How did the lunar maria form? A. Rivers carried sediments from the
highlands to the lowlands.

B. Lava flowed from the moon's interior onto its surface.

C. Meteorites flattened the mountains.

D. Shallow oceans evaporated, leaving broad areas covered with sand.

According to an observer on earth, planet x is stationary. maria and samir depart earth on their spaceships at the same time, each flying at 0.5c. maria flies toward planet x and samir flies in the opposite direction. according to maria, her voyage to planet x takes 9 years. how many years does maria's voyage take according to samir?