willvasco
willvasco t1_iy4gk95 wrote
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.
willvasco t1_ja8l1m1 wrote
Reply to Eli5: what’s the difference between a graduate and undergraduate degree by deadpuppy101
Undergraduate is anything before you graduate college (Bachelors, Associates). Graduate is anything after you graduate college (Masters, PhD, etc).