2. Gold nuggets
3. Everything else
The whole of Planet Earth came from space, it's just a load of rocks and iron and stuff which was whizzing around in space and which clumped together over a period of millions or billions of years.
One of those rocks will have had "life" on it, and I'm not sure it's relevant which one. We can decide an arbitrary date for when the clump was big enough to count as Planet Earth, so whether life originated on Planet Earth or not depends entirely on whether that that date is after or before the time that the rock bearing life arrived here.
And I suppose the order in which things arrived is quite interesting, but they all came from space.
Friday, 20 September 2013