- The Moon is Earth's sole natural satellite and nearest large celestial body
- It is a spherical rocky body, probably with a small metallic core, revolving around Earth in a slightly eccentric orbit at a mean distance of about 238,855 miles
- Its equatorial radius is about 1,080 miles
- The moon is the brightest and largest object in the night sky on Earth
- The moon is responsible for tides and helps moderate Earth's wobble on its axis, which contributes to a stable climate
- The moon's rotation is locked to Earth's rotation by gravitational pull, so the same side of the moon always faces Earth ... this means that a lunar day is 29.5 Earth days long, which is the same length as a lunar month
Ham Radio Moon Bounce ==> A radio signal transmitted to the Moon and back (a "moon bounce") takes approximately 2.56 seconds on average for the round trip. This is due to the distance between the Earth and the Moon, which is roughly 384,400 kilometers (238,855 miles). Radio waves travel at the speed of light, and the round-trip time is calculated by dividing the distance by the speed of light and then doubling it (to account for the outbound and return journey). Moon Bouncing is one of the favorite activities of "Amateur Radio" geeks, or "hams" as they are commonly known.