Colors of Planets in The Solar system (With Reasons)

Have you ever wondered, why there are different colors of planets in our solar system? Does color plays any role in universe? In this article, we will discuss everything related to the color of planets, their cause and importance. But, First lets learn little about our solar system.

The solar system is located in the Milky Way’s Orion star cluster. Our Solar system is one of over 500 known solar systems in the Milky Way Galaxy. The solar system came into being about 4.5 billion years ago, when a cloud of interstellar gas and dust collapsed, resulting in a solar nebula, a swirling disc of material that collided to form the solar system. Among the 15% of stars which hold the planetary system, the Sun is one of them. 

Our solar system comprises eight planets in order revolving around the nearest star, i.e. our Sun. The eight planets are  Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. The planets are divided into two categories based on the composition of their surface: Terrestrial and Jovian. The first four planets near the Sun, i.e. Mercury, Venus, Earth and Mars fall under the terrestrial category which are primarily made of rocky material. They possess the following characteristics:

• Their surfaces are solid, 
• They don’t have ring systems, 
• They have few or no moons and 
• They are relatively small.

Let’s start with the smallest and closest planet to the sun Mercury, which has the shortest orbit in the solar system at about three Earth months or 36 million miles. Then comes Venus, which is the hottest planet, with temperatures of up to 867 degrees Fahrenheit, due to an atmosphere of carbon dioxide and extensive lava flows. Next to this world of fire is the world of water, Earth. The water system on Earth is the only known environment capable of sustaining life in the universe. The last on the terrestrial planets are Mars, which may have supported life 3.7 billion years ago when the planet had a watery surface and moist atmosphere. 

Beyond the first inner terrestrial planets lies the outer four planets called Jovian planets. They include gas giants Jupiter and Saturn and Ice giants Uranus and Neptune. The gas giants are predominantly made of Helium and Hydrogen. The ice giants also contain ice crystals, rock and a mixture of water vapour, methane and Ammonia. They possess the following characteristics:

• They do not have solid surfaces,
• They have support ring systems,
• All four jovian planets bear multiple moons,
• They are immense.

The first Jovian planet is Jupiter which is the largest planet in the solar system. Near to it lies the second largest planet, Saturn. Saturn possesses a signature ring that is wide enough to fit between Earth and the moon but is barely a kilometre thick. The last two are the ice giants, among which Uranus is slightly larger and is famous for rotating on its side. Neptune is the outermost and also the coldest planet in the solar system. 

What is interesting while learning about these planets is their unique colors which make them easily distinguishable. We can quickly identify the planets by looking at their color in the picture clicked from space. The colors of the planets in our solar system signifies their composition and the different components surrounding them. The color a planet mainly depends on two of the following points:

• The characteristics of the chemical substances its surface is made of. The color of the planets depends on what they are made of. Mercury is gray because of its rocky silicate surface. Earth is blue due to water. Mars is red due to dust made of hematite minerals.

• Absorption and reflection of sunlight by the surface or the atmosphere.

The next factor on which the colors of planets depends on is how light interacts with the planet’s surfaces and atmospheres. Each surface has different gases and chemicals in its atmosphere and clouds, which results in different colors striking with the sunlight of different wavelengths. In Saturn, as sunlight passes through the rings, it reflects off the particles and creates a unique effect on Saturn’s coloration. Water on the Earth’s surface absorbs six out of those seven colors and reflects only blue. That is the reason Earth appears Blue when looked at from space. Venus forms glory when sunlight interferes with cloud droplets. Here, We have made a quick overview table showing the colors of planets in solar system along with the cause of their colors:-

S.N.	Planet Name	Color	Cause of their color
1	Mercury	Slate grey	Thick layer of dust and igneous silicate rocks
2	Venus	Light yellowish, Pearly white	Thick carbon dioxide atmosphere and sulphuric acid clouds
3	Earth	Blue, Green, White, Brown	Oceans and rivers, Vegetations, clouds, barren land
4	Mars	Reddish-orange	Dust layer with iron oxide
5	Jupiter	White, Brown, Orange, Red	Hydrogen and Helium in the outer atmosphere
6	Saturn	Yellowish-brown	Hydrogen and Helium with traces of ammonia, phosphine, water vapour, and hydrocarbons
7	Uranus	Greenish-blue	Lots of Methane gas mixed with Hydrogen and Helium atmosphere
8	Neptune	Bluish	Some methane gas mixed with Hydrogen and Helium atmosphere

Now, Let’s study about the different colors of the planets and the reason behind it briefly below. 

Colors of Planets in Solar System

1. Mercury

Mercury is the closest planet to the Sun. It is Gray in color. Mercury’s surface is rocky in nature due to the presence of a lot of dust. Mercury has no particular atmosphere and thus it cannot absorb or retain the heat from the sun. The dust is so much in quantity that the surface is almost covered with a layer of dust. Despite its small size, it is the second most dense planet in the solar system.  As you know, dust is composed of many silicates, making the surface appear slate gray in color.  The surface with craters and its size is very similar to that of the moon.  

