There are many more asteroids known now than there were back when space missions were being planned (by an order of magnitude). I wondered if on their way to the outer solar system, did the Pioneers, Voyagers, or Galileo happen to pass by an asteroid that at the time was unknown? How many asteroid-imaging opportunities were missed because such-and-such object wouldn't be discovered for another 10 years? I don’t necessarily mean very close passes that would have been a hazard to the probe or gravitationally alter its trajectory, but flybys close enough that significant imagery could have been performed.
If such missed-opportunity asteroids exist, I thought it would be an interesting article for Sky & Telescope. But someone would have to figure all that out, and I sure couldn't do the computations! I sent the query to a couple of asteroid researchers, but no one had time to devote to it. Anyone want to give it a go?