English: Drawing of passage of "auroral beam" of November 17, 1882.
Drawing of passage of "auroral beam" of November 17, 1882, by astronomer and aurora expert Rand Capron, Guildown Observatory, Surrey, UK. Also described by prominent British astronomer Edward Walter Maunder. Drawing first published in Philosophical Magazine, May 1883. Reprinted by astronomer Morris K. Jessup in "The Case for the UFO," 1955, p. 32, Citadel Press. Electronic version of Jessup book with illustration online
Maunder in The Observatory journal of the Royal Greenwich Observatory, in June 1883 and April 1916, described the phenomenon as about 30 degrees long, 2-3 degrees wide, with distinct edges and an opaque central portion. It was whitish or whitish-green, about the same color as auroral displays, but much brighter. It moved steadily across the sky from (magnetic) east to west in under 2 minutes. It moved "as the Sun, Moon, stars and planets move but nearly a thousand times as quickly." When first seen it was low down in the E.N.E. and circular or disc-like in shape, but as it moved it turned into "a very elongated ellipse", variously described as "cigar-shaped," "like a torpedo," "a spindle", or a "shuttle." In 1916, Maunder likened it to "just like a Zeppelin."
In 1916, Maunder commented that it was "a celestial object unique in my experience" and "unlike any other celestial object that I have ever seen. The quality of its light, and its occurrence while a great magnetic storm and a bright aurora were in progress, seem to establish its auroral origin. But it differed very widely in appearance from any other aurora that I have ever seen."
The described phenomenon has some similarity in appearance to
Upper Tangent arc, frequent in the northern regions, described and studied by meteorologists. Upper Tangent arc is produced by horizontally orientated column-shaped ice crystals reflecting the sunlight (articles in
Arbeitskreis Meteore e.V. ). However, the 1882 phenomenon, according to Maunder, moved rapidly across the sky, whereas Upper Tangent arc would remain relatively stationary and can only occur during daytime, since it is created by and is tied to the position of the sun.