09/02/2026
Why Is Mars Red?
The Red Planet: A Story Written Over Billions of Years
This infographic is part of the ((Astronomical Infographic)) project, dedicated to simplifying astronomy for Arabic-speaking audiences.
Mars is instantly recognizable by its red color.
But this color is more than appearance—it is a geological and chemical record of the planet’s long evolution.
The Direct Answer: A Rusty Planet
Mars appears red because its surface is rich in oxidized iron.
Over billions of years, iron in Martian rocks and soil reacted with oxygen, forming iron oxide (rust) that now blankets the planet.
Iron oxide makes up roughly 5–14% of Martian soil—enough to color the entire planet.
A Journey Through Time: How Mars Changed
Stage 1: Blue Mars (Over 4 Billion Years Ago)
•Thick atmosphere
•Strong magnetic field
•Rivers, lakes, and possibly oceans
•Stable liquid water on the surface
Stage 2: The Great Loss (Since ~3.7 Billion Years Ago)
•Magnetic field weakened and vanished
•Solar wind stripped the atmosphere
•Surface water was lost
•Rapid iron oxidation began
Stage 3: Modern Mars
•Very thin atmosphere
•Cold, dry surface
•Global dust storms
•Widespread iron oxide gives Mars its red color
Mars Colors: Not Just Red
Mars shows a surprising range of colors:
•Rocks: Reddish-brown
•Polar caps: White (water ice and carbon dioxide ice)
•Sky: Pinkish-yellow due to fine dust
•Dunes: Dark or black (volcanic sands)
Why Is Earth Blue and Mars Red?
Earth
•Strong magnetic field
•Dense atmosphere
•Persistent liquid water
•Balanced oxidation
Mars
•Lost magnetic field
•Thin atmosphere
•Water loss
•Widespread surface oxidation
Evidence for a Watery Past
Missions such as Curiosity and Perseverance have found:
•Ancient river channels
•Sedimentary deltas
•Water-formed rocks
•Minerals that only form in wet environments
Did Life Ever Exist?
Mars once had key ingredients for life:
•Liquid water
•Energy sources
•Essential chemical elements
So far, no direct evidence of past life has been found.
Current missions focus on searching for ancient biosignatures preserved in rocks.
Final Thought
Mars’ red color tells the story of a planet that lost its protection and water.
It is a powerful reminder of how worlds evolve over time—and what they can teach us about planetary futures.
لماذا المريخ أحمر؟
الكوكب الأحمر… قصة عمرها مليارات السنين
هذا الإنفوكرافيك هو جزء من مشروع ((الإنفوكرافيك الفلكي)) لتبسيط علوم الفلك للناطقين باللغة العربية.
عندما ننظر إلى المريخ، يلفت انتباهنا لونه الأحمر المميز.
لكن هذا اللون ليس مجرد مظهر سطحي، بل هو سجل جيولوجي وكيميائي يحكي قصة طويلة عن تحوّل كوكب كان مختلفاً تماماً في الماضي.
