—Nor the comet that came unannounced out of the north, flaring in heaven; Nor the strange huge meteor procession, dazzling and clear, shooting over our heads, (A moment, a moment long, it sail’d its balls of unearthly light over our heads, Then departed, dropt in the night, and was gone;)
— Exerpt from Walt Whitman's Year of Meteors, 1859
John Lundberg tells here of a physicist, Donald Olson, who recently saw the above painting, and cleverly put 2 and 2 together. He realized that the painting depicted a once-in-a-century physical phenomenon, a meteor that entered the atmosphere at a super-low angle. Based on the timing of the poem, he then identified this as the physical event which likely inspired Whitman's poem.
I passed Lundberg's story on to UT graduate student and Whitman scholar Travis Brown, and he told me that though the discovery was pretty neat, Whitman penned a reply long ago (Whitman, Leaves of Grass 180, first published in Drum-Taps, 1865):
When I heard the learn'd astronomer;
When the proofs, the figures, were ranged in columns before me;
When I was shown the charts and the diagrams, to add, divide, and measure them;
When I, sitting, heard the astronomer, where he lectured with much applause in the lecture-room,
How soon, unaccountable, I became tired and sick;
Till rising and gliding out, I wander'd off by myself, In the mystical moist night-air, and from time to time,
Look'd up in perfect silence at the stars.