Why is Earth's surface not riddled with craters like the Moon?
360341
We have an atmosphere and weather.  That is always changing the surface of the earth.  Erosion takes place and over time things flaten out.\nIn other cases the craters are still there, they just happen to be so large the only way we see them is through pictures from satellites.  The vegitation also help mask the craters
790097
Just look at the moon.  The moon has is made up of mantle rocks, just like the Earth's crust.  But there's no water, nor is there an atmosphere.  \n\nIt's actually not a fair question.  The Earth is in a wonderful position in that water is a liquid (too close it's a gas, too far it's ice).  Water is a very abundant substance - if a planet has an atmosphere, it has water.  The moon is too small and cannot hold an atmosphere, but there's no way the Earth would lose its atmosphere due to its size.  Therefore, there's really no way for the Earth to lose water.\n\nSo assuming the Earth COULD lose its atmosphere, you'd have a surface like the moon.
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.
85952
(You probably mean NON-terrestrial planets.)  Craters (whether you mean meteor craters or valocanic craters) on earth are less evident because they are constantly being eroded by weather effects such as wind, rain including floods, and geological activity such as volcanoes and plate tectonics.  The moon for example, does not have any of that, so the only thing that might make meteor craters less evident is another later meteor strike.
830771
Craters of the Moon is a late-stage volcanic event related to the hot-spot track of Yellowstone.  It is in the weak, thin crust underneith the snake river plane.
216980
No. The Moon rocks that the astronauts brought back and are in the Smithsonian Institute in Washington, where millions of people have seen them, tell the story. They are glazed on the top side, just a little. \n\nDirect sunlight on the Moon is hot, but not hot enough to melt rock. (it gets to around 320 degrees F.) To cause rocks to glaze like pottery in a kiln, you would need about 1100 degrees F. So we see evidence of Lunar warming.\n\nNo process on Earth can affect the temperature on the Moon. But the Sun, which warms both the Moon and Earth, is unstable. We know the Sun is 4% variable, but we have only had the instruments to study the Sun for about the past fifty years. Maybe it gets more variable sometimes. \n\nTen or twenty thousand years ago-- we can't be sure-- the Sun flared up. It was very brief, or the rocks on the Moon would have become molten and flowed. It had to have lasted less than 24 hours (one rotation of the Earth) or nothing would have survived. I think the American continents were in sunlight at the time. \n\nSo it got hot enough on the Moon to cause the rocks to start to glaze over, but not hot enough long enough to melt them all the way through.\n\nOn Earth, the oceans boiled. There were hurricanes of live steam. A lot of species died, and there were only a few survivors like Noah.\n\nWhen the flare died out, there was all that excess water vapor in the atmosphere. It had to precipitate somewhere, and the first place was at the colest points on the planet, which were still the poles. \n\nYou see, you can't have an ice age, you can't have polar ice caps, you can't have glaciers, without water vapor in the atmosphere. The water tied up in ice was thousands of times more than the Sun would evaporate under normal circumstances. \n\nNow, the icepacks are finally melting back to the size they used to be before the flare. The planet is reaching thermal equilibrium once more. \n\nThere is evidence of other ice ages before that. They may have been caused by comets hitting the earth (in an ocean.) They would have impact energies equivalent to thousands of megatons of TNT, and would similarly put massive amouns of warter vapor into the atmosphere, with the same results.\n\nWhy don't you hear people talking about this? Because there's nothng that we could do about it. It sells more ad time on radio and tv to say that we did it to ourselves with polution. The ice will melt and the oceans will rise about 50 to 100 feet, and the coastal cities will all disappear, and there's nothing we can do to stop it. So the best bet is to move the cities inland and figure out where the new harbors and beaches will be.\n\nYes, we should pollute less, but here's something else to consider. Remember Mount Saint Helens? Biggest volcanic eruption in America in the last few hundred years. But volcanic eruptions happen a few times a century around the world, and that one wasn't especially big by global standards. \n\nNational Geographic did an article on it; you can look it up. They had a beautiful two page photo spread. The pictures one week after the eruption looked like the surface of the Moon. It was all cold grey ashes, dead tree trunks sticking out, and little craters (ponds). The other picture was one year later. It had the exact same tree trunks and ponds (the same spot) but now everything was green and growing. \n\nThe heat of the volcanic ash burned away dead leaves and underbush that kept the sunlight from reaching the forest floor, while the ashes are very good fertilizer. The heat also caused long-buried seeds to germinate.\n\nHere's the point: that one eruption put more dirt, gas, dust and radioactive particles into the atmosphere than everything we've done since day one. And the planet survived. The planet does this to itself REPEATEDLY and survives. \n\nEven the Trinity site, the site of the first atom bomb test, has things living there now, and the radiation level is barely abo
439809
The moon is basically a great big lump of dull coloured rock that floats around quarter of a million miles from us.  Just like earth, it's illuminated by the sun so what you're seeing is reflected sunlight.\n\nIt can appear as different colours due to the atmosphere here on earth.\n\nWhen the moon is up in the sky you're looking at it through a thin layer of atmosphere but when it's low on the horizon you're looking through a greater amount of atmosphere.\n\nThe way that our atmosphere breaks up sunlight into differnt colours (Rayleigh Scattering) affects the colour that the moon appears to be.  So too can particles in the atmosphere - particularly dust and volcanic ash which often gives it a reddish tinge.
817223
Maybe because the sea is so big, very big, unimaginably big that we don't know as much about the oceans as we do about the surface of the Moon. There is so much we don't know about the sea because we are not designed for this environment
86914
It's probably all land - some lowlands, some highlands, *LOTS* of craters.
