A few points:
I wish more new posters could see your post. They think that all they have to do is attach a video or article from a different site and we must rush to vew/read and shower them with upvotes. You did it very nicely, enough info in your own words to wet the appetite and deserve our upvotes - and to avoid flagging from the self-appoint police force of steemit.
All good posters (they are usually the ones with some voting power) recognise the effort of making a good post an upvote - they do not need to be asked. Those who need to be asked, usually have zero voting power. I am not telling you not to ask, after all, there are posters with Reps of over 70 who still plead... I just wanted you to be aware of how some might see it.
As for the subject matter: Imagine we turn into such PC idiots that we (after developing the technology) send back teams to help the dinos grow smarter and to develop nuclear weapons so as to save themselves from that big asteroid that wiped them out. If we do, it would not worry me, as they would then use the bombs to wipe themselves out of existence. It seems to be a law of nature - have bombs, will go bang.
RE: Do You Know How Many Asteroids Are In Collision Course With Earth?