>> Thursday, August 13, 2009
The Mother said: Kids were asking what the heck a "gibbous" moon is when Wired said that it would make the meteor shower hard to see tonight. Since you have the moon phases on RS, I figured you're the person to ask.
I'm certain a person to ask. Fortunately for me, it's not difficult. A gibbous moon is one between a half moon and a full moon (as opposed to a crescent moon which is between a half moon and a new moon). It can be waxing, when the moon is on it's way to full, and it can be waning when it's on it's way to a half moon.
How much light a gibbous moon gives off has a great deal to do with how close it is to a full moon. If it's close to full, it will be bright, nearly as bright as a full moon. If close to the half moon, it could be just a bit more than half that.
Of course, you probably know that the same side of the moon faces the surface of the earth at all times (although the other side isn't always dark; it just faces away from us). And the phase of the moon has to do with where the light hits the moon with relation to where the moon is to us.
A new moon happens when the moon is between us and the sun (so that the sun is light up it's far side). A full moon is where we're between the moon and the sun.