The first frame of a 3D movie flyover of Tycho Crater on the Moon as seen by Kaguya. It displays the classic terraced crater walls and central peak of a complex crater.
Select the image to go to the Selene website for a great flyover of the crater.
This assumes, of course, that the cratering rate has been fairly constant for the last few billion years.
The heavy bombardment of about 3.8 billion years ago must be taken into account when using the crater age dating technique.
Also the pressure from the surrounding solid rock squeezes the molten rock upward.
Even Venus with its thick atmosphere has impact craters, though they all have diameters measured in kilometers because smaller projecticles burn up in its atmosphere.At such speeds, the projecticle explodes on impact and carves out a round bowl-shaped depression on the surface. How can you distinguish an impact crater from a volcanic crater?Volcano craters are above the surrounding area on mountaintops while the craters from impacts are below the surrounding area with raised rims.Volcanism is any eruption of molten lava onto the surface.The molten rock has a lower density than solid rock so it rises.The rock on the surface of the planet or moon is bent backward, upward, and outward so the amount of material ejected is much larger than the projectile.Large craters will have a central peak formed by the rock beneath the impact point rebounding upward and they may also have terracing of the inner walls of the crater from the collapsing of the crater rim inward.The oldest fossil evidence of ancient organisms dates back to 3.5 billion years ago and evidence for biological activity based on isotopic ratios of carbon date back to about 3.85, even up to 4.2 billion years ago, though the carbon isotope ratio evidence is controversial.The number of craters per unit area on a surface can be used to determine an approximate age for the planet or moon surface if there is no erosion.Victoria Crater on Mars as seen by the Mars Reconnaissance Orbiter. It is a simple crater that has been partially filled in with sand---note the sand dunes on its floor.If you download the full-resolution version of this picture from the link on the picture, you will be able to see the rover, Opportunity next to the top left crater rim.