tag:blogger.com,1999:blog-7791684492971893366.post8964936245011648482..comments2023-06-18T05:20:07.541-05:00Comments on Wind & Sky: Geek's Night OutNathan Eatonhttp://www.blogger.com/profile/09500769945494277145noreply@blogger.comBlogger1125tag:blogger.com,1999:blog-7791684492971893366.post-38293650006959859782009-02-19T11:37:00.000-06:002009-02-19T11:37:00.000-06:00Pluto is not just like any other Kuiper Belt Objec...Pluto is not just like any other Kuiper Belt Object. Saying that is ignoring the fact that by being spherical, due to being in a state of hydrostatic equilibrium, Pluto is far more akin to the larger planets than to shapeless Kuiper Belt Objects. Tyson chooses to ignore hydrostatic equilibrium, but it is the hallmark of what makes an object a planet. He is also ambivalent about the IAU vote, on the one hand describing it as "flawed," and on the other citing it to vindicate his decision to leave Pluto out of the Rose Center display.<BR/><BR/>Saying a dwarf planet is not a planet at all (which is what the IAU did) makes no scientific or linguistic sense. It is inconsistent with the use of the term "dwarf" in astronomy, where dwarf stars are still stars, and dwarf galaxies are still galaxies.<BR/><BR/>An alternative planet definition favored by many astronomers keeps the term planet broad to include any non-self-luminous spheroidal object in orbit around a star. By that definition, our solar system currently has 13 planets, of which Pluto is the tenth: Mercury, Venus, Earth, Mars, Ceres, Jupiter, Saturn, Uranus, Neptune, Pluto, Haumea, Makemake, and Eris.Anonymousnoreply@blogger.com