sighting distance
41Liancourt Rocks — Dokdo redirects here. For other uses, see Dokdo (disambiguation). Takeshima redirects here. For other uses, see Takeshima (disambiguation). Liancourt Rocks Disputed islands Other names: Dokdo, Takeshima …
42Paul R. Hill — (1909 ndash;1990) was a pioneering aeronautical research engineer who spent a lifetime on the cutting edge of research and development for NACA and NASA.He is also well known in the field of Ufology for his scientific research into the subject of …
43Hand compass — Parts of a hand compass A hand compass (aka hand bearing compass or sighting compass) is a term for any compact magnetic compass capable of one hand use and fitted with a sighting device to record a precise bearing or azimuth to a given target or …
44New moon — For other uses, see New moon (disambiguation). The new moon phase In astronomical terminology, the new moon is the lunar phase that occurs when the Moon, in its monthly orbital motion around Earth, lies between Earth and the Sun, and is therefore …
45Pluto — This article is about the dwarf planet. For other uses, see Pluto (disambiguation). Pluto   …
46Shen Kuo — Infobox Scientist name = Shen Kuo zh. 沈括 image width = 280px caption = Shen Kuo, a Chinese scientist famous for his concepts of true north and land formation, among others. (Modern artist s impression) birth date = 1031 birth place = Qiantang… …
47unidentified flying object — also called flying saucer any aerial object or optical phenomenon not readily identifiable to the observer. UFOs became a major subject of interest following the development of rocketry after World War II and were thought by some… …
48Ship gun fire-control system — Mk 37 Director c1944 with Mk 12 (rectangular antenna) and Mk 22 orange peel Ship gun fire control systems (GFCS) enable remote and automatic targeting of guns against ships, aircraft, and shore targets, with or without the aid of radar or optical …
49List of extinct birds — This page refers only to birds that have gone extinct since the year 1500 A.D./C.E. and usually were subject to scientific study while alive.Since 1500, over 190 species of birds have become extinct, and this rate of extinction seems to be… …
50Black triangle (UFO) — This article is about UFO s: for other uses see the disambiguation page Black triangle . Black triangles is the name given to a class of unidentified flying objects (UFOs) with certain common features which have reportedly been observed from the… …
