Mars Facts



Modified: 02 Jun 2022

Facts About Mars, Mars

Also known as the Red Planet, Mars stands out in the universe for its distinct color and significantly small size. Of all the planets in the Solar System, Mars also gained a reputation for being the planet closest to supporting life. Find out the truths and myths about this planet with these facts about Mars.

  1. Mars measures 6,780 km across at its equator.
  2. It also orbits the Sun at an average distance of 227.9 million km.
  3. The surface of Mars measures an area of 144,798,500 km².
  4. A Martian day is only 40 minutes longer than a single day on Earth.
  5. In contrast, a Martian year lasts 687 days long.
  1. The Sumerians associated Mars with their god of plague, Nergal.
  2. Ancients Mesopotamians in general considered Mars the star of judgment for the dead.
  3. Astronomers of the Neo-Babylonian Empire made regular records of Mars’ movements in the night sky.
  4. Chinese astronomers knew of Mars by the 4th Century BC.
  5. Aristotle used observations of Mars and the Moon to conclude that Mars was further away from the Earth than the Moon.
  6. Ptolemy of Alexandria also conducted observations of Mars in the 1st Century AD.
  7. In the 17th Century, Johannes Kepler and Tycho Brahe managed to calculate Mars distance from the Earth.
  8. It was also in the 17th Century that Galileo Galilei first observed Mars using a telescope.
  9. Giovanni Cassini also studied Mars with a telescope in the 17th Century.
  10. Christiaan Huygens also made the first maps of Mars in the 17th Century.
  1. East Asian cultures traditionally regard Mars as the fire star.
  2. Mars’ title of the Red Planet comes from the rich iron oxide in its soil giving it a red color.
  3. The gravity on Mars is only 38% of that we experience on Earth.
  4. Mars orbits the Sun at a speed of 24.007 km/second.
  5. Temperatures on the Martian surface average at -63° C.
Table of Contents

Mars Facts Infographics

Mars Facts Infographics

Mars has a volcanically-active history.

Volcanoes are a common sight on the Martian surface, with probes collecting many samples from their slopes. Through these samples, scientists discovered that the volcanoes on Mars date as far back as 3.7 billion years ago. More surprisingly, Mars’ volcanoes may have been around for much longer, with the evidence being erased by the atmosphere over time.

Mars may still have geological activity in the future.

To date, astronomers have found no active volcanoes on Mars, nor have they detected any marsquakes. That said, geologists have also decided against declaring Mars as a geologically-extinct planet. Evidence recovered from rocks in Mars’ southern hemisphere also suggests that geological activity on Mars operates slower than on Earth.

Specifically, scientists believe that the geological activity on Mars occurs over intervals lasting millions of years. The discovery of volcanic flows from only 2 million years ago further supports this theory.

Martian volcanoes are both bigger and more powerful than those on Earth.

Due to Mars’ smaller size and weaker gravity, scientists believe that the Martian volcanoes were much violent than those on Earth. The volcanoes on Mars had deeper and bigger magma chambers. While this meant a longer interval between eruptions, it also increased the magnitude of lava drastically.

If you still can’t picture it, scientists once discovered that the solidified lava flow of an ancient eruption in Mars’ Elysium Planitia region measured as big as Oregon. How’s that for explosive facts about Mars?

Martian volcanoes have much in common with hotspot volcanoes on Earth.

Many volcanoes on Earth grow from subduction zones, where oceanic crust sinks under continental crust and into the mantle. Once the oceanic crust melts under the constant heat and pressure, it turns into magma that erupts into the volcanoes above. A well-known example of a subduction zone is the Pacific Rim of Fire.

However, Mars doesn’t have tectonic plates, thus making it impossible for the planet to have subduction zones. Instead, the Martian volcanoes work like the volcanoes of Hawaii and Iceland. In these cases, magma from the mantle burns up through the crust like a blowtorch. Once the magma breaks through the crust, the result is a volcano.

Mars’ Olympus Mons is the biggest volcano in the entire Solar System.

With a height of 21.29 km, Olympus Mons stands taller than the Earth’s tallest mountain and volcano. For one, Mount Everest only measures a height of 8.85 km, while Mauna Kea – including those parts of the volcano underwater – only measures 10.2 km high.

At around 750,000 km³, Olympus Mons also has 10 times more volume than Mauna Kea. With an area of 300,000 km², the volcano’s size rivals smaller countries on Earth, such as Italy or the Philippines. Definitely one of the facts about Mars that shows how unique it is.

Facts About Mars, Olympus Mons
Photo by NASA from Wikipedia

Olympus Mons is the youngest of Mars’ volcanoes.

Based on rock samples, geologists concluded that the volcano is at least 115 million years old. Its age could even go further back than that, since older rocks usually get buried under new ones. Since its last eruption has been discovered to occur only 25 million years ago, experts believe that Olympus Mons is only dormant, and not yet extinct.

