Question

The average distance from the Earth to the Moon is DTL = 3.84 × 105 km and that of the Earth at
Sun is DTS = 1,495 × 108 km. The radius of the Moon is RL = 1.74 × 103 km and that of the
Sun RS = 6.96 × 105 km.
a) Calculate the apparent diameters (in degrees) subtended by the Sun and the Moon.
b) Calculate the solid angles subtended by the Sun and the Moon.
c) Which of the two stars appears bigger seen from the Earth?
d) If the calculated values were constant, would it be possible to observe a total eclipse
of the Sun?

Answer 1

c) So the sun seen from the earth appears to be slightly bigger since its subtended angle as well as the its solid angle on the earth are greater than the moon.

d) No if these values remajned constant total solar eclipse would not be possible since the moon appearing smaller than the sun would never be able to cover the entire sun for a total solar eclipse. Though obviously partial solar exlclipaes will be possible. Total solar eclipse occur because in reality these values don't remain constant since the distance between earth and moon and earth and sun changes through the he course of the year.