Parallax

Parallax is the apparent motion of an object based on different lines of sight.

Calculating Parallax


In the example to the right, we see that from the movement of the Earth, there has been an angle $$\theta$$ introduced between where the earth was and where it currently sits.

In this sort of problem, we will primarily be using the fact that :

$$tan\theta = \frac {1 AU}{d}$$

Therefore, given either $$d$$ or $$\theta$$, we can solve for the other. Note that $$d$$ is the distance from the sun to the object.