No other planet has captivated the human mind quite like Mars and the prospect of life on the planet remains deeply embedded in human consciousness. The desert-like surface of Mars has many similarities to the surface of Earth with its soaring mountain ranges, ice caps, towering volcanoes, and long, deep valley systems. Read on to discover some interesting Mars facts.
Facts about Mars
1. Mars is popularly known as the “Red Planet.”
Mars is nicknamed the “Red Planet,” due to the reddish hue caused by the rust (oxidized iron minerals) contained in the soil and rocks on its surface.
2. Mars is the fourth planet from the Sun.
Mars is the fourth planet from the Sun and the furthest terrestrial planet before the Jovian planets (Jupiter, Saturn, Uranus, and Neptune). On average, Mars is 228 million km (142 million miles) from the Sun.
At its closest (perihelion), Mars is 205 million km (127 million miles) from the Sun. At its furthest (aphelion), Mars is just over 249 million km (155 million miles) from the Sun.
The Sun appears about half the size on Mars as it does on Earth.
3. Mars is named after the Roman God of War.
The reddish color of Mars led the Romans to name it after their bloodthirsty god of war who was second only to the king of gods, Jupiter.
4. It takes 12.6 minutes (760 seconds) for the Sun’s light to reach Mars.
In comparison, it takes 8.3 minutes (499 seconds) for the Sun’s light to reach Earth.
5. You could fit 6 Mars’s inside Earth and still have room to spare.
The volume of Mars is 1.63118×1011 km3 whereas the volume of Earth is 1.08321×1012 km3. To be precise, it would take 6.638 Mars’s to fill the volume of Earth! Ergo, the volume of Mars is only 15.1% of the volume of Earth.
6. Earth is almost twice the size of Mars.
With a mean diameter of 6,779 km (4,212 miles), Mars is the second-smallest planet in the Solar System with only Mercury being smaller. Mars is 1.95 times larger than the Earth’s moon.
Earth has a mean diameter of 12,742 km (7,918 miles) which means that Earth is 1.88 times wider (or larger) than Mars.
7. Earth is over nine times as heavy as Mars.
Although Earth is only 1.88 times as big as Mars, it is 9.3 times heavier! Being the least dense terrestrial planet in the Solar System, Mars has a lower density than Earth. Mars is only 10.7% as massive as Earth.
8. Mars lacks a global magnetic field.
In contrast to Earth, which has a global, dipolar magnetic field, there isn’t a global magnetic field on Mars, so its internal dynamo is now either extinct or much weaker than Earth’s.
It’s believed that Mars once had a global magnetic field, like Earth’s, but the iron-core dynamo that generated it shut down about 4.2 billion years ago, and today the Martian magnetic field exists only in local regions on the surface.
Without a planetary magnetic field to defend itself, an outpouring of radiation from the sun—known as the solar wind—gradually eroded much of Mars’s ancient atmosphere, turning a potentially life-supporting world into the cold, barren planet that it is today.
Thus, the lack of a global magnetic field to shield from the sun’s deadly rays leaves the possibility for life on Mars virtually nonexistent.
9. Mars had liquid water in the ancient past.
One of the lesser-known Mars facts is that it once (about 3-4 billion years ago) had flowing water. Today, numerous flybys, orbiters, landers, and rovers have confirmed that virtually all of Mars is as dry as a desert except for ice deposits in its polar regions.
Courtesy of data from rovers and other spacecraft, we know that Mars was once wet and replete with water due to desiccated deltas, riverbeds, lake basins, and inland seas stamped into its surface.
Early in its history, Mars may have possessed enough liquid water on its surface to have covered the entire planet with water perhaps up to 1.5 km (0.93 miles) deep. So, how did Mars lose its water?
Scientists aren’t exactly certain how Mars’s water dried up, but there are a few theories. One of the most popular theories suggests that after Mars’s magnetic field shut down, its water escaped to outer space as its atmosphere was stripped away by the solar wind.
Another theory that has been gaining traction postulates that Mars’s water may not have all escaped into outer space, but rather some of it may have gone underground. The study theorizes that anywhere 30-99% of Mars’s water went into the planet’s crust and it remains trapped within minerals and salts, while the remaining amount escaped into space.
10. Today, Mars has frozen water.
Now that we’ve established that Mars was once flowing with liquid water, it’s good to know that there is still water on Mars. However, it’s not quite like water on Earth.
Today, there is still enough detected water on the surface of Mars to cover the whole planet to a depth of 20-40 meters (65-130 ft), but that is mostly frozen in the polar ice caps. It’s difficult to measure how much subsurface ice is on Mars.
