What is a planet's Roche limit?
What will be an ideal response?
Question 2
An observer on a planet sees a spaceship approaching at 0.5c. A beam of light projected by the ship would be measured by this observer to travel at:
A) 0.25c.
B) 0.5c.
C) c.
D) 1.5c.
E) 2.5c.