Each planet in the solar system has a different appearance . Enough so that at a simple glance we are able to distinguish them. This appearance is of course determined by the chemical composition and structure of its surface or atmosphere . Since this is inevitably different for each body in the solar system, although there may be similarities, it has as a consequence that visual differentiation of each planet. Let’s review the origin of the color of each of the eight planets of our solar system.
Mercury
Mercury is the smallest of the planets and the only one without a perceptible atmosphere , due to its small size but also because of its proximity to the Sun, which exposes it to the solar wind. Its surface is uniformly gray, very similar to that of the Moon. However, their compositions are different. Silicon, magnesium, and iron oxides predominate on Mercury’s surface, and large amounts of sulfides are also found. On the Moon, feldspars predominate, which have a greater presence of aluminum or calcium. All of these minerals, like most geological solids, have a dull, grayish appearance , giving the planet Mercury its appearance.
Venus
The surface of Venus is also grayish in color, but it is invisible to us from space due to the dense atmosphere that surrounds the planet. Venus is about the same size as Earth, but it is surrounded by an atmosphere much more voluminous than ours, causing pressures of more than 90 times the atmospheric pressure on the Earth’s surface . This atmosphere has a rather pale whitish-beige color and is composed mainly of carbon dioxide. However, its color does not seem to come from this gas, which is colorless, but from the clouds of sulfuric acid and other compounds that form in it.
The earth
Our planet is the largest of the rocky planets and the only one that harbors liquid water on its surface and , of course, life . This is in fact what gives the Earth its characteristic color, or amalgamation of colors. The blue of the oceans accounts for 70% of the surface. The rest being a combination of the green of plants and forests , the brown of the earth and the white of glaciers and polar ice caps. All of this covered by a changing white cloud layer . The bluish color of the oceans comes from water absorbing light with longer wavelengths (red or infrared light), which allows blue light to pass through more easily.
Marte
The red planet owes its name to the obvious reason that its entire surface appears to be bathed in a reddish or orange hue. So present is the coloration, that it is red to the naked eye from the surface of the Earth and since ancient times this planet has been known by its color. This color is due to the entire surface being oxidized , as an exposed, unattended piece of iron might be. The little oxygen in the thin Martian atmosphere reacts with the iron in surface minerals to give it that color. However, if we dig just a few centimeters under this reddish layer, we soon find grayish minerals .
Jupiter
The largest planet in the solar system is made up primarily of hydrogen and helium , like the Sun, but it is again the minor gases that give Jupiter its characteristic color, or colors. The upper layers of the gas giant’s atmosphere, which we can see from a distance, are differentiated into two zones with different colors and compositions . On the one hand we have the belts , which are darker, and on the other the ” zones “, lighter . In the case of the latter we are quite sure that their whitish color is due to a higher concentration of ammonia crystals . The belts are usually located below the zones, at a lower altitude, and although we do not know exactly what mechanism gives them their brownish and reddish color , we do believe that it has to do with the presence of sulfur, phosphorus and carbon .
Saturn
The atmosphere of the planetary Lord of the Rings is considerably duller than Jupiter’s , with hardly any banding or noticeable structure, like the storms we have seen on Jupiter, Uranus, and Neptune. Its yellowish color has the same origin as Jupiter’s light bands: clouds of ammonia crystals . Under these clouds of water crystals can also be found, although they are not responsible for the color observed. However, certain activity can be observed, such as the hexagonal -shaped structures that form near the poles, or fleeting storms like the one that crossed the planet in 2011.
Uranus and Neptune
Both icy giants have a similar bluish hue , though lighter for Uranus than for Neptune. In both cases, the main contribution to this color comes from methane , the third most present gas in the atmosphere of the two planets, after hydrogen and helium. However, this gas should give these planets a cyan hue , like that of Uranus, so it is believed that another gas must be contributing to darken Neptune’s blue hue , although at present we do not know what it is.
