In my Nature Notebook series, I take a look at natural phenomena and try to explore the science & nature facts behind them in order to improve the accuracy of my paintings. I am not a realistic painter by any means, but still, I feel like a grounding in natural reality is helpful even for loose landscapes – maybe even more so when there’s so little else to go on.

This time, I’m looking at the moon!

It’s easy to look at it in the sky or in a photo and think “Sure, that looks right.” But when I started painting the moon, I realized how little I actually knew for sure about our big cheesy sky friend. I had questions such as: what times of day is the moon visible at various points in the sky? Does the full moon always look the same, or are different sides sometimes visible? Does the moon look the same from different areas of the world? When is the crescent or half moon at an angle, and when it is straight up-and-down?

These are the questions I’ll explore below, with an eye to relating them back to artistic concerns.

A Caution about Working from Moon Photos

Many nature inaccuracies can be avoided by painting from life or from photographs. The moon is trickier. It’s uncommon to paint en plein air at night (it’s dark, for one thing), but painting from photos won’t save you because most moon photos are composites – collages put together from more than one photo.

There are very practical reasons for this. The moon is so bright that if you want it to look like anything but a white smudge, you have to set up your camera to minimize the amount of light you let in. But then you won’t be able to see anything else in your (likely low-light) landscape: everything other than the moon, including a starry sky, will just look like a plain black background. The way to get around this lighting problem is to take two photos with different settings and then put them together in post.

Of course, not everyone limits themselves to composites of two photos from the same place and time. You can take a moon from one photo and drop it into a totally different photo. This is a great way to introduce major Moon Mistakes. A common one is dropping the lit part of a crescent moon onto a field of stars, creating the impression that the dark shadowed part of the moon orb is actually transparent, or that distant stars are somehow closer than the Moon.

If you want to paint from an undoctored photo of the moon, it’s best to find photos where the moon looks tiny, washed-out, and undetailed; those are the real ones. Of course, there’s no reason you can’t make your own painted moon look larger and more impressive, the way it strikes you in real life. The moon feels big, even if it’s not actually very big in the sky.

The Moon Questions

What shapes can the moon be?

The moon “shines” because of light reflected from the sun off the surface of the moon. As the moon completes its orbit of the Earth (a 29.5 day cycle), we see different amounts of the side that’s facing the sun.

• 🌑 New Moon: the moon is lined up pretty directly between the Earth and the sun, so all of the light side is facing away from us.
• 🌓 Half Moon: the moon is perpendicular to the earth along its orbit around the sun.
• 🌕 Full Moon: the Earth is lined up pretty directly between the moon and the sun, so the moon is pointing at us and the sun at the same time.

“Waxing” means the moon is getting bigger, and “waning” means it’s getting smaller. Both of these are antiquated terms, but “waning” is sometimes still used to mean getting smaller, as in “The daylight is waning.” I have only ever seen the verb “to wax” used to mean “to grow” outside of a moon context in Jane Eyre, when Mr. Rochester gets mad at his guests for freaking out about the weird noises in his house at night.

“All’s right!–all’s right!” he cried. “It’s a mere rehearsal of Much Ado about Nothing. Ladies, keep off, or I shall wax dangerous.”

Jane Eyre

A note about moon shapes from an artistic standpoint is that the crescent moon’s points don’t extend further than the halfway point. Those long-pointed, art-nouveau style crescent moons can give a painting a cartoony look, which may or may not be what you’re going for.

What’s your favorite moon phase? Personally I think that half and gibbous are underutilized moon phases in paintings!

Does everyone in the world see the same moon phase?

Yes. It can’t be a full moon for you and a half-moon for someone else on Earth.

However, the side the moon is lit on will be reversed depending on your hemisphere.

• In the northern hemisphere, a waxing moon is lit on the right and waning on the left.
• In the southern hemisphere, it’s opposite.

The angle of the crescent may also be different depending on your latitude (see “What angle is the crescent moon?” below).

