The Mars Alien Artefact in ED can have only two explanations:
1) It’s just a vague tribute to the Arnie film Total Recall, where the atmospheric engine was triggered by Arnie’s hand pressing the alien hand shape on the top of the column.
2) It’s a clear indication that in ED aliens visited Sol in ancient history.
Though 2) doesn't preclude 1).
I find 1) a bit unconvincing, since the ED artefact is clearly stated to be a small object, no larger than a child’s hand, whereas the alien hand shape in the film was quite a bit bigger than Arnie’s large hands, and IIRC only 4 fingers (does that match the Guardians description by Ram Tah?). So I’m left with the hint that aliens have visited Sol, specifically Mars, in ancient history. But there are no consequences to that, no follow-on story/clues. The only thing that is obviously odd about Sol is that Triton is permit locked...could Triton be Raxxla? This hypothesis seems to hang, since there appears to be no storyline mechanics to explore it.
We are told explicitly that the Guardians had sentient AI, and so did humans, before it was banned and some escaped to deep space...so there’s two potential other species for you!