What Is Mars?

Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, being larger than only Mercury. In English, Mars carries the name of the Roman god of war and is often referred to as the "Red Planet". The latter refers to the effect of the iron oxide prevalent on Mars's surface, which gives it a reddish appearance distinctive among the astronomical bodies visible to the naked eye. Mars is a terrestrial planet with a thin atmosphere, with surface features reminiscent of the impact craters of the Moon and the valleys, deserts and polar ice caps of Earth.

The days and seasons are comparable to those of Earth, because the rotational period as well as the tilt of the rotational axis relative to the ecliptic plane are very similar. Mars is the site of Olympus Mons, the largest volcano and highest known mountain on any planet in the Solar System, and of Valles Marineris, one of the largest canyons in the Solar System. The smooth Borealis basin in the Northern Hemisphere covers 40% of the planet and may be a giant impact feature. Mars has two moons, Phobos and Deimos, which are small and irregularly shaped. These may be captured asteroids, similar to 5261 Eureka, a Mars trojan.

Understanding Mars is essential for the future of space exploration. From ancient astronomers mapping its path across the sky to modern rovers driving across Jezero crater searching for ancient microbial life, humanity's fascination with our celestial neighbor continues to grow. Knowledge of its thin carbon dioxide atmosphere, its fraction of Earth's gravity, and its extreme temperature variations is crucial for any future manned missions.

Can Humans Live On Mars?

The prospect of humans living on Mars, establishing a permanent colony, and eventually becoming a multiplanetary species is one of the most ambitious technological and engineering goals of the 21st century. Spearheaded by organizations like NASA and private aerospace companies like SpaceX, the colonization of Mars is no longer strictly science fiction.

However, the challenges are monumental. Humans evolved in a very specific environment on Earth, characterized by a thick atmosphere, a protective magnetic field, liquid water, and 1G of gravity. Mars offers none of these. The Martian atmosphere is roughly 1% as thick as Earth's and consists of 95% carbon dioxide, making it lethal to breathe. A human exposed to the Martian surface without a spacesuit would suffocate rapidly while the liquids in their body boiled away due to the incredibly low pressure (the Armstrong limit).

Therefore, early habitats will need to be fully pressurized and completely sealed off from the outside environment. To survive, colonists will rely heavily on In-Situ Resource Utilization (ISRU). This means living off the land—mining subsurface ice and extracting carbon dioxide from the air to create drinkable water, breathable oxygen, and rocket propellant. NASA's MOXIE experiment on the Perseverance rover has already successfully demonstrated extracting oxygen from the Martian atmosphere on a small scale.

Another massive hurdle is radiation. Mars lacks a global magnetic field, and its thin atmosphere provides almost no shielding against deadly solar flares and cosmic rays. To prevent severe radiation poisoning and a massively increased risk of cancer, habitats will likely need to be built underground, buried under several meters of Martian regolith, or located within ancient lava tubes.

Despite these challenges, the ongoing development of heavy-lift reusable rockets like SpaceX's Starship makes the logistics of transporting thousands of tons of cargo and eventually humans to the Red Planet increasingly viable. Living on Mars will require immense resilience, cutting-edge technology, and a mastery of closed-loop life support systems, but the theoretical foundation for making it happen is already being laid.

20 Amazing Mars Facts

• Mars is the fourth planet from the Sun.
• It is named after the Roman god of war.
• Its red color comes from iron oxide (rust) on its surface.
• A Martian year is roughly 687 Earth days.
• A Martian day (Sol) is 24 hours and 37 minutes.
• Gravity on Mars is only 38% of Earth's gravity.
• Mars is home to Olympus Mons, the tallest volcano in the solar system.
• It features Valles Marineris, a canyon system 2,500 miles long.
• Mars has two tiny moons: Phobos and Deimos.
• The atmosphere is 95% carbon dioxide.
• Mars experiences global dust storms that can last for months.
• Average surface temperature is around -81°F (-62°C).
• Sunsets on Mars appear blue.
• Mars once had liquid water flowing on its surface.
• It is the only planet we know of inhabited entirely by robots.
• Pieces of Mars have fallen to Earth as meteorites.
• The Mars helicopter, Ingenuity, was the first aircraft to fly on another planet.
• Martian soil is toxic due to the presence of perchlorates.
• It has roughly the same amount of dry land surface area as Earth.
• Due to its orbit, we can only efficiently launch missions to Mars every 26 months.

Frequently Asked Questions (Mars Quiz)

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