99942 Apophis (also known as 2004 MN4) is a near-Earth Asteroid that may crash into the Earth in 2029, 2036 or 2037. Since it's about 350 meters (1,100 ft) long, it would be devestating. The potential impact is estimated to be the equivalent of 880 megatons of TNT, and, if it hits a populated area, could result in 10 million deaths. Previous estimates had listed it at over a million megatons, with the potential to wipe out life on the surface of our planet.
When it was initially detected, the Apophis was calculated as having a 2.7% chance of impacting with the earth in 2029, and it was for a while the highest-rated (ever) impact threat on the Torino Scale. It has since been downgraded, thankfully, and the current estimate is that there's only a 1 in 45,000 chance of the impact.
It will definitely pass near the earth in 2029, though, and there's a chance it will pass through a gravitational keyhole - a particular path that would result in it getting deflected in such a way it would swing around and definitely smash into the earth 7 years later (in 2036). The specific day when it will pass near that gravitational keyhole is Friday, August 13, 2029… on that day it will pass inside the orbit of geosynchronous communication satellites, and will be visible in the night sky with the naked eye. That's gonna be an exciting day.
Game and Story Use
- A nasty disaster scenario for 2029, 2036 or 2037 - and note that it all starts on a Friday the 13th.
- Similar threats could endanger other planets, or this planet at other times. You could base a whole campaign around PCs who are the astronaut crew of an asteroid-deflecting spacecraft.
- This sort of nastiness would happen a lot more often if we didn't have Jupiter out there, sucking up comets and asteroids for us.
- A game set between 2029 and 2036 could be interesting - especially if calculations show that the 2029 keyhole passage occurred and life on earth will end in less than 7 years. Various groups would be desperately working to get off the planet, build impact-proof bunkers, or deflect it. Meanwhile, the public would be in chaos and disorder, because people with less than 7 years till the end will start getting desperate (or just not caring about tomorrow). "May you live in interesting times" indeed.