The making of the Earth

The nebular hypothesis is the most widely accepted theory of how our planet formed, at roughly the same time as rest of our solar system’s worlds

predictions that can still be observed today billions of years after the fact.

“the general limitation of any moon model

[both single- and multiple-impact models] is that we have only one system to check – we don't have statistics of many moons and their properties. the other limitation is that overall the phase space of possible collisions and impacts is very large, and it is therefore difficult to model any possible type of collision. We only run a grid sampling the huge phase space of possibilities. Nevertheless, there are clear trends that suggest we can generalise our results to a wide range of collisions, so this is not a main obstacle.”

So, if the new mini-moons theory is correct and the first continents on earth really were formed by moonfalls, how exactly would we go about proving this?

“the best evidence might be on the moon,” explains Perets. “For example, if we find that the composition on the far side of the moon is significantly different than that found on the near side, it could be a clear signature of multiple moons making up the current moon. that being said, finding a small difference, or not, would not exclude it. the Chinese are planning a mission to the far side of the moon in the coming years, so hopefully we might have data on that sooner than we think.”