Annular solar eclipse is expected to be visible across much of the western U.S. between 5:16 and 7:40 p.m. Sunday.
That's when the Earth's moon will be farthest away on its orbit, and as it passes in front of the sun it will cover up 94 percent of the surface.
But astronomers advise you look ver-r-r-r-y carefully. How carefully? Start by turning your back to the sun. Really.
"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 you will hear for much of the coming week," , and a frequent radio commentator on all things astronomical.
People can watch by making do-it-yourself pinhole projectors. They view the eclipse by turning their back to the sun and letting the sun shine through the pinhole onto a piece of paper. From there, the progression of the moon's path can be seen.
Viewing the Sun without proper protection is dangerous and can cause serious eye damage. Fraknoi started on Monday by distributing a link for safe eclipse viewing through all his networks.
The experts are also using this as a teachable, festive moment. 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.
In Los Altos Hills, the Peninsula Astronomical Society will open the Foothill Observatory from 5 p.m. to sunset, and members of the public can safely see the eclipse through the observatory's Hydrogen-alpha and white light telescopes, its newsletter says. (Be prepared to pay $3 in quarters to the parking machine).
In the East Bay, the will have an Eclipse Viewing Party for $5, beginning at 5 p.m. the Lawrence Hall of Science in Berkeley will have a viewing for free on its deck, and charge $5 for activities inside. "This will be the best partial eclipse seen from Berkeley until 2045," it says says enticingly on its website. "Don’t miss it. And bring the whole family!"
The San Francisco Amateur Astronomers are hosting two events. One, a viewing party on the Marina Green, promoting safe viewing, and the other, alluringly called the "Ring of Fire Road Trip to Mt. Shasta," which is in the path of the eclipse, and from which the "full annular" effect can be seen.
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.
The last solar eclipse visible in the U.S. was in 1994.
DIY: How Can One Watch the Eclipse Safely?
The following is from "Astro-Prof" Andrew Fraknoi: The best way to see the eclipse is to project an image of the sun (and not to look at the sun directly.) One easy way is to make a pinhole projector: Take two pieces of cardboard or thick paper. Put a pinhole in one (taking care to make a clean hole). Then stand with your back to the Sun, and let the Sun’s light fall through the hole and onto the other sheet. You’ll get a small but distinct image of the Sun. (A way to get a sharper pinhole is to cut a square out of the middle of one cardboard, tape a sheet of aluminum foil over the hole and put the pinhole in the foil instead of paper.)
Additional reporting by Claudia Cruz