How many moons does the Earth have? (seriously) - Page 2 - GoFuckYourself.com

Juge · 09-16-2002, 02:36 PM

Quote:

Originally posted by mika
Scientifically it's not Earth's second moon. Read the FAQ next time

"Does asteroid 3753 Cruithne orbit the Earth like a moon or satellite?

No. The asteroid's behaviour is more complicated than that: it doesn't orbit the Earth, but rather it shares the Earth's orbit. The relationship of a moon to its planet is called a two-body because there are only two important players (ie. the moon and the planet). However, in the case of Cruithne, the Earth and the asteroid both share the same orbit about the Sun, but are choreographed in such a away as to remain stable and avoid colliding with each other. This is called a three-body relationship as there are three main players: the Earth, the asteroid and the Sun. Please see the 3753 Cruithne main page for more details on the asteroid's motion. "

Case closed. Stupid poll

If this is true, then this explains the simulations, and would indicate that the asteroid is not in orbit around the Earth, and is thus not a moon.

Give a URL to the above quote, please.

Oh, and if the poll was so stupid, why are you spending so much time here?

SpaceAce · 09-16-2002, 02:39 PM

Quote:

Originally posted by Juge

The simulations seemed very strange to me, as well... But I don't think that just beacuse it is close to the Earth's orbit around the sun that it is considered a moon of Earth's... It should be shown to orbit the earth. There are two moons going around Jupiter or Saturn that swap places every orbit when they get close, so they are sort of orbting each other according to the definition you gave there... but they are considered two moons of Jupiter (or Saturn, I can't remember which). It's really weird... To be honest, according to the sims, this second moon does not appear to be a moon of Earth's... I wish I knew more about it. They have categorized it as Earth's second moon, though... back in 1986, I believe.

Is there somewhere that shows as an actual "categorization" instead of just a term used to describe it? Acording the sims, the "second moon" passes behind the Earth crossing directly through our orbit around the sun.

SpaceAce

mika · 09-16-2002, 02:44 PM

Quote:

Originally posted by Juge

Oh, and if the poll was so stupid, why are you spending so much time here?

No offense, but I felt like answering a challenging Trivial Pursuit question only to find out that the company who made that question didn't know the correct answer themselves.

http://www.astro.queensu.ca/~wiegert/3753/faq.html

The question itself (about that asteroid) was interesting, though

Friday · 09-16-2002, 02:53 PM

quote:
--------------------------------------------------------------------------------
Originally posted by Friday
Not true.
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Quote:

Originally posted by HQ
You are also wrong. Tell us how it is not true.

Do you believe there is such definition as "super natural"?
If you do I can't answer your question you won't understand - no offence.

Juge · 09-16-2002, 04:18 PM

Quote:

Originally posted by mika
No offense, but I felt like answering a challenging Trivial Pursuit question only to find out that the company who made that question didn't know the correct answer themselves.

http://www.astro.queensu.ca/~wiegert/3753/faq.html

The question itself (about that asteroid) was interesting, though

Dude, you're criticizing me, and patting me on the back at the same time.

When I made the post, I read that this moon was categorized as a moon. Is it now? According to your article... no. Take a look at this:

http://www.space.com/scienceastronom...on_991029.html

To quote a bit of this:

Quote:

"Eventually these same channels provide the moons with escape routes. So the main difference between the moon (we?ve always known) and ?the new moons? is that the latter are temporary -- they come and go, but they stay for a very long time before they leave."

Quote:

"A moon typically is defined as an object whose orbit encompasses a planet, say, the Earth, rather than the sun, said Carl Murray, who worked with Namouni and Christou on the research.

But it?s hard to say what a "true" moon is, he said.

In his view, there are three classes of moons ? large moons in near-circular orbits around a planet, having formed soon after the planet; smaller fragments that are the products of collisions; and outer, irregular moons in odd orbits, or captured asteroids like Cruithne. In the past year, astronomers have reported finding such objects around Uranus."

Quote:

"At some stage you have to consider the definition of ?moon,?" he said. "Is a dust particle orbiting the Earth a ?moon? of the Earth?"

- very interesting because, as I said before, there is no minimal size of a satellite.

Quote:

"As for Cruithne, Namouni said it?s not really a "moon" because it moves around the Earth at this time but may not forever. Earth is causing Cruithne?s present trajectory, but it could eventually escape.

So it?s not a moon of Earth, but it might become one."

It appears that they have to define "moon" more precisely than just "a natural satellite that orbits the earth. I guess this is ok; what they really have to define is "orbit"... if he object does not appear to "orbit" the planet, then it cannot be a moon. This object does not appear to, so it is not a moon. The Moon appears to, so it is a moon. The problem lies in that the gravity of all objects effect all others, so when does a 3 mass system (such as the Sun, Earth, and Moon) make a planet-moon system going around the sun, and when does it be just 2 objects orbiting the Sun (which appears to be the case with the Sun, Moon, and Cruithne.

And dude... I could not possibly know the "correct answer" if the party who defines the answer changes their mind.

Nevertheless, this is an interesting thing that not many people knew about... so I thought I'd bring it up. There is nothing wrong with enlightening some people with some information that they knew nothing about which is so close to home (astronomically, anyway).

