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 Screens The Screens The Screens () is a play by the French dramatist Jean Genet. Its first few productions all used abridged versions, beginning with its world premiere under Hans Lietzau's direction in Berlin in May 1961. Its first complete performance was staged in Stockholm in 1964, two years before Roger Blin directed its French premiere in Paris. Genet began writing the play in 1955 and continued to develop it over the following few years, completing a first version in June 1958. He re-wrote the play further while in Greece towards the end of 1959. Marc Barbezat's publishing company L'Arbalète published