A question I’ve been wondering about: To what extent is the contemporary Earth’s crustal composition a mix of Theia and the proto-Earth? If Theia was roughly one tenth of Earth by volume, where did all that matter end up?
This model puts the composition of the moon at around a 70:30 mix of Earth to Theia. This doesn't square with titanium composition of the moon rocks that indicate that the moon was formed from <i>cooled</i> earth materials.<p><a href="https://www.wired.com/2012/03/moon-formation-collision/" rel="nofollow">https://www.wired.com/2012/03/moon-formation-collision/</a>
Reading about things like this (matter ejected from Earth into space) + recent research on extremophiles makes wonder if panspermia might be an accurate theory:<p><a href="https://en.wikipedia.org/wiki/Panspermia" rel="nofollow">https://en.wikipedia.org/wiki/Panspermia</a>