What are some of Earth's greatest sky events? Here's the Almanac's take on the most spectacular, memorable, and even scary sky phenomena visible to the naked eye since 1792.
Solar Eclipse of July 29, 1878
For any spot on Earth, a total solar eclipse occurs an average of only once every 300 to 400 years. The 1878 eclipse is one of only 16 eclipses since 1792; it ran down the Rockies over Boulder, Denver, and Colorado Springs, then across Texas and Louisiana.
Astronomer Samuel Langley (later director of the Smithsonian Institute) drew a naked-eye sketch that showed coronal streams extending an amazing 12 times the Sun's diameter (more than 10 million miles).
His drawing made the cover of Harper's Weekly. But Langley may have been upstaged by the young Thomas Edison, who observed the eclipse from a chicken yard in Wyoming, where his preposterous new invention, the "tasimeter," accurately measured heat from the corona.
Lunar Eclipse of July 6, 1982
Just eight total lunar eclipses have occurred in the past 200 years. The 1982 eclipse, which many Almanac readers may remember, was the Western Hemisphere's longest total lunar eclipse since 1736!
There was an extra bonus to the 1 hour and 46 minutes of totality. The acid haze from Mexico's El Chichon volcano had spread only far enough to darken part of the Earth's shadow. The result was a Moon black at the top and middle, deep red at the bottom.
The Great Comet of 1882
This magnificent comet could be seen easily in broad daylight, a shining knife beside the blazing Sun. When visible at the Sun's edge, it shone 100 times brighter than the Moon!
As the comet pulled away to become visible in twilight, the first ten degrees of the comet's tail was brighter than the brightest star. Comet hunter E.E. Barnard of Tennessee dreamed he saw the sky filled with comets; he went outside and found that the Great Comet had spawned many smaller comets.
Return of Halley's Comet, 1910
Halley's has paid the Earth three visits since 1792. The 1910 show was the best. In May of that year Halley's Comet got as bright as the brightest star, and Earth passed right through an outer edge of its tail.
Many people feared (unnecessarily) being poisoned by the gases. At its closest approach, the comet's glowing tail extended two-thirds across the entire sky.
Leonid Meteor Showers of November 17, 1966
The greatest meteor "storms" have been supplied, usually about every 33 years, by the annual Leonid showers. In 1799 meteors were reported to fall "like snowflakes." On November 18, 1833, came the night "the stars fell on Alabama" and all over America; the brightest of the 14,000 meteors an hour woke people from their beds.
But the night of November 17, 1966, was even more dazzling. The western states got the best show. Folks out that night, especially Kitt Peak in Arizona, said it was like a waterfall of shooting stars pouring down from the sky—as many as 500,000 meteors an hour!
The Great Meteoric Procession of 1913
Thousands of people from Saskatchewan to Bermuda sighted the procession of several hundred meteors streaming across the sky on February 9, 1913, taking about three full minutes to complete the arc.
When last spotted from a ship in the South Atlantic, they were going strong. The best guess is that they were fragments of a temporary small "second moon" of Earth as it entered the atmosphere for one last fiery orbit.
The Northern Lights of 1989
When charged particles from the Sun are accelerated by Earth's magnetic field toward the poles, they collide with atoms and molecules of upper atmospheric gases. Thus is born the sky's greatest display of moving lights, the aurora borealis, or northern lights .
The best documented is the March 13, 1989 outbreak, in which red northern lights were seen as far south as Central America and the associated magnetic storm knocked out electric power for about six million people in Quebec.
The Meteorological Optics Effect (i.e., Beautiful Sky Colors) of 1883 and 1950
The 1883 eruption of the Indonesian volcano Krakatoa threw huge amounts of volcanic ash into the air and caused numerous meteorological phenomena worldwide.
Most prominent were the vast crimson and purple twilights that glowed for as long as 1 1/2 hours after sunset.
In 1950, a different-sized particle—ash from vast forest fires in Alberta—caused green, blue, and brass-colored sunshine and odd "dark days" over much of the northeastern United States.
But the full Moon on September 25, by strangest luck, was the most memorable of all. The Moon, already blue from the smoke, was totally eclipsed that night. The reddening of the eclipse across the blue Moon created the rarest lunar sight of all—a purple Moon!