2. Venus

Venus is yellowish-white in color. Venus is the largest of Earth’s nearby planets similar in size and mass. It is called Morning and evening stars. Even though it is not the closest planet to the sun, it is the hottest planet in the solar system due to its heat-retaining atmosphere. Its surface is also rocky and gray in color. You can observe yellowish-white clouds when you observe Venus from space. The color of the clouds is due to the presence of sulfuric acid. The surface of Venus is not visible from space because of its dense clouds. So basically Venus’s color is the result of the cloud color that surrounds the planet. Venus possesses a dense atmosphere with a lot of carbon dioxide. So, the carbon dioxide from the atmosphere and sulphuric acid from the cloud makes the venus appear yellowish-white in color. It is thought that Venus was once a very different planet potentially even covered in oceans of liquid water, but a runaway greenhouse effect occurred drastically changing the conditions on the surface.

3. Earth

Our home planet, when seen from different layers of atmosphere, Earth is Blue in color with green plants and brown land surrounded by white clouds. It is the densest planet in the solar system. When you look at the earth from space you can observe beautiful blue oceans, green vegetation and brown land. As we know, the Earth’s surface is predominated by water,i.e. almost 71 per cent of the surface is occupied by water and the other 29 per cent is made up of land part. Water is responsible for the absorption of the radiation from the sun. We know that the sun emits the radiation of white light which is the combination of seven colors. Water on the surface absorbs six out of those seven colors and reflects only blue, making the Earth appear blue when looked at from space. But as you look deeper, you can see green, brown and white color reflecting at the Earth’s surface.

4. Mars

Mars is commonly known as the red planet. The surface of Mars is cold and dusty which contains a high concentration of Iron oxide. S, we can say that the surface of Mars covered by dust particles with a lot of iron oxide is what is responsible for the reddish-orange appearance of Mars. The reddish glow of its surface can be distinguished from other planets because of this it is called the Red Planet. 

5. Jupiter

The next is a gas giant that has a stunningly colorful appearance. The largest planet in the solar system is Jupiter. Hydrogen and helium, two of the lightest gases, make up the majority of its atmosphere. This planet is regarded as a gas giant because of this. A wide band of many colors, including red, brown, yellow, orange, and white, encircles the entire planet. Jupiter’s atmosphere is prone to storms, which can cause changes in hue. The presence of substances like ice crystals, ammonia crystals, and water droplets causes this broadband to appear. The red spot on Jupiter’s surface is a hurricane-like storm that is at least twice the size of the entire Earth. It can be observed from the Earth with the help of a telescope. Although it lacks a solid surface, beneath the clouds is a liquid ocean of metallic hydrogen that is constantly swirling. The hydrogen is kept in a liquid condition by the intense air pressure 

6. Saturn

Saturn is also a gas giant like Jupiter. It has a yellowish-brown appearance resulting from different chemical substances present in its atmosphere. It contains hydrogen, helium, a trace amount of hydrocarbons, steam, ammonia and phosphine. Saturn has 3 layers of clouds and the coloration change as you venture through them. The upper layers are made of ammonia ice and the lower layer contains frozen water. The ring is of the same appearance as the planet itself. However, the color of these rings depends on the concentration of gases. 

7. Uranus

Uranus has a greenish-blue appearance due to the presence of Methane gas in the atmosphere. The atmosphere is mainly made up of hydrogen and helium with traces amount of water and ammonia. Uranus is the coldest of all the planets. The reason why Uranus is so cold is nothing to do with its distance from the Sun. It is because it has an icy layer of clouds around it. It’s surprising how the temperature of the cloud can get even below -200 to -224 degree Celsius. Despite its frigid temperatures, the majority of its mass comes from a hot dense fluid of icy materials such as water, methane, and ammonia, meaning you’ll sink if you try to land on the surface of Uranus.  

8. Neptune

Lastly we have, the outermost and farthest planet from the Sun. Neptune’s atmosphere is also made up of hydrogen and helium with a lower concentration of methane than Uranus. It has a dense fluid made up of icy water, methane, and ammonia with an atmosphere of mostly hydrogen and helium, as well as methane. Neptune therefore also appears blue from the space since the Methane gas in the atmosphere absorbs red light and reflects only blue. 

Final Verdict

Without chemistry, the reasons behind planets having different colors cannot be explained. The colorful nature of planet is because of the composition of chemical substances present in their surfaces, nature of cloud, atmosphere, their reflective and absorbtive reaction towards the sunlight. Thanks to these unique colors of planets, we can identify different planets in our solar system, study their formulations, and compositions and research the possible activities which can be carried out there. Understanding their nature based on their color is fun. This is complete information on colors of planets in solar system. The FAQs below will further clear your confusions related to the topic:-

FAQs