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NASA is tracking 93% of all giant asteroids that could smash into Earth

• deleted 15y ago
  [deleted]
• firebones 15y ago
  How do they come up with the estimated number of asteroids larger than 1 km? Is it based simply on sampling a volume of observed space and extrapolating? Or do they have some way of inferring based on gravitational effects and anomalies?
  • Nick_C 15y ago
    > Is it based simply on sampling a volume of observed space and extrapolating Yes, that's pretty much it. It's not as bad as perhaps it sounds. The age of the solar system means that the asteroid belt is mostly stable, which means the distribution can be inferred. The Kuiper belt and Oort cloud may throw some outliers in occasionally, though. We don't know enough about them yet.
• feral 15y ago
  Is 93% really an acceptable amount of the 'giant asteroids that could smash into Earth' to track? Clearly, its a better number than, for example, 50%; and its great that NASA is doing any tracking; but this is an species level existential threat that's being talked about. I'd really prefer to live in a world whereby a joint international effort (ideally; or just anyone) was tracking 99.9999% of such asteroids, as a matter of priority. I think that the LHC, or the moon landings, were great projects - but shouldn't we do this, first?
  • Nick_C 15y ago
    The issue is how. It's the old 80/20 rule, although perhaps in this case it is more like the 93/07 rule. We've got the "easy" ones, but we infer there are others we haven't detected. How do we detect them? Space is really really big.