Animation of the moon as it cycles through its phases. The apparent wobbling of the moon is known as libration.
This month's lunar cycle calendar
More in-depth details on this month's lunar activity related to above link
Another nice lunar cycle calendar
Our solar system in scale.
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Neptune, Uranus, Pluto (not shown, not counted anymore)
What and when are the summer and winter solstices---The days with the longest and shortest amounts of daylight of the year?
What and when are the vernal and autumnal equinoxes-- The days of equal daylight and darkness?