587803
The moon's gravity as felt on earth is indeed much weaker than that of earth, but it acts on the entire area of the earth, in particular on the earth's water layer, a shell 8000 miles in diameter. This weak but widespread gravity force raises slight bulges only a few feet in height, a small distortion of such a huge shell. The two bulges are located close to the areas nearest to and farthest from the moon, the points of greatest and smallest moon gravitational pull. Rotation of the earth causes these bulges to travel around the earth's water layer. Tide can be thought of as an extremely long wave that occurs at predictable times (about twice a day) with predictable amplitudes. Resonant sloshing in the ocean basins amplifies the water height disturbances on shore.\nThe greater tidal amplitude at full and new moons is due to the additive effect of solar gravity when the sun, earth and moon are all more or less in line. Incidentally, the size of ordinary waves is only marginally related to tides.
438648
The Moon has a surface area of 152 million square kilometers.\nThe Earth is 13.5 times larger.
131167
Ah! that happens like one time per some 100 years!!!\nAnd besides, it will 75% chance hit the ocean! And no tsunami! And, the moon is a shield. It protects 15% of the hits! And theres a 5% chance that it will hit near you. So its a -5% chance you will "get scared" of a metor hitting Earth. I did the math!
736681
During my Time Travels I did do some Intergalactic Exploration. When I was in Grid 946 Quadrilateral 47, the solar system was similar to your solar system. Basically we ( my Friends and myself) observed than any planetary structure is protected from outside forces due to Gravity and Atmosphere. Moons, as you are accustomed to calling them lack those two important aspects, thus, any outside forces bombard those structures and they similar to the moon as larger structures with gravity and atmosphere are similar to Earth. It simple Physics according to Earth's Concept. Once your Scientist understand Dimensions, then you understand the many things you now consider mystery.
935068
Now, I can't swear to this, because I was half asleep when I watched this, but I watched this show on the Discovery channel about a week ago.  They were talking about how the earth has a molten core that is constantly moving around, so therefore we have earthquakes.  The moon is solid, so therefore, no earthquakes.  That's also why we don't see many of the craters from asteroids that hit us over the millions of years because our earth's surface is continually changing from these earthquakes.
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
73511
GREAT QUESTION !!!\n\nYour question takes us back to the very beginning of our Solar System. The Earth, Sun, and the other planets began to form from a spinning cloud of cosmic debris called a Nubula. With the Sun at the center, everything else that was left over became the Solar System we see today. \nBut the Early Solar System just had small and large clumps of matter orbiting the center. Through eons of time, the larger clumps grew bigger because the smaller clumps hit them. Eventually, the Solar System was a choas of hundreds of little "planets" surronded by and emense plane of orbiting debris. At some point, the bigger objects became large enough to gravitationally pull in the rest of the debris around it. These objects grew much quicker than the rest, but each new impact made them even bigger and capable of pulling in even more rock and debris. \nLet's now just concentrate on the Earth-Moon system, eventhough we use crater counts to date any planet or moon anywhere in the Solar System that we can:\n Once the rocky inner planets formed, it's believed that the early Earth was smacked by a Mars sized body which totally reformed the Earth and created the Moon. Objects still rained down on the early Earth and Moon, however. Some of the largest impacts on the Moon are the oldest and filled up with lava. This is the "Man on the Moon" face we see today. Remember that the Earth was being hit more often than the Moon at this time because it had a stronger gravity, but most of these impacts aren't visable today because of weathering (rain, wind, etc.), plate techtonics, volcanic eruptions, the creation of Oceans, and stuff like that. But the Moon had no atmosphere and it cooled a lot quicker than the Earth did, because it was smaller. \nOnce the Solar System got to a point that it wasn't "swimming" in a cloud of debris, we basically had the nine planets left as the survivors of this early bombardment. This left the Moon scarred with all kinds of impact craters which would be the oldest craters we see today.\nFinally there came a point where most of the larger rocks (asteroids) floating around had been absorded by the planets, and this left just the smaller chunks of rock. This is the start of the second phase of cratering where most of this remaining debris eventually was "sucked up" by the Earth and Moon (and planets). This second phase ended about 3 billion years ago. The third phase we are still in today with occasional impacts occuring, but nothing like the first two stages.\n\nSo how does this answer your question?????\n\nLet's just concentrate on the Moon now: \n Imagine the Moon early in the first phase just covered with shoulder to shoulder craters. Each new crater formed over the top of older ones. In other words, when you see a large crater today that has smaller ones inside it, you know that the large impact had to occur before the smaller ones. If this wasn't true, the larger crater would have wiped out any evidence of the smaller ones, right?\n Then there came the point when the lava I mentioned earlier covered up the lower impact basins we see today as the "Man on the Moon." We can tell--just from counting craters-- that this occured afer the first phase, because the lava covered all of these earlier shoulder to shoulder impacts and left relatively smooth plains. Impacts still happened on the plains, but nothing like in the first phase of cratering.\n So you can begin to see that the older an area on the Moon is, the larger the crater density. That plot of ground was around when the first phase of cratering was still going on. It's covered with crater after crater of different sizes with no smooth, craterless areas at all!  Any area on the Moon that has a lower crater density would of had to have been reworked by larger impacts or covered by lava, AND IS, THEREFORE YOUNGER THAN HEAVILY CRATERED TERRAIN.\n The only other "weathering&quot
410954
The Earth is round.\nObviously at lower latitudes you view the moon from a different angle than what you would at higher latitudes.\nSo that at the equater the moon when rising would look like a bowl from that angle in that phase.