The Population of Mars and 5 Other Truths About the Red Planet

Written by Sammi Caramela
Updated: July 13, 2023
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Mars, also called the Red Planet because of the rusty iron in its soil, is one of the most interesting planets to study. The planet is the easiest to spot from Earth, appearing bright and large in comparison to other planets — likely because it is the closest planet to Earth. Since it’s one of the most explored planets in our solar system, many have wondered about the population on Mars.

Similar to Earth, Mars features volcanoes, polar ice caps, dirt, thin clouds, hillsides, and different weather patterns. However, it is much colder — but is it too cold for survival? Read on to learn about the population on Mars — and five other intriguing facts about the Red Planet.

1. Mars Has a Population of Zero

As you probably guessed, there is no known life on Mars. However, if you count robots like rovers and landers, that answer would change. NASA has sent space vehicles to study Mars and gather information. 

Some people believe there used to be life on Mars before it became too cold and inhabitable. In fact, if this was the case, those living organisms likely caused their own extinction by contributing to dangerous changes in the atmosphere.

Again, there is no proof that life ever existed on Mars — and that remains true to this day. However, we are continuing to study the planet and its history and future. 

Mars 2020 Perseverance Rover is exploring surface of Mars. Perseverance rover Mission Mars exploration of red planet. Space exploration, science concept. .Elements of this image furnished by NASA.

NASA has been studying Mars since the 1960s.


 2. Mars Is the Fourth Planet from the Sun

Between Mars and the Sun lies Mercury (closest to the Sun), Venus, and Earth — in that order. Mars is the furthest terrestrial planet (containing a compact and rocky surface like Earth) from the Sun, with 1.5 astronomical units between the two. That’s 142 million miles (228 million kilometers). 

Many believe Mars is hot because of its red coloring, but really, as the fourth planet from the Sun, it’s actually quite cold — too cold for any known living organism to thrive there, with a mean temperature of -85 degrees Fahrenheit. For reference, Earth’s mean temperature is 59 degrees Fahrenheit. 

Solar System Planets with the Sun

The solar system consists of the Sun, Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto.


3. Mars Has Two Moons

You read that right — Mars has two different moons, which experts believe are captured asteroids. The moons, named Phobos and Deimos, orbit Mars at different rates. They’re both irregularly shaped — similar to that of a potato.

Phobos, the larger moon, is 13.8 miles and orbits Mars three times a day; Deimos, the smaller moon, is 7.8 miles and orbits Mars every 30 hours. Phobos is much closer to Mars (6,000 km above the planet) than Phobos and gets six feet closer every hundred years. On the other hand, Deimos is 23,458 km away from the planet.

A closeup shot of the moon

Mars’s two moons are called Phobos and Deimos.


4. Mars Is About Half the Size of Earth

Mars has a radius of 2,106 miles (3,390 kilometers), making it about half the size of Earth, which is 3,958.8 miles. According to NASA, Earth’s moon is about half the size of Mars — or one-fourth the size of Earth. Additionally, it would take over six Mars volumes to fill Earth’s volume. 

Planet Mars, view from orbit. Relief and craters on the surface of the desert red planet. Cosmic landscape.

Mars is only twice as large as Earth’s moon.


5. You Would Weigh Less on Mars than You Do on Earth

According to NASA, if you weigh 100 lbs on Earth, you’d weigh only 38 lbs on Mars — or 38% of your weight. This is because there’s less gravity on Mars than on Earth.

Sir Isaac Newton coined this formula for determining your weight: F=Gmm/r2, with M being the mass of the planet, m being your mass, and r being the distance between you and the planet’s center. Since Mars’s mass is 11% less than Earth’s mass, it makes sense why you’d weigh less there. Additionally, Mars has about 15% of Earth’s volume and is not perfectly spherical, with an equatorial diameter of 4,222 miles (6,794 km). From pole to pole, Mars has a diameter of 4,196 miles (6,752 km) — significantly lower than Earth’s parameters.

Picture of Mars the Red Planet

Mars has less mass than Earth, making its surface gravity much lower.

©WR Studios/

6. There Are 687 Days in a Year on Mars

Mar’s year is almost twice the amount of days as Earth’s 365. This is because Mars has a speed (velocity relative to the sun) of 53,858 mph, while Earth’s speed is 66,622 mph. 

Earth and Mars have similar tilt degrees, meaning Mars has seasons just like Earth. However, because Mars’s year is almost twice as long as Earth’s, its seasons last much longer than our four seasons. Depending on the hemisphere on Mars, some seasons are longer than others. Mars’s day is only 40 minutes longer than Earth’s.

While Mars has the same hours in a day as Earth, its years are almost twice as long.


The photo featured at the top of this post is © Artsiom P/

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About the Author

Sammi is a writer at A-Z Animals primarily covering cats, nature, symbolism, and spirituality. Sammi is a published author and has been writing professionally for six+ years. She holds a Bachelor's Degree in Writing Arts and double minors in Journalism and Psychology. A proud New Jersey resident, Sammi loves reading, traveling, and doing yoga with her little black cat, Poe.

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