How exactly could you measure the distance from the Earth to the Moon by triangulation? How is it done?

Question

I’m reading Bill Bryson’s book and came across this concept. Still can’t get my head around it. Would appreciate a proper explanation. Thanks.

In: Physics

Answer 1

Imagine you’re standing in a room with an overhead light on a ceiling painted with stars. You want to know the distance to from the centre of the room. You could walk to opposite corners and look the light. It looks different with respect to the background stars, because you’re at a different angle. From both the corners of the room you take a picture and compare them. From the way the stars look, you can find the angle between the lines from the light to the corners. Then measure the distance between the corners. you can now draw a line from the light straight down to get a right-angle triangle. using some simple geometry to calculate the hight of the light. It works basically exactly the same with the moon instead of a light, just with bigger distances and smaller angles.