The appearance of meteors has sparked the imaginations of observers through the ages, with earlier civilizations regarding them as omens of good or wicked things to come. These so-called shooting stars (which are not actually stars at all) are comprised of bits of rock and dust spewed from icy comets — and the occasional asteroid — that burn up as they encounter Earth's atmosphere. Clusters of these streaks recur on an annual basis and even sport the names of the familiar constellations from which they seemingly originate, a point known as the “radiant.”
While meteor showers largely follow a predictable pattern, the night sky occasionally has a surprise for viewers. Here are five cases in which the sky lit up with a stunning light show that left a searing mark on those around to bear witness.
Records of the Lyrids date back to 687 BCE, and while these annual spring streaks from the constellation Lyra the Harp average a modest output of 15 meteors per hour, the April 1803 sighting was one for the ages. The most famous description of this shower came in a letter to the Virginia Gazette, which recounted: "From one until three [a.m.], these starry meteors seemed to fall from every point in the heavens, in such numbers as to resemble a shower of sky rockets. ... One in particular seemed to fall from the zenith, of the apparent side of a ball of 18 inches in diameter, that lighted for several seconds the whole hemisphere." The spectacle was outrageous enough to spark accusations that a prankster in a local armory was behind the detonations, though that wouldn't explain why witnesses as far north as Massachusetts and New Hampshire also wrote about the remarkable display.
There are meteor sightings, and then there are eruptions that scare the daylights out of the populace and change the course of astronomy. The latter aptly describes the November 1833 Leonid shower, which produced around 100,000 meteors per hour and, according to one account published in an 1889 handbook, ignited such mayhem that "upwards of 100 lay prostrate on the ground ... with their hands raised, imploring God to save the world and them." However, less frightened observers across the eastern United States realized that the streaks were originating from an area near the constellation Leo, prompting more intensive study of the subject. By the 1860s, Italian astronomer Giovanni Schiaparelli had demonstrated the link between meteors and larger orbiting objects, with the recently discovered comet Tempel-Tuttle recognized as the parent body of the Leonids.
The November 1872 Andromedids made their luminous presence felt over a wide swath of sky that stretched from Asia to America. Chinese skywatchers noted that the "stars fell like rain," while in Italy, observer P. F. Denza and two cohorts logged the appearance of some 33,400 meteors over a six-and-a-half-hour span. But the most notable thing about this display may be how it marked the peak of a once-prominent shower that pulled a vanishing act for more than a century. Linked to Biela's Comet, which split in two in the mid-19th century, the Andromedids delivered another strong showing in 1885 before fizzling out by the early 1900s. However, the Andromedids once again resurfaced in 2011, the impact of their return serving as a reminder of the wallop these showers once packed.
While there's no topping the 1833 Leonids as a tipping point for modern astronomy, the November 1966 shower may have surpassed its predecessor's showing for pure firepower. This time reportedly producing a peak rate of 40 meteors per second, which translates to 144,000 per hour, the lights arrived too late for quality East Coast viewing but dazzled onlookers to the west. One observer in Texas noted how the stream took the shape of a "gigantic umbrella" that seemed to "waterfall" from Leo. While the concept of God's vengeance wasn't as overwhelming as it had been 133 years earlier, the flurry still drew a visceral reaction, with an astronomer at California's Table Mountain Observatory describing how he and colleagues "sought to shield our upturned faces from imagined celestial debris."
2014 Siding Spring Shower
Finally, there's the one-off shower produced by the October 2014 arrival of Comet C/2013 A1, aka Siding Spring, which terrified viewers beneath the skies of ... Mars? That's according to data compiled by NASA's Mars Atmosphere and Volatile Evolution (MAVEN) orbiter, which recorded a dizzying 108,000 meteors per hour at the peak of the three-hour show. But while the rate rivals that of the top Leonid showers, several factors contributed to this unusual output, including the comet's close passing (87,000 feet from the surface) at the height of the Martian dust season. It remains to be seen whether Siding Spring can produce a repeat performance the next time it approaches the Red Planet, although, by some estimates, we'll have to wait another 740,000 years to find out.
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