11. Mars has an atmosphere but it’s only 1% as thick as Earth’s atmosphere and it is mostly composed of carbon dioxide.
Mars has an atmosphere that is roughly 100 times less dense than the one we have here on Earth. While our atmosphere is rich in nitrogen and oxygen, the Martian atmosphere is composed of 95.1% carbon dioxide, 2.59% nitrogen, and 1.94% argon, with the remainder a mixture of other gases.
Oxygen molecules are present in the Martian atmosphere, but in a minuscule amount of just 0.16 percent. In contrast, the Earth’s atmosphere is filled with breathable oxygen, amounting to 20.95 percent of our air.
Needless to say, you won’t get a breath of fresh air on Mars unless you’re wearing an oxygen suit.
12. Nobody knows who first discovered Mars.
If you’re wondering who discovered Mars, the problem is nobody really knows. No one can take credit for “discovering” Mars because the red planet is easily visible to the naked eye and has been observed since antiquity by the people of many different cultures.
13. A year on Mars is 687 Earth days.
The closer an object is to the Sun the faster it needs to move to maintain its orbit. Since Mars is further away from the Sun than Earth, it has a slower orbital velocity (24.1 km/s) compared to Earth’s (29.8 km/s). Thus a year on Mars is equivalent to 1.88 Earth years.
14. One day on Mars lasts for 24 hours and 37 minutes.
The length of a day on a planet is the time it takes for the planet to rotate or spin once on its axis. Mars rotates at a slower speed of 0.241 km/s on its axis as compared to the speed at which the Earth rotates (0.43 km/s).
Since Mars is about half the size of Earth and spins at about half the rate of Earth, the length of a day on Mars is quite similar to that of Earth, with a full Martian day (or “sol”) lasting 24 hours, 37 minutes, and 22 seconds (24.62 hrs).
15. If you weigh 100 kilograms (220 lbs) on Earth, you would weigh 38 kilograms (84 lbs) on Mars.
Looking to lose weight instantly? Then head to Mars! The Red Planet has the second-lowest surface gravity (3.71 m/s2) of all the planets in the Solar System, only behind that of Mercury.
The surface gravity of Mars is 0.38 times the gravity on Earth. Hence, you would be 62% lighter on Mars than on Earth.
16. The weather on Mars is much colder than that on Earth.
Though the desolate surface of Mars looks as hot as the Wadi Rum Valley in Jordan, it is actually pretty darn cold. The reason for this is Mars’s CO2 rich atmosphere, which is about 100 times thinner than Earth’s, meaning the Red Planet isn’t able to retain much heat.
Mars is an extremely cold planet with an average temperature of around −63 °C (−82 °F), a full 77 °C (138 °F) colder than Earth’s average temperature.
Temperatures can dip to −143 °C (−225 °F) around the poles. A summer day on Mars may get up to 20 °C (70 °F) near the equator for a brief time.
17. The two hemispheres of Mars are more different from any other planet in our Solar System.
One of the most interesting facts about Mars is that there is a striking dichotomy between the planet’s northern and southern hemispheres, to an extent unlike any other planet in the Solar System.
Most of the southern hemisphere of Mars is high-standing and heavily cratered. The northern hemisphere, by contrast, is low-lying and sparsely cratered. The difference in the mean elevation between the two hemispheres is roughly 5 km (3 miles).
No one knows for sure why Mars’s northern and southern hemispheres are so different. Some researchers think that patterns of internal magma flow caused the difference while others claim the contrast is because an object the size of Earth’s moon slammed into Mars near its south pole in the early history of the Solar System.
18. Mars is home to the tallest mountain in the Solar System.
Mars’s tallest summit is also the Solar System’s highest volcanic peak, measuring nearly 21.9 km high (13.6 miles) above the Mars areoid (a reference datum similar to Earth’s sea level). However, its height is about 26 km (16 miles) above the surrounding lowlands.
That makes Olympus Mons almost 2.5-3 times higher than Mount Everest. What’s even more impressive is that it is about 600 km (373 miles) wide, roughly the distance between Los Angeles and San Francisco.
19. The largest canyon in the Solar System can be found on Mars.
At over 4,000 km (2,500 miles) long and up to 7 km (4 miles) deep, the gigantic Mariner Valley of Mars is the largest canyon in the Solar System. It spans about 20% of the circumference of Mars and runs along the Martian equator
Mariner Valley is about nine times as long, seven times as wide, and three times deeper than the Grand Canyon in the U.S. If placed in the United States, Mariner Valley would stretch from New York City to San Francisco.
