The building blocks for RNA-based life have been found… in the center of the Milky Way

We don’t know exactly how life arose on Earth.

For one thing it was a long time ago: Roughly 3.8 billion years in the past, give or take, and records of anything that happened from that period in Earth’s very ancient history are spotty. For another, we don’t know the chemical path life took. Surely simple molecules built up into more complex ones, eventually becoming able to store information and self-replicate. And then, abracadabra, DNA popped up and the rest is biological history.