3 ms·

Do we have an idea of what percentage of impacts were prevented this way? What likelihood is there that the moon saved humanity (more than once?) since the time

• gehwartzen 4y ago
  I imagine once you figure out which craters correspond to ones that came in at an angle which would have hit earth and compare that to all the impacts you have had on earth one could figure it out. The thing is that on the moon the craters remain visible for a much longer period of time while on earth they get covered up by plate shifts, erosion, ocean impacts, etc. So instead it might be a way to calculate how many asteroids likely have hit earth in general throughout history whether we have found the craters on earth or not. Then you could calculate based on the size of the craters on the moon which ones would have been earth catastrophic events (taking into account any diminishing impact energy due to our atmosphere). Which would tell us how many the moon saved the earth from. In terms of how many since human ancestors were evolving we would have to then date earth catastrophic craters on the moon. I'm not sure if this can be done through photographs or if we would have to get surface samples. Then comparing that number to the fraction of earth covered/protected by the moon to the total area on earth we would have a decent idea of how many of these events happened one earth even if we haven't discovered the evidence for them on earth.