OT: Moon!

[Wulf2k]

http://www.math.nus.edu.sg/aslaksen/teaching/convex.html

Also, can everybody prefix their posts with "News" now, or did I just upgrade my awesomeness somehow?

 

[Chad Sexington]

The moon orbits the earth. The earth orbits the sun. If this were a physics problem, you would consider the moon + earth as one mass when calculating their orbit together. The moon's mass, speed, and distance from the sun by itself will not support an orbit.

In other words:
-The earth orbits the sun.
-The moon orbits the earth.
-The earth + moon orbits the sun.
-The "orbit" described in the link is a byproduct of its relation to the earth + moon acting as one mass.

This is also the answer to: How does the moon keep from falling into the sun then?

It's the same as saying that a person orbits the sun. The person is standing on earth and the earth orbits the sun; therefore the person also orbits the sun. That's only because we're considering the earth + person as one mass. The person by themselves would never orbit the sun. You could also make a mathematical / graphical representation of the person's "orbit" of the sun just like the one for the moon in that link.

If that's what you meant, then you're right. But everyone else is more right.

(Ye swine!)

 

[Vortex]

Good grief, you use a website from Singapore to illustrate your opinion??

Chad did a good job arguing my point.

 

[Wulf2k]

Ok, let's take this to the basics.

What makes the moon not a planet? It's bigger than Pluto was, and it's roughly 27% the size of Earth. ( http://www.universetoday.com/guide-to-space/the-moon/moon-compared-to-earth/ ) Take the Earth out of the equation and slow it down, and it would maintain its current orbit around the sun no problem.

Is it not a planet because it's close to Earth? Would Earth stop being a planet if it drifted close enough to Jupiter to start wobbling in its orbit?

 

[Sweeney]

Ok, let's take this to the basics.

What makes the moon not a planet? It's bigger than Pluto was, and it's roughly 27% the size of Earth. ( http://www.universetoday.com/guide-to-space/the-moon/moon-compared-to-earth/ ) Take the Earth out of the equation and slow it down, and it would maintain its current orbit around the sun no problem.

Is it not a planet because it's close to Earth? Would Earth stop being a planet if it drifted close enough to Jupiter to start wobbling in its orbit?

A moon orbits a planet. A planet orbits a star. If the earth were removed and the moon remained with it's current position and velocity, it would fly off into space. If magic intervened and the moon slowed down to the velocity required to maintain it's orbit.. then yes it would be a planet.

The definition of planet is semantic at best.. but the main requirement is that it orbits a star, which the moon does not. Remove the sun and all planets but earth.. and the moon would still orbit the earth.

 

[Wulf2k]

If the earth were removed and the moon remained with it's current position and velocity, it would fly off into space.

Depending when the Earth let go, the Moon would just develop a highly eccentric orbit, it wouldn't fly off into space. If the Moon was gone, the Earth would also change its orbit, though to a lesser degree.

The definition of planet is semantic at best.. but the main requirement is that it orbits a star, which the moon does not. Remove the sun and all planets but earth.. and the moon would still orbit the earth.

Agreed on the fact that we're already well into semantic argument territory. But two objects, holding each other with gravity, while both orbiting the sun, doesn't make the smaller one not the same as the larger one. Just smaller.

 

[Skylark SP]

I have the feeling I missed something, such as the first part of the discussion this is related to. Either that or Wulf is defiantly doing home projects while disregarding the warning labels on various solvents that advise to only use in well ventilated areas.

-Skylark

 

[Speedy Orkit]

Stop trying to mess with things. I am so pissed Pluto is no longer a planet.

 

[Vortex]

Stop trying to mess with things. I am so pissed Pluto is no longer a planet.

Why? Its right behind Uranus...

 

[Falon of Eldor]

3 things that cannot hide: The Sun, The Moon and The Truth!

 

[Vortex]

Would Earth stop being a planet if it drifted close enough to Jupiter to start wobbling in its orbit?

If by wobbling in its orbit you mean that Earth starts to orbit Jupiter instead of the Sun, then yes we become another moon for Jupiter.

Leave it to NASA...

First, you have to define a planet. By international consensus, a planet must be a body that orbits a star or a dead star (in any incarnation of a dead star) and exhibits three characteristics:

1) It must be rounded by the forces of its own gravity (i.e. spherical, as most asteroids and comets are not big enough to be)

2) It must be cool enough NOT to have thermonuclear fusion occur (that would make it a star)

3) It must have cleared its orbital path (this is why Pluto is not a planet- it's part of a larger group of objects from the Kuiper Belt)

If you've got a body that you can determine, by these characteristics, is a planet, then a natural body orbiting it will be a moon.

 

[Wulf2k]

Ok, so the moon meets all three of those criteria.

As you see, the moon never goes backwards, it just wobbles back and forth as it goes forward in its orbit around the sun.

If the Earth gave the moon some mass so they were exactly equal, would they be two planets or two moons? If you then threw a rock from one to the other, would the heavier one then become the planet, and the one that's now short one rock become the moon? If so, then I concede that by your definition the moon is not a planet.

I have the feeling I missed something, such as the first part of the discussion this is related to. Either that or Wulf is defiantly doing home projects while disregarding the warning labels on various solvents that advise to only use in well ventilated areas.