Mars also has the biggest impact crater ever discovered.

While approximately 4 billion years old, this crater went unnoticed for decades due to its condition. Even so, scientists managed to recover enough evidence to agree on the crater’s existence. Covering an area of 90.1 million km², scientists believe that an impact between Mars and a dwarf planet as big as Pluto caused the crater.

Martian soil is poisonous.

After probes collected soil samples, scientists discovered that the soil on Mars is highly toxic for plants. With a pH reading of 7.7 a 0.6% perchlorate content, scientists concluded that Martian soil would kill any Earth plant that tried to grow in it.

Ironically, Martian soil also includes minerals that would support Earth life, such as chlorine, magnesium, potassium, and sodium. Additionally, scientists consider the possibility that the toxic soil samples may just be a local occurrence. If so, other parts of Mars might have soil more capable of supporting life.

Scientists have also discovered organic compounds in Mars’ soil.

For as long as 3 billion years ago, these organic compounds on Mars include methane and formaldehyde. While scientists consider these compounds as building blocks of life, they aren’t necessarily evidence of life on Mars. Still, scientists consider the possibility of undiscovered life evolving on Mars.

Mars has water.

Though it has water, you can’t expect to have a drink on Mars anytime soon. Due to its thin atmosphere, Mars doesn’t have enough air pressure for water to stay liquid. Instead, Mars’ water reserves are all in frozen form, found its polar ice caps or in the soil of Mars’ temperate areas.

In fact, scientists think that there’s enough ice in Mars’ south pole alone that if melted, it would cover the planet with an ocean 11 meters deep.

Facts About Mars, Martian South Pole
Photo by NASA from Wikipedia

Mars once had plenty of liquid water.

Since Mars has valley systems exactly like those formed by the Earth’s great rivers, scientists strongly believe that it used to house bodies of water. One of Mars’ valleys, Ma’adim Vallis, even spans greater than North America’s Grand Canyon, at an estimated 700 km long, 20 km wide, and 2 km deep.

This has also led scientists to think that ancient Mars might have had a thicker atmosphere, which provided the air pressure needed to keep water liquid, but enough heat to keep it from freezing.

Mars may still have water today.

Based on dark streaks on Mars’ surface observed by telescopes, scientists suggest that there may be liquid water on Mars. Even then, the low pressure and temperatures of the planet only allow for liquid water to flow for a few days a year.

Scientists believe Mars’ moons are actually captured asteroids.

Upon close observation, Mars’ moons structurally resemble asteroids found around the Solar System. In line with this, scientists think that both Phobos and Deimos may have passed Mars in prehistoric times, but came too close to the planet. As a result, Mars’ gravity captured the two asteroids in a stable orbit, turning them into its moons.

The idea of Mars having life goes back to the 19th Century.

This resulted from how early telescopes only had a limited ability to magnify incoming light. The 19th Century astronomers noticed dark lines running for long distances across the Martian surface, believing that they were canals for water to pass through.

This led American astronomer Percival Lowell to hypothesize that Martians built those canals to channel Mars’ limited water supplies. That said, it wasn’t until better telescopes arrived in the 20th Century that astronomers discovered the truth. Sadly, the astronomers found that the dark lines weren’t canals, but valleys.

H.G. Wells wrote one of the most famous stories about Mars in history.

In 1897, H.G. Wells first published War of the Worlds in Britain. The sci-fi novel tells the story of a Martian invasion of Earth, with the Martians crushing any and all human resistance. In the end, though, the invasion fails, and the Martians all die from their lack of resistance to Earth’s native microorganisms. The novel has since become a classic of science fiction, and one of the most critically-analyzed and commented novels in history.

Facts About Mars, H.G. Wells
Photo from Wikipedia

War of the Worlds gained infamy in 1938.

In 1938, the novel received an audio adaptation set in the USA instead of Britain, which was then broadcast live on radio across the country. Unfortunately, many in the audience didn’t know that War of the Worlds was a fictional work, leading them to believe that Martians were actually invading Earth.

This led to a minor panic, and while no riots resulted, public outrage erupted in the following days. Many people felt tricked and called for increased government regulation of radio media to prevent another incident, no matter how unintended it may be. How’s that for morbidly funny facts about Mars?

War of the Worlds also received a film adaptation in 2005.

Directed by Steven Spielberg of Jurassic Park and Indiana Jones fame, the film features Tom Cruise as the leading character. The critically-acclaimed film refurbishes the original novel and audiobook into a modern day adaptation. Other than that, it follows the general plot of the novel.

The United States was the first to successfully send probes to Mars.

The U.S. launched Mariner 4 on November 28th, 1964. It arrived on Mars in July 14th the following year, staying within range of the planet until the following day. In that time, it collected many data, before continuing its journey to the outer system.

