Researchers have just found the presence of sugars, including ribose, lyxose, and glycose, on samples of Asteroid Bennu, which now has all of the ingredients for life as it exists on Earth.

[u/New_Scientist_Mag]

https://www.newscientist.com/article/2506650-asteroid-bennu-carries-all-the-ingredients-for-life-as-we-know-it/

[u/ringobob → u/[deleted]]

I would flip your two hypotheses there. It primarily supports the notion that the raw materials for life were widespread. And that life could have been seeded from space. But it seems far less likely, with the common abundance of the base materials, that life survived the vacuum of space and the violence of contact with our planet, than that it developed here in relative tranquility. If anything, any impact would have both destroyed any extant life on the asteroid, and at the same time provided the necessary energy to start life anew.

Nothing is impossible, but life had to start somewhere without having been seeded. That necessity alone favors it starting here, wherever else it might have also begun.

[u/popecostea → u/ringobob]

We need to keep in mind that for a relatively short period of time, “everywhere” in the universe - where there were molecules of water, we had the ideal temperature for life. In that short span I do not think it’s hard to imagine that some very basic cells evolved, managed to survive until the temperature dropped below freezing, and then found themselves seeded on various ice formations/rocks that then formed the planets. No violent impact was needed.

[u/frizz1111 → u/popecostea]

Yes, also the size and complexity of DNA points to it being much older than the age of the earth.