Although the Moon’s surface is always the same color (and has been for billions of years), there are nights when it appears to be a different hue. This occurs for many reasons, and they all have to do with the atmospheric conditions above you as you gaze up at the sky. First, it’s important to understand that the Moon doesn’t shine on its own. Instead, it reflects light from the Sun, which bounces back to Earth and makes the Moon visible. Those light waves have to travel a long way to reach stargazers down on Earth, and the many particles in our atmosphere can make the waves scatter. The color a person sees when they look at the Moon depends on the light waves that reach their eyes, and that light can vary due to pollution in the air or the Moon’s position on the horizon. If those things change, sometimes the color of the Moon appears to change too.
Is the Moon Really Blue? Explaining the Moon’s Colors
The Moon is our closest neighbor in the galaxy, orbiting Earth just 238,855 miles (384,400 kilometers) away. Earth has only this one natural satellite, unlike other planets in our solar system, most of which have several moons. Most of us have gazed up at the night sky and admired the Moon—and if you’ve spent enough time looking, you’ve probably noticed that it sometimes appears to change colors. Are your children curious why this floating rock looks white, yellow, blue, or orange at different times of the year? We have the answers. Here’s everything your young space enthusiasts need to know about the Moon’s colors.
If you were to fly to the Moon, you’d land on a rock made up of shades of gray. This is because the lunar surface consists mostly of magnesium, iron, feldspar, and other minerals, which create a fine gray dust. This is the Moon’s true color, and it keeps this appearance all year long.
Why Does the Moon Change Colors?
Although the Moon’s surface is always the same color (and has been for billions of years), there are nights when it appears to be a different hue. This occurs for many reasons, and they all have to do with the atmospheric conditions above you as you gaze up at the sky. First, it’s important to understand that the Moon doesn’t shine on its own. Instead, it reflects light from the Sun, which bounces back to Earth and makes the Moon visible. Those light waves have to travel a long way to reach stargazers down on Earth, and the many particles in our atmosphere can make the waves scatter. The color a person sees when they look at the Moon depends on the light waves that reach their eyes, and that light can vary due to pollution in the air or the Moon’s position on the horizon. If those things change, sometimes the color of the Moon appears to change too.
Why does the Moon look blue one night and red another? Let’s examine the most common Moon colors and the things that cause them to appear.
Blue
Blue moons are very rare—that’s where the saying “once in a blue moon” gets its meaning. They can occur when moonlight travels through an atmosphere full of dust and smoke. People are most likely to see a blue moon after a volcanic eruption. When the Indonesian volcano Krakatoa erupted in 1883, the Moon appeared green-blue in that region for almost two years.
Pink or Red
Sometimes, the Moon appears pink or red—a phenomenon known as a “blood moon.” This change in color is the result of a total lunar eclipse, when Earth sits between the Moon and the Sun, blocking most of the light traveling toward the Moon. The light that does reach the Moon passes through Earth’s atmosphere first, and light with shorter wavelengths, like blue and violet, scatters before reaching the Moon. This leaves only longer-wavelength colors, like red, to reflect back at us.
Yellow or Orange
“Harvest moon” is the name for a yellow or orange moon, which usually occurs in late summer or early fall. A harvest moon usually occurs when our dusty neighbor is sitting close to the horizon, meaning that the light reflecting off the Moon has to travel through more of the atmosphere to reach our eyes. As with a total lunar eclipse, short-wavelength colors, like blue scatter, causing us to see longer-wavelength colors like orange and yellow.
The Phases of the Moon
Some nights, the Moon isn’t just a different color—it also appears to be a different shape. This is because the Sun only illuminates half the Moon: the side facing the Sun. As the Moon orbits our planet, the side facing the Sun isn’t always fully visible from Earth. Because little light reaches the side of the Moon facing away from the Sun, the shape we see in the sky changes, showing us different “types” of moons. It takes about one month for the Moon to orbit Earth. In that time, the Moon rotates through the same eight appearances, known as its “phases.” Here’s some interesting information you can share with your kids about the phases of the Moon.
New Moon
During this phase, the Moon sits between Earth and the Sun. The Moon’s illuminated half faces the Sun while its dark half faces Earth, causing the Moon to appear to be missing (even though it’s still orbiting around our planet). The new moon signals the beginning of a new lunar cycle and occurs approximately every 29.5 days.
Waxing Crescent
As the Moon orbits around Earth, more of its illuminated side becomes visible to stargazers on the ground. For the subsequent phases (until a full moon), astronomers say the Moon is “waxing,” which means it looks like it’s growing. The first waxing phase is called a waxing crescent, which appears as a tiny sliver of the right side of the Moon.
