Is Mars Really Red? A Physicist Explains the Science Behind Its Colour and More

Mars appears red due to iron oxide, but telescopes reveal it in many colors across light spectra.

Written by Gadgets 360 Staff | Updated: 21 June 2025 19:00 IST

Is Mars Really Red? A Physicist Explains the Science Behind Its Colour and More

Photo Credit: NASA / JPL-Caltech / USGS

Mars looks red to the naked eye, but telescopes show a broader, more complex spectrum

Highlights

Mars appears red due to iron oxide, similar to rust and even human blood
Probes reveal Mars is more tan or brown than red across its surface
Ice caps contain dry ice that grows and shrinks with Martian seasons

Mars has been inspiring human imagination for millennia, mainly because it has a reddish colour, which earned it the title “Red Planet”. Its colour was associated by the ancient Romans with blood and war; thus, they named it after their god of war. The redness is the result, scientifically, of iron oxide — rust that coats the surface of Mars. Yet images of the surface produced by robotic probes have shown a more subtle spectrum. Much of the terrain appears more like dusty tan or rusty brown. Even the poles defy the planet's nickname, presenting as bright white due to water ice and frozen carbon dioxide that expand and contract with seasonal sunlight.

Mars Is Not Just Red: Telescopes Reveal a Complex Palette of Colors, Ice Caps, and Hidden Features

As per a recent article published by The Conversation and republished on Space.com, the iron-rich minerals of Mars have rusted, which is why it looks rusty. Like how iron and oxygen give blood its colour, Martian dust also rusts naturally. The polar caps, which are composed of frozen water and carbon dioxide and have a clearly different colour, are generally white. The sunshine prompts the layer of dry ice to sublimate and refreeze, making these caps expand and contract with the seasons.

Images taken by previous missions and rovers reveal Mars's palette, but telescopes and spacecraft equipped with ultraviolet and infrared cameras capture false colour images, leading to some confusion about the true colour of Mars.

Fast Radio Bursts Reveal Universe’s Missing Matter Hidden in Cosmic Intergalactic Fog

Spectral observations, infrared and ultraviolet images, and the broader array of the electromagnetic spectrum are assisting scientists in investigate Mars' appearance, history, composition and potential past habitability.

Mars might still look red in the sky, but its actual narrative is rather more complex. Thanks to science and high-resolution cameras, our understanding of this neighbouring world is still unfolding.

Comments

For the latest tech news and reviews, follow Gadgets 360 on X, Facebook, WhatsApp, Threads and Google News. For the latest videos on gadgets and tech, subscribe to our YouTube channel. If you want to know everything about top influencers, follow our in-house Who'sThat360 on Instagram and YouTube.