Thursday, May 10, 2012

Ring of Fire

An Annular Eclipse of the Sun

I'd like to take this opportunity to invite everyone to enjoy a pair of impressive celestial events over the next few weeks. I would think that anyone would be interested in these visible demonstrations of the movements of the bodies of our solar system, and that children especially will be fascinated.

First, a brief caveat...

WARNING: Never look directly at the Sun! The Sun's light, either seen with the naked eye or with optical magnification, can do permanent and irreparable damage to your eyes, including partial or permanent blindness. Observe the Sun--or any event involving the Sun--ONLY through properly filtered and operated instruments.

Ring of Fire

The first--during the afternoon of the 20th of May--is an Annular/Partial eclipse of the Sun by the Moon. It will be visible from a large part of the USA and much of Asia (on the morning of the 21st), and should be quite a show.

An Annular eclipse is one in which the Moon passes before the Sun's disk, but the Moon is too distant in its orbit to cover the Sun completely. The result is a ring of Sun surrounding the blackness of the Moon's disk, as seen in the attached image--a spooky vista to be sure. The Annular eclipse will be visible along a narrow track that runs from Taiwan across the Pacific Ocean and the western states, ending in Texas. (See the the map--shamelessly filched from this month's Sky and Telescope magazine)

If you don't happen to live within that track, not to worry! You'll still have the dramatic view of the Moon's disk creeping across a large extent of the Sun's disk...certainly an unusual and unique way to spend a Sunday afternoon. Given the dangers of staring at the Sun with either naked eye or optical equipment, I recommend you check online to see what your area's local amateur astronomers are planning for the event, or call the nearest planetarium and ask about their eclipse activities. Chances are that there will be at least one observing event (a "Star Party") within easy driving distance. They will have properly filtered instruments that will allow you to observe the eclipse in safety and comfort available for public use. I can almost guarantee that there will be a LOT of astronomical attention for this eclipse!

Two and a half weeks later--on the 5th of June--there will be yet another opportunity for you to stare at the Sun! Just make sure you do it safely.

Transit of Venus

Step outside tonight about an hour after sunset; if the skies are fairly clear you'll see a dazzling white "star" dominating the western sky. This is Venus, next planet in from Earth toward the Sun. On the evening of 5 June this planet will cross the disk of the Sun in what is called a 'transit', quite a rare event. In fact, the next time this will occur will be the year 2117, so THIS apparition is literally a "once in a lifetime" event!

Again, the transit will be visible in the late afternoon hours of June 5, and there should be quite a bit of astronomical activity surrounding it's observation; use those stargazing "contacts" you made for the eclipse and take advantage of the opportunity to get the kids away from the TV or computer to experience first-hand the "music of the spheres". The sight of our sister planet slowly crossing the Sun's face will be amazing.

I won't be able to watch the solar eclipse--Joshua Humphreys is sailing in the wrong hemisphere--but weather permitting I WILL be observing the Transit of Venus with properly-filtered binoculars. I hope you'll all take advantage of these two sky-watching opportunities, and further that you'll write me with your observations and impressions. Let me know what you see and what you think about these visible demonstrations of planetary and lunar motion. Above all, enjoy the spectacle--and be SAFE!

If you have any questions about these events--or any astronomical matters--I would be pleased to assist.  Write me at my webmail address of

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