It is going to be pretty much impossible to judge distances when you have no frame of reference up in the sky. On the ground, your brain knows how tall a telephone pole is or the rough size of a SUV, so it can make decent guesses about how far away those things are.

In the air you can only see a bit of the wing and then land features 7 or more miles away. Your brain has no reference for determining distance. Not being able to determine the type of plane makes it even worse. A 747 would look closer than a CRJ when they were at the same distance.