Today's partial solar eclipse is expected to darken the sun between 5:16 and 7:40 p.m., and astronomers are warning would-be viewers of the dangers in looking directly at the eclipse at any point during the event.
"It is very important that everyone tempted by the sight of 84 percent of the sun's area being covered by the Moon take heed of the warnings," said , and a frequent radio commentator on all things astronomical.
Solar eclipses, even partial ones, are rare and special events. But if you want to be able to observe one without damaging your eyesight, there's one important rule: Look in the opposite direction.
It's easy to watch an eclipse by making a do-it-yourself pinhole projector: Poke a hole in a box or piece of cardboard, turn your back to the sun and allow the light to shine through the hole onto a piece of paper.
From there, without risking your eyesight, you can watch the progression of the eclipse and the ring-like or "annular" effect created when the moon passes directly in front of the sun.
While it's not a total eclipse, Sunday's event is still pretty special. The last time an annular eclipse took place was 18 years ago.
Optimum viewing time is 6:33 p.m. for this eclipse, which begins at 5:16 p.m. and is expected to end by 7:40 p.m.
if you're unprepared, or like to leave things to chance Sunday afternoon, you can even look at the shadows cast by leaves on trees. If there are bug holes in the leaves, they pretty much do the same thing as a pinhole projector, writes Gary Baker in the newsletter of the Peninsula Astronomical Society newsletter.
And while you're under that tree, you might notice what a NASA Science's Science News article says is special about an annular eclipse, described as having "a particular charm of its own." It renders sunbeams into "little rings of light," easily seen in the shadows of a leafy tree.
The NASA article on the partial eclipse quotes NASA's leading eclipse expert, Fred Espenak of the Goddard Space Flight Center, as saying he gives it a '9' on a scale of 1 to 10, In terms of visual spectacles.
For those wondering what places, besides Mt. Shasta, get "the full annular" the Mt. Diablo Astronomical Society posted a link from Bruce Kruse of the Astronomical Society of the Pacific. The interactive Google map, made by Xavier M. Jubier, is worth taking a look to see the path of the eclipse.
This is the first of a "triple-play," Chabot points out. After the annular eclipse on Sunday comes a partial lunar eclipse on June 4 between 2 and 4 a.m., followed by an even rarer once-every-120 years, "Transit of Venus," which is Venus traveling between us and the sun. And yes, your astronomer buddies will be out watching.