The Moon
Earth's only natural satellite, about 384,000 km away.
The Moon doesn't make its own light. We see the half lit by the Sun, and as the Moon circles the Earth every month, we see more or less of that lit half. Those are its phases.
It always shows us the same face, because it spins exactly once for every trip around the Earth.
It rises about 50 minutes later each day, so over a month it drifts from the evening sky, to all night (full Moon), to the morning sky.
Facts
- Distance
- about 384,000 km — you could fit all the planets in the gap
- Size
- about a quarter of Earth's width
- One lap around Earth
- 27.3 days (29.5 days from one full Moon to the next)
- Light from the Moon
- takes 1.3 seconds to reach you
Did you know?
Understand it
Why does the Moon change shape?
We see different amounts of its sunlit half as it circles the Earth.
Why does the Moon rise later every day?
While the Earth spins, the Moon also moves along its orbit, so the Earth needs about 50 extra minutes to catch up with it.
What is an eclipse?
When the Sun, Earth and Moon line up exactly, one casts a shadow on the other.
Why can I see the dark part of a crescent Moon?
Sunlight reflected off Earth lights up the Moon's night side — earthshine.