planets
This is the average length of time it takes for the moon to complete its cycle.
What are 28 days?
The moon's gravitational pull causes these rises and falls.
What are tides?
The different shapes of the moon we see.
What are phases?
When the light shows on less and less of the moon, we say it is doing this.
What is waning?
These two things cause the earth to experience seasons.
What is the tilt of the earth and its revolution around the sun?
This is what you call a natural object, like the moon, that revolves around a bigger object.
What is a satellite?
What is an equinox?