Pluto's not a planet - was Pluto Saved! (was going to be "no longer a planet") Merged

lostexpectation

Capt'n Midnight wrote:

If it's bodies that orbit the sun the Charon does too. The argument is that Pluto and Charon orbit a point out side either planet.
And as for atmsophere Mercury has none worth talking about compared to most of the moons listed above.

Oh and it's not downsizing - like the corporate gimps say it's rightsizing

TBH
maybe we need new definitions, Gas Giants is very good,
Terrestial planets is also good.
Not sure how much I like Dwarf Planets
Maybe "Moons" leaving "moonlets" for the smaller ones.
Why can't we call Mercury a moon of the sun ??

what about a planetoid I would have accepted that over dwarf planet

mike65

Vertically Challanged, Short Stature?

Mike.

Black NG-60-90

Maybe its a reality game show where they vote off a different planet every decade. What ever happened to Planet X?

mike65

The Tenth Planet either does'nt exist or could be the generic name for any number of Kuiper Belt Objects.

Back in the day (late 19th/early 20th century) it was supposed to be an undiscovered gas giant but quite how a gas planet could be missed is beyond me with modern astonomy techniques and technology.

Some belive its out there and will appear and come close to the earth and turn our magetic field upside down! But these people are Battlefield Earth fans.

Mike.

Black NG-60-90

I was looking up some info on 'Xena'. Its actually larger than pluto and has it's own moon. Why was this never classified as the 10th planet?

galactus

Capt'n Midnight wrote:

weasel words

Pluto's orbit was inside Uranus not so long ago so of course it wasn't dominant in that accretion zone.

Jupiter is the dominant body in the accretion zone of the outer solar system. It protects us from comets. So the Earth isn't a planet then ?

edit http://en.wikipedia.org/wiki/Clearing_the_neighbourhood#_note-1

The point here is that the accretion zone is only of consequence when the nascent planetesimal begins to form.

As for Jupiter being the dominant accretion zone in the outer solar system - if only it were that simple.


PS Correction - Until 1999 Pluto was within Neptune's orbit not that of Uranus.

Flukey

Lostexpectation wrote:

i think childrens science books have a lot to answer for, not displaying the distance between the planets properly, displaying them all as if there on the same plane,

If they were to do it to scale, let's just say that those books would need considerably larger pages. The page, if it were to hold the entire Solar System to scale, would be considerably larger than the schoolyard and indeed many a university campus. Remember too that Pluto does not mark the edge of the solar system, as many of those diagrams imply, but its distance from the Sun is only a miniscule fraction of the distance to the edge of our Solar System. So in the interests of the rainforests and the ability for children to be able to carry their books to school, I think we have to go along with the type of diagrams that they do have in those books.

Thirdfox

Or they could make the diagrams tiny and children need to buy microscopes to read them... electron microscopes mwah ha ha ha!

galactus

Flukey wrote:

If they were to do it to scale, let's just say that those books would need considerably larger pages. The page, if it were to hold the entire Solar System to scale, would be considerably larger than the schoolyard and indeed many a university campus. Remember too that Pluto does not mark the edge of the solar system, as many of those diagrams imply, but its distance from the Sun is only a miniscule fraction of the distance to the edge of our Solar System. So in the interests of the rainforests and the ability for children to be able to carry their books to school, I think we have to go along with the type of diagrams that they do have in those books.

Lostexpectaton is also refering to the fact that Pluto/Charon is inclined at 17 degrees to the plane of the ecliptic - which raises the question why?

Kids are like sponges - why not add in KBOs, Oort cloud etc.

Lostexpectaton wrote:

saying the atom is smallest thing

This used to drive me bananas! Why the big secret about anti-matter? What is worse is perpetuating the 19th century idea that atoms are minature solar systems.

Although in fairness to the writers of kids science book, where do you draw the line? Adding things like "most of the universe is thought to be composed of dark matter and scientists aren't in agreement as to what its made of" might cause undue angst.

Flukey

Well Galactus, I mentioned some of those things myself in another post I put up:

Flukey wrote:

There has always been a lot of debate about Pluto and what it is and what accounts for its strange orbit. Maybe it is a KBO or maybe it was a moon of Neptune. There is a lot of questions about our solar system that have intrigued astronomers for years. Why Venus and Uranus rotate in the opposite direction to all the other planets; why Uranus rotates almost on its side; the 17° tilt in the orbit of Pluto and the way it in comes inside Neptune at times. Is there some connection between those things? Did some cataclysmic event(s) occur to knock Uranus on its side and to send Pluto, possibly a moon, away from Neptune into its own unusual orbit. There are theories on all of these and other questions. The truth is we don't know. That is part of the fascination of astronomy and other science subjects. Striving for additional knowledge and coming up with and testing theories; fully accepted theories being thrown out in favour of new ones.

galactus

The final nail in the coffin: Pluto now just a number

I didn't know that in May Hubble had discovered that Pluto, I mean asteroid number 134340, had another couple of buddies apart from Charon: Nix and Hydra.

Flukey wrote:

Well Galactus, I mentioned some of those things myself in another post I put up:

Apologies Flukey!