Here’s a cool collection of crescent moon photos taken from around the world within a few days of each other. (Note that some within the same hemisphere & latitude point opposite ways, probably because of the difference in dates – just a few days is enough to get you from waning to waxing crescent.)

What colors can the moon be?

We usually see the moon as white, but depending on atmospheric conditions, it can appear various colors.

• Along the horizon, as it rises or sets, it sometimes appears yellowish, orangeish, or reddish.
• The deep red “blood moon” is seen during a total lunar eclipse.

How big is the moon?

The numeric answer (1076.9 mile radius! one-fourth the size of Earth!) is meaningless to me as an artist. From my perspective on Earth, the moon looks like it’s about the size of my fingernail.

When it’s rising or setting, the moon on the horizon looks enormous. When it’s high in the sky, it looks pretty tiny. This is due to an optical illusion called the Moon Illusion.

This happens because we’re comparing the size of the moon to the size of known objects that appear to be a similar distance away – such as distant trees or mountains or buildings that appear only slightly closer than the moon – so the moon naturally looks friggin’ gigantic. It’s bigger than a building!! When it’s high in the sky without those reference objects nearby, we see it more like a lost balloon – a tiny shape in a big sky. As humans, we are simply not accustomed to evaluating the size of objects that are so far away that they don’t change size, no matter from which vantage point we view them.

What does this mean for your paintings? Not much, I think it’s actually really fun to paint the moon as absolutely gigantic when it’s on the horizon to match our emotional reality rather than the actual reality.

Do we always see the same side of the moon?

Yes!

Due to a phenomenon called “tidal locking,” the same side of the moon is always facing us on Earth, even though we’re both spinning. Weird, huh?

According to NASA:

Earth’s Moon rotates, but it takes precisely as long for the Moon to spin on its axis as it does to complete its monthly orbit around Earth. As a result, the Moon never turns its back to us, like a dancer circling ― but always facing ― its partner.

Nasa.gov

So the moon may not have a permanent dark side and light side, it does have a near side and a far side, relative to Earth. We are always looking at the near side. That’s why the “man in the moon” looks the same from one full moon to the next. What changes is the amount of light on his face.

What are those dark areas on the moon?

Even with the naked eye, we can sometimes see features on the near side of the moon, at least when it’s full. The dark area are called lunar maria – Latin for “moon seas” – and they’re not water seas but plains of basalt (dark-colored volcanic rock). Interestingly these “seas” are only on the near side, with the far side just being sort of plain and cratered. The idea is that asteroid strikes on the far side triggered volcanic activity on the near side. Weird, huh?

Let’s be real: even if I’m painting a full moon that’s detailed enough to have visible lunar maria, I’m probably just going to drip random grey shadows into a white circle. Random drips look fine and get the point across. Still, it’s nice to have at least a general idea of the near side of the moon’s topography in order to have something to aim for.

The moon actually appears different from the northern and southern hemisphere. What looks like the “top” of the moon depends on where you are on our spherical planet.

Here’s a quick guide to the lunar maria locations from each viewpoint.

Artistic conclusion: whether you put the big blob on the upper left or bottom right may have an implication on the part of the world your painting takes place in!

When is the moon out?

Like the Sun, the moon rises (i.e. appears over the horizon) in the east and sets in the west. We’re able to see the moon about 12 hours per day, but depending on which day we’re in on the moon’s monthly cycle, it’s a different 12 hours. Moonrise and set are about 50 minutes later each day. The different rise and set times correspond to what phase it’s in.

Here are some quick highlights that may be of interest to artists. (Note: I use the moon emojis corresponding to the side they’re lit in the northern hemisphere.)

