why do metoers sometimes crash into earth?
152829
After the solar system was formed millions of years ago, there were lots of massive objects left over that didnt form into planets, they just wound up in orbits around the sun.\nThey continue to orbit the sun, going round and round, but their orbits are not necesarily as nice as Earths almost circular orbit, they can get quite wild sometimes.\n\nWith all these massive objects wizzing around the solar system, srossing in and out of the orbits of the major planets, it is just a matter of time before there is a collision.\n\nFor some of the smaller meteors, they can burn up harmlessly in the Earth's atmosphere, but if not and they strike Earth, they can become quite dangerous.  When a meteor actually hits Earth, it is called a meteorite.\n\nLuckily for us, meteorites hitting Earth isnt too common any more (we will ocassionally get a few big ones), usually they burn up harmlessly, or land far off away from anything.  There have been instances of meteorites actually crashing through people's houses or hitting cars, but this is extreamly rare.  Even more rare indeed are large meteorite impacts, like the one that is theorized to have killed of the dinosaurs or the "meteor crater" impact site, these only happen once in a few million years.
85170
Not long after "sliding" in to a black hole your body will be totally shredded down to individual atoms. When you stand here on Earth your feet are actually pulled downward more forcefully than your head. This is because your feet are closer to Earth's center of mass where the 'pull' of gravity is strongest. Same thing happens inside a black hole, only the difference in gravity pulling at your feet and head are many millions of time greater--you get ripped apart.
970160
Yes, I do because Earth is not a closed system. If it were, meteorites would never hit.  I have an interesting comparison (to me at least)  about comets "seeding" the earth....... have you ever noticed that earth resembles an "egg" and comets resemble sperm?  they have heads & tails like sperm...... and the term panspermia......... just a thought.......
817981
As others have said, it's all about speed. \n\nIt's a minor point really, but it's a common misconception that it is the friction with the air that causes objects hitting the Earth's atmosphere at high speed to heat up. Actually it's not friction. The heating up is caused by the fact that the air in front of the object cannot get out of the way fast enough, so it's gets compressed in front of the object. As the air gets compressed the pressure rises and as the pressure rises so does the temperature. This is what causes the burning up effect.\n\nWhen a space craft is blasting off into orbit, as its speed rises it's also gaining altitude. At higher altitudes the atmosphere is less dense, so this compression of the air in front of the space craft never becomes a problem.\n\nIf a space craft used its rockets to slow its decent back to Earth then it wouldn't have any problems with burning up on re-entry. The reason they don't do this is because of the weight of the fuel that would be needed to do it. With current technology, no spacecraft could carry that amount of fuel and still be able to get into orbit.
934952
They burn up in the atmosphere.  Meteors are brilliant flashes in the night sky. They travel 60,000 km per hr.  At those speeds friction with air particles vaporizes an average size meteor in less that a second. The flash of light is caused by the intense heat of vaporization. Only on rare occasions a chunk large enough to survive the plunge hits the ground.  This is called a meteorite. The largest meteorites surviving the plunge do damage the surface of the earth and cause craters but this  rarely ever happens. You probably wont ever see it in your lifetime.
209347
"...Small stones to a few millimeters in size are slowed down so much by the atmosphere that they end up drifting slowly to the ground. \n\nPieces of space rock of a few millimeters to a few centimeters burn up completely in the atmosphere of the Earth before they can reach the ground, and can be seen at night as falling stars. If it is sufficiently dark and clear outside, then you can see a few falling stars every night. \n\nIf the rock is bigger, then part of it can survive the trip through the atmosphere and reach the ground as a meteorite. If the stone weighs less than a few tons, then it doesn't fall very fast anymore in the end, and it makes a small dent in the ground.   "\n\nhttp://www.phys.uu.nl/~strous/AA/en/antwoorden/meteorieten.html
981828
This is because as the Earth moves around the Sun, the side of Earth where dawn is occurring is plowing into any meteoroids (that's what they're called when they're still floating around in space) that happen to be in Earth's path. Whether they're travelling fast or slow, all kinds of meteors get swept up by Earth's dawn side.  Meteors you might see before midnight are ones that have actually caught up to Earth because they were traveling faster around the sun relative to the Earth.\n\nHere's a simple animated gif I found to help illustrate some of what's happening: \nhttp://space.com/media/h_in_refmeteors_orbitinto_02c.gif
1091055
Because of it's velocity. It's the same principle that holds objects in orbit around the earth. The Objects are freefalling towards the ground, but they also have velocity that propels them forward in what, if the earths effect was removed would have been a straight line. As it is it becomes an arc, a sort of parabole. If the initial velocity is great enough the earth will be curving under the object faster than the object is falling towards it, so it will never reach the ground - it goes into orbit.
