Mars is Earth’s rusty-red neighbor in space—and it’s way more exciting than just a dot in the night sky! Did you know Mars has the tallest volcano in the solar system? Or that its day is only 40 minutes longer than Earth’s? Scientists have sent robots like NASA’s Curiosity rover (launched in 2011) and Perseverance rover (landed February 18, 2021) to explore its surface, and they’ve found strong clues that rivers and lakes once flowed there billions of years ago. Mars is about half the size of Earth, has two tiny moons named Phobos and Deimos, and experiences dust storms big enough to cover the entire planet. In this article, we’ll break down real facts—using actual mission data, precise measurements, and trusted sources like NASA, ESA, and JAXA—so kids ages 7–12 can understand what makes Mars so special, mysterious, and full of possibility.
Why Is Mars Red?
Mars isn’t painted red—it’s rusted! The surface of Mars contains a lot of iron, just like the iron in your blood or in a steel paperclip. Over billions of years, that iron reacted with oxygen and tiny amounts of water vapor in the thin Martian air, forming iron oxide—the same chemical that gives rust its reddish-orange color. When sunlight hits all that rust-covered dust and rocks, the whole planet glows red-orange, earning it the nickname ‘the Red Planet.’
NASA’s Mars Reconnaissance Orbiter (MRO), launched in 2005 and still operating today, has taken high-resolution photos showing iron oxide layers up to 3 kilometers thick in places like Valles Marineris—a canyon system longer than the entire United States. Even though Mars looks dry now, scientists believe water helped create that rust long ago. In fact, the European Space Agency’s (ESA) Mars Express orbiter confirmed widespread hematite—a type of iron oxide mineral—across the southern highlands using its OMEGA spectrometer instrument.
Fun fact: If you stood on Mars, the sky wouldn’t be blue like Earth’s. Because of the fine red dust suspended in the air, sunsets on Mars appear bluish! That’s the opposite of what happens here—and it was captured by NASA’s Spirit rover in 2005 using its Pancam camera system.
Mars Is Smaller Than Earth—but Bigger Than You Think
Mars is often called Earth’s ‘little brother,’ but it’s still huge compared to anything humans build. Its diameter is 6,779 kilometers—about half of Earth’s 12,742 km. To put that in perspective: if Earth were a basketball (about 24 cm wide), Mars would be roughly the size of a softball (about 12 cm). Its surface area is nearly identical to Earth’s total land area—about 144.8 million square kilometers—because Earth’s oceans cover 71% of our planet, while Mars has no oceans at all.
Gravity on Mars is only 38% of Earth’s gravity. That means if you weigh 100 pounds on Earth, you’d weigh just 38 pounds on Mars! Astronauts training for future missions practice in NASA’s ‘Mars Gravity Simulator’ at the Johnson Space Center in Houston—using harnesses and tilted treadmills to mimic how movement feels under reduced gravity.
How Long Is a Day and Year on Mars?
A day on Mars—called a ‘sol’—lasts 24 hours and 37 minutes. That’s just 37 minutes longer than an Earth day, which makes scheduling robot operations easier for NASA teams. But a year on Mars is much longer: 687 Earth days (or about 669 sols). That’s because Mars orbits farther from the Sun—about 228 million kilometers away on average—compared to Earth’s 150 million km. Its orbit is also slightly more oval-shaped (elliptical), causing bigger seasonal changes in the southern hemisphere.
Seasons on Mars last about twice as long as Earth’s because of its longer year. Spring in the northern hemisphere lasts 194 sols, summer 178 sols, autumn 142 sols, and winter 154 sols. NASA’s InSight lander, which operated from 2018 to 2022, used its seismometer to detect ‘marsquakes’ linked to seasonal shifts in carbon dioxide ice freezing and thawing at the poles.
Mars Has Two Moons—And They’re Tiny!