First Quarter
When the Moon reaches its first quarter phase, it sits at a right angle to the Sun, respective to Earth. This means viewers on Earth can see about half of its illuminated side (on the right). Many call this a “half moon” because it looks like a semicircle in the sky. However, this term isn’t exactly correct, as they only see half of the Moon’s illuminated side (or a quarter of the Moon).
Waxing Gibbous
At this point in the lunar month, more than half of the Moon’s illuminated side is visible. This phase is called the waxing gibbous, which comes from the Latin word for “hump.” A waxing gibbous moon isn’t quite a circle yet, but its right side is larger (and brighter) than the first quarter moon.
Full Moon
A full moon is a point in the lunar month when all of the Moon is illuminated. During this phase, the Moon is directly opposite the Sun, allowing reflecting sunlight to give us a complete look at the side of the Moon facing us. This lunar cycle phase typically lasts just three days before the Moon’s orbit changes our view.
Waning Gibbous
The full moon is the halfway point in the lunar month, which means the Moon appears smaller in every phase after. This process is called “waning.” After a full moon, the next phase is called waning gibbous. It looks similar to the waxing gibbous, except that the bright side of the Moon is on the left instead of the right.
Last Quarter
The last quarter moon, sometimes also called the third quarter moon, occurs when the Moon reaches a second right angle with the Sun (similar to the first quarter). However, in this phase, the Moon’s illuminated side is on the left, showing the side that appeared invisible during the first quarter phase just a few weeks earlier.
Waning Crescent
The last phase in the lunar cycle is the waning crescent. It occurs when the Moon looks like a thin sliver illuminated from the left side. By the time the Moon reaches this point, it’s nearly completed its orbit—which means it’s almost time to start over with another new moon.
Colors of the Moon
Have you ever seen the true colors of the Moon? Both in photographs taken from the Earth and in close-ups of the lunar surface taken by Apollo astronauts, the Moon is colored in blacks, whites and grays, with no blues, reds, or other colors to brighten the view. So, is it really a colorless, barren land as everyone commonly believes?
Take a look at these images & decide for yourself:
Can the Moon really be this colorful? In a way, yes. The lunar surface actually does have quite a bit of color, although in reality it is very subtle. I was pretty much inspired by ‘enhanced’ color images of the Moon, and wanted to see if I could also produce something similar with much less expensive equipment. In these lunar images, color saturation has been enhanced to bring out the subtle differences in colors of the various areas of the lunar surface. Note that the hues are still real & no artificial colors were added, it’s just that enhanced saturation is giving much more vivid images.
However note that you would need high resolution raw images of the Moon to boost the saturation to enhance subtle color contrasts to produce colorful lunar images similar to these, otherwise you will end up with poor quality images with lot of random color noise.
Other than making an interesting aesthetic presentation, these enhanced lunar colors also give clues as to the mineralogy of the Moon’s surface, and the chemical composition of the lunar rocks. Blue and orange shades indicate volcanic lava flows. The dark blues indicate that those areas are richer in titanium-bearing minerals. Pink colors indicate iron-poor, aluminum-rich feldspars (which is a group of rock-forming tectosilicate minerals) that make up the lunar highlands. Orange and purple indicate regions that are relatively poor in titanium and iron.
It is also interesting to observe that at the impact crater sites the deeper minerals are exposed & scattered by the impacts, and different compositions of minerals can be seen in contrasting colors compared to the material on the original surface.
Perhaps what is more interesting is that true colors of the Moon is also a hot topic among conspiracy theorists who believe that Apollo astronauts indeed saw Moon as something colorful, however NASA is covering it up for some unknown reason. Below are some of the supposedly genuine Bellcomm Apollo 10 Photo Debriefings that they often quote to support their theory:
- “The lunar maria were described as brown at high sun angles, and grayish brown near the terminator…”
- “….They noted a color mottling of Mare Serenitatis, light brown and tan brown, as compared to the darker ‘chocolate brown’ color of Mare Tranquillitatis.”
- “The color of the lunar highlands was described as tan …. Deviations from the tan color are caused by mare material (brown), fresh impact craters (chalky white) and a number of ‘jet black‘ layers and blocks.”
- “As expected, they were unable to see much before passing over the sunlight terminator, but as soon as this is done, the moon glows at us…this moon looks like a Christmas tree here in the dark side…it is highly illuminated from the earth.”
While these original astronaut quotes are repeatedly describing Moon maria terrain as being various shades of tan and brown where both Apollo 10 and 17 landed, why we are not seeing those colors in any of the lunar images publicly released by NASA is anybody’s guess.
