Amateur astronomers across the Bay Area will keep their eyes on the skies Tuesday to see a rare astronomical event -- the passing of the planet Venus in front of the sun.
During the so-called "transit of Venus," which is similar to a solar eclipse by the moon, the planet passes directly between the sun and Earth and becomes visible as a small dot drifting across the sun.
Several sites around the Bay are inviting the public to see the transit for what will likely be the last time in their lives. The rare event occurs in pairs, most recently in 2004, and will not be seen again from Earth until December 2117. To see live coverage online, NASA is showing it here.
The viewing begins shortly after 3 p.m. and will last for about six hours and 40 minutes, according to Michele Johnson, a spokeswoman for NASA, which is hosting a viewing of the transit at its Ames Research Center at Moffett Field.
Attendees can watch a live broadcast of the transit that is being filmed from atop the Mauna Kea volcano in Hawaii and will also be able to safely view the event themselves using solar filter glasses and telescopes, Johnson said.
She said the event is significant because "it's the last chance for the next two generations to see it," and added that the most dramatic sights will be at the start and finish of the transit.
The Chabot Space and Science Center in Oakland is also hosting an event to mark the transit of Venus.
Members of the public can view the transit through the center's special solar telescopes and sun spotters and talk about it with astronomers.
The Lafayette Library and Learning Center is setting up several telescopes too at its outdoor amphitheater and will also show NASA's live video feed.
For people unable to make it to a site specializing in space studies, the hilltop at Mare Island Shoreline Heritage Preserve in Solano County will be opened up to the public to provide people with their own telescopes or solar glasses a chance to view the transit.
The transit can also be followed online at www.venustransit.nasa.gov, which also has more information about various viewing events, as well as safety precautions for viewing the transit.