History of the telescope of the IRAS satellite in 1983 revolutionized infrared astronomy from space. This reflecting telescope which had a mirror, operated for nine months until its supply of coolant (liquid helium) ran out. It surveyed the entire sky detecting 245,000 infrared sources—more than 100 times the number previously known. Although optical telescopes can image the near ultraviolet, the ozone layer in the stratosphere absorbs ultraviolet radiation shorter than 300 nm so most ultra-violet astronomy is conducted with satellites. Ultraviolet telescopes resemble optical telescopes, but conventional aluminium-coated mirrors cannot be used and alternative coatings such as magnesium fluoride or lithium fluoride are used
The empire on which the sun never sets the sun encircles.” Mesopotamian texts contemporary to Sargon of Akkad (c. 2334 – 2279 BC) proclaim that this king ruled “all the lands from sunrise to sunset.” In the early 16th century, the phrase, ""el imperio en el que nunca se pone el sol"" ("the empire on which the sun never sets") originated with a remark made by Fray Francisco de Ugalde to Charles I, who as king of Spain and as Holy Roman Emperor by the name of Charles V, had an empire, which included many territories in Europe, islands in the Mediterranean and Atlantic, cities in North Africa