Astrophysics Flashcards
1
Q
When is retrograde motion observed?
A
When the earth catches up and passes the rest of the planets in its orbit around the sun.
2
Q
Why is a day 24 hours?
A
Because it is the amount of time it takes for the earth to rotate on its axis
3
Q
Why isn’t there an eclipse every month?
A
A lunar eclipse happens when the moon enters the earth’s shadow. A solar eclipse happens when the moons shadow falls on the earth. They do not happen every month because the earth’s orbit around the sun is not in the same plane as the moons orbit around the earth.
