Quantifying the release of climate - active gases by large meteorite impacts with a case study of Chicxulub. (sciencenews.org)
As for the asteroid: There are a few large craters in the world that are said to be the results of large meteorites — we could reclassify them as asteroids... Even with that, there have been few detected «asteroid» collisions in the past 4 billion years. (slaw.ca)
«It's no coincidence life appeared on Earth around the same time it was being pelted by large meteorites» (newscientist.com)