Educational "Picture Of The Day" Sites

Here are several sites that have a "Picture of the Day".

Space
Astronomy Picture of the Day
NASA Image of the Day
Lunar Photo of the Day

Earth
Earth Image of the Day
Earth Science Picture of the Day
National Geographic Photo of the Day

Weather
Weather Picture of the Day
The Weather Picture of the Day

Nature
Botany Photo of the Day
Insect Picture of the Day

Science
Live Science Image of the Day
Woods Hole Oceanographic Institution Image of the Day

History
American Heritage's Picture of the Day
Old Picture of the Day