20. Mars has two moons.
Mars is well known for its two moons – Phobos and Deimos, whose names mean fear and panic in Latin. The moons are named for the sons and chariot drivers of the Greek god Ares (the Roman equivalent of Mars).
Phobos and Deimos are so dark and small that they were undetected for centuries, even after the invention of the telescope, and were only discovered in 1877 by American astronomer Asaph Hall.
Phobos and Deimos are not round in shape like the Earth’s moon but are rather shaped like potatoes. Phobos has a diameter of 22.2 km (13.8 mi) while Deimos measures only 12.6 km (7.8 mi) in diameter.
Because of Deimos and Phobos’ irregular shape, it’s speculated the moons could have formed from material thrown into Mars’s orbit by impacts or that they are simply asteroids that got dislodged from the nearby Asteroid Belt and got absorbed into Mars’ gravity field. However, the origin of the Martian moons is still fiercely debated.
21. Mars will potentially have a ring in the future.
Although currently ringless like the other three terrestrial planets, Mars may one day have a ring around it. This is because its moon Phobos rotates around Mars faster than the planet spins, meaning that each century it gets about 1.83 m (six feet) closer to the planet’s surface.
In about 50 million years or so, Phobos is projected to crash into Mars’s surface or rip apart because the tidal force of the red planet will prove too much to resist. The scattering debris will be potentially locked in a ring around Mars.
22. Mars has four distinct seasons just like Earth.
Annual changes in temperature on a planet are caused by a combination of two factors: axial tilt and variable distance from the Sun. On Earth, axial tilt determines nearly all of the annual variation, because Earth’s orbit is nearly circular.
But Mars has the highest orbital eccentricity (elliptical orbit) of any planet except Mercury. This means that for part of the year the planet is quite a bit closer to the Sun than at other times.
The seasonal changes on Mars are far greater than we experience here on Earth. The seasons on Mars are roughly twice as long as those on Earth.
In the northern hemisphere of Mars, spring lasts 194 Earth days, autumn (fall) lasts 142 days, summer is 178 days in length, and winter is only 154 days. By way of comparison, in the northern hemisphere of Earth, spring lasts 93 days, autumn (fall) lasts 90 days, summer is 93 days in length, and winter is 89 days.
23. On Mars, sunsets are blue.
One of the more unique Mars facts is that sunsets on the red planet appear blue due to fine dust scattering the red light from the Sun.
24. Mars has been visited by spacecraft since the early 1960s.
Due to the human fascination with Mars, the red planet has remained a favorite target for exploration. There have been over 50 attempts to send spacecraft to Mars (either flyby missions, orbiters, or landers) and just over 20 have been fully successful.
The first successful flyby of Mars was in 1965, by NASA’s Mariner 4. In November 1971, NASA’s Mariner 9 became the first space probe to orbit another planet when it entered into orbit around Mars.
The first successful landing on Mars came on July 20, 1976, when NASA’s Viking 1 lander touched down in Chryse Planitia (The Plains of Golf). The Red Planet continues to attract ambitious rover missions to explore its rocky terrain. Mars is currently the only planet in the Solar System solely inhabited by robots.
25. The 2013 film Gravity was more expensive than India’s Mars mission.
As it turns out sending a probe to Mars costs less than it costs to make a space movie. One of the most unbelievable facts about Mars is that India’s Mars Orbiter Mission (MOM), or Mangalyaan, which successfully entered Mars’s orbit in September 2014, cost less than the 2013 film Gravity starring George Clooney and Sandra Bullock.
While the price tag of Gravity was about $100 million, the entire Indian Mars Orbiter Mission cost $74 million! The Mars Orbiter Mission is by far the cheapest successful interplanetary mission ever carried out and cost a fraction of other successful Mars missions.
However, the bargain-basement price of India’s mission to the red planet means that the mission is less scientifically complex than others and is able to collect fewer data.
26. In 1952, the famous rocket scientist Wernher von Braun wrote a book called “Project Mars” in which the leader of the Martian government is called “Elon.”
Call it clairvoyance, conspiracy, or just an eerie coincidence but the famous space pioneer Wernher von Braun may have predicted Elon Musk’s plan to colonize Mars in 1952 when he described a male Martian leader with the title “Elon” ruling over Mars.
Von Braun’s 1952 novel Project Mars: A Technical Tale is set in the 1980s and tells about the first human mission to Mars and their encounter with the Martians on the planet. In the book, Von Braun outlines how the “Elon” heads the Martian government, which is elected by the general population for five years.
Billionaire Elon Musk has vehemently expressed his desire to colonize Mars within the next few decades. In 2021, his company SpaceX recently became the first private outfit to launch astronauts into space. Musk hopes that a million people will live on Mars by the 2060s.