Foothill College Astronomy Chair Andrew Fraknoi has some advice for what not to do during the solar eclipse on Sunday, May 20: Don't look at the sun with unprotected eyes.
"Normally, who's stupid enough to stare at the sun?" he said. "Mom taught you that, pain taught you that ... but somehow during an eclipse, especially if it's in the newspaper, people go crazy."
In the Bay Area, the eclipse will be visible in the northwest portion of the sky, with the moon beginning to move in front of the sun at 5:16 p.m. At its peak at 6:33 p.m., the moon will cover 84 percent of the sun.
Fraknoi suggests people interested in seeing the eclipse go to a viewing site, such as the Foothill College Observatory, where viewing equipment with proper filters will be available.
For people who wish to view the eclipse on their own, Fraknoi recommends cutting a pinhole in a piece of cardboard or thick paper and allowing the sun to shine through the hole onto another piece of paper. The projected image will be safe to view.
"It will be as if the sun is covered up more and more by a black disc," Fraknoi said. "In the old days people thought a monster was eating the sun."
Sunglasses, exposed film and smoked glass do not provide sufficient protection for direct viewing. No. 14 arc-welder's glass is a suitable filter but not the lower numbered glass.
Viewers in other parts of the western United States, including Redding and Chico, will see what is known as an "annular" eclipse, in which the moon will appear to be surrounded by a ring of fire.
Bay Area residents last had the chance to see an eclipse in 1994, and those who miss Sunday's event will have to wait until 2017 for their next opportunity.
The observatory at Foothill, which is operated by the Peninsula Astronomical Society, will be open on Sunday to the public from 5:30 to 7:30 p.m.
Telescopes with filters that allow for direct viewing of the sun will be available, including a hydrogen alpha solar telescope that filters out most of the color spectrum and allows viewers to see the chromosphere, the outermost layer of the sun that is normally invisible to the human eye.
Members of the society will be present to provide information to the public. Board member William Phelps said the anticipation of seeing the eclipse was giving him "goosebumps."
This will be the 17th eclipse viewing for Phelps. He's trekked around the globe to see these astronomical events, with previous destinations including China, Tahiti, Russia and the Caribbean island of Guadeloupe.
"Eclipses are a great excuse to travel," he said.
Fraknoi said that while the eclipse is not an event of great astronomical significance, he appreciated that it can pique peoples' interest in the cosmos.
"I like anything that make people think there's a bigger world out there besides the argument you're having with your boss," he said.
Viewing sites for Sunday's solar eclipse
More eclipse information is posted at www.astrosociety.org/2012eclipse.
Half Moon Bay
Cameron's Campground, Inn, and Restaurant
1410 Cabrillo Highway South, Half Moon Bay
Host Steve White will have a special telescope that allows for viewing of solar flares and prominence.
Foothill College Observatory
12345 El Monte Road, Los Altos Hills
Telescopes will be set up both inside and outside the observatory from 5:30 to 7:30 p.m.
San Carlos Library
610 Elm St., San Carlos
A solar eclipse event will be held from 4 to 7 p.m., with telescopes and eclipse and lunar-phase models.
California Academy of Science
55 Music Concourse Drive, San Francisco
Telescopes and other viewing devices will be set up in front of the Music Concourse side of the academy from 5 to 7:40 p.m.
San Jose Astronomical Association
150 feet north of the intersection of Twilight and Rupert Drives, San Jose
5 to 7:40 p.m.
Source: Andrew Fraknoi