Look up! Winter solstice features full moon, Ursid meteor shower

This weekend offers a rare celestial trifecta: the winter solstice on Friday, a full moon on Saturday and a showy meteor shower over the entire weekend.

“This is a cosmic coincidence,” said Andrew Fraknoi, emeritus chair of Foothill College's Astronomy Department in Los Altos Hills. While delightful, “it's of no scientific significance whatsoever.”

We had a preview Wednesday night, when a brilliant meteor did a death dive shortly after sunset. A chunk of rock from space, its intense heat created a long visible cloud of gas and liquid on the horizon, resembling a wiggly tail or a question mark. It wasn't necessarily linked to our ongoing meteor shower, said Fraknoi. It could have just been an independent chunk of cosmic matter.

Wait, there's more!

Already, the three bright stars of constellation Orion's belt are ascending into our mid-evening's eastern sky. And the biggest and smallest of the solar system's major planets - Jupiter and Mercury - stage a get-together at dawn.

We'll need a break in the clouds for a good view. The forecast for the next several days is a moody assortment of fog, clouds and clear skies, with possible brief showers.

Inland areas could see more dense morning fog - so-called tule fog, caused when moisture on the ground radiates out into the cool atmosphere, said meteorologist Jan Null of Golden Gate Weather Services. But clear winter evenings offer gorgeous sunsets. Thanks goes to all the mid-level clouds - 10,000 to 20,000 feet up - that gather before or after storms.

These heavenly events bring joy to a world already weary of fruitcake, shopping malls and Hallmark television.

“We get to see the sky assume its winter aspect, as the earth goes around the sun,” said William Phelps, a board member of the Peninsula Astronomical Society. “This time of year is always gorgeous,” he said.

The solstice - our shortest day of the year and thought to be the oldest continuously celebrated holiday in human history - almost didn't happen. If Earth was like Venus and Jupiter, it would spin straight, its head held high. Instead, we tilt.

“We think that at the beginning of the solar system, when mini-planets were first coming together to make the planets, one such mini-planet hit the forming Earth so hard, we tilted over,” explained Fraknoi. “And, like many victims of serious traffic accidents, we were not ever able to straighten out again.”

Far from the sun, early humans sought to cheer each other up and win the favor of the sun god, so it would spend more hours with us, said Fraknoi. Christmas celebrations have taken on many of the characteristics of this ancient winter solstice festival. Modern humans mark this darkest week of the year with New Age retreats, $79.95 “light therapy boxes” and rich eggnog spiked with booze.

“In the winter solstice, many emotions are coming out. Many things arrive in your consciousness. It is a good time to be in a community, in a safe container,” said Liya Garber, host of Thursday night's “Solstice Kundalini Activation: Rebirthing Light Into The World” retreat at Berkeley's Shambhala Meditation Center, which will mark the solstice with yoga, meditation, chanting and dancing.

There will be an 8-mile winter solstice night bike ride Friday in Los Altos, with participants decorating bikes with lights and singing carols. On Saturday, hikers will watch the sunrise at a 7 a.m. Solstice Hike at Novato's Deer Island. On Sunday, Greenbelt Alliance is hosting a “Winter Solstice Wander” on Mount Diablo.

Birders also are scanning the skies during annual Christmas Bird Counts, a long-running wildlife census to assess the health of avian populations. In Mountain View's Forebay, a ring-necked pheasant flew into cattails. A barn owl was spotted over Telegraph Avenue in Berkeley. A bald eagle soared over Stanford.

Meanwhile, as you're searching for Dasher and Dancer, Vixen and Blitzen, keep your eyes peeled for something else: The peak full Moon occurs on Saturday. Illuminating the darkest night, Native Americans called it the Cold Moon or the Long Night Moon, marking the cold and dark time of year.

The last time a solstice and full moon coincided was in 2010 - but the next time won't be until 2094.

To top it off, the Ursid meteor shower will peak on the morning of Dec. 21, sometime after midnight but as late as possible before sunrise. It's not a rich shower, and the moonlight will make seeing shooting stars even harder, said Fraknoi.

An annual event, it gets its name from the constellation Ursa Minor, nicknamed the Little Dipper. The event is caused by Earth's passage through a comet's orbit. While called “shooting stars,” the meteors are actually the comet's rocky debris.

“It's diffuse,” said Phelps. “The best viewing tool is your eyes. Get out a lawn chair and a blanket and just spend time looking at the sky.”