Btw, isn't this cool:

Showing a camera view in which the Earth and Sun remain fixed, it shows the moon. Notice that it flies around the Lagrange points of the Sun-Earth system... it would be impossible to categorize this 'moon' as a simple orbit around the Sun by itself when it is so tied to Earth's orbit (just as the many Trojan Asteroids orbit in the Lagrange points around Jupiter).

Definition:
Lagrange points: Lagrange Points mark positions where the gravitational pull of the two large masses precisely cancels the centripetal acceleration required to rotate with them.
http://www.physics.montana.edu/facul.../lagrange.html

Juge · 09-16-2002, 04:20 PM

Quote:

Originally posted by SpaceAce
Is there somewhere that shows as an actual "categorization" instead of just a term used to describe it? Acording the sims, the "second moon" passes behind the Earth crossing directly through our orbit around the sun.

SpaceAce

As I stated in the post above (er, as the article stated), there appears to be no categorization. Therefore, the same problem exists here as does with Pluto. Given all the general facts of planets and asteroid, Pluto is no where near a planet, but is actually an asteroid. You would think scientists, of all people, would be the first to change their minds upon receiving new information (as I am - I would never argue that this 2nd moon is actually a moon giving the new information regarding it), but they refused, and seemlingly just because it is know to millions of kids as the 9th planet, a panel of scientists ruled that it remains a planet.

mika · 09-16-2002, 04:35 PM

Quote:

Originally posted by Juge

Dude, you're criticizing me, and patting me on the back at the same time

So let me make it more clear, very interesting post, indeed.

And it does seem that they need to define what is a moon and what is not.

But with the current definitions I WILL stick with my vote, Earth has one moon

Because that asteroid is not orbiting earth, and moon in my opinion has to orbit a planet.. Do you agree?

HQ · 09-16-2002, 06:27 PM

Quote:

Originally posted by SpaceAce
It is obvious that actually BE a moon it would have to orbit the Earth, but that does not appear to be the case.

Agreed.

HQ · 09-16-2002, 06:32 PM

Quote:

Originally posted by Friday
Do you believe there is such definition as "super natural"?
If you do I can't answer your question you won't understand - no offence.

Super natural? Of course it has a definition, just as any word does. No offense taken, but what are you getting at?

eRock · 09-16-2002, 09:41 PM

Here's a moon for ya!

(Ah jeez...too easy)

Juge · 09-17-2002, 04:34 AM

Quote:

Originally posted by mika
So let me make it more clear, very interesting post, indeed.

And it does seem that they need to define what is a moon and what is not.

But with the current definitions I WILL stick with my vote, Earth has one moon
Because that asteroid is not orbiting earth, and moon in my opinion has to orbit a planet.. Do you agree?

Actually, you didn't need to make it more clear... I followed what you were saying exactly.

I agree 100% with you.

What do you think about this, though: "The problem lies in that the gravity of all objects effect all others, so when does a 3 mass system (such as the Sun, Earth, and Moon) make a planet-moon system going around the sun, and when does it be just 2 objects orbiting the Sun (which appears to be the case with the Sun, Moon, and Cruithne)?" Take a bunch of intermediate cases between the two, and at some point people are going to have to question which category it belongs to...

GFED · 09-17-2002, 04:46 AM

I think there is only one moon that orbits the Earth, but two satellites that orbit the moon... and I think they're called satellites, not moons...

a1ka1ine · 09-17-2002, 04:49 AM

Quote:

Originally posted by Juge

I would be interested in what you think that big white round thing that keeps moving through the sky is?

THE DEATHSTAR!!!!

all i need is a smiley of darth vader!

Juge · 09-17-2002, 06:39 AM

Quote:

Originally posted by a1ka1ine

THE DEATHSTAR!!!!

all i need is a smiley of darth vader!

Yes, you are most likely right. They just haven't turned it around, yet.

HQ · 09-17-2002, 07:17 AM

Quote:

Originally posted by a1ka1ine

THE DEATHSTAR!!!!

all i need is a smiley of darth vader!

Making fun of the crib?

View Poll Results: How many NATURAL moons (not rocks) does the Earth have? (seriously)
0 moons. The white rock in the sky is an illusion.	4	5.80%
1 moon - The Moon.	42	60.87%
2 moons - The Moon and another smaller moon.	7	10.14%
3 moons - The Moon and two smaller moons.	7	10.14%
4 moons - The Moon and three smaller moons.	0	0%
5 moons - The Moon and four smaller moons.	0	0%
6 or more moons - The Moon, and TONS of uncountable smaller moons.	9	13.04%
Voters: 69. You may not vote on this poll

09-17-2002, 04:46 AM	#62
GFED Confirmed User Industry Role: Join Date: May 2002 Posts: 8,120	I think there is only one moon that orbits the Earth, but two satellites that orbit the moon... and I think they're called satellites, not moons... __________________ https://www.flow.page/savethechildren

09-16-2002, 09:41 PM	#60
eRock Confirmed User Join Date: Apr 2001 Location: Chi-town Posts: 3,112	Here's a moon for ya! (Ah jeez...too easy)