m111
Define "cynical"
Ok, so it's not really course related, but today it became official - they are TEN planets in our solar system. It remains as yet "unnamed", but hooray for being the last HSC class ever NOT to have to learn about it!
They're thinking now of changing the definition of 'planet' because this new one and Pluto aren't really planets.Slide Rule said:You can hardly call it or pluto planets. They're actually asteroids.
Over 800 Kuiper belt objects (KBOs) (a subset of trans-Neptunian objects (TNOs)) have been discovered in the belt, almost all of them since 1992. The largest are Pluto and Charon, but since the year 2000 other large objects that approached their size were identified. 50000 Quaoar, discovered in 2002, which is a KBO, is half the size of Pluto and is larger than the largest asteroid 1 Ceres. Three objects, designated 2003 UB313, 2005 FY9 and 2003 EL61, were announced on 29 July 2005. The former is thought to have a diameter larger than Pluto but less than 3000km, while the others are thought to be smaller than Pluto. Other objects, such as 28978 Ixion, which was discovered in 2001, and 20000 Varuna are smaller than Quaoar. Other known KBOs are progressively smaller. The exact classification of these objects is unclear, since they are probably fairly different from the asteroids of the asteroid belt.
Initial calculations show that 90377 Sedna may be larger than Charon. However, while some astronomers claim that Sedna is part of the Kuiper belt and that the current outer limit of the belt should be revised, most say that Sedna is too far out for the Kuiper belt (it is beyond the gravitational effect of Neptune) and may actually be an inner Oort cloud object. If so it is not unique; 2000 CR105, which was discovered before Sedna, may also be an inner Oort cloud object or (more likely) a transitional object between the scattered disk and the inner Oort cloud.
Neptune's moon Triton is commonly thought to be a captured KBO.