Basic Properties of the Moon (48)

Introduction

The idea of this post is to present some of the very basic properties of the Moon in a way that we can easily relate to, that is by using Earth comparisons. With this basic information about the Moon we can a tiny bit of a feeling of what it would be like to visit the Moon.

Size

The Moon has a radius of about one quarter of the Earth's radius, making it in relation to the planet that it orbits (the Earth), quite large in fact.

Surface Area

In surface area the Moon has 38 million square kilometres, making it in surface area slightly larger than the continent of Africa.

Atmosphere

Its atmosphere is almost a perfect vacuum, that is there are no weather phenomena at all, and the sky is always black. You can see the stars during the day but the glare reflecting off the Moon’s surface makes it difficult for the human eye to see them.

Temperature

At high noon the Moon's surface temperature can rise to above 100°C and it can drop to be as low as -150°C at midnight.

Rotation (Day and Night)

The time the Moon takes to rotate once on its axis is 29 Earth days or 708 hours so a day on the Moon lasts 708 hours and from sunrise to sunset there is about 2 weeks of daylight. That’s one very long day.

Mass

The Moon has about 1% of the mass of the Earth and gravity is about one sixth as strong on the moon. So if a person weighs 60kg on Earth that same person would weigh 10kg on the moon.

Summary

Mass:                    7.35×10²² kg (1% of the Earth mass)

Radius:                 1738km (27% radius of the Earth)

Surface area:        3.79×10⁷ km (17% area of Earth)

Density:               3340 kg/m³ (3.34g/m³).

Gravity:                                                    1.62m/s² (17% of Earth)

Average surface temperature:                  102°C day;-153°C night.

Surface temperature in polar areas:        -50°C in the light and -230°C in the shade.

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