The 1833 Leonid storm rained up to 100,000 meteors an hour

The Leonid meteor storm of 12-13 November 1833 is often called the greatest meteor display on record: NASA puts its rate at tens of thousands, perhaps even 100,000, meteors an hour over eastern North America, and it launched the scientific study of meteor showers.

At the top estimate, that is close to 30 meteors every second. On a good night of the August Perseids, under ideal skies, you see about one a minute. NASA defines a meteor storm as at least 1,000 an hour, so 1833 cleared the bar many times over.

The show peaked before dawn on 13 November, waking people across the country; NASA’s Astronomy Picture of the Day notes that a young Abraham Lincoln was among them. An account from South Carolina describes more than 100 people lying prostrate on the ground, praying for the world to be spared.

“Never did rain fall much thicker than the meteors fell towards the Earth.” (South Carolina eyewitness, 1833)

Yale astronomer Denison Olmsted turned the panic into data. He saw that the streaks all radiated from a point in the constellation Leo, and that the point moved with the stars through the night, so the meteors had to come from space rather than the weather. His analysis is credited as the birth of the study of meteor showers.

Why it hasn’t happened since

The Leonids are dust from Comet 55P/Tempel-Tuttle, which takes 33 years to orbit the Sun. Earth crosses its trail every November, but storms come only when we hit a dense, fresh patch, roughly once a generation:

• 1833: the great storm, at up to 100,000 meteors an hour.
• 1966: observers see thousands of meteors a minute for about 15 minutes.
• 2002: the most recent Leonid storm, according to NASA.

In an ordinary year the shower manages only a few meteors an hour.