Plutoids: a new class of objects beyond Neptune, Astronomy, politics or damage control |
Plutoids: a new class of objects beyond Neptune, Astronomy, politics or damage control |
Jun 12 2008, 09:44 AM
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Member Group: Members Posts: 340 Joined: 11-April 08 From: Sydney, Australia Member No.: 4093 |
Article on the BBC website: 'Non-planet' Pluto gets new class
http://news.bbc.co.uk/2/hi/science/nature/7449735.stm QUOTE Now an IAU committee, meeting in Oslo, has suggested that small, nearly spherical objects orbiting beyond Neptune should carry the "plutoid" tag. It also goes on to say that not everybody is too excited about it: QUOTE "It's just some people in a smoke-filled room who dreamed it up," he told the Associated Press. "Plutoids or haemorrhoids, whatever they call it. This is irrelevant." -------------------- |
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Jun 13 2008, 05:39 PM
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Director of Galilean Photography Group: Members Posts: 896 Joined: 15-July 04 From: Austin, TX Member No.: 93 |
Stu,
Here's an idea on how to explain it. For many things there is progression, for example a tree. First it's a seed, then a sprout, then a sapling, and then a mature tree. These are nice, discrete words, but the world they are trying to describe is continuous. Is there a moment in time you can say that an oak has gone from a sapling to a mature tree? It's true of many things (I was going to use an example of miniskirts, but that might not fly for your audiences. ) that the names we give them represent a range that doesn't exist in reality. What astronomers essentially decided was that previously, we didn't know enough about planets to classify Pluto properly. Now that we do, they felt the need to move pluto over the line from "mature" to "sapling". Honestly, the only real solution would be to use fuzzy logic. They have a couple of definitions, they need to just extrapolate them: A planet must be self-gravitating such that it is spherical, with a range dependent on how circular it is A planet must clear the area around it So Pluto and Ceres would be about 50% planet, Vesta and 2003 EL61 about 30%, etc. Additional criteria and their limits can also be easily added, such as diameter or mass. This way instead of a hard cut-off, there is a nice gradual tail, just like there should be. -------------------- Space Enthusiast Richard Hendricks
-- "The engineers, as usual, made a tremendous fuss. Again as usual, they did the job in half the time they had dismissed as being absolutely impossible." --Rescue Party, Arthur C Clarke Mother Nature is the final inspector of all quality. |
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