I think the title explains itself
In: 4
Earth is geologically active. The moon is not. Volcanoes cover and “heal” those craters. We DO have them but they’re far less pronounced.
Well for one thing the earth does have craters, but they’re often underwater, but the earth also has a thick atmosphere (compared to the
moon’s) which breaks up most of the asteroids before they can do much damage to the surface of earth.
I think little space debris that slams into the moon at astronomical speeds does not make it through to us because of our atmosphere. We do have huge craters on earth, so inevitably we will have another. I wonder when.
In short: Atmosphere.
A lot of meteors that come in contact with earth burn up in the atmosphere, and don’t make an impact.
Furthermore, there are a lot of impact craters that have been worn down by weather, covered over by plant growth, and so forth – again, essentially due to the fact that we have an atmosphere.
Earth has a much more active surface than the moon. Plate tectonics constantly recycles crust by burying it and making new crust, weather erodes crust, etc. Granted, this is a slow process, but it took the moon billions of years to look how it does today, because those processes don’t operate there. So there is virtually nothing to erase those craters.
The earth has an atmosphere. When the earth passes through a cluster of asteroids (this is what causes meteor showers) the vast majority of them burn up in the atmosphere due to air resistance before they can reach the ground to make a crater. The moon technically also has an atmosphere but it is so thin that we don’t really consider it an atmosphere. It can’t be breathed and it won’t slow down, heat up, and burn away objects that pass through it like earth’s atmosphere. This means that when the earth and moon pass through an asteroid field the earth is protected while the moon just gets slammed over and over again.
On top of that, the earth has geological activity such as erosion which can erase the signs of old meteor impacts. The moon doesn’t have this so every time a meteor strikes, the crater remains there until another meteor hits and obscures or covers it up with another crater.
There are three major causes:
1) Erosion. Wind, rain, snow, ect. gradually wear down craters on Earth’s surface over time.
2) Fewer surface impacts per m^2 . Because the Earth has a relatively thick atmosphere, a lot of the smaller rocks break up before hitting the surface or slow sufficiently to mitigate their impact on the surface.
3) Tectonic activity. Unlike the Moon, the Earth is still tectonically active, with volcanos faults gradually erasing some craters.
Lots of reasons, but primarily because of our atmosphere. Lots of things try to hit Earth, but get burnt up on the way down. That, and our landscape has so many other factors acting on it (weather, tectonic plates, things living on it) that what craters do form can quickly be worn away.
1. The moon itself. It’s a pretty big thing in its own right with its own gravitational field, and it’s orbiting around Earth. A lot of things that would hit our planet end up hitting our moon instead because it’s out there playing defense.
2. The atmosphere. If it’s not big enough, it just burns up, and even if it is big, it’s both smaller and slower by the time it makes it to the surface, both resulting in smaller craters. When the moon gets hit, it’s full-size and full-speed.
3. Weather and plate tectonics. The surface of Earth is changing all the time and even a huge crater will eventually disappear. Craters on the moon more or less just stay that way until another crater lands in the same area and makes a new overlapping crater.
The Moon has no air. So that means if an asteroid hits it, it leaves a crater. Then there’s nothing to get rid of that crater. It just stays and stays forever.
The Earth has air. And volcanoes. And plants. And water. So if an asteroid landed in the middle of Ohio ten thousand years ago, that’s ten thousand years of rain and wind and stuff to get rid of the crater. It might still be there, but it’ll look a lot more like a natural valley now. Floods and rivers and tornadoes will knock down some of the hard ridges, and trees and plants and things will gradually soften the landscape as well.
Plus the atmosphere acts like a shield, burning up most asteroids before they cause big impacts. So something that causes a big crater on the Moon will cause a really small crater on Earth, and something that causes a small crater on the Moon will never even hit ground on Earth.
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