A total lunar eclipse will occur on Sunday evening, and as a full moon plunges into the Earth’s dark inner shadow, its surface will turn a dark, rusty red. For this reason, lunar eclipses are often called blood moons.
The view from the San Francisco Bay Area will be unusual as the May 15 eclipse begins at 6:32 p.m., before the moon rises in the east at 8:04 p.m., said Gerald McKeegan, adjunct astronomer with the Chabot Space & Science Center in Oakland.
“So when the moon rises, it already will be partially in the Earth’s umbra shadow, exhibiting that familiar rusty red color,” McKeegan wrote in an email. “Maximum totality will occur in evening twilight at 8:29 p.m, when the moon will be still very low in the east. The moon will begin to emerge from the umbra at 9:54 p.m., by which time the sky will be fully dark.”
Because the eclipse will be underway when the moon rises in the east, Bay Area residents will want to observe the celestial event from a location with an unobstructed view of the eastern horizon. McKeegan recommends catching the show in the sky from a high ridge line location and said ideal viewing spots include Skyline Boulevard in the East Bay, Inspiration Point near Tilden Park in Berkeley or off Highway 92 on the Peninsula.
The view is also dependent on weather conditions, and the National Weather Service said that as of Wednesday, clouds were in the forecast for Sunday. This could change in coming days, though.
“There’s still a lot of variability with how the actual system tracks into the Pacific Northwest,” weather service meteorologist David King said. “If it stays farther north, we could see more clearing.”
King said that fog could also obstruct views of the moon along the coast.
Unlike solar eclipses, lunar eclipses are safe to look at directly with your eyes, binoculars or a telescope, NASA advises.
Lunar eclipses are infrequent, but not rare, McKeegan said. The last total lunar eclipse occurred on May 26, 2021. There were two lunar eclipses last year, and this year, a second one will happen in the nighttime hours spanning Nov. 7 and 8.
A lunar eclipse unfolds when the sun, Earth and moon align, and the moon passes into the Earth’s shadow. McKeegan explained that the Earth’s shadow consists of two concentric circular shadows, the fainter outer penumbra shadow and the darker, reddish inner umbra shadow. When the moon passes fully into the umbra shadow, it turns a glowing red color and astronomers call it a total lunar eclipse.