The Moon Earth’s natural satellite

Basic Facts The Moon orbits the Earth at a distance of approximately kmThe Moon orbits the Earth at a distance of approximately km Its diameter is a quarter of Earth’s, while its mass is eighty times less than Earth’sIts diameter is a quarter of Earth’s, while its mass is eighty times less than Earth’s This means that it’s gravity is 1/6 that of the EarthThis means that it’s gravity is 1/6 that of the Earth So a man who weighs 100N on Earth would have a weight of 16.67N on the MoonSo a man who weighs 100N on Earth would have a weight of 16.67N on the Moon The Moon has no atmosphere and this means it has no protection against meteorite strikes, thus it is covered by many cratersThe Moon has no atmosphere and this means it has no protection against meteorite strikes, thus it is covered by many craters

One giant leap One giant leap… The Moon is the only object in the Solar System that humans have walked on (other than Earth obviously!)The Moon is the only object in the Solar System that humans have walked on (other than Earth obviously!) In 1969 Neil Armstrong became the first man to walk on the MoonIn 1969 Neil Armstrong became the first man to walk on the Moon

The phases of the Moon The Moon orbits the Earth approximately once every 28 daysThe Moon orbits the Earth approximately once every 28 days At the same time it spins on its axis. This means that only one side of the Moon faces the Earth.At the same time it spins on its axis. This means that only one side of the Moon faces the Earth. As the Moon orbits the Earth, a larger area of the nearside becomes illuminated by the SunAs the Moon orbits the Earth, a larger area of the nearside becomes illuminated by the Sun It is this that causes the phases of the MoonIt is this that causes the phases of the Moon

The phases of the Moon (2) SUNLIGHT 3. Further round and a waxing half moon is formed 5. Fourteen days after the New Moon, and now all sunlight is falling on the nearside of the Moon– a Full Moon 4. Waxing gibbous Moon 6. Waning gibbous 7. Waning half moon 8. Waning crescent 1.New Moon – All sunlight falls on farside of Moon facing away from the Earth. 2. As Moon orbits around Earth a waxing crescent forms Shows portion of Moon visible to an observer on the Earth Inner circle = Position of Moon in its orbit around Earth Outer circle = What Moon looks like from Earth

Eclipses An eclipse occurs when light from a body in space is blocked by another objectAn eclipse occurs when light from a body in space is blocked by another object Eclipses can either be solar or lunarEclipses can either be solar or lunar In a solar eclipse the Sun is obscured by the MoonIn a solar eclipse the Sun is obscured by the Moon In a lunar eclipse the Moon is obscured by the Earth itselfIn a lunar eclipse the Moon is obscured by the Earth itself

Partial eclipse Total eclipse Solar Eclipse SUNMOONEARTH In a solar eclipse the Moon passes between the Earth and the Sun. The Moon casts a shadow on the Earth’s surface. The shadow consists of two areas: the umbra where a total eclipse can be seen; and the penumbra an area where a partial eclipse can be observed. NOT TO SCALE!

Lunar Eclipse SUNMOONEARTH In a lunar eclipse, the Earth is between the Sun and the Moon. The Earth casts a shadow, blocking out light that can reach the Moon. The Moon often goes a deep red colour, as opposed to being obscured completely – this is because red light is refracted by the Earth’s atmosphere. NOT TO SCALE!