A partial solar eclipse as seen on the horizon.
Posted on 06/01/2002 11:09:39 PM PDT by green team 1999
Solar Eclipse June 10 over North America
By Joe Rao
Special to SPACE.com
posted: 07:00 am ET
20 May 2002
A partial solar eclipse as seen on the horizon.
One of Nature's most interesting sky shows, an eclipse of the Sun, will be visible to most North Americans on Monday, June 10, weather permitting.
For most locations within the western and mountain time zones, the entire eclipse will be visible from start-to-finish, beginning in late afternoon. In central and eastern time zones, however, it will be interrupted by sunset. Some residents along the Eastern Seaboard will miss out entirely, since the Sun will set before the eclipse gets underway.
The event will not be a total eclipse, but interesting nonetheless, astronomers say.
"Observers along a line from Houston, St. Louis, Chicago and Detroit, will witness maximum eclipse just about the same time that the Sun sets," says Fred Espenak, a NASA astrophysicist and widely recognized eclipse expert. "In fact, the eclipse will still be in progress from much of the central and southern U.S. during sunset, making for a memorable sight."
How it will work
The narrow path of an annular eclipse of the Sun will streak across the Pacific Ocean. In this type of eclipse, the Moon is far away enough away from the Earth so that it appears slightly smaller than the Sun and does not block the Sun entirely.
When the Moon's center coincides with the Sun's center, a thin ring of the Sun, called an annulus, briefly becomes visible. This ring effect will be seen only from a few fortuitously placed Indonesian Islands near the beginning of the eclipse track, and a small region along the Pacific coast of Mexico, not far from Puerto Vallarta, near the very end of the track.
"Such opportunities enable us to glimpse the clockwork of the universe in action," Espenak has said.
For much of North America, the event will be termed a partial eclipse, in which the Moon appears to take a bite out of a portion of the Sun.
From the Hawaiian Islands, where the track of the annular eclipse passes far to the north, about half of the Sun will appear to be covered during the early afternoon hours. From the contiguous United States, the most favored viewing locations will be over southern California and southern Arizona, where the Moon will appear to hide at least three-quarters of the Sun's diameter at maximum eclipse, and where an eerie "counterfeit twilight" may briefly fall.
Places farther to the north and east will see progressively less of the Sun obscured by the Moon.
Important caution
When watching a solar eclipse, special precautions must be taken in observing the partially eclipsed but still blindingly bright Sun. It is a popular misconception the eclipse itself makes the Sun dangerous to observe. It is in fact the Sun that is dangerous.
Do not look at the Sun.
Staring directly at the Sun, even during an eclipse, can cause permanent damage to your eyesight. Nor should you look directly at the Sun through any optical device not specifically designed for the task.
There are a several types of safe filters designed for Sun viewing, although by far the safest way to watch the eclipse is indirectly by projecting the Sun's image through some device and onto a wall or ceiling. Various methods include using a simple hole punched in cardboard or, for an enlarged view, projecting through binoculars or a telescope onto a shaded wall.
Where the action is
Annular solar eclipses are most interesting to specialists involved in the motions of the Earth and the Moon. This event, however, is expected to attract amateur astronomers and eclipse chasers in droves to the Pacific Coast of Mexico, approximately 20 miles to the south of Puerto Vallarta.
Those who properly position themselves within the path of the annular eclipse will bear witness to a spectacular sight: the Sun becoming briefly transformed, for just over a minute, into a thin, blazing ring of fire hovering just above the western horizon.
The next solar eclipse visible across this much of North America will occur in 2012.
for information and discusion only,not for profit etc,etc.
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Exposed color film.
Color film negatives (I don't care how many layers - still unsafe!)
Cheap "solar screen" mylar filters - they may have a pinhole or scratched coating!
Sunglasses. Even two pair of "crossed polaroids" will do nothing to protect your sensitive sight.
Binoculars or telescope without the proper filters. Of course not! They may be safe during TOTALITY, but ONLY THEN. NEVER point them toward a partial solar eclipse!
Squinting won't do, either. Neither will peering through your fingers.
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Welder's goggles of density 14 or greater. Inexpensive, works well.
Special "eclipse glasses", sold by REPUTABLE companies and rated at optical density 5.0 or greater! Check them carefully for pinholes/scratches!!!
A good quality solar filter (at least optical density 5.0 or greater). Check it for pinholes or scratches by observing the filament of a brightly-lit lightbulb first. I still recommend you use these very sparingly, though.
You can expose TRUE black-and-white film (like Kodak Tech Pan) to bright sun, and use the developed negatives in 2 layers for safe viewing of the sun. But unless you're a professional photographer, you probably don't have easy access to this method. Use another one.
Safest of all methods is an indirect one: The pinhole projector. Various types exist, but basically you need 2 pieces of cardboard. Use a very small needle to punch a TINY hole in one piece. Hold that piece in front of the other cardboard, while FACING AWAY from the sun, and move it until the sun's light passes through the pinhole and onto the other cardboard. A small inverted image of the sun (eclipse bite and all) will be projected on the 2nd piece of cardboard. NEVER use the pinhole to directly look at the sun!
WRONG. The sun emits energy over the entire electromagnetic spectrum, from radio waves to gamma rays. You might be comfortable looking at the sun through that insufficient filter, but your eyes are being bombarded with ultraviolet and infrared rays you don't see, and may not be filtering. These both will do irreparable damage. It may not be apparent immediately, but the damage is there.
AND of course enjoy the eclipse!
On the other hand, "been there, done that".
AKA "voice of experience". :-)
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