May 20 2012 Annular Eclipse
Annular eclipse - A solar eclipse in which the Moon's antumbra shadow traverses Earth (the Moon is too far from Earth to completely cover the Sun). During the maximum phase of an annular eclipse, the Sun appears as a blindingly bright ring surrounding the Moon.
Antumbra - The antumbra is that part of the Moon's shadow that extends beyond the umbra. It is similar to the penumbra in that the Sun is only partially blocked by the Moon. From within the antumbra, the Sun appears larger than the Moon which is seen in complete silhouette. An annular eclipse is seen when an observer passes through the antumbra.
Central eclipse - A solar eclipse in which the central axis of the Moon’s shadow cone traverses Earth thereby producing a central line in the eclipse track. The umbra or antumbra falls entirely upon Earth so the ground track has both a northern and southern limit. Central solar eclipses can be either total, annular or hybrid.
Eye safety - The only time that the Sun can be viewed safely with the naked eye is during a total eclipse, when the Moon completely covers the disk of the Sun. It is never safe to look at a partial or annular eclipse, or the partial phases of a total solar eclipse, without the proper equipment and techniques. Even when 99% of the Sun's surface (the photosphere) is obscured during the partial phases of a solar eclipse, the remaining crescent Sun is still intense enough to cause permanent retinal damage, especially when viewed through binoculars or other optical aids.
eclipse.gsfc.nasa.gov/SEhelp/SEglossary.html#annular
The safest way to view the Sun's disk is by indirect projection. This can be done by projecting an image of the disk onto a white piece of paper or card using a pair of binoculars (with one of the lenses covered), a telescope, or another piece of cardboard with a small hole in it (about 1 mm diameter), often called a pinhole camera. The projected image of the Sun can then be safely viewed; this technique can be used to observe sunspots, as well as eclipses. Care must be taken, however, to ensure that no one looks through the projector (telescope, pinhole, etc.) directly. Viewing the Sun's disk on a video display screen (provided by a video camera or digital camera) is safe, although the camera itself may be damaged by direct exposure to the Sun. The optical viewfinders provided with some video and digital cameras are not safe. Securely mounting #14 welder's glass in front of the lens and viewfinder protects the equipment and makes viewing possible. Professional workmanship is essential because of the dire consequences any gaps or detaching mountings will have. In the partial eclipse path one will not be able to see the corona or nearly complete darkening of the sky, yet, depending on how much of the sun's disk is obscured, some darkening may be noticeable. If two-thirds or more of the sun is obscured, then an effect can be observed by which the daylight appears to be dim, as if the sky were overcast, yet objects still cast sharp shadows.
en.wikipedia.org/wiki/File:Ecl-ann.jpg
While the event is nine months away, we must start to prepare.
Questions
Do we buy solar eclipse glasses with our name logo and date?
Do we contact each local TV station or wait for them to come to us?
Do we contact the school district and have a professional development day for science teachers on Who, What, When, Where, and How?
Do we have a tech team to find out how to capture in print and video for the club and/or public?
Do we have a strike team if it is cloudy, go where the sun is?
