The Roche limit is the point at which
A) the mass of an object classifies it as a moon.
B) a moon orbiting a planet experiences synchronous rotation.
C) the external tidal forces on an object are strong enough to be felt by the object.
D) the external tidal forces on an object become greater than the internal forces that hold it together.
E) the internal forces that hold an object together weaken so that the object falls apart.
Question 2
The cratering of the lunar highlands shows us:
A) they are younger than the maria.
B) they are older than the smoother maria.
C) they have been unchanged for the last 4.6 billion years.
D) they are like the Earth's continents, removed from the tectonic cycle of the mare.
E) they were made of more rigid lavas than the basalts that made the maria.