synchronous belt
31Trans-Hudson orogeny — [ North American craton, also called Laurentia.] [ Wyoming, Superior and Hearne cratons] The Trans Hudson orogeny, Trans Hudsonian orogeny, Trans Hudson orogen (THO), or Trans Hudson Orogen Transect (THOT), (also referred to as the Trans… …
32Neptune — This article is about the planet. For other uses, see Neptune (disambiguation). Neptune   …
33Electric generator — U.S. NRC image of a modern steam turbine generator In electricity generation, an electric generator is a device that converts mechanical energy to electrical energy. A generator forces electric charge (usually carried by electrons) to flow… …
34Phobos (moon) — Phobos Enhanced color view of Phobos obtained by Mars Reconnaissance Orbiter on March 23, 2008. Stickney crater, the largest, is on the right side. Discovery Discovered by …
35Utility frequency — The waveform of 230 volt, 50 Hz compared with 110 V, 60 Hz. The utility frequency, (power) line frequency (American English) or mains frequency (British English) is the frequency at which alternating current (ac, also AC) is transmitted from a… …
36Pilbara craton — The Pilbara craton (the Pilbara province in northwest Western Australia), along with the Kaapvaal craton (the Kaapvaal province of South Africa) are the only remaining areas of pristine Archaean 3.6 2.7 Ga crust on Earth. Similarities of their… …
37Wide-field Infrared Survey Explorer — (WISE) WISE prior to its mission into orbit …
38Retrograde motion — This article is about retrograde motions of celestial bodies relative to a gravitationally central object. For the apparent motion as seen from a particular vantage point, see Apparent retrograde motion. Retrograde orbit: the satellite (red)… …
39Phonograph — Turntable redirects here. For other uses, see Turntable (disambiguation). Edison cylinder phonograph ca. 1899 …
40List of gravitationally rounded objects of the Solar System — Objects in the Solar System By orbit By size By discovery date …
