Mars and Earth Size Comparison
Simulated by Astrosyo
Mars and Earth rendered to scale. Mars’s radius is about half of Earth’s, and its volume is just 15% that of our planet.
About this simulation
This interactive scene places Mars and Earth side by side so you can see their difference in scale. Based on real measurements: Earth’s mean radius is about 6,371 kilometers, while Mars’s is about 3,390 kilometers. That makes Mars just over half the size of Earth in diameter. When it comes to volume, Earth is more than six times larger, with Mars holding only about 15% of Earth’s volume.
Why this is interesting
Comparing Mars to Earth highlights both the similarities and differences between our home planet and its smaller neighbor. Despite its modest size, Mars has long fascinated scientists as the most Earth-like planet in the Solar System, with mountains, valleys, polar ice caps, and even evidence of ancient water flows. This comparison reminds us why Mars is a key target in the search for past or present extraterrestrial life, and why it continues to be central to future human exploration.