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Poor old Pluto. Demoted from planet to dwarf planet, or worse … panetoid!
In 2006 the International Astronomical Union ruled that Pluto was no longer a planet, leaving just eight planets proper in our Solar System.
For the record, a planet is:
“A celestial body that (i) is in orbit around the Sun, (ii) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (iii) has cleared the neighbourhood around its orbit.” (IAU Resolution B5)
Pluto satisfies (i) and (ii), but not (iii): there are other things sharing its orbit around the Sun. Bigger planets, with stronger gravitational fields, plough everything else out of the way as they go around the Sun. Pluto is just too small to make that kind of impact.
Off you go now, Pluto. It’s been fun.
I’m a physicist, science communicator, certified iNerd, lover of (and amateur dabbler in) design, and rabid fan of quality science. This is where quirky ideas, fun science, wearable geekery and occasional accidentally cool photography gather.
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Comments
haha
lol this cracked me up! nice tshirt Kip
:) I like this
Yeah … you know you’re growing old(er), I’d say, when the Solar System itself changes.
A ripper. Like it.
coool
very cool!
Love it :)
Cool work! Hope you’ll add it to Cutting Edge!
Love it.