[14] Brahe made thousands of very precise measurements of the comet's path, and these findings contributed to Johannes Kepler's theorizing of the laws of planetary motion and realization that the planets moved in elliptical orbits.

[16] In order to compare to the comet to known stationary celestial objects Brahe used a simple sextant which was simply a graduated sixth of a circle.

[16] Kepler, who was Brahe's assistant during his time in Prague, believed that the comet's behavior and existence was proof enough to displace the theory of celestial spheres, although this view turned out to be overly optimistic about the pace of change.

[20] Brahe's finding that comets were heavenly objects, while widely accepted, was the cause of debate up until and during the seventeenth century, with many theories circulating within the astronomical community.

On November 7, in Ferrara, Italy, architect Pirro Ligorio described "the comet shimmering from a burning fire inside the dazzling cloud.

The Sultan Murad III saw these observations as a bad omen for the war and blamed al-Din for the plague which spread at the time.

[25] Other observers include Helisaeus Roeslin, William IV, Landgrave of Hesse-Kassel,[26] Cornelius Gemma, who noted the comet had two tails[5][27] and Michael Mästlin[28] also identified it as superlunary.

This comet and the observation that it was traveling on the earth’s atmosphere was also what helped Maestlin to explain the gaps in Copernicus’s planetary system.

[35] The comet was mentioned in the 17th century Vietnamese chronicle Đại Việt sử ký toàn thư, Book 17, part 1: "In November 1577 (lunar calendar), comet appears, pointing at the southeastern sky, its luminous tail is as long as 40 zhàng with rose and purple tint, everyone was frightened.

On first date of December, the comet disappears".Due to this observation, King Lê Thế Tông changed his era name to Quang Hưng (光興) meaning bright and rising in the next year, 1578.

Rosh Hodesh Kislev (November 11), after sunrise, a large star with a long tail, pointing upward, was seen in the southwestern part of the sky.

On the fifteenth of Kislev, I went to live in Jerusalem".In Ireland, the Great Comet was observed, and an account of its passing was later inserted in the Annals of the Four Masters: "A wonderful star appeared in the south-east in the first month of winter: it had a curved bow-like tail, resembling bright lightning, the brilliancy of which illuminated the earth around, and the firmament above.

I can affirm thus much, as a present witness by mine own experience· that when divers upon greater scrupulosity then cause, went about to dissuade her majesty (lying then at Richmond) from looking on the Comet which appeared last: with a courage answerable to the greatness of her state, she caused the window to be set open, and cast out this word [motto, quotation] Iacta est alia the dice are thrown, affirming that her steadfast hope and confidence was too firmly planted in the providence of God, to be blasted or affrighted with those beams, which either had a ground in nature whereupon to rise, or at least no warrant out of scripture, to portend the mishaps of Princes.

That the Comets hinder not the lives of Princes, I have proved heretofore at large, and shall have opportunity likewise to confirm hereafter, but thus much I dare affirm, that albeit the malice of the same were no less to be feared then some think: yet her contented mind, her harmless thoughts, her temperance in diet, abstinence from excess of all things that offend, with moderation of exercise, were enough to verify that proverb which hath been rife of old, Sapiens domabitur astris [‘the wise subdue the stars’].