The night is cold and moonless. Stars twinkle in frosty stillness. My breath rises from my lips as a thick fog, circling my head before it dissipates into the silence.
I am out late in the dark, standing on a butte more than a mile from the nearest street light, because there's a chance of showers. Meteor showers.
Falling stars, or meteors, are not uncommon. You can catch site of one almost any night of the year, and some are even large enough and bright enough to break the light of day. But showers of meteors -- when long streaks of flame arc across the heavens not once, but many times -- are another matter. Most of these are caused by clouds of dust left in the path of passing comets and they come round again like the seasons, year after year.
"Comets race through space, the heat of the Sun boiling off and ionizing their ices into deep blue tails. Dust grains, trapped in those ices, become entrained in the rushing outflow of gases and form into a second tail, red to yellow in color. Thus each mote of dust, freed from its comet, becomes a microscopic body defining its own orbit around the Sun," astronomer Carolyn Sumners and geologist Carlton Allen explain in their book, 'Cosmic Pinball'.
As the Earth passes through these clouds of comet dust, ranging in size from grains of sand down to mites smaller than specks of flour, the collisions with these particles of matter are marked by streaks of light -- meteors -- as they burn up in the atmosphere.
Most meteor showers occur about the same time each year, producing a meteor every few minutes. But now and then a light shower becomes a downpour, as happened on the night of November 13, 1833, along the east coast of the U.S.
"Imagine a constant succession of fireballs, resembling rockets, radiating in all directions from a point in the heavens... meteors of various sizes and degrees of splendor: some mere points but others were larger and brighter than Jupiter or Venus," wrote a Yale professor who witnessed the event. "The flashes of light were so bright as to awaken people in their beds."
Astronomers estimate that some 10,000 meteors, at a rate of about three per second, fell between 5 a.m. and 6 a.m. that day in New England. No Fourth of July display was ever so grand.
December is a good month for meteor watching. Two showers appear regularly. First, in mid-month, the "Geminids" emerge after dark from the northeastern sky. These meteors tend to be bright and yellowish as they carve slow, graceful arcs across the heavens. If the night is clear and moonless, as many as 75 meteors an hour may be spotted.
Later in the month, just before Christmas, a weaker shower called the "Ursids," makes its appearance. This display of faint, but long-lasting meteors, is found in the area around the Big Dipper in the northern sky.
These showers can be experienced by anyone in the Northern Hemisphere with dark skies and a clear view of heaven. Bring along some mittens, a hat, boots and a warm drink to spite the chill. No umbrella needed.