Denison Olmsted
The Yale professor who studied the great Leonid meteor storm of 1833 and showed that meteors come from space.
Key facts
- Born
- 1791
- Died
- 1859
- Nationality
- American
- Field
- Astronomer and physicist
Denison Olmsted taught at the University of North Carolina and then for many years at Yale College, writing popular textbooks on natural philosophy and astronomy.
In the early hours of 13 November 1833, people across eastern North America woke to an astonishing sight. Meteors were falling like snow, tens of thousands an hour, so many that some people thought the end of the world had come. It was a storm of the Leonid meteor shower.
Olmsted collected reports from observers in many places and studied them carefully. He noticed that the meteors' trails, traced backwards, all seemed to spread out from one point in the constellation of Leo, wherever the observer stood. This point, now called the radiant, did not move with the observers but turned across the sky with the stars. That meant the meteors were not made in the air by the weather; they came from far out in space.
Olmsted suggested that Earth had run into a cloud of particles travelling around the Sun. That is essentially right: we now know meteor showers happen when Earth crosses a stream of dust shed by a comet, and the Leonids come from Comet Tempel–Tuttle. His study of 1833 is often counted as the start of the scientific study of meteors.
Did you know?
The 1833 storm inspired paintings and even a popular song, and many people dated events in their lives from the night the stars fell.
Leonid storms return roughly every 33 years, when the comet passes close by, though not every return produces one.
On the timeline
- 13 November 1833The night the stars fell