Hypothetically, could an asteroid become a planet? If it caught in orbit around the sun could we technically consider it a planet? Wasn't Pluto an asteroid? I thought it was, we went to the planetarium with my son on his field trip and they said they didn't really classify Pluto as a planet. Anyone know why?

Size does matter!

john

Well, there are a lot of objects out there that are called 'planetoids'.... and there are extraordinarily large asteroids that DO have nearly circular orbits around the sun. Right now, in fact, there is a debate concerning whether or not Pluto should be considered a planet or just a large planetoid... A point that has come up in the debate is that, if the currently accepted nine planets are still to be considered planets, that the definition of 'planet' is somewhat arbitrary.

In general, though, I think that an object's size and gravitational influence determine if we consider something a planet.

As a sidenote, you might want to look on the net for info regarding Sedna, Qoaor(i know I'm not spelling that right), and Ixion. They're large objects on the edge of the solar system like Pluto.

You might also want to read about Ceres. It is a very large asteroid that orbits between Jupiter and Mars. I believe that, when it was discovered, there was some debate over whether or not it should be called a planet.



[edit on 16-6-2004 by onlyinmydreams]

humorously, if you consider Ceres, Sedna, and Quoar to be planets then we have a 12 planet solar system. That should make all you Nibiru lovers happy.

As they say, size does matter.

In general, a planet is something with a globular shape, that has gravity, and could sutain an atmosphere if the conditions were right. There are large globular bodies out there (Sedna) that are sort of marginal planets, but they're really pushing the border.

There's a special class of objects (as has been mentioned) that are large, round bodies that lurk around the edges of the solar system. They're called Kupier Bodies but none are as large as the Earth (none that we've seen.)

...and I just ran out of everything I know about them.

Well, if size does matter in this regard, I certainly hope it doesn't result in a whole new genre of spam!

Wasn't there speculation that Pluto used to be the moon of another planet?

I thought the topic name alluded to a different subject. What about turning an asteroid into an artificial plantet? Introducing the appopriate elements to create a core, water, and an atmosphere. Maybe even do this to the moon.

Originally posted by kaoscreator
Hypothetically, could an asteroid become a planet?

technically asteroids are classified as "minor planets." but i'm sure you mean as in a round planet... and not unless it had enough mass. they formed into random globs of rock as they cooled because they lacked the mass to collapse in upon themselves as planets did.

If it caught in orbit around the sun could we technically consider it a planet?

asteroids do orbit, most commonly, around the sun in the asteroid belt. there are other asteroids that lurk outside this belt though, such as: the amor asteroids, which cross mars' orbit; the apollo asteroids, which cross earth's orbit and the trojan asteroids, which lurk 60 degrees ahead of and behind jupiter in its orbit.

Wasn't Pluto an asteroid?

no. it's hypthesized to eb an escaped moon of neptune's though, as Indy stated.

I thought it was, we went to the planetarium with my son on his field trip and they said they didn't really classify Pluto as a planet. Anyone know why?

according to the board of scientists who decide what is and what isn't a planet, pluto still is one. there has been an ongoing debate since pluto's discovery over this though because of its size and orbit.

I do not know about asteroids; but, Many theories suggest that Venus was once a comet. It rotates in an opposite direction than all other planets, it is the only planet without magnetic poles, its the only planet with a day which is longer than its year, and it has a tail that may? reach earth during a transit.

If a comet can become a planet, what is to say an asteroid cannot?

this one falls into the "...what the hell have you been reading?" category. i have NEVER heard any theories supporting ANY of what you just said. let's review a titch before i dive into what you said.

Venus
diameter: 7500 miles
distance from the sun: 67 million miles
atmosphere: mostly CO2, sulferic acid, and at +900 F

the largest of comets
nucleus diameter: 5-10 miles
coma (the gas/debris around the nucleus) diameter: up to millions of miles
atmosphere: really none, but coma is composed of H, H2O, CH4, CO, O, and many others.

Originally posted by mo_trot
I do not know about asteroids; but, Many theories suggest that Venus was once a comet.

please give me some information saying this.

It rotates in an opposite direction than all other planets,

this is true, but what about uranus? it's rotation is inclined 98 degrees to the ecliptic. meaning it rotates on its side! the way a planet rotates doesn't mean much.

it is the only planet without magnetic poles, its the only planet with a day which is longer than its year,

that is true, but when planets get old and their core cools this may be what happens. it's sort of like a top slowing down. when the energy begins to leave things start to break down.

and it has a tail that may? reach earth during a transit.

venus has a tail? please. let me see some information supporting that.

If a comet can become a planet, what is to say an asteroid cannot?

comets cannot become planets, neither can asteroids. they simply are not large enough or have enough mass.

[edit on 6/17/2004 by cmdrkeenkid]

A planet is a mass large enough to have gravity force it into a spherical shape, and orbit a star. Pluto, despite its small size, manages to qualify as a planet here. A moon is a mass that orbits a planet. A moon can be large enough to be spherical in shape, or it can simply be a captured asteroid (unlike planets, which are spherical in shape, asteroids are irregular in shape).

What makes Pluto so unusual is that its orbit is not in the solar system's plane of orbits that the other planets lie on; its orbit is more like that of an asteroid. It likely was a large asteroid that was captured by the Sun, and over time gravity made its shape more spherical.

So yeah, Pluto is a planet, though an unusual one...

Originally posted by Jamuhn
What about turning an asteroid into an artificial plantet? Introducing the appopriate elements to create a core, water, and an atmosphere.

Presense of atmosphere requires enough gravity... which smaller bodies doesn't have.

Isn't it agreed that one of Jupiter's moons is just an asteriod that was attracted by Jupiter's gravitational pull? If an asteroid can become a moon the surely an ateriod can become a planet if it is in a regular orbit round the Sun and is big enough to be classed as a planet.

Originally posted by Eddie999
If an asteroid can become a moon the surely an ateriod can become a planet if it is in a regular orbit round the Sun and is big enough to be classed as a planet.

Logic... logic... logic.
If it's in stable orbit around sun and is big enough why it would have been classified as asteroid/planetoid at first point?

And BTW, Also both Mars moons are asteroids. (and propably almost all these small moons of gas giants are small asteroid/planetoids)

Logic... logic... logic.
If it's in stable orbit around sun and is big enough why it would have been classified as asteroid/planetoid at first point?

What I'm trying to say is the asteriod may have entered our solar system from outer space and then become trapped in a stable orbit around the Sun by the Sun's gravity.

Originally posted by mo_trot
Did you know that Venus has a tail? First discovered in the late 1970's by Pioneer Venus Orbiter, the tail of charged particles was discovered 70,000 km from the planet.

Pretty much every planet with magnetosphere has that.