Posted on behalf of Richard A. Lovett

Fifteen years ago, when Donald Olson, a physics professor at Texas State University in San Marcos, was looking for readings for a course in astronomy in art, history, and literature, he found a poem by American poet Walt Whitman, called Year of Meteors (1859-60).

Whitman is one of America’s most revered poets, and the poem, in his book Leaves of Grass, is important enough, Olson says, that ten previous scholars had tried to figure out what Whitman was describing when he referred to “the strange huge meteor-procession dazzling and clear shooting over our heads” in “balls of unearthly light”.

The vital clue turned out to be an 1861 painting by American artist Frederic Church, who, like Whitman, lived in New York State. “I realized it matched Whitman’s description perfectly,” Olson says.

In the July issue of Sky & Telescope magazine, Olson and colleagues reveal that the event was indeed a “meteor progression” – something that occurs when a large meteor grazes the Earth’s atmosphere and breaks into pieces that chase each other across the sky. “Meteor progressions are so rare that most modern astronomers have not even heard of them,” Olson says. “In all of history, we can list only four.”

The one described by Whitman, he adds, occurred on 20 July 1860 – a date that his team unearthed by searching the archives of newspapers and scientific journals.

For such an event to happen, the meteor has to be on a near-miss trajectory penetrating to within about 60 to 70 kilometres of the Earth’s surface. “If it’s higher, it won’t light up, and you won’t see it well,” Olson says. “If it’s significantly lower, the atmosphere it will nose dive and reach the Earth’s surface.”

The meteor doesn’t “skip” off the top of the Earth’s atmosphere, like a stone thrown across a pond. It’s more like a bullet passing so close you can almost feel it, without actually hitting.

Such events are truly spectacular. “Earth-grazing progressions can be watched by one observer for 30 seconds, even a minute, as they traverse the sky,” Olson says.

Image: The Meteor of 1860 by Frederic Church / Judith Filenbaum Hernstadt