Posted on 09/11/2002 11:35:35 AM PDT by Cultural Jihad
Much uncertainty surrounds the mysterious object, designated J002E2. It could be a passing chunk of rock captured by the Earth's gravity, or it could be a discarded rocket casing coming back to our region of space.
It was discovered by Bill Yeung from his observatory in Arizona and reported as a passing Near-Earth Object. It was soon realised however that far from passing us it was in a 50-day orbit around the Earth.
Paul Chodas of Nasa's Jet Propulsion Laboratory in California says it must have just arrived or it would have been easily detected long ago. Calculations suggest it may have been captured earlier this year.
Moon or junk?
When he detected the object Bill Yeung contacted the Minor Planet Centre in Massachusetts, the clearing house for such discoveries, which gave it the designation J002E2 and posted it on their Near-Earth Object Confirmation webpage.
Soon however, its motion suggested it was in an orbit around the Earth. Its movements had all the hallmarks of being a spent rocket casing or other piece of space junk.
But experts are not completely sure what exactly the object is.
Observations made by Tony Beresford in Australia indicate that the object's position does not match any known piece of space junk. Observations made in Europe have failed to see any variations in brightness that might be expected from a slowly spinning metallic object.
Nasa's Paul Chodas says the object must have arrived quite recently or else it would have been easily detected by any of several automated sky surveys that astronomers are conducting.
Its trajectory suggests that it may have been captured in April or May of this year, but there is still some uncertainty about this.
If it is determined that J002E2 is natural it will become Earth's third natural satellite.
Earth's second one is called Cruithne. It was discovered in 1986 and it takes a convoluted horseshoe path around our planet as it is tossed about by the Earth's and the Moon's gravity.
Astronomers, professional and amateur, are carrying out further observations to determine if J002E2 is really another moon of the Earth, or just a piece of space junk.
Project Orion, anyone?
"Space JOO" alert...
Foolish Gentiles!
Your puny weapons are no match for our orbiting matzo balls! The earth will be ours!
HAHAHAHAHAHAHAHAHAHAHAHA!
How big is this rock, and just how close does it come to earth?
This shot of the newly discovered moon from the Hubble telescope indicates yet another key element of the highly vaunted "Clinton Legacy."
There is wide speculation that there is also a carving of Bill -- with several interns -- on this newly discovered moon. But since he does his best work out of the light, it is on the dark side.
LOL!!! Maybe they'll go back and take Howard Zinn with them!
It is three miles across, and it reaches its closest approach to earth (9.3 million miles away) every 385 years. Its next close approach is 2285.
Physicist could better answer your questions, but a 50 day orbit of an object requiring a telescope to see seems to imply a great distance.
Somebody call Art Bell...
Holy Cow, I never heard of this moon! Thanks for posting this. Here's some more info I found about Cruithne. Apparently, there may be a whole bunch of these things out there.
From Andrew Yee [http://helix.nature.com/nsu/991007/991007-2.html] Many moons The Moon might have a whole clutch of hidden siblings, according to planetary scientists Carl Murray and colleagues of Queen Mary and Westfield College in London, UK. In a paper published in the 27 September issue of Physical Review Letters[1] they show that asteroids that pass close to the Earth can become trapped in weird orbits around our planet. One such asteroidal companion to the Earth has already been discovered. In 1997, scientists in Canada and Finland reported that the asteroid Cruithne, a chunk of rock wandering between the orbits of Mercury (the innermost planet) and Mars, is following a path that is linked to the motion of the Earth (see Nature 387, 685; 1997). Cruithne does not go around the Earth, like the Moon itself -- its trajectory is considerably more complex. Basically it travels in loops shaped like a kidney bean, which lie beyond the Earth. As the Earth circles the Sun, it drags Cruithne's loopy path with it. But the motion is even more complicated than this, because the loop runs slightly ahead of the Earth, completing almost a full circle until it approaches the planet from the other side -- whereupon it changes direction and creeps back again. At its closest point (which it reaches every few hundred years), Cruithne comes within just 10 million miles of the Earth. Its path actually overlaps the Earth's position, but there is no risk of collision because the kidney-bean loops are tilted at an angle to the plane of the Earth's orbit -- so Cruithne passes over our head, as it were. The only other known examples of such peculiar "horseshoe" orbits are those of two of Jupiter's satellites, Janus and Epimetheus. But neither has such a complex relationship to its mother planet as does Cruithne does to the Earth, and Murray and colleagues have examined the theoretical aspects of the asteroid's motion to develop a better understanding of how it arises. What they found was that Cruithne's strange dance represents just one manifestation of a whole class of "co-orbital motions" -- that is, of asteroids whose orbits are tied to those of a planet. These motions become possible if the asteroids pass by a planet on orbits that are very elongated (rather than circular) and tilted with respect to the plane of the Solar System. Under these conditions, the planet can capture the asteroid, forcing it into co-orbital motion for periods of several thousand years. But because the motion of many-body gravitationally bound systems like the Solar System is intrinsically chaotic, these periods of capture don't last forever -- the asteroid might escape to drift at random, before perhaps then being recaptured in a different kind of orbit. The researchers identified at least one other known near-Earth asteroid that might share Cruithne's fate, becoming temporarily enslaved to the Earth. They say that both this asteroid, called Khufu, and Cruithne itself could in the future adopt orbits that do actually circle the Earth, like the Moon -- but going "backwards", in the other direction. Their calculations predicted that, in the past, Khufu could already have behaved in this way for 35,000 years. It may be that our planet even now has such "retrograde" moons, too small to be easily spotted. See the York University and Tuorla Observatory site http://www.asteroid.yorku.ca/ to learn more about the asteroid Cruihne. [1] Namouni. F, Christou A.A., & Murray C. D. Coorbital Dynamics at Large Eccentricity and Inclination. Physical Review Letters 83, 2506; (1999) © Macmillan Magazines Ltd 1999 - NATURE NEWS SERVICE MANY MOONS
By PHILIP BALL
California has just been smoked!!!
Cruithne. It was discovered in 1986 and it takes a convoluted horseshoe path around our planet as it is tossed about by the Earth's and the Moon's gravity."I thought I was reasonably up to date on the easy stuff, like earth's moon(s). Somehow this one went right by me. How could I have missed something like that? Didn't it get any publicity? Or was I just out of it more than usual back in 1986?
Yes, it is a moon of earth. Not all orbits are round, other shapes are possible. Taking orbit as being somnething of a permanent, related, and periodic motion, a horseshoe orbit is a perfectly good orbit. If you want to just go around and around in a boring round orbit, take Lance Bass's seat on the Russian Soyuz rocket.
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