The Moon: There are four types of lunar months, something we on Earth may not notice as the days go by the moon waxes and wanes.

The first type of lunar month is anomalistic, which means the length of time it takes the moon to circle the Earth is 27 days, 13 hours, 18 minutes and 37.4 seconds. This is measured from the moon’s closest point in its orbit to the Earth.

The next type is nodical, which is the length of time the moon takes to pass through one of its nodes (the point where it crosses the plane of the Earth’s orbit. This takes 27 days, 5 hours, 5 minutes and 35.9 seconds.

Third is the sideral variety of lunar month, where the stars are used as a reference and the length of time the moon takes to circle the Earth is 27 days, seven hours, 43 minutes and 11.5 seconds

Finally, synodical — which is the length of time it takes the moon to circle the Earth using the sun as the reference point. This is 29 days, 12 hours, 44 minutes and 2.7 seconds.

Meanwhile, other interesting facts about the moon that may not be on the average person’s radar:

Reference books tell us that we typically see only half the moon’s surface because of its single rotation as it revolves around the Earth. However, the truth is that we see about 3/5th of its surface during that time. This is because its rate of revolution is not uniform, so people on Earth can see around the edges on occasion.

However, 41% of the moon’s surface can not be seen from Earth and anyone on that area of the Moon can never see the Earth either.

The full moon shines at a magnitude of -12.7, compared to the sun’s magnitude of -26.7. This means that, the ratio of brightness of the sun to moon is 398,110 to 1.

In order to have a comparable magnitude, it would require more than 206,264 full moons all in the sky at the same time.