The moon will turn a deep copper color for several hours Thursday night. It won’t be because the world is ending and a plague of frogs is looming but because a total lunar eclipse — the first visible from the Bay Area in three years — will be upon us.
Unlike a total solar eclipse, in which the sun is darkened for a few minutes, a lunar eclipse creeps toward completion. Although the forecast calls for rain, any breaks in the clouds will allow viewers in Northern California to view this rare celestial phenomenon starting at 8:57 p.m. The so-called blood moon, as it passes through the Earth’s shadow, will begin at 10:09 p.m. and achieve its darkest state by 11:26 p.m., at which point the process will appear to reverse.
This eclipse — easily seen with the naked eye and perfectly safe to watch without protection — won’t end until 3 a.m. Friday.
Whether the clouds part or not, the Chabot Space & Science Center in the Oakland Hills will host a viewing party from 9 p.m. to 1:30 a.m., complete with hot cocoa and a remote viewing set-up using a camera positioned in a location with clear skies.
The last time a total lunar eclipse was visible in California from start to finish was May 2022. When one occurs, the moon takes on its sanguine color as sunlight passes through the Earth’s atmosphere. It’s the same phenomenon that occurs when the sun and moon rise and set — only higher in the sky.
For the superstitious or astrologically inclined, Friday is a busy day. Apart from the lunar eclipse, the dreaded Mercury retrograde starts at 11:46 a.m. and lasts until April 7. These periods of apparent backward motion are said to cause communication breakdowns and travel snafus, although there is no scientific basis for the belief.