system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars] In Force Awakens, how did Han throttle back from lightspeed at the precise moment to be below radar but not crash into the planet? That's maybe a 500m window, so you'd have to come out of hyperspace with the precision of 1/600,000th of a second. Is it just "it was the will of the force"?
gpt
Large objects like planets have a "mass shadow" that forces ships out of hyperspace. The exact point where you drop out depends on your hyperdrive configuration. Civilian ships are designed to drop into realspace on the edge of the planet's atmosphere, to prevent people crashing into planets if they get the coordinates slightly wrong.

Military ships want to drop out later, so they can reach a short way into an artificial mass shadow and surprise an enemy who is trying to jam hyperdrives. If you try to do that on a planet you'll materialise inside the planet's crust, so it's adjustable.

Han tuned the cutoff to the level of gravity that there was 500m above the ground. An incredible feat, definitely only possible by a very skilled pilot who knows his ship like the back of his hand, but it doesn't require microsecond reflexes.