD. All rights reserved.