Club Planet: It's Not Hard to Join
There was a time when the solar system we lived in was only nine planets (and that last - or sometimes the eighth or seventh one, depending on where it is in its orbit is questionable. Always has been). You should know them but I've seen Howard Stern and Jeno Leno ask people (models for the former and just anyone on the street for the latter) if they knew how many planets are in the solar system. It is rather staggering how many people don't know this! Which is just wrong. I love astronomy and I know my planets and not just who they and where they are but their nomenclature and the number of moons, siderial days/months/years and whole host of other information. I also own an absolutely gorgeous telescope that can zero in on the planets (as well as other things when the air isn't so poluted with... stuff - light, junk, clouds, ha, ha). I love astronomy.
Well, I am not sure that astronomers love astronomy, because either someone thinks more planets will get more funding or maybe our standards are just sinking lower. I really don't know. And yet, there was the headline on My Yahoo! page on... let me see... oh. Just yesterday. Obviously it's on my mind a lot. Seems like I have been thinking about this rather preposterous idea for days, not hours (or just a day).
Quite honestly, let's redefine our solar system as eight planets and give Pluto an oppotunity to be itself - the rogue asteroid that it really is. Its elliptical orbit immediately suggests that something other than our sun is butting in and lending some pull to its path... it wanders in and out of Neptune's orbit periodically (granted the periods are really long in comparison to anything we put up with from Terra or any of our immediate neighbours. But Pluto is tiny, and not as polite as Mercury (also tiny). Personally, I think Percival Lowell was just looking to leave his mark on the solar system or curry favour with the scientists of his day or maybe he really thought he had something. Planet X became Pluto, the ninth planet in our select little group, which ironically has a moon, Charon, about the same size... hmmm...
So a quick review. The Greeks found a handful of bright objects and called them planets (meaning "to wander"). The list got bigger and then planet was redefined as "one of nine bodies, bigger than asteroids, that orbited the sun". Done. Finished. Good to go. The article states that the definition of 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 equillibrium shape (meaning close to round), and (b) is in orbit around a star, and is neither a star or a satellite of a planet". OK. Not terrible. Maybe still a little incomplete in detail but still a good strong definition. Jupiter got lucky... a little more mass and it would have had the possibility to initiate fusion and be reclassified as a star...
But I don't have any beef with Jupiter. Sure, its core may be tiny, but the whole gassy thing going on around that tiny core, complete with storms, high winds and gasses that would just about kill anything outright is a planet, one of our gas giants. We can't all look like Terra or Venus or Mars. Personally, Uranus and Neptune are my favourites. They've odd things like smaller less visible rings and Uranus rotates on its side - top to bottom instead of "side to side". Of course, there is no "up" in space, so maybe we are all rotating on our sides and Uranus has it right...
OK, let's start at the beginning. There is a sun. Big, monstrous, bright yellow G-type star, shines during the day, is occasionally occluded by our ferocious little Moon. It puts out tons of radiation. Its hydrogen reactor seems to have many billions of years before our sun reaches retirement age and begins to have fusion issues. It's a good star.
Inside that you have Mercury, with a year of 88 days, a day that is acutually 56 days long (it's a slow rotator), and a teeny diameter of 4,879km. I've been given to understand that it is the hottest and coldest planet we have.. simultaneously. The daytime soars up to 430 C and the night side? A chilling -183 C. BBBBR-R-R-R-R!
Next on the roster is Venus, sort of planetary hothouse. Venus is a little wacky. It has a year of 227 days, but its rotational speed is a variable thing... its planetary rotation is 243 days. but the winds just 60km above the surface go zipping along at 100m a second. Scary place. The surface temperature at 464 C, is a tad hot.
I certainly hope you know what follows Venus but precedes Mars. Welcome to Earth, or by its real name, Terra. We have it all, here. Volcanoes, craters, meteor strikes, etc...
Then we have Mars, following us. Its pretty, somewhat temperate, in the part at the right time. I usually know the right time, but I'm tired and running out of steam and shall finish this anon...
Well, I am not sure that astronomers love astronomy, because either someone thinks more planets will get more funding or maybe our standards are just sinking lower. I really don't know. And yet, there was the headline on My Yahoo! page on... let me see... oh. Just yesterday. Obviously it's on my mind a lot. Seems like I have been thinking about this rather preposterous idea for days, not hours (or just a day).
Quite honestly, let's redefine our solar system as eight planets and give Pluto an oppotunity to be itself - the rogue asteroid that it really is. Its elliptical orbit immediately suggests that something other than our sun is butting in and lending some pull to its path... it wanders in and out of Neptune's orbit periodically (granted the periods are really long in comparison to anything we put up with from Terra or any of our immediate neighbours. But Pluto is tiny, and not as polite as Mercury (also tiny). Personally, I think Percival Lowell was just looking to leave his mark on the solar system or curry favour with the scientists of his day or maybe he really thought he had something. Planet X became Pluto, the ninth planet in our select little group, which ironically has a moon, Charon, about the same size... hmmm...
So a quick review. The Greeks found a handful of bright objects and called them planets (meaning "to wander"). The list got bigger and then planet was redefined as "one of nine bodies, bigger than asteroids, that orbited the sun". Done. Finished. Good to go. The article states that the definition of 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 equillibrium shape (meaning close to round), and (b) is in orbit around a star, and is neither a star or a satellite of a planet". OK. Not terrible. Maybe still a little incomplete in detail but still a good strong definition. Jupiter got lucky... a little more mass and it would have had the possibility to initiate fusion and be reclassified as a star...
But I don't have any beef with Jupiter. Sure, its core may be tiny, but the whole gassy thing going on around that tiny core, complete with storms, high winds and gasses that would just about kill anything outright is a planet, one of our gas giants. We can't all look like Terra or Venus or Mars. Personally, Uranus and Neptune are my favourites. They've odd things like smaller less visible rings and Uranus rotates on its side - top to bottom instead of "side to side". Of course, there is no "up" in space, so maybe we are all rotating on our sides and Uranus has it right...
OK, let's start at the beginning. There is a sun. Big, monstrous, bright yellow G-type star, shines during the day, is occasionally occluded by our ferocious little Moon. It puts out tons of radiation. Its hydrogen reactor seems to have many billions of years before our sun reaches retirement age and begins to have fusion issues. It's a good star.
Inside that you have Mercury, with a year of 88 days, a day that is acutually 56 days long (it's a slow rotator), and a teeny diameter of 4,879km. I've been given to understand that it is the hottest and coldest planet we have.. simultaneously. The daytime soars up to 430 C and the night side? A chilling -183 C. BBBBR-R-R-R-R!
Next on the roster is Venus, sort of planetary hothouse. Venus is a little wacky. It has a year of 227 days, but its rotational speed is a variable thing... its planetary rotation is 243 days. but the winds just 60km above the surface go zipping along at 100m a second. Scary place. The surface temperature at 464 C, is a tad hot.
I certainly hope you know what follows Venus but precedes Mars. Welcome to Earth, or by its real name, Terra. We have it all, here. Volcanoes, craters, meteor strikes, etc...
Then we have Mars, following us. Its pretty, somewhat temperate, in the part at the right time. I usually know the right time, but I'm tired and running out of steam and shall finish this anon...
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