Question: Are we aliens

There is an idea called Panspermia that life started elsewhere and was carried to Earth in comets and meteorites, which would make some or all life on Earth alien. However, it lacks evidence and isn’t generally favoured. All life on Earth discovered so far seems to be related to each other in some way or another, even if distantly. There’s not been any evidence of unrelated life. It might be argued that life arrived as a single seeding event and then diverged, but only if we could find life on another planet, say Mars, and then show that it also shared a common ancestor with life on Earth would there be evidence to support the idea. Panspermia is sometimes seen as a way around the the old question “How did life arise on Earth”, but it’s not a good answer, it just leads to the question “How did life arise elsewhere then?”.

There is evidence for some of the molecules critical to life in space. Simple sugar-like molecules, simple amino acids for proteins and nucleobases for R/DNA but these are not life, just some things life uses.