972025
Well, the rocks don't float away because even though they may float very high, they still come back down, they usually don't have enough velocity to break the gravitational pull of the moon, even the shuttles are effected by gravity, but it SEEMS weightless because they're in a state of constant freefall while maintaining a certain horizontal velocity so they orbit the earth, in simpler terms, they're falling over the side of the world all the time.  Anyway, those rocks that may fly up, come back down, and they bounce, however they don't bounce as high, and eventually come to a rest, and as for anything that's not bolted down floating away, that's just stupid, because the moon has gravity, it's only 1/6th of Earth's gravity, but it's still there. (By the way, the level of stupidity in your question is aggravating me.)  The moon suits had to be weighted so when the astronaughts pushed on the ground with their feet, they didn't just blast off about a hundred meters into the sky.\n\nPS.  ANYONE who asks that sort of question sounds like an uneducated mendicant.\n\nPPS. If yer curious about my age, I'm 17
1162500
To answer some of your question......\nThe average velocity of meteoroids entering our atmosphere is 10-70 km/second. The smaller ones that survive the trip to the Earth's surface are quickly slowed by atmospheric friction to speeds of a few hundred kilometers per hour, and so hit the Earth with no more speed than if they had been dropped from a tall building. For meteorites larger than a few hundred tons (which fortunately are quite rare), atmospheric friction has little effect on the velocity and they hit the Earth with the enormous speeds characteristic of their entry into our atmosphere. Thus, for example, it is estimated that the meteorite that produced the Barringer Crater(http://csep10.phys.utk.edu/astr161/lect/meteors/meteor.jpg) was still travelling at 11 km/second when it struck what is now the Arizona desert 49,000 years ago. Such objects do enormous damage, because the kinetic energy carried by the meteorite is the product of the mass and the square of the velocity. A meteorite that large hitting the ocean would create a Tsunami. Whether it would cause as much damage as the one in Indonesia/india/africa, would depend on how close to land the meteorite struck. Change in our ecosystem would not be that great. On the other hand if we were to be struck by an asteroid as in the case of the K-T Extinction, there would be a dramatic effect on the ecosystem. ( just a quick note on asteroids,comets and meteors: Asteroids and comets are both classified as near-Earth objects. Asteroids are made of rock or metal and are thought to have been created in the warmer inner solar system. Comets are composed of ice, rock, and organic (carbon-based) compounds, and are believed to have formed in the cold outer solar sytem. Scientists believe both are "...ancient remnants of the earliest years of the formation of our solar system more than four billion years ago." When asteroids collide, meteroids, smaller rocky bodies, often result. Meteroids are also formed when a comet passes near the sun, and the heat releases dust particles from the comet's icy tail. When a meteroid or asteroid enters the Earth's atmosphere, it ignites, creating a visible streak of light called a meteor. If the object doesn't vaporize completely and crashes into the Earth, it's called a meteorite. \nFinaly, a meteorite, because of its size, would not cause dramatic changes to our eco-system, however, large one can would be able to produce a tsunami.....\n\nChris
804491
If there was a hole right through the center of the earth?\n\nAlright.  In order to understand the answer, you have to understand the difference between potential energy and kinetic energy.  Potential energy is stored up energy.  (Like a rubber band stretched and ready to snap.)  Kinetic energy is moving energy.  (Like the rubber band in the process of snapping.  \n\nThe moment that a person steps over the hole through the earth., that person has complete potential energy.  The earth's gravitation is pulling on them, but they are not yet falling.  As they fall, that potential energy is converting to kinetic energy.  They fall faster and faster.  Once they reach the center of the earth, they have no potential energy, only kinetic energy.  \n\nThis kinetic energy keeps them moving down the hole towards the other side of the earth.  As they are moving away from the earth's gravitational pull, they slow down.  The kinetic energy is converting back to potential.  \n\nOnce they reach the surface, they once again have full potential energy and zero kinetic.  \n\nSo, they yo-yo back and forth between the two mouths of the tunnel.\n\nWhat ends up happening depends on if you are taking air resistance into concideration.  \n\nIn a complete vacuum, the person would yo-yo between the two openings of the tunnel forever.   The person's potential and kinetic energies would have an inverse relationship.  Back and forth.\n\nIf you are taking air resistance into account, then some of the energy is lost from friction between the person falling and the air.  (It's lost through heat energy.)  During each yo-yo, the person's fall would be less and less.  Eventually, all of the energy in the person would be lost through the heat energy and the person would be stuck in the center of the earth, suspended there for all time.\n\nKinda cool, huh?
1059599
just like the other guys. \nit will not fall down because there is no down and up in space. it has a very low gravity that you cannot feel. \nhere in earth we say up because when you look up its up and when you look down its down but is that really the thing that is happening. no. We say down, towards the earths center because, relatively to the earth down is the center of the earth where, also, the earth's center of gravity.\na good example of this is, picture yourself in the north pole. you looked down. imagine the earth is transparent. now picture someone in the antartica looking down also. it is like looking at a mirror. Who is down and who is up? Make sense???\nUp, down, etc... are relevant to attraction or gravity if it is in earth.\nfrom the first law F=m1*m2/d.\nwhen a man fall in a building he isattracted to the earth's gravitational pull, towards the earth's center. So relatively to the audience seeing the man's fall. we can say he is falling down but in fact he is being attracted to the earth's center.
579588
When a big asteroid or a meteor finds it's way to Earth.
842816
The weight (or actually the mass) of the asteroid has very little to do with it, except that really light ones would burn up in the atmosphere, and really heavy ones are much rarer.\n\nThe gravity of the earth has practically nothing to do with it, either.\n\nEvery asteroid is in some orbit around the Sun, all different, and the Earth has an orbit too.  Whenever these orbits happen to intersect, the asteroid could hit the Earth.  Fortunately, there are only a very few asteroid orbits which cross the Earth's orbit at all.  Wherever they do cross it, there is only 1 chance in about 35,000 that the Earth will be at that same point at the same time anyway.  It is far less than the risk of being hit by the only car going around a speedway track if you suddenly ran across it at some random moment.
439545
No, they can occur just about anywhere. They are most common in the seismically active areas, like tectonic lines, but they can also happen from other reason, like in the mountains if a piece of the rock would crumble and fall down, or if a meteor falls on earth, or if there is an underground cave or a river and it collapses... there are many reasons.
145985
the world is roughly spherical, (a ball) and the reason for this is because something as big as earth pulls itself toogether so that everything falls to the center of the sphere, if there were a substantially eneven spot on the earth (let's say a huge spike 40 miles high) it would most likely fall down into place. I magine a bunch of rocks that are pulling themselves together one rock sticks to the other you have two rocks keep on going now you have three so on and so on. If you take a bunch of weird shape magnets they'll stick together in the shape of a ball because they'll all want to be as close as possible and the only way to do that is a sphere since every point in the surface to the center will give you the same distance. Same as if you pushed clay from every side with equal force it'd form a ball.\n\nDUDE!!! PICK A BEST ANSWER!!!!
195652
the earth is a oblate spheroid....we do not fall to the edges because of the gravitational pull...