A few days ago an article wrestled its way through the swimming and badminton stories on the BBC to deliver some fresh, unsporty science to anyone who cared, and because back then Team GB hadn’t done anything impressive, this included me.
The article related to a report published in Icarus, which casts some doubt on our prevailing moon formation mechanism. I personally believe the moon is made of Swiss cheese, which explains all the craters we can see, but science in general seems to hold the view that the moon was created from a condensing cloud of material which was formed when a mars-sized planet and earth collided. This was way back in the early history of the earth, and no dinosaurs were harmed. The complication (aside from the fact that this is all semantics as it’s clearly emmental) is that if 2 bodies collide and throw off a cloud of rocks and ejecta which then form a moon, then the moon should have a chemistry which is a mix between the Earth and the theoretical colliding mini-planet.
What we see, however, is a moon with nearly identical chemistry to the earth (we see this using isotopes; atoms of the same element with different atomic masses) which suggests that the material which formed the moon should have come from the earth itself. The new research therefore suggests that a fast-moving object smashed into our planet at a glancing angle and cleaved off a chunk. This chunk was hot enough to then reform into a sphere and became entrained in the Earth’s gravity to orbit indefinitely.
The research still has a long way to go before it is able to explain the observations of Wallace and Gromit who arrived on the moon around 20 years after Apollo 17, had a picnic, tasted the cheese, then went home. Further research is clearly needed, beginning with me eating some cheese.