I’m doing some research on the middle ages and got a book called “The Annals of Fulda”
Essentially it’s a 9th century logbook, with whoever logging interesting events for each year for about 60 years.
One caught my interest.
Among the entries for 840 AD, is this:
“At this time an exceptional redding of the sky appeared from the south-east for several nights; another appeared from the North-west until they met in a cone and gave the apperence of a clot of blood in the heavens directly overhead.”
The book doesn’t have the original text in it, and my german is pretty lousy(so it wouldn’t matter anyway), so I can’t tell if the translation is accurate, but there is a distinct lack of editoralizing here.
I’m not superstituous, but if I were(and somehow, I suspect the people who saw this were), I’d be disturbed by what they are describing. As it stands, I live in the 21st century and am realtivly secular, and it still somewhat creeps me out.
But anyway, does anyone have any clue what Mr. 9th century German is probably describing?
The account possibly isn’t isolated, in that there are similar accounts from elsewhere for the same year. Quoting from An Additional List of Auroras from European Sources from 450 to 1466 by Dall’Olmo, which in turn is quoting from the contemporary Chronique de Michel le Syrien, Barry Hetherington’s A Chronicle of Pre-Telescopic Astronomy (Wiley, 1996) lists several similar events for the year.
Thus in March “a red sign like a fire appeared in the northern part of the sky.” Then in April “a red sign like a fire appeared for three nights, rising in the northern part, after the first hour of the night, until the dawn. Short streaks of light, as if they were lamps, were seen.” And on the 24th of September “a fiery cloud appeared in the northern part of the sky, moving from east to west. Its upper part was as red as blood, and the lower part resembled the image of the moon, so that … the walls and the buildings facing toward the north, were receiving its light and their southern sides were plunged into darkness. This sign appeared after the twelfth hour of the night and lasted until cockcrow; then the darkness became extremely heavy.”
An aurora was also recorded in another chronicle earlier in the year.
The Fulda account sounds distinctly like an auroral corona.
I’ve been working on an article about this sort of thing for a slightly different effect. Both volcanic action and forest fires (and meteor falls, too) have been known to produce anomalous colors in sunsets/sunrises/moonsets/moonrises/ appearance and color of sun/moon. The actual color depends upon the size of the dust injected and how uniform the sizes are. Normally, however, the color is uniform across the sky. Having color across only part of the sky, and especially on two sides, with an unaffected area in the center (if I’m reading you correctly) is pretty odd. I’ve seen optical phenomena that were “broken up” because nearby clouds didn’t cover the whole sky – rainbows, sundogs, ice crystal halos – but phenomena caused by injected dust always seem tobe sky-wide effects.
I’ll have to check my copy of Corliss’ Handbook of Unusual Phenomena, or Minnaert’s book on Light and Color in the Open Air (and his follow-up JOSA article) to see if there are any similar cases reported anywhere.
Yeah, I’d have to go with aurora. If you get one of those once-in-a-lifetime auroral displays that really lights up the night in the middle latitudes, it can just be astounding. And they’re rare enough so that even in the pre-electric lighting days when the skies were still dark, people may not have been used to seeing them. Although convention wisdom would have the aurora appearing mostly in the north sky, once the auroral oval expands far enough, it can also appear in the south as well.