Not all holes in the ground are the same.
-Alison Since I spend a lot of time thinking about holes in the ground, from the ones I make with dynamite , to volcanic craters, I have to spend some time thinking about other mechanisms, both human and natural, that make similar looking holes in the ground. If I want to say anything about volcanic holes in the ground, such as maar volcanoes , I need to know what makes them unique. If I want to recognize just one type of hole in the ground remotely on Earth, or other planets, I need to know more about holes in the ground in general. Google Earth Image of Hole in the Ground Maar (left) and its neighbor Big Hole (right), these maars are located in Western Oregon. Let's start with the largest holes in the solar system, impact craters. One of the most important processes for changing the surface of a planet, or any planetary body (moons, asteroids, etc.) is meteorite impact. There is a lot of junk flying around in space. This junk (rock, dust, ice) runs into other junk an...