I have been putting asteroid strikes in the category of potentially catastrophic but so rare as to not worry about. I have also assumed we would see a really big one coming for decades if not centuries and would at least have a chance to get organized and do something about it (a big if, given the lack of coordinated international response to climate change and the pandemic.) But according to this Jerusalem Post article, a fairly sizable asteroid could sneak up on us by passing close to the sun on its way to us. This happened on September 16, 2021 with an asteroid somewhere in the 50-100 m diameter range. The article doesn’t do the math on what size conventional or nuclear weapon this would be the equivalent of if it hit. I thought that was pretty standard…

The article has an interesting (and chilling) photo of the 2013 Chelyabinsk asteroid streaking in, which was about 17 m wide. The article says that on April 13, 2029, a 340 m asteroid is supposed to “safely pass by” the earth at a distance of “under 32,000 km”. Assuming the article has the number right, that is only about one-tenth the distance from the Earth to the moon. This sounds like one to watch.