The new definition of a planet is:
A planet is a celestial body that (a) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (b) is in orbit around a star, and is neither a star nor a satellite of a planet.
Robin
razor@edgarbv.com
https://www.edgarbv.com
Euhm, nobody is happy with this definition, because they say eg. the moon will become a planet when it loses gravitational pull with the Earth in a few hundred million years or whenever, so they’ve now voted to strip us of Pluto and make it a dwarf planet.
“It also must be large enough in mass for its own gravity to pull it into a nearly spherical shape and have cleared the neighbourhood around its orbit.
Pluto was disqualified because its oblong orbit overlaps with Neptune’s.”
http://go.reuters.com/newsArticle.jhtml?type=topNews&storyID=13284690&src=rss/topNews
Of course people aren’t taking this sudden switch lying down – apparently many astronomers feel that the new definition won’t pass peer review and that there were not enough voters for the result to be representative of the astronomers opinions worldwide.
http://news.bbc.co.uk/2/hi/science/nature/5283956.stm
And yet again confusion reigns in planet definition land…
http://space.com/scienceastronomy/060907_chrx73b.html
This story just doesn’t end!
Pluto has just been redesignated a number: 134340
http://msnbc.msn.com/id/14789691/
And Xena is now called Eris
http://news.bbc.co.uk/2/hi/science/nature/5344892.stm