back deutsch english language


Phase of the Moon
and phases on the Earth

Date:10.05.2008 Camera:f=135mm,
Nikon D200
Place:Donntal, Germany Photo:Till Credner

Watch the phase of the moon! It was about noon when the young crescent moon was hovering above this rock formation in southern Germany. And do you notice the similar "phase" of the rocks in the foreground? What can we learn from this?

If you look at the moon at day and see other sunlit stuff on the earth in the same viewing direction, you might notice that the direction of illumination is the same. Furthermore the angle of incident seems to be the same: the moons phase is nearly the same as the "phase" of the rocks in the above image. The light on the moon and on the rock comes from the same direction!
Just take a white ball, hold it next to the moon and compare the sunlit areas:

Date:20.10.2008 Camera:f=135mm, Nikon D200
Place:Progymnasium Rosenfeld, Germany Photo:Till Credner

First, this little experiment is a strong hint that the moon is illuminated by the same source as the earth, aka the sun. And it also explains more or less the phase itself.

But furthermore it shows that earth and moon have the same large distance to the sun. The moons motion around the earth is quite small compared to the suns distance. If the moon were much further away from earth, its phase would be fuller.

By the way, which item do you think fits the moon best? Considering the shape, it is probably a round ball. Considering color and albedo, it resembles a bit more the one on the stick right to the center.
Well ... , that is a Mozarella cheese.

© Copyright AlltheSky.com