Mars, a planet that has fascinated humans for centuries, is known for its distinctive red colour. It is one of the most exciting places in the solar system to explore, with many rovers and orbiters searching for evidence of life.
The red color of Mars is caused by the oxidization of iron oxide found in rocks and dust on the planet’s surface. This process is similar to the way that iron on Earth rusts.
The Red Planet
The Red Planet, Mars, is a dry, rocky world that has fascinated people throughout history. It is one of the most explored planets in the solar system and is home to many rovers and orbiters searching for evidence of life, past or present.
The blood-red colour of the planet is caused by iron-rich minerals in its regolith oxidizing, or rusting, to give it a bright appearance. This process has been spotted by visiting spacecraft, and scientists believe that it is the reason it was named the ‘Red Planet’.
Like Earth, Mars has a thin atmosphere and ice caps at its poles. The atmosphere is mostly carbon dioxide, but there is also nitrogen and argon.
The Colour of the Atmosphere
The colour of Mars the planet depends on the amount of dust that is thrown up from the surface. This dust is mainly made up of oxidised iron minerals that are kicked up into the thin Martian atmosphere.
This dust is able to scatter red light more than blue. During the sunrise and sunset the sunlight has to pass through this dust and the red wavelengths are scattered out of the picture making the Sun appear blue.
The same effect can also happen at night. This is because the same Rayleigh scattering that occurs during the daytime will also occur at night on Mars.
The Colour of the Surface
If you look at Mars through a telescope, or view pictures of it taken by spacecraft, it looks a lot like blood. That’s because a lot of the rocks on Mars are rich in iron oxide.
When they’re out in the rain, these rocks oxidize, and that gives them the red colour that we see on Mars. The same thing happens when rusty dust is kicked up by Martian winds.
But while all of these things give mars the red colour we see, there’s a hidden layer underneath the surface that’s not entirely red.
This is a layer of oxidized iron that’s been pushed to the bottom by relentless dust storms. This is a thin layer, and it’s only skin deep on most parts of the planet.
The Colour of the Water
Mars is famous for its iconic red color, but the colour of its water is also incredibly important. This is because it determines the overall tone of its landscape.
On Earth, the sky is blue because it reflects off of our oceans. On Mars, however, it’s a lot more muted because its dusty surface blocks out the light of the Sun.
The result is that sunsets on Mars are bluish to our eyes. This is because fine Martian dust, which makes up most of the planet’s surface, would scatter the blue wavelengths of light coming from the Sun like Rayleigh scattering does on Earth.
In the past, liquid water flowed through gullies and riverbeds on the planet. Curiosity has found evidence of this on some of the red planet’s driest slopes. These channels are likely to have formed when a local source of heat caused a sudden release of water. These rapid runs of water could have carved out the gullies, which are not wide enough to see from Earth and don’t follow straight lines.