Sunday	Monday	Tuesday	Wednesday	Thursday	Friday	Saturday
1	2	3	4	5      42 years ago, in 1843: The Great Comet of 1843 is first observed.	6	7
8	9	10	11      85 years ago, in 1800: While testing filters for observing the Sun, William Herschel discovers infrared radiation in sunlight.	12	13	14
15      321 years ago, in 1564: Galileo Galilei is born in Pisa, Duchy of Florence, Italy.      40 years ago, in 1845: The 72-inch Rosse (Leviathan of Parsonstown) Telescope sees "first light".	16	17	18	19      412 years ago, in 1473: Nicolaus Copernicus is born in Thorn, Royal Prussia, Kingdom of Poland.      98 years ago, in 1787: William Herschel's 40-foot (Great Forty-Foot) Telescope sees "first light".	20	21
22	23	24	25	26      269 years ago, in 1616: Galileo Galilei is ordered by the Inquisition to abandon the Copernican theories.      102 years ago, in 1783: NGC 2360 (Caroline's Cluster), an open cluster in the constellation Canis Major, is discovered by Caroline Herschel.	27      42 years ago, in 1843: The Great Comet of 1843 makes a very close perihelion of less than 515,000 miles (830,000 km).	28      329 years ago, in 1556: The German astronomer Joachim Heller discovers the Great Comet of 1556 (C/1556 D1).