Look up at the moon on any clear night and you’ll see a cratered world shining down on you, in some phase of illumination or perhaps even full and round, with a few lighter or darker areas but for the most part all in cool, bright shades of whites and greys. The moon’s real colors are hidden from us here on Earth, blown out by the brilliance of harsh reflected sunlight. But, from its intimate location in lunar orbit, the LRO can use its wide-angle camera to capture image data in the red, green and blue spectral wavelengths that our eyes can most easily see. Combine these filtered images and you get what’s shown here: a true-color view of the lunar surface around the location of the Apollo 17 landing site (darkest cratered region at center.)
The color variances are caused by different amounts of titanium and iron. Darker areas have higher amounts of iron oxide, and the darkest bluish regions are high in titanium oxide. The large dark area at the bottom of this image is Mare Tranquilatis – the “Sea of Tranquility” – and it is a large field of basaltic lava flows clearly much richer in titanium than the bordering Mare Sereniatis – “Sea of Serenity” – at the upper left, which is tinted a warm brown. Both these regions are visible from Earth on the moon’s northern hemisphere, just right of center, but to most of us the only variation in color is a slightly darker grey against the white of the surrounding area. We tend to see the moon in shades of grey but the reality is it’s quite a colorful place, if subtly so.
Read more on the Lunar Reconnaissance Orbiter site.
The original LROC image had a lot of missing areas…I filled them in by duplicating surrounding spots and blurring any obvious copied features or division lines. As a result the image here isn’t 100% accurate for landforms but shows the general colorations with less distraction.
Image: NASA/GSFC/Arizona State University. Edited by J. Major.