“is it true that you can use stars like a map?”
“Yeah, if you understand celestial navigation.”
“Is it hard?” I’m thinking maybe I should learn. A backup plan, for all those times I feel like I’m just wandering in circles.
“It’s pretty jazzy math– you have to measure the altitude of a star, figure out its position using a nautical almanac, figure out what you think the altitude should be and what direction the star should be in based on where you think you are, and compare the altitude you measured with the one you calculated. Then you plot this on a chart, as a line of position. You get several lines of position to cross, and that’s where you go.”
– Quoted directly from Jodie Picoult, My Sister’s Keeper (New York: Pocket Books, 2009), 306.