Video footage claimed to have obtained in December, 2013 by China’s ‘Yutu’ rover (‘Jade Rabbit’) carried by the Chang’e 3 lunar lander showing bright brown & orange tans of the lunar surface which is in stark contrast to NASA’s images of grayish surfaces just added fuel to the conversation. You can watch these videos on YouTube, and below are some of the still images released by the China National Space Administration (CNSA):
While the true colors of the Moon might remain as a mystery for some time and conspiracy theorists & debunkers alike trying hard to solve this lunar mystery, it’s time for the rest of us to ponder on these fascinating & colorful lunar images that anyone could easily obtain using a small telescope & a cheap webcam, and a bit of image processing…
Colored representation of the moon
What in the world — or more accurately, out of this world — is going on below? The Moon never shows any color save for the reddening our atmosphere causes when it is close to the horizon. Both in photographs taken from the Earth and in closeups of the surface taken by Apollo astronauts, the Moon is colored in blacks, whites and grays, with no blues, reds, or other colors to brighten the view.
A false-color Moon? Not exactly. but certainly not “normal”. A composite of several images including a mosaic of exaggerated-color images of the lit portion of the Moon, a “cut-out” representing the unlit portion of the Moon, and a starry background that required a much longer exposure than the Moon itself. The captions of the images shown below explain the various ways in which lunar images are manipulated to achieve such a colorful image, and the reasons for doing that. (Noel Carboni, apod060907)
A true-color image of the Moon shows virtually no color. (Image of Moon at perigee by Ant�nio Cidad�o , apod041021)
Eugene Cernan on the lunar surface during the Apollo 17 Moon mission. Not one bit of color is evident on the lunar surface save for the items (such as the American flag) brought there by the Apollo astronauts. Click here for a panoramic view of the Moon from the same mission, similarly devoid of color. (Apollo 17, NASA (image scanned by Kipp Teague), apod051217)
There are times when features are found on the Moon which are not completely colorless. The inset in the image below shows some orange-tinted soil discovered by the Apollo 17 astronauts in the Taurus-Littrow region, which was created by volcanic activity during the formation of the lunar maria; but such colored features are rare on the lunar surface, which is the reason this feature was noticed.
The inset at lower left shows an anomaly in the appearance of the lunar surface. A small area of “orange” soil is visible on the normally colorless lunar surface. The grains which make up the soil, shown in the microphotograph which fills most of the image, are mostly black angular pieces of basaltic rock pulverized by meteoritic impacts, and orange-colored glassy particles which solidified from small droplets of molten rock sprayed into the airless lunar surroundings by a volcanic eruption. On the Earth such glassy fragments would noticeably weather and erode within tens of years, so when Harrison Schmidt noticed the off-color patch there was great excitement at having found evidence of “recent” geologic activity on the Moon. But as it turned out, with no water or air to provide weathering or erosion, fresh-looking lunar deposits can be surprisingly old, and the soil sample shown here was dated (by an analysis of the ratio of radioactive atoms to their decay products) to an explosive eruption 3.64 billion years ago, making it older than almost all Earth rocks. (Apollo 17 Crew, NASA, apod010523)
Still, as demonstrated by the images below, it is possible to photograph a “colored” Moon and not be exactly lying. What was done in the image on the left below, and in the image at the top of this page, was to use graphics software to exaggerate (apparently by about twenty times) any slight differences in the tint of the lunar features, so that regions which have an unnoticeably slight orange or bluish tint in “true-color” images appear bright orange or bright blue. To show how this works, the image on the right reverses the process, removing 95% of the coloring; the result is an essentially black and white image such as is normally seen in photographs of the Moon. (On left: Johannes Schedler, Panther Observatory, apod060216; On right: 95% desaturation by Courtney Seligman)
As the exaggerated false-color composite image above shows, slight differences in lunar color can be used to map the composition of lunar rocks from a distance. The image is a view of the lunar near side taken by the Galileo spacecraft as it passed above the North Pole of the Moon on its way to Jupiter in 1992. Blue and orange shades indicate volcanic lava flows. The dark blue of Mare Tranquillitatis, at bottom center, indicates that it is richer in titanium-bearing minerals than the green and orange maria to its left. Above and to the right of Mare Tranquillitatis, the dark oval of Mare Crisium is surrounded by pink colors indicative of the iron-poor, aluminum-rich feldspars which make up the lunar highlands. (Galileo Project, JPL, NASA, apod030829)
A similar image created from images taken while Galileo was approaching the Moon, shows the familiar near in a familiar orientation — as it would be seen from the Earth save for the severely exaggerated hues. Again, blue hues indicate titanium rich regions, orange and purple regions relatively poor in titanium and iron, and pink regions rich in aluminum. (Galileo Project, JPL, NASA, apod020316)
