permanent side reflector
41Gold — This article is about the metal. For the color, see Gold (color). For other uses, see Gold (disambiguation). platinum ← gold → mercury …
42Hubble Space Telescope — Infobox Space telescope name = Hubble Space Telescope (HST) caption = The Hubble Space Telescope as seen from Space Shuttle Discovery during its second servicing mission (STS 82) organization = NASAESASTScI alt names = nssdc id =… …
43Wireless access point — In computer networking, a wireless access point (WAP or AP) is a device that allows wireless communication devices to connect to a wireless network using Wi Fi, Bluetooth and related standards. The WAP usually connects to a wired network, and can …
44Observational astronomy — Mayall telescope at Kitt Peak National Observatory Observational astronomy is a division of the astronomical science that is concerned with getting data, in contrast with theoretical astrophysics which is mainly concerned with finding out the… …
45United States Coast Guard Yard — U.S. Coast Guard Yard Curtis Bay U.S. National Register of Historic Places U.S. Historic district …
46Nuclear proliferation — World map with nuclear weapons development status represented by color.   Five nuclear weapons states from the NPT …
47Satellite — This article is about artificial satellites. For natural satellites, also known as moons, see Natural satellite. For other uses, see Satellite (disambiguation). An animation depicting the orbits of GPS satellites in medium Earth orbit …
48Tidal acceleration — is an effect of the tidal forces between an orbiting natural satellite ( i.e. a moon), and the planet (called the primary) that it orbits. It causes a gradual recession of a satellite in a prograde orbit away from the primary, and a corresponding …
49John Herschel — Infobox Scientist name = Sir John Herschel box width = image width = 200px caption = 1867 photograph by Julia Margaret Cameron birth date = birth date|1792|03|07 birth place = Slough, then Buckinghamshire now Berkshire, England death date = death …
50Surveying — For other uses, see Survey (disambiguation). US Navy Surveyor at work with a leveling instrument …
