Mars facts for kids

The planet itself

1. Mars is red because it's rusty. The soil is full of iron oxide — the same stuff as rust on an old bike — and it coats almost the entire planet.
2. Mars has the biggest volcano in the solar system. Olympus Mons stands about 22 kilometers (13.6 miles) high — nearly three times the height of Mount Everest — and its base would cover the state of Arizona.
3. It has a canyon that makes the Grand Canyon look small. Valles Marineris runs about 4,000 kilometers, roughly the distance from New York to Los Angeles, and plunges up to 7 kilometers deep — about four times deeper than the Grand Canyon.
4. Gravity is only 38% of Earth's. You could jump nearly three times higher on Mars, and your best long jump would suddenly look Olympic.
5. A Mars day is 24 hours and 39 minutes. It's called a sol, and it's so close to an Earth day that your bedtime would barely change. (It would sneak 39 minutes later every night, which you could try explaining to your parents.)
6. A Mars year lasts 687 Earth days. Mars takes almost two Earth years to circle the Sun — so you'd celebrate two Earth birthdays for every one Mars birthday.

Weather report

7. Mars is seriously cold. The average temperature is about −63°C (−81°F), and near the poles in winter it can drop to about −125°C (−195°F). The warmest summer afternoons at the equator can feel almost pleasant — briefly.
8. It snows dry ice. Around the poles, carbon dioxide freezes straight out of the sky as dry-ice snow. NASA spacecraft have watched it fall.
9. Dust storms can swallow the whole planet. Every few Martian years, a storm grows until it wraps around all of Mars and can last for weeks. A giant one in 2018 blotted out the sun and ended the Opportunity rover's mission.
10. Martian dust devils are taller than skyscrapers. Swirling towers of dust can reach 8 kilometers high — many times taller than the tallest building on Earth.
11. The air is thin and unbreathable. Mars's atmosphere is about 95% carbon dioxide, with a surface pressure less than 1% of Earth's — around 0.6% of what you're breathing right now.
12. Sunlight is less than half as strong. Mars is farther from the Sun, so high noon there delivers only about 43% of the sunlight Earth gets. Bring a jacket, and maybe a nuclear-powered rover.

Moons & sky

13. Mars has two moons, and their names mean Fear and Dread. Phobos and Deimos are small, lumpy, and shaped like potatoes — Phobos is only about 22 kilometers across.
14. Phobos is falling. It spirals about 1.8 meters closer to Mars every century. In around 50 million years it will either crash into the planet or be torn apart — possibly giving Mars its own ring.
15. Sunsets on Mars are blue. Fine dust in the air scatters light differently than Earth's sky does, so the glow around the setting Sun turns cool blue. Rovers have photographed it.
16. The daytime sky is butterscotch. Instead of Earth blue, the Martian sky glows a dusty caramel-orange all day long.

Robots on Mars

17. Real rovers are driving on Mars right now. NASA's Curiosity (landed 2012) and Perseverance (landed 2021) are car-sized robot geologists, still working and still sending home pictures.
18. A helicopter flew on Mars 72 times. Ingenuity, a small drone that hitched a ride with Perseverance, made the first powered flight on another planet in 2021 and kept flying for almost three years.
19. Sound is strange there. In the thin air, sound travels slower and fades fast — Perseverance's microphones caught Ingenuity flying nearby, and it sounded like a faint distant hum instead of a roaring drone.
20. The first spacecraft to orbit another planet orbited Mars. NASA's Mariner 9 arrived in 1971 — during a global dust storm, so it had to wait weeks for the dust to settle before it could see anything.
21. Pieces of Mars have landed on Earth. Ancient asteroid impacts blasted Martian rocks into space, and hundreds of them have been found on Earth as meteorites. You can hold a piece of Mars in your hand.

Could we live there?

22. There's water — but it's frozen. No lake or river can survive on the surface today (the air is too thin and cold), but both poles have ice caps made of water ice topped with dry ice, growing and shrinking with the seasons.
23. Mars used to have rivers and lakes. Billions of years ago, water carved valleys and filled craters — Perseverance is exploring an ancient river delta in Jezero Crater right now, looking for signs of ancient life.
24. You'd weigh way less. A 100-pound kid would weigh about 38 pounds on Mars. Try your own number in our weight on Mars calculator.
25. Recess would be legendary. In 38% gravity you'd jump nearly three times higher, hang in the air longer, and launch a kickball far past the fence. Tag would need new rules. Everything would need new rules.

Questions kids actually ask

Keep going: find your age on Mars · check your weight on Mars · learn why a Mars day is called a sol