# Measuring parallaxes from the moon

If one were to measure star parallaxes from the moon, what (if any) changes would you have to make compared to someone making the calculation from earth? What about on another planet in our solar system?

• On another planet, you could simply use the same techniques and calculations as on earth, but accounting for the planet's different orbit size (instead of earth's). The Wikipedia page on parallax gives the general concept of parallax; you can apply that to any planet. As for the moon. . . tat might be harder. – HDE 226868 Aug 7 '14 at 18:32

$\textbf{The method utilized to measure parallaxes from the Earth frame:}$

We utilize the distance from the "us" to the Sun (as a reference point of sorts). Here is a visual:

If one were to measure the parallaxes from the Moon, they would have adjust their method in accordance with the position of the Moon with respect to the Earth–Sun reference line (note that this is a time dependent measurement, the value will, of course, be different depending on when you make the calculation).

If you were measuring parallaxes from another planet(x), you would need to use the distance from that planet(x) to the Sun as the baseline. In addition, you would need to convert "earth years" to the "planet(x) years", as the other planet(x) would have a different orbital period than earth.