Mars has not one, but two moons: Phobos and Deimos. Both are small, lumpy, and look more like asteroids than round moons. Phobos is the larger of the two—about 22.2 kilometers across—and orbits just 6,000 kilometers above Mars’ surface. That’s closer than any other moon orbits its planet! In fact, Phobos is so close that it zips around Mars three times every Earth day—rising in the west and setting in the east, unlike our Moon.
Deimos is even smaller—only about 12.4 kilometers wide—and orbits much farther out, at 23,460 kilometers. It takes about 30 hours to circle Mars once. Both moons were discovered in 1877 by American astronomer Asaph Hall using the U.S. Naval Observatory’s 26-inch refractor telescope—the largest in the world at the time.
Phobos Is Falling Toward Mars
Because Phobos orbits so close, Mars’ gravity is slowly pulling it inward—by about 1.8 centimeters per year. Scientists estimate that in about 50 million years, Phobos will either crash into Mars or break apart and form a ring around the planet—like Saturn’s rings, but much fainter. Japan’s space agency JAXA plans to launch the Martian Moons eXploration (MMX) mission in 2026 to land on Phobos, collect surface samples, and return them to Earth by 2031.
Giant Landmarks: Canyons, Volcanoes, and Polar Ice Caps
Mars holds some of the most extreme geography in our solar system. Its biggest volcano, Olympus Mons, stands 21.9 kilometers tall—more than two and a half times the height of Mount Everest (8.85 km). Its base spans 600 kilometers—about the width of Arizona! Olympus Mons formed over a ‘hot spot’ in Mars’ crust, where lava built up for over a billion years without plate tectonics shifting the land beneath it.
Valles Marineris—the solar system’s largest canyon system—is over 4,000 kilometers long, up to 200 kilometers wide, and 7 kilometers deep. That’s ten times longer and four times deeper than Earth’s Grand Canyon. It likely formed when Mars’ crust cracked as the planet cooled and shrank after its formation 4.6 billion years ago.
The north and south poles of Mars are covered in ice caps made mostly of frozen carbon dioxide (‘dry ice’) mixed with water ice. During winter, the CO₂ layer grows to about 1–2 meters thick; in summer, it shrinks, revealing underlying water ice. NASA’s Mars Odyssey orbiter, operating since 2001, mapped subsurface water ice using its Gamma Ray Spectrometer—finding enough ice near the surface (within 1 meter depth) to fill Lake Michigan twice over.
What’s Under the Surface?
Beneath the dusty surface, Mars hides surprising secrets. In 2018, the ESA’s Mars Express detected a 20-kilometer-wide underground lake of liquid, salty water beneath the south pole’s ice cap—using radar signals that bounced off a reflective layer. Later studies suggest there may be multiple such reservoirs, kept liquid by pressure and dissolved salts like magnesium perchlorate. These findings come from MARSIS (Mars Advanced Radar for Subsurface and Ionosphere Sounding), an instrument built by Italy’s ASI space agency.
Rovers, Landers, and What They’ve Discovered
Since 1965, over 50 spacecraft have been sent to Mars—though only about half succeeded. NASA leads in Mars exploration, with active missions including the Perseverance rover (launched July 30, 2020, landed February 18, 2021), Curiosity rover (landed August 6, 2012), and the MAVEN orbiter studying the upper atmosphere since 2014. China’s Tianwen-1 mission, which arrived in February 2021, deployed the Zhurong rover—the first Chinese robot to drive on another planet.
Curiosity carries 10 scientific instruments—including the Sample Analysis at Mars (SAM) suite, built by NASA Goddard Space Flight Center and Honeybee Robotics. SAM heats soil samples to over 1,000°C and analyzes the gases released. It found organic molecules—including thiophenes and benzoic acid—in 3.5-billion-year-old mudstone at Gale Crater, suggesting ancient environments could have supported microbial life.
