Great Comet of 1556
The Great Comet of 1556 was a comet that first appeared in February 1556, and which was observed throughout much of Europe. The comet appears to have been seen in some places before the end of February, but it was not generally observed until the middle of the first week in March. Its apparent diameter was equal to half that of the Moon, and the tail was said to resemble "the flame of a torch agitated by the wind." Cornelius Gemma said that the head of the comet, when it first appeared, was as large as Jupiter, and that its color resembled that of Mars.
The course of the comet of 1556 was observed by Paul Fabricius, a mathematician and physician at the court of Charles V, Holy Roman Emperor.
According to NASA, the comet was first reported on 27 February 1556. It was in perigee on 13 March and in perihelion on 22 April.
Charles V comet
The Great Comet of 1556 is called the comet of Charles V. When the Emperor first caught sight of it he stood aghast, and exclaimed: "By this dread sign my fates do summon me". Charles had long meditated about retiring from the world after his conquests. Regarding the comet as a sign of Heaven's command to do so, he hastened towards the peaceful monastery of St. Juste, Placentia.An anonymous English treatise on "Blazing Stares" spoke of the comet as follows: