Here is your answer. (The REAL answer.) You better pick me after all this typing.- I will try and condense the story for you. It's not the Kuiper belt that is the main factor. It's the even bigger Oort cloud that surrounds the entire solar system. The Dinosaur extinction 65 million years ago was only the last of 5 major mass extinctions. Years ago scientists were investigating why they actually follow a pattern, and here is what they found.
As our solar system goes around our Galaxy, it also bobs up and down through the galactic plane.(The disk of the Galaxy.) The timing of this coincides with the mass extinctions. When we go through the thickest densest part it perturbs the outer Oort cloud which is comprised or trillions of comets. Stuff smashes together and lot and lots of material comes flying in towards the Sun hitting planets and moons along the way. Some material also strikes the Kuiper belt and also the Asteroid belt, bringing along even more debris flying inward. Everything along the way including Earth takes a hell of a beating. 2 out of 3 times we have been hit by stuff big enough to cause a mass extinction. 1 out of 3 times it was less and little enough for life to trudge along. The last big one was 65 million years ago. The time before that the dinosaurs were lucky. (It is every 60-70 Mil years that averages out to 65.) Here is the previous pattern of the last five but there were also no doubt more events before that too. >>> Hit-Hit-miss-HIT-HIT-miss-HIT-(NOW) right now we are actually going through the disk again and are due for another one. (Don't start Panicking.) They used to wonder why it would go through a cycle but now they know. (And so do you.)
The above paragraph only describes the major impacts. There are of course many smaller events of different size and frequency all the time between those periods. Space is just full of stuff flying all around. The Earth actually is constantly receiving space dust and small meteors each and every day and sometimes bigger ones. Meteors are called meteorites once they touch the ground. The actual figures from NASA are 100 tons per day of material from space.(Mostly dust and small chunks.) The fact that Earth is covered with 70% water means that most of the impacts go unnoticed. When something hits land and we see it, it makes the news.
As for the water part of your question...when the Earth was very young it was still a ball of molten hot lava and slightly cooled rock. It under went a long period of comet bombardment and took on trillions and trillions of tons of ice which melted into the water we now have. Good thing for that or we would not be alive here today.
So as you see...the kuiper belt is only part of the equation. Mother Nature has a way of cleaning house every now and then. This just happens to be our time (Humans) to live and evolve on Earth...until it is no longer our time. You wanted the truth and the facts so there they are. I have studied Astronomy, Science and Physics all of my life and know what I am talking about. Contact me directly if you want more information. I hope this helped you and hope you pick my answer.
2006-08-24 21:36:46
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answer #1
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answered by Smart Dude 6
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There have been quite a few theories involving Kuiper Belt objects and mass extinctions, but nothing conclusive. Among the more popular:
1. The Death Star: A possible red dwarf star or brown dwarf orbiting our sun 50,000 to 100,000 AU away, just beyond the Oort cloud. The theory is that by disrupting the cloud and/or other objects in the outer solar system, debris could be hurled into the inner solar system (earth's neighborhood).
2. Bobbing and weaving: Other theorists argue that the cycle of extinctions are caused when the solar system is oscillating across the galactic plane during its orbit around the galaxy, disturbing outer solar system objects. However, this theory is not well-constrained observationally, and may differ from the 26 million year cycle by as much as 40%.
3. Neptune did it: Much of the Kuiper Belt objects are there now because the gravity of Neptune kind of keeps them herded there. However in the early Solar system, there were a lot more objects whizzing around in space at the time, and nothing was quite established yet. The gravity of the outer planets would have either shoved out a lot of the errant bodies from our solar system, herded them into stable orbits, or sent them inward.
4. It came from Outer Space!: In this case, another star brushed too close to our solar system, nudging some outer objects into a death spiral toward our world. This can occure quite often, and in fact, we may experience it in reality. Gliese 710, a red dwar star, is on its way to passing within a light year away. The good news though is you'll have plenty of time to prepare....it won't take place for at least a couple of million years!
2006-08-24 20:48:40
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answer #2
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answered by swilliamrex 3
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The Kuiper Belt does have something to do with the mass extinctions on Earth. Asteroids in this orbit don't need a lot of gravity to give them a push out of orbit. Jupiter does this often, and when this happens one of them could drop into a stable orbit, or it could collide with a planet. This could be the source of the KT event that killed the dinosaurs. The Kuiper Belt is inside of Pluto's orbit and the Ort Cloud is outside of Pluto's orbit.
Comets usually start from the Ort Cloud, once again Jupiter is the main suspect in pulling them slightly out of orbit so they fall in toward the sun. A large comet could also have caused the KT mass extinction. Some organic chemicals are known to exist in space, and in comets. A recent experiment proved that some amino acids could survive a comet impact with the Earth. Comets may be the source of life on Earth.
If a Neutron Star were close enough to affect our solar system then astronomers would have discovered it by now. Even black holes give off radiation, so a Neutron Star could be seen by a space born telescope with the proper instruments. If a Neutron Star were close enough to Earth to affect it then there would be other effects on the various planets, very noticeable effects that would have been detected.
Space Probes like Voyager and Galileo fly very precise orbits that are calculated on computers using Newton's Laws of Physics. The formulas are simple and very clear; they need to take in the effect of all the various gravitational bodies that the probe would encounter. If a Neutron Star was close to Earth, even if it couldn't effect the planets and moons, it would have effected those probes and astronomers would then be searching for why that happened, so I don't think we need to worry about a Neutron Star being close by.
However, there are wandering planets and stars. Uranus may have been such a wandering body that was captured by the sun. It is possible that at some point in the past a Neutron Star came close to our solar system and then moved on. But, if it had been within the last billion of years or so then the Star would have been discovered and the orbital permutations that it may have caused could have been traced (too many ifs for me).
2006-08-24 20:44:33
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answer #3
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answered by Dan S 7
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Sounds pretty hokey to me. It is probable that the extinction of the dinosaurs was precipitated by an object striking the earth near Yucatan, Mexico, but the object is more likely to have been an asteroid than have come from the Kuiper belt as the delta-v for the latter would be very large.
2006-08-24 20:25:17
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answer #4
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answered by Anonymous
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