Perseverance is even more advanced. It’s equipped with PIXL (Planetary Instrument for X-ray Lithochemistry), built by NASA’s Jet Propulsion Laboratory, which maps chemical elements in rock samples at resolutions finer than a human hair. It’s also collecting rock cores in ultra-clean titanium tubes—43 in total—to be returned to Earth by NASA and ESA’s joint Mars Sample Return mission, scheduled for launch in 2028.
How Do Rovers Stay Powered?
Curiosity uses a Multi-Mission Radioisotope Thermoelectric Generator (MMRTG)—a nuclear battery that converts heat from decaying plutonium-238 into electricity. It produces about 110 watts continuously—enough to power a bright LED lightbulb. Perseverance also uses an MMRTG, while smaller rovers like Spirit and Opportunity relied on solar panels. Opportunity operated for nearly 15 years—far exceeding its planned 90-day mission—thanks to Martian winds occasionally cleaning dust off its panels.
Was There Ever Life on Mars?
We don’t know yet—but all signs point to Mars having had the right ingredients for life billions of years ago. Evidence includes ancient river valleys, lakebeds, and minerals like clays and sulfates that only form in liquid water. NASA’s rovers have found sedimentary rocks layered like pages in a book—especially in Gale Crater and Jezero Crater (where Perseverance landed). These layers preserve a record of changing environments over millions of years.
Jezero Crater once held a lake about 3.5 billion years ago—and at its edge sits a well-preserved river delta. Perseverance’s Mastcam-Z camera spotted cross-bedded sandstone there—rock patterns created by flowing water. On Earth, similar formations often trap and preserve microscopic fossils. The rover drilled into rocks like ‘Rochette’ and ‘Montagnac,’ finding high concentrations of organic carbon—up to 1,000 parts per million in some samples.
That doesn’t mean aliens lived there—but it does mean Mars had habitable conditions: liquid water, energy sources (like sunlight and chemical reactions), and essential elements (carbon, hydrogen, nitrogen, oxygen, phosphorus, sulfur). As Dr. Ken Farley, project scientist for Perseverance, said in a 2023 NASA briefing: ‘We’re not looking for little green men—we’re looking for the building blocks and conditions that make life possible.’
Humans on Mars: When and How?
NASA’s Artemis program aims to return humans to the Moon by 2026 as a stepping stone to Mars. The agency’s official goal is to land the first astronauts on Mars in the late 2030s—most likely during the 2037–2040 launch windows, when Earth and Mars align favorably every 26 months. SpaceX’s Starship rocket—currently in testing—has been designed specifically for Mars transport and could carry up to 100 people per flight.
Around 2028, NASA plans to launch the first Mars Ascent Vehicle (MAV) and Earth Return Orbiter as part of the Mars Sample Return campaign. These will rendezvous with Perseverance’s cached samples, lift them into orbit, and bring them back to Earth for analysis in high-security labs—like those at NASA’s Astromaterials Research and Exploration Science (ARES) division at Johnson Space Center.
Living on Mars won’t be easy. The atmosphere is 95% carbon dioxide, with only 0.13% oxygen—far too little to breathe. Radiation levels are about 2.5 times higher than on Earth’s surface due to weak magnetic fields and thin air. To protect future astronauts, habitats will need thick shielding—possibly built using local materials. NASA’s Mars Dune Alpha simulation habitat in Houston tested 378-day isolation missions in 2023 using regolith (Mars-like soil) mixed with sulfur-based binders to create ‘Martian concrete.’
Food will come from hydroponic gardens—like those tested aboard the International Space Station using Veggie and Advanced Plant Habitat systems. Brands like Bayer Crop Science and AeroFarms are already developing fast-growing, nutrient-dense crops (e.g., dwarf wheat, red romaine lettuce, and radishes) optimized for low-light, low-gravity conditions.
| Mission Name | Agency | Launch Year | Landing/Arrival Date | Key Discovery | Current Status |
|---|---|---|---|---|---|
| Curiosity Rover | NASA | 2011 | August 6, 2012 | Organic molecules in 3.5-billion-year-old lakebed rocks | Operating (as of June 2024) |
| Perseverance Rover | NASA | 2020 | February 18, 2021 | Carbon-rich rocks in ancient river delta; 43 sealed sample tubes | Operating (as of June 2024) |
| Tianwen-1 / Zhurong | CNSA (China) | 2020 | May 15, 2021 | First Chinese surface mission; confirmed wind-blown dunes and subsurface layers | Not operational since May 2022 (dust-covered solar panels) |
| InSight Lander | NASA | 2018 | November 26, 2018 | Detected over 1,300 marsquakes; measured core size (1,830 km radius) | Ended operations December 2022 |
| Mars Express Orbiter | ESA | 2003 | December 25, 2003 | Subsurface water lake at south pole (2018); global mineral maps | Operating (extended mission through 2026) |
How You Can Explore Mars—Right Now!
You don’t need a rocket to explore Mars! NASA offers free, real-time tools anyone can use. Go to eyes.nasa.gov and click ‘Eyes on the Solar System’ to fly alongside Perseverance, zoom into Olympus Mons, or watch how Mars rotates. You can also download the ‘Mars Trek’ web app (mars.nasa.gov/mars-trek), which lets you measure distances between craters, calculate slopes, and view terrain in 3D using data from MRO’s HiRISE camera—whose images show objects as small as a kitchen table from 300 km up!
Schools across the U.S. use NASA’s ‘Mission to Mars Student Challenge,’ where kids design their own rover, write mission logs, and present findings—just like real engineers. In 2023, over 120,000 students from 42 states participated, using kits from LEGO Education and curriculum guides aligned with Next Generation Science Standards (NGSS).
Want to see Mars in the sky? It’s visible with the naked eye as a bright, reddish ‘star’—best seen when it’s closest to Earth every 26 months (next opposition: January 16, 2025). With binoculars, you might spot its disk; with a backyard telescope (even a 4-inch model like the Celestron PowerSeeker 127EQ), you can see polar ice caps and dark surface markings.
- Five Things Mars Has That Earth Doesn’t:
- Olympus Mons—the tallest volcano in the solar system (21.9 km tall)
- Phobos—orbital period of just 7.6 hours
- Dust devils up to 8 kilometers tall (observed by Mars Reconnaissance Orbiter)
- Global dust storms that can last for months and block sunlight
- No liquid water on the surface today—but abundant water ice underground
- Three Ways Mars Is Like Earth:
- It has seasons, weather, and polar ice caps
- A day is almost the same length—24 hours 37 minutes
- It has mountains, valleys, volcanoes, and dried-up river channels
Mars reminds us that planets change—and that Earth’s story is still unfolding. Studying Mars helps us understand climate change, geology, and even how life began. Every photo from Curiosity, every drill core from Perseverance, and every radar ping from Mars Express brings us closer to answering one of humanity’s oldest questions: Are we alone? Whether you dream of becoming an astronaut, a robotic engineer, or a planetary scientist, Mars is waiting—not just as a destination, but as a classroom stretching across 228 million kilometers of space. And the best part? You can start learning about it right now—with curiosity, questions, and a little bit of wonder.
Scientists keep discovering new things: In early 2024, data from NASA’s MAVEN orbiter revealed that Mars loses about 100 grams of atmosphere every second to solar wind—helping explain why its air is so thin today. Meanwhile, ESA’s ExoMars Rosalind Franklin rover (scheduled for 2028) will carry a 2-meter drill to search for biosignatures deeper than ever before—below the radiation-baked surface layer.
So next time you look up and see that rusty-red dot in the sky, remember: it’s not just a planet. It’s a world of ancient rivers, silent volcanoes, whirling dust storms, and robot explorers sending home messages from another world—one pixel, one sol, one discovery at a time.
Mars is real. It’s reachable. And it’s full of stories waiting for the next generation to uncover.
