The Great Comet of 1472 (C/1471 Y1) passed 0.0690 AU (10.3 million kilometres, 26.9 lunar distances) from the Earth on the 22nd January 1472.
The Great Comet of 1472 (C/1471 Y1) was discovered on the 21st December 1471, and was visible for a total of 59 days. The English 'Chronicles of the White Rose of York' (1483) reported that "...this star was seen two or three hours before the Sun('s) rising in December, four days before Christmas, in the southwest".
In Japan, the comet was first observed on the 2nd January with a 4-5° long tail. It was observed there at least until the 10th February. In China and Korea, the comet was also seen from the beginning of January to February, with the tail reaching a length of 30° by the 20th January.In Italy in mid-January, a tail of 36° length and width 4° was observed, with the head of the comet being described as "almost as big as the moon". At this time, the comet was observed by German mathematician Regiomontanus who estimated the angular extent of the tail length and Coma. Using the angle of parallax, Regiomontanus tried to estimate its distance from Earth.
The Chinese, who recognised the apparition on 15 January as a comet, reported that the comet "stretched over the sky" and appeared on the 22nd of January "even at noon". Around this time, the comet likely passing very close to the Earth only ~15° from the celestial north pole. It is estimated it passed 0.0690 AU (10.3 million kilometres, 26.9 lunar distances) from the Earth on the 22nd January 1472.The comet reached magnitude -3.0 on the 32rd January 1472.
The comet reached perihelion on the 1st March 1472 at a distance of 0.4859 AU (73 million km) from the Sun, and between the orbits of Mercury and Venus. On the 24th January it approached about 42 million km from Venus, and passed about 31 million km from Mercury on the 25th February. The comet was last sighted on the 1st March 1472.The comet will probably return to the inner solar system after many tens of thousands of years.The orbit of the comet was determined to be parabolic and tilted 170.9° to the ecliptic, and running almost in the same plane, but in the opposite direction (retrograde) as the planets.