I wonder how they can say that, when the range of possible trajectories is between 11,000 and 9 million miles from Earth. That is a pretty huge range--is that a confidence interval, or is that a standard error or deviation in measurement? Either way, that huge range does not tell me that the chance of it colliding with Earth is negligible.
Maybe it will hit a piece of space junk, which will deflect it enough to avoid entering the atmosphere.
I'm a biochemist, not an astrophysicist, so I have no idea how they make those calculations or the assumptions behind them.
Those are very good questions. But I’m afraid I don’t have any good answers.
As seen from Earth, this asteroid has been close to the Sun most of the time since it was discovered, and so has been unavailable for viewing; the amount of data on it is meager.
As I recall, there are a handful of “orbital elements” that completely determine any orbit. Maybe they have interval estimates for each of them, and by plugging in those numbers they can get a best and worst case scenario?