Monday, February 20, 2006
Lunar phases

Why do you see different portions of the Moon lit by the sun

The Moon has no light source of its own. It "shines" because it reflects sunlight. At any given moment, half of the surface is lit while the other half is dark. On the Moon there is night an day, just as on Earth. But what causes the changing appearance of the Moon, what causes the lunar phases?
Posted by Math on 02/20 at 05:27 AM | (3) Comments | filed in: Lunar basics | Print