There’s a difference between a hard proposition and something being within the realm of possibility. There are some things that we will never be able to know for certain, and this is one of those.

Hell, the cells that we all evolved from might not even be the first life to form on the planet.

It’s not a subject like astronomy that better instruments will be able to improve our knowledge. This is a history question, not a scientific question, and you can’t answer those questions if evidence doesn’t exist.