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Sednoid Orbits
A sednoid is a trans-Neptunian object with a perihelion well beyond the Kuiper cliff at . Only four objects are known from this population: 90377 Sedna, , 541132 Leleākūhonua (), and , but it is suspected that there are many more. All four have perihelia greater than . These objects lie outside an apparently nearly empty gap in the Solar System and have no significant interaction with the planets. They are usually grouped with the detached objects. Some astronomers, such as Scott Sheppard, consider the sednoids to be inner Oort cloud objects (OCOs), though the inner Oort cloud, or Hills cloud, was originally predicted to lie beyond 2,000 AU, beyond the aphelia of the three known sednoids. One attempt at a precise definition of sednoids is any body with a perihelion greater than and a semi-major axis greater than . However, this definition applies to objects such as , which has a perihelion at 50.02 AU and a semi-major axis of about 700 AU but it is thought to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sednoid Orbits
A sednoid is a trans-Neptunian object with a perihelion well beyond the Kuiper cliff at . Only four objects are known from this population: 90377 Sedna, , 541132 Leleākūhonua (), and , but it is suspected that there are many more. All four have perihelia greater than . These objects lie outside an apparently nearly empty gap in the Solar System and have no significant interaction with the planets. They are usually grouped with the detached objects. Some astronomers, such as Scott Sheppard, consider the sednoids to be inner Oort cloud objects (OCOs), though the inner Oort cloud, or Hills cloud, was originally predicted to lie beyond 2,000 AU, beyond the aphelia of the three known sednoids. One attempt at a precise definition of sednoids is any body with a perihelion greater than and a semi-major axis greater than . However, this definition applies to objects such as , which has a perihelion at 50.02 AU and a semi-major axis of about 700 AU but it is thought to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galactic Tide
A galactic tide is a tidal force experienced by objects subject to the gravitational field of a galaxy such as the Milky Way. Particular areas of interest concerning galactic tides include galactic collisions, the disruption of dwarf or satellite galaxies, and the Milky Way's tidal effect on the Oort cloud of the Solar System. Effects on external galaxies Galaxy collisions Tidal forces are dependent on the gradient of a gravitational field, rather than its strength, and so tidal effects are usually limited to the immediate surroundings of a galaxy. Two large galaxies undergoing collisions or passing nearby each other will be subjected to very large tidal forces, often producing the most visually striking demonstrations of galactic tides in action. Two interacting galaxies will rarely (if ever) collide head-on, and the tidal forces will distort each galaxy along an axis pointing roughly towards and away from its perturber. As the two galaxies briefly orbit each other, thes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2012
2012 was designated as: *International Year of Cooperatives *International Year of Sustainable Energy for All Events January * January 12 – Violent 2012 Romanian protests, protests occur in Bucharest, Romania, as two-day-old demonstrations continue against President Traian Băsescu's economic austerity measures. Clashes are reported in numerous Romanian cities between protesters and law enforcement officers. * January 13 – The passenger cruise ship ''Costa Concordia'' Costa Concordia disaster, runs aground off the coast of Italy, causing 32 deaths. * January 23 – Iran–European Union relations: the European Union adopts an embargo against Iran in protest of its continued effort to enrich uranium. * January 27 – Spanair ceases operations after talks with Qatar Airways for a prospective takeover fall through. February * February 6 – The Diamond Jubilee of Elizabeth II, Diamond Jubilee of Queen Elizabeth II marks the 60th anniversary of her ac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
