Is there anywhere on Earth that the moon is not visible on any given night?

Question

This question was asked by my 6 year old daughter Maddie.

No clouds, at night, while awake. As in ultimate darkness other than starlight.

Answer 1

There are a couple of days around the new moon when the moon can't be seen from anywhere because it's too close to the sun and only the side away from us is lit. Also, in the arctic and antarctic there is a part of the lunar month when the moon can't be seen, same as there's a part of the year when the sun can't be seen. At this time of year the full moon can't be seen from the north pole.

Answer 2

That's a great question. I love hearing about young kids thinking from a different perspective. Not a lot of adults would even think to ask this one.

It probably isn't visible at the North and South Poles all the time. The sun doesn't rise at the poles for half the year, due to the Earth's axial tilt of 23 degrees.
The moon orbits close to the ecliptic and not in the same plane as the Earth's equator, so it orbits in a similar way to how the sun appears to us. But instead of not rising for 6 months a year, the moon is probably not visible for about 2 weeks each month (it orbits the Earth once a month).

Perhaps you and Maddie can visit a planetarium or contact an astronomy group in your area (there are lots of amateur groups around). You both might really enjoy exploring more of the universe.

Answer 3

The moon does not always stay on the opposite side of the sun with respect to Earth. It has its own orbital properties. In other words, it does not rotate around Earth at the same period as the Earth spins.

That being said, the moon is not always visible at night. At some points in the evening it may be beyond the horizon, ought of sight. Also, you can on some clear days see the moon during the day. Just to give you an idea, tonight at my location (Ontario) the moon will be rising at 7:43 PM and setting at 2:36 AM.

The other situation where you would not be able to see the moon is when it is on the exact opposite side of the planet to the sun, called a "new moon". The moon does not produce its own light, rather what we observe is light from the sun being reflected off of the surface of the moon. If the Earth is directly between the two it blocks the sunlight, no light travels to the moon, so no light is reflected from the moon, so we cannot observe it.

Answer 4

When I read your question, I immediately thought of the Midnight Sun. I had never thought about the Moon's visibility at the poles! Thanks for the incentive to learn something new! Actually, thank your daughter. My daughters are five and seven, so I'll share this with them the next time they're in the mood to learn more about this sort of thing.

When reading the article linked below, keep in mind that when the Sun is at it's highest in the summer months around June 21, the Full Moon will be at it's lowest. This is why it is the New Moon that is in the sky for 2 weeks in the summer, and it is the Full Moon that is in the sky in the winter.

Sounds like you have a future scientist on your hands! :)

Answer 5

Given the parameters - the moon would not be visible above a certain latitude based on it's orbit relative the the ecliptic (that is, the path the sun follows). Much like the sun in polar regions, certain times of the year it would not be visible above a north or below a south latitude line.

The moon is inclined 5 degrees above an below the ecliptic - thus it varies between 18.29 and 28.58 degrees. So, subtracting these values from the north or south pole you get
a range of about 71 and 62 degrees above or below the equator where the moon would not be visible at any time during a 24 hour period.

Where this occurs varies depends on the regressing ascending node of 18.6 years.

So, the answer is yes - somewhere N or S of 62 to 71 degrees of latitude - depending on the 18.6 year period and the time of year on Earth.

Answer 6

The moon is visible about half the time from any given spot on the earth. The other half it is on the other side of the earth.

Answer 7

When there is a blue moon, when there is cloud coverage or a barrier blocking you from seeing the sky where the moon is positioned, otherwise, the moon is visible at night everywhere except for the half of the earth that is day of course just like the stars and the sun.

Answer 8

Near the poles it is sometimes below the horizon for up to 2 weeks. Just like the Sun can be below the horizon for 6 months there.

Answer 9

It's not visiable anywhere at "new moon" phase. Too close to the sun.

Answer 10

When you have a new moon or lunar eclipse.