Why do all planets have different colours?
Before we hop on to knowing the colour of all the planets in our solar system, let’s first examine the factors determining planets’ colour.
The primary reason every planet has distinctive colours is the different atmospheres, surfaces, sunlight absorption, and other substances. Every planet is covered with multiple diversified layers of gases. For instance, Mars has a rocky surface with a thick layer of dust, whereas Venus is covered with sulphuric acid clouds and a thick carbon dioxide atmosphere.
Colour of Sun
Although the Sun is a star, not a planet, still you ought to know its colour. The colour of the Sun is red, representing energy and power. It is a hot fireball of gas, and its outer surface is called the photosphere. Evidently, it is a colossal star and the only source of light to all the planets.
Colour of Mercury
Mercury has the closest proximity to the Sun, which is why it is virtually impossible to take clear pictures of the planet. Only the spacecraft named MESSENGER probe and Mariner 10 have taken decent photographs of Mercury, and it was found that it resembles our moon and looks grey or slightly brownish.
As per the pictures taken by these spacecraft, it was perceived that Mercury is composed of mostly iron, nickel, and silicate rock, which is differentiated between a rocky mantle, and a metallic core, and a crust.
Colour of Venus
This planet looks pale-yellow in colour. Venus is a terrestrial planet and consists of a yellow landscape, although it is not why it looks yellow.
It comprises a thick layer of certain gases making its atmosphere dense, including Nitrogen, Sulphur Dioxide, and Carbon Dioxide. It is one reason why it looks yellow as most of the light (yellowish colour) seen does not come from the surface, but the sense of sulphuric clouds reflects it.
Colour of Earth
The colour of our planet, Earth, is mostly blue with white clouds. Earth’s atmosphere comprises thick nitrogen-oxygen layers, enabling the light-scattering effect of our planet’s atmosphere. Due to its short wavelength, blue light scatters more than any other colour. Also, the gigantic water bodies absorb light from the red end spectrum making its appearance blue from the sky.
For Earth, the surface may feature different colours depending upon the area one is looking at. It may range from yellow to brown (mountainous and desert regions), green (forests and agricultural lands), to white (large ice formations or mountains and clouds).
Colour of Mars
Mars is also known as the red planet because it looks like a red ball from outer space. It also has a few white ice patches, and some of its surfaces look reddish-brown in colour.
It looks red because iron minerals in the Martian soil oxidize or rust, causing the atmosphere and the surface to look red. Unlike other planets, Mars has comparatively a very thin layer of the atmosphere, which makes the colour of its soil very expressive.
Colour of Jupiter
The largest planet in the Solar System is mostly in shades of red, orange, yellow, and brown with whitish bands. Jupiter is 1300 times bigger than the Earth and is more than twice as massive as all the other planets combined.
The clouds of this colossal planet comprise hydrogen-helium and other gases. Moreover, violent storms and heavy winds across the planet keep changing the bands of colours.
Colour of Saturn
Saturn reflects a pale gold colour. It is the second-largest planet and has a banded appearance due to the peculiar nature of its composition. The rings surrounding the planet are very bright because snow reflects sunlight powerfully. Saturn is known to have a very low density of the atmosphere. The planet is comprised of helium, hydrogen, and other volatiles like ammonia in trace amounts.
One of the reasons the Saturn clouds acquire a deep red colour is hydrogen in the atmosphere. However, the ammonia clouds obscure this red colour causing it to create the outermost layer and cover the entire planet. When the deep red colour blends with the white ammonium, it forms a pale gold colour.
Colour of Uranus
Uranus looks just like a pale-blue ice ball. The planet is colder as it is far distant from the Sun. It is also known as ice-giant, comprised of molecular hydrogen and helium and other elements, including ammonia, hydrogen sulfide, and trace amounts of hydrocarbons.
The presence of methane and the prominent absorption bands in the visible and near-infrared spectrum gives it a blue or aquamarine colouring.
Colour of Neptune
Neptune and Uranus have almost similar composition; that’s why they have the same appearance; pale blue. Most of the area of Neptune is covered with massive ice formations. Its composition primarily includes hydrogen, helium gas, and the traces of nitrogen, hydrocarbons, ammonia, and methane.
Its far distance from the Sun and a higher proportion of ammonia and methane result in a pale blue appearance from outer space.