Question

scientist measures the angle x and the distance y between the Sun and moon. Explain how the scientist can use only two measurements to calculate the distance between the earth and moon

Answer 1

Observe Moon;s center on a Full Moon night from two places 100 km apart for parallax
θ
.. Then
α
= 100/6378 radian = 0.0156789 radian = 0.8983346 deg. The distance of the Moon then will be approximately 6378 sin(0.449167)/sin (
θ
/2). The other way about , if the distance is known to be 384000 km, theta is nearly 0.1492 deg = 54", nearly.. .