Haumea is a dwarf planet in the Kuiper belt one-third the mass of Pluto. It was discovered in 2004 by a team headed by Mike Brown of Caltech at the Palomar Observatory in the United States, and in 2005 by a team headed by J. L. Ortiz at the Sierra Nevada Observatory in Spain, though the latter claim has been contested. On September 17, 2008, it was accepted as a dwarf planet by the International Astronomical Union (IAU) and named after Haumea, the Hawaiian goddess of childbirth. Haumea's extreme elongation makes it unique among known trans-Neptunian objects. Although its shape has not been directly observed, calculations from its light curve suggest it is an ellipsoid, with its greatest axis twice as long as its shortest. Nonetheless, its gravity is believed sufficient for it to have relaxed into hydrostatic equilibrium, thereby meeting the definition of a dwarf planet. This elongation, along with its unusually rapid rotation, high density, and high albedo (due to a surface of crystalline water ice), are thought to be the results of a giant collision, which left Haumea the largest member of a collisional family that includes several large TNOs and its two known moons.
Read the rest of this article: <http://en.wikipedia.org/wiki/Haumea_%28dwarf_planet%29> _______________________________ Today's selected anniversaries: 1863: American Civil War: The Army of Northern Virginia, led by Robert E. Lee and Stonewall Jackson, scored a decisive Confederate victory at the Battle of Chancellorsville near Spotsylvania Courthouse, Virginia. <http://en.wikipedia.org/wiki/Battle_of_Chancellorsville> 1882: The United States Congress passed the Chinese Exclusion Act, implementing a ban on Chinese immigration to the United States that eventually lasted for over 60 years until the 1943 Magnuson Act. <http://en.wikipedia.org/wiki/Chinese_Exclusion_Act_%28United_States%29> 1937: The German zeppelin Hindenburg caught fire and was destroyed while trying to land at Lakehurst Naval Air Station in New Jersey, killing over 30 people on board. <http://en.wikipedia.org/wiki/LZ_129_Hindenburg> 1994: The Channel Tunnel, a 50.5-kilometre (31.4 mi) undersea rail tunnel beneath the English Channel at the Strait of Dover connecting Folkestone, Kent, England to Coquelles, France, officially opened. <http://en.wikipedia.org/wiki/Channel_Tunnel> _____________________________ Wiktionary's word of the day: lax (adj): 1. Lenient and allowing for deviation; not strict. 2. Loose; not tight or taut <http://en.wiktionary.org/wiki/lax> ___________________________ Wikiquote quote of the day: Being entirely honest with oneself is a good exercise. --Sigmund Freud <http://en.wikiquote.org/wiki/Sigmund_Freud> _______________________________________________ Wikipedia Daily Article mailing list. To unsubscribe, visit: https://lists.wikimedia.org/mailman/listinfo/daily-article-l Questions or comments? Contact [email protected]