I was worried about the ventilation bringing me non-ventilated air, so I built an airtight box out of ventilating ducts to do solvent-related work in. Also, the topic was started in the "yay" thread and brought out here to the streets so people could step up while bringing it on.

 

[Scuzzlebutt]

If by wobbling in its orbit you mean that Earth starts to orbit Jupiter instead of the Sun, then yes we become another moon for Jupiter.

Leave it to NASA...

First, you have to define a planet. By international consensus, a planet must be a body that orbits a star or a dead star (in any incarnation of a dead star) and exhibits three characteristics:

1) It must be rounded by the forces of its own gravity (i.e. spherical, as most asteroids and comets are not big enough to be)

2) It must be cool enough NOT to have thermonuclear fusion occur (that would make it a star)

3) It must have cleared its orbital path (this is why Pluto is not a planet- it's part of a larger group of objects from the Kuiper Belt)

If you've got a body that you can determine, by these characteristics, is a planet, then a natural body orbiting it will be a moon.

The IAU (which is the organization responsible for removing Pluto's classification as a planet and thus ruining the sweet mnemonic My Very Educated Mother Just Served Us Nine Pickles.) Uses the definition you have provided plus one point you left off. It must not be a sattelite. A sattelite is defined as a celestial body which orbits a planet, therefore disqualifying our moon as a planet. So to sum it up, a planet must orbit a star and nothing else.

 

[nightstalker22]

If the Earth gave the moon some mass so they were exactly equal, would they be two planets or two moons? If you then threw a rock from one to the other, would the heavier one then become the planet, and the one that's now short one rock become the moon? If so, then I concede that by your definition the moon is not a planet.

It doesn't matter which one is larger, the moon is labeled as such because it is the satellite of a planet. If Earth were revolving around the moon, we'd be the satellite of it, and we'd be reclassified as the moon.

Both arguments are correct, as Chad stated, because technically, both objects do circle the Sun, just not on the same orbital path.

 

[Wulf2k]

Which brings us back to my first comment about dumb 5th graders, where calling the moon a planet is only wrong because it's a matter of classification, not a matter of intelligence. The moon is a perfectly fine planet on its own, it just has the bad luck of being too close to the Earth to get the "Welcome To The Planet Fraternity" gift basket.

 

[Wulf2k]

It doesn't matter which one is larger, the moon is labeled as such because it is the satellite of a planet.

They both orbit each other regardless. The one with less mass is just affected more, thus classified as the satellite. The moon makes the earth wobble in its orbit too, and if they were the same size, they'd both spin around each other equally (assuming they had the correct velocity to not crash into or escape each other)

 

[Sweeney]

Which brings us back to my first comment about dumb 5th graders, where calling the moon a planet is only wrong because it's a matter of classification, not a matter of intelligence. The moon is a perfectly fine planet on its own, it just has the bad luck of being too close to the Earth to get the "Welcome To The Planet Fraternity" gift basket.

It was actually the adult that made those comments.

 

[nightstalker22]

Which brings us back to my first comment about dumb 5th graders, where calling the moon a planet is only wrong because it's a matter of classification, not a matter of intelligence. The moon is a perfectly fine planet on its own, it just has the bad luck of being too close to the Earth to get the "Welcome To The Planet Fraternity" gift basket.

I think there are other classifications to planethood too, but I dont think they matter for the sake of this argument.

Any rock in space doesnt qualify as a planet, and the moon doesn't qualify on it's own, nor do comets or meteors.

One possible classification might be that it spins on its own axis.... which the moon doesn't, it is always facing us on the same side. I may be wrong on this, and I don't care to research it!

 

[nightstalker22]

They both orbit each other regardless. The one with less mass is just affected more, thus classified as the satellite. The moon makes the earth wobble in its orbit too, and if they were the same size, they'd both spin around each other equally (assuming they had the correct velocity to not crash into or escape each other)

They are not equal size in your example, as you tossed a rock from one to the other, making one larger.

 

[Wulf2k]

http://www.cnn.com/2006/TECH/space/08/18/moon.planet/index.html

Also, this thread is starting to come up when I search the intergooglewebs.

 

[Wulf2k]

http://blogs.nasa.gov/cm/blog/moon_missions.blog/posts/post_1247240047519.html

NASA doesn't answer their own question. DAMN YOU NASA!

 

[Lorddog]

I guess the first myth that makes you think the moon path around the sun would have all those loops is
most people would say without thinking that the moon goes around the earth each day.
where the truth is the moon is much slower and we are spinning so giving the effect that the moon goes that fast. but it doesnt. it is much slower going around the planet.
also is the orbit exactly 90% to the plane of the sun? i doubt it. probably either moves around to dif angles. so those loops would be different shapes then too.

 

[Spree]

Stars also wobble in their orbits around the universe, if they have planets. This is how they can tell if a star has a planet orbiting it. I would then imagine the the moon has an effect on the earths orbit too.

 

[Spree]

While we are on the topic of the moon did you know we bombed it today

http://www.nasa.gov/mission_pages/LCROSS/main/index.html

 

[Wulf2k]