Starseed

The "starseed" theory has been around for a while. It postulates that life on Earth actually had some kind of origin in outer space.

The more "cinematic" version blames aliens - we were put here on purpose and then left to evolve either deliberately or because something happened to the aliens right after they sent the first terraforming ships.

However, there's a more prosaic version - that life, or its building blocks, was carried to Earth on asteroids or comets.

And it just got a major boost. It turns out that the interstellar medium is the perfect place to turn phosphine, which is poisonous, into oxoacids of phosphorus, which are a required building block for life as we know it.

There's no equivalent situation on Earth, although we might of course be having problems simulating that early environment, so cataclysmically different from Earth today.

But it looks like those building blocks are out there - and we have one more piece in the puzzle. If we do find life based on DNA on another planet, then those oxoacids of phosphorus are why.

See you at Capclave!