Remembering The Great Leonid Meteor Storm of 1966
While the annual Leonid meteor shower will peak early on Thursday morning, November 17th, it will be pretty much squelched by the brilliant light of a nearly-full Moon, so not much is expected to be seen this year. But this year marks the 50th anniversary of the Great Leonid Meteor Storm of 1966. In that year, one of the most stupendous meteor showers ever witnessed took place over central and western North America.
Fifty years ago, beginning at around 5 a.m. Eastern Time, dawn was breaking along the Eastern Seaboard. Where clear skies prevailed, viewers were able to see Leonids falling at rates of up to six per minute before it finally became too bright to see the stars. Farther west, where it still dark, Leonids were falling at a rate described by many as “too numerous to count.” One observer, stationed north of Mission, Texas, said that meteors falling in all directions gave the impression of a “gigantic umbrella,” appearing to “waterfall” out of the head of Leo.
From 6,850-foot Kitt Peak in southern Arizona, thirteen amateur astronomers were trying to guess how many could be seen by a sweep of their heads in one second. The consensus of the group was that the peak occurred at 4:54 a.m. Mountain Time, when the staggering rate of 40 per second (144,000 per hour) was reached!
The Leonids occur every year on or around November 18, when Earth glides through a diaphanous trail of dust left behind by the Comet Tempel-Tuttle. Each year, stargazers are tempted with a drizzle of maybe a dozen ultrafast meteors streaking across the sky every hour. But, every 33 years or so, a rare and dazzling Leonid storm can occur after the comet swoops near the Sun, closely followed by thicker concentrations of dusty, icy particles no larger than Rice Krispies. Earth then plows straight through the comet’s refreshed wake, producing a stupendous meteor display.
Today, we know that a thick trail of dusty debris shed by Comet Tempel-Tuttle back in 1899 was what caused the Great 1966 Leonid Storm. That material had made two revolutions around the Sun before colliding head-on with the Earth on that memorable night 50 years ago. Because such a trail of cosmic flotsam and jetsam is invisible until it enters our atmosphere, astronomers back then were, in essence, playing a game of blind man’s bluff, not knowing exactly if or when we might encounter it.
Now, with computer technology, it’s a much different situation — astronomers can readily locate the position of Leonid dust trails from the distant past or far into the future. Indeed, the Leonids will periodically shower our planet in the years to come; in the year 2034, Earth is forecast to move through several clouds of dusty debris shed by comet Tempel-Tuttle from the years 1699, 1767, 1866 and 1932. If we’re lucky, we might see Leonids fall at the rate of hundreds per hour, perhaps briefly reaching “storm” rates of 1,000 per hour, experts have estimated.