• 🌑 New Moon: Rises at sunrise, sets as sunset. You’ll never see this guy for two reasons – totally in shadow, and not out at night.
• 🌒 Waxing Crescent: Late morning to late evening. This is the one I associate with sunset, because that’s when it’s close to the horizon and aesthetically visible near the sun.
• 🌓 Waxing Half Moon (First Quarter): Noon to midnight, like me in college. I feel like I see this one as an afternoon day moon a lot.
• 🌕 Full Moon: up all night! Rises at sunset, sets at sunrise, and is straight overhead at midnight.
• 🌗 Waning Half Moon (Last Quarter): Midnight to noon. You might see this one as a morning day moon.
• 🌘 Waning Crescent: Predawn to early afternoon. If you see a crescent at sunrise, it’s this one.

What moon shapes do you feel like you notice the most often at different points during the day or night?

Where can I find the moon in the sky?

The moon sometimes appears high in the sky and sometimes appears close to the horizon, just like the sun, depending on where it is in its rise/set cycle.

It also seems to “travel” from one spot in the sky to another, cycling around the sky through the month. As shown in the photo above, this “path” looks more like an arc than a loop, a phenomenon known as analemma.

Here’s a cool simulation from PBS that shows how the moon phase and position relative to the sun changes over the month. You can see that the full moon is furthest from the sun in space and time, while the crescent moons can be quite close.

Quick summary:

• 🌑 New Moon: Close to the sun, another reason you’ll never see it – it’s totally overshadowed.
• 🌒 Waxing Crescent: Slightly left of the sun (right in Southern Hemisphere)
• 🌕 Full Moon: Opposite the sun, rising in the east as the sun is setting in the west.
• 🌘 Waning Crescent: Slightly right of the sun (left in SH)

Is the lit part of the crescent moon is always facing the sun?

Yes, but it doesn’t always quite look that neat from our perspective. It’s not like if you put a ping pong ball next to a light bulb. Because the orbs involved are so large and distant, and our perspective is also looking at all of it from a different sphere, the moon’s lit side may not necessarily exactly appear to be pointing right at the sun. This is called the Moon Terminator Illusion.

At the same time, you’ll never see a crescent moon lit on the opposite side as the sun. Just like other objects in your painting, the moon has the same light source – the sun – so if you’re deciding how to orient it, it’s a good idea to take the sun’s position into account… roughly.

What angle is the crescent/half moon?

Depending on where you are in the world, the time of day, and the season, the crescent moon may be at an angle, or lit from the bottom like a smiley face.

The smiley face shape is known variously as a horn moon (with “horns” pointing straight up), Cheshire Cat moon, wet moon, or, confusingly, dry moon. In the temperate zone of the Northern Hemisphere, where I live, it is a rare occurrence, but can be seen up to twice a year on particular spring evenings (waxing) or fall mornings (waning). According to Wikipedia,

Wet moons occur routinely in the tropics (where the Sun and Moon rise and set nearly vertically), but rarely in the polar regions (where the Sun and Moon rise and set at a glancing angle or not at all).

Wikipedia, Wet Moon

It’s possible to see a perfectly upright “C” or “D” shaped moon as well, but this only happens when the sun is above the horizon, so it’s more likely to be a daymoon. It’s also more common in the Polar regions.

The rest of the time, the moon is at an angle. The precise angle could probably be calculated by an astronomer, but “at an angle” is probably all you need to know as an artist.

Key Takeaways for Artists

• Photos lie.
• You cannot see stars inside the crescent moon.
• The crescent moon’s horns don’t go more than halfway around.
• The crescent moon’s lit side roughly faces the sun.
• Like the sun, the moon rises in the east and sets in the west, but at different times of day corresponding to its phase.
• The full moon is only seen at night, other phases can be seen during the day as well.
• The moon on the horizon looks huge and may be tinted yellow/orange. The moon high in the sky appears smaller and cooler in color.
• In the northern hemisphere, a crescent moon lit on the left could be seen at sunrise and a crescent moon lit on the right could be seen at sunset. For the southern hemisphere, reverse the directions.
• The crescent moon is usually at an angle, but could be “U” shape especially in the tropics, or upright like a “(” or “)” especially in the daytime or the Polar regions.
• The face of the moon has some dark blobby bits in the upper left (northern hemisphere) or lower right (southern hemipshere).