Physics, Earth & Space Icon Physics, Earth & Space

Earth — The Mystery of Our Colorful Home

Guillermo Gonzalez

Earth

“Oh my God! Look at that picture over there! There’s the Earth coming up! Wow, that’s pretty!” These were the words William Anders spoke to the other two Apollo 8 crew members, Jim Lovell and Frank Borman, just before he took the now famous “earthrise” picture on December 24, 1968. Since then, other Apollo astronauts and even unmanned lunar spacecraft have taken similar pictures (see above).

Notice how Anders reacted to the view of Earth rising over the lunar limb; these were obviously spontaneous reactions to something that caught him off guard. He expressed surprise and noted how pretty it looked. These are expressions of beauty. A beautiful thing surprises us. The fact that the earthrise pictures have been reproduced so many times speaks to their universal appeal. Probably most people react the same way Anders did the first time they see the picture.

A Universal Appeal

Reflecting on his experience from 50 years before, Anders wrote, “The Earth we saw rising over the battered grey lunar surface was small and delicate, a magnificent spot of color in the vast blackness of space…. We are all, together, stewards of this fragile treasure.”

When we look at the picture, we can’t help but make comparisons, especially with the lunar landscape. Earth’s vivid colors contrast with the moon’s dull grey surface. To Carl Sagan and his followers Earth is merely a pale blue dot set against the vast emptiness of space (when viewed from a great distance), but to those with different eyes Earth is like a precious jewel in the rough (think emerald). 

Up close, Earth offers yet more beauty — verdant hills, white sandy beaches, turquoise lakes, towering mountains, deep red canyons, rainbows, and colorful sunsets and sunrises, to name a few instances. Closer still, we see beauty among the living (peacock, birds of paradise, colorful reef fish, butterflies and other insects, flowers) and the non-living (gem stones, crystals). In most of these cases, vibrant color is an important part of what makes a thing beautiful.

True Colors

Space artist Don Davis has produced a helpful website where he discusses the true colors of the planets (and some moons) in the Solar System. Scrolling down near the bottom of the page, you will see color patches representing the colors present on the surfaces of the bodies in their proper proportions. Earth displays a more diverse range of colors than the other bodies. It comes closest to having all the colors of the rainbow. Some, like Io, Mars, Uranus, and Neptune have almost pure saturated colors, but the range is limited for each. The least colorful are the Moon and Mercury, and probably Venus (Davis doesn’t even bother showing patches for it).

Color, Beauty, and Life

It seems curious that the only body in the Solar System known to be inhabited would be the most colorful and, arguably, the most beautiful one. Why would color and beauty be associated with life? Materialists have attempted to explain beauty in living things by appealing to natural and sexual selection, but these seem inadequate. Note that merely providing physical explanations for these phenomena, such as rainbows and green plants, will not answer our question. Certainly, there is no logical reason why life should be wedded to the transcendental value of beauty.

Photo: Lunar Reconnaissance Orbiter image (2015), by NASA / Goddard Space Flight Center / Arizona State University [Public domain].