In 1748, Spanish explorer Antonio de Ulloa (1716–1795) and six other travelers each observed a colorful atmospheric phenomenon around their distorted shadows on a thin cloud in the distance. As French astronomer and science popularizer Camille Flammarion explained in his 1872 book, L’Atmosphère
(“The Atmosphere”): “The image was in the centre of three rainbows of different colors, and surrounded at a certain distance by a fourth bow with only one color. … All these bows were perpendicular to the horizon; they moved in the direction of, and followed, the image of the person whom they enveloped as with a glory.”Astronomy magazine subscribers can read the full column for free. Just make sure you're registered with the website.