In 24 years, an asteroid will pass under our satellite belt, and be visible even in bright city night skys. No, it won't hit us, but you gotta love the NASA folks' experience pattern:
Of course we could change our orbit, or the asteroid's, in the near future (and wouldn't that make a really good bad movie?)....
Killer Asteroid! headlines generally appear between steps 3 and 4, but that's another story.
- Step 1: An asteroid is discovered.
- Step 2: Uncertain orbits are calculated from spotty tracking data.
- Step 3: Possible Earth impacts are noted.
- Step 4: Astronomers watch the asteroid for a while, then realize that it's going to miss our planet.