A few questions/comments: * What is the "4 billion years ago impact" that is refered in the video? At first I thought it was the Theia impact, but the sizes an

A few questions/comments: * What is the "4 billion years ago impact" that is refered in the video? At first I thought it was the Theia impact, but the sizes and speeds don't quite match, and the simulation doesn't result in a second moon. * It also mentions that it has happened 6 times. The only impact large enough I can remember of the top of my head that sort of matches that scale would be the canadian impact basin. A quick search on wikipedia tossed me to this list [0] but everything there seems to be on a different scale than what's described in the video. Are those impacts mentioned in the full program? * It was recently reported that an expedition drilling in a part of the ocean where the crust is thin had found microbes near the magma, but I can't find any link. Given that it has been theorized even Venus may hold life in it's upper atmosphere [1], my guess would bethat, life is far more resilient than we imagine it to be. [0] https://en.wikipedia.org/wiki/List_of_impact_craters_on_Earth https://en.wikipedia.org/wiki/List_of_impact_craters_on_Eart... [1] http://web.archive.org/web/20110807004311/http://gltrs.grc.nasa.gov/reports/2003/TM-2003-212310.pdf http://web.archive.org/web/20110807004311/http://gltrs.grc.n...