News article: ‘Lost’ asteroid to pass closely May 15
On wikipedia: https://en.wikipedia.org/wiki/2010_WC9
How accurately can the future path of this (or any) object passing 1/2 the distance of the moon from earth be predicted? I would think that the variables would be rather difficult, to say the least. Can all the factors be accurately worked out (gravitational effects of the Earth, Moon, Sun, Jupiter, Mars, etc.) ? And how far down the time line can the predictions be reliably made?
The biggest issue at first is the number of observations. To get really good predictability we need several distinct observations, preferably spread out over time.
For a first pass by an asteroid we only get observations over a few days. Apparently for this one it was over a 10 day period. Tiny objects like this just aren’t visible near us for long.
While Gauss came up with the basic equations that make plotting orbits of comets and such practical, once you get into “hit or miss” questions, you need a lot more detailed equations. Factors like the oblateness of the Earth and the Yarkovsky Effect.
For the latter you need to know rotational period, albedo, etc.
When passing near Earth, one complicating factor is whether or not an asteroid hits a gravitational keyhole. A couple special regions where a small difference in incoming path results in a surprisingly large change in outgoing path.
Predicting whether an object will definitely pass thru a keyhole requires a lot of observations. Nevermind what happens when it does pass thru one.