Six years later, Mariner 9 became the first probe to successfully enter into Martian orbit on November 14th, 1971. It stayed operational until October 1972, collecting data and sending it back to Earth until its systems died.

The Soviet Union made the first landings on Mars.

While the U.S. was the first to succeed in sending probes, Russia had attempted it long before this feat. In 1972, the Mars 2 probe landed on November 27th, while Mars 3 landed on December 2nd.

Despite successfully landing on Mars, the probes failed in their missions, dying out during descent or immediately after landing. Now there’s one for unfortunate facts about Mars.

America’s Viking program enjoyed great success.

Viking 1 and 2 were both automated landers with built-in laboratory systems. This allowed the probes to collect and study samples one their own without sending them back to NASA. Launched in 1975, they landed a year later in 1976. Viking 2 only stayed operational until 1979, but Viking 1 remained operational until 1982.

Facts About Mars, Viking 2 on Mars
Photo by NASA from Wikipedia

The Soviets also sent probes to Mars’ moon of Phobos.

Both launched in 1988, Phobos 1’s systems failed even before it reached Mars. In contrast, Phobos 2 reached Mars and captured many photos of both the planet and the moon. Following his feat, the Russians then tried to send two landing probes to Phobos, but the probe’s systems failed before the landers could launch.

Mars missions enjoyed increasing success in the 21st Century.

As of 2019, missions to Mars have suffered a failure rate of 54.5%. Out of 55 missions in all, only 25 succeeded in their goals. However, 12 out of those 25 were actually launched from 2001 onward, while 8 continue with their mission to this day.

Opportunity is the most successful probe ever sent to Mars.

Officially called the Mars Exploration Rover – B (MER-B), NASA launched Opportunity in 2003, though the probe only arrived on Mars in 2004. They expected Opportunity to only operate for around 3 months, but it stayed active until 2018, 14 years after its launch.

In that time, it traveled a distance of over 45 km, discovered meteorites on the Martian surface, and did in-depth studies of craters across Mars. Opportunity’s success made it an internet phenomenon, gaining a wave of mourning as it shut down in 2018. In honor of its achievements, astronomers later named an asteroid in the probe’s honor: 39382 Opportunity.

Plans for manned landings on Mars go back to the 1940s.

Thanks to the cost, distance to Mars, and risks, none of these Mars expeditions have set flight. In recent years, Elon Musk of SpaceX aired plans to send a manned mission to Mars by 2024, though it’s not expected to launch until 2027 or much later.

In 2016, US President Barack Obama committed the USA to a manned mission in the early 2030s. A year later, the US Congress followed this up with the NASA Authorization Act of 2017.

Mars could be a promising planet to colonize.

For one thing, the Martian day almost has the same number of hours in it as an Earth day. There’s also water on Mars, in the form of water ice, which reduces the need to send water from Earth to support a Martian colony. How’s that for cool facts about Mars?

Facts About Mars, Mars Colony Concept Art
Photo by NASA from Wikipedia

Mars also presents challenges for any future colony.

Most importantly, Mars’ atmosphere is too thin for Earth life and composed almost completely of carbon dioxide. The lower Martian gravity will also cause negative, long-term effects on the colonists’ bone and muscle mass, unless they take certain precautions.

The average temperature on Mars is also around that of Antarctica at its coldest. Mars’ lack of a magnetic field also means colonists would always face the risk of exposure to solar and cosmic radiation. Any future colony would need heavy radiation shielding, limiting any trips outside to avoid dangerous levels of radiation.

Just reaching Mars alone is a major challenge.

At present, it takes around a year to reach Mars from Earth, putting even unmanned craft under heavy pressure. Manned missions to Mars would find themselves under heavier pressure, between the long trip and equally-long time in a closed environment. Currently, scientists and engineers busily research new rocket technologies to speed up space travel. One concept under study, nuclear rockets, could actually bring travel times to Mars from Earth down to just 2 weeks.

Martian colonies would have good long-term economic prospects.

Any Martian colony that succeeds in putting down roots can look forward to plenty of opportunities. The metal-rich Martian crust provides opportunities for mining and refining for both local use and export. The Martian colonies would also provide an excellent base from which to explore and develop the Asteroid Belt.

They can also provide bases for ships from Earth to land and refuel, or even stock up on food and water. Raw materials mined from asteroids can also pass through, and get refined before continuing their journey to Earth. That, or stay on Mars for local use. Definitely an encouraging example of Facts About Mars.

Martian colonization faces ethical challenges.

Critics argue that space colonization revives the colonial and imperial spirit of the 19th Century. They also argue that with their revival, the issues of racism and exploitation would only return, if in a 21st Century context.

Terraforming is another long-term option for human development of Mars.

Terraforming involves the process of turning Mars into an Earth-like planet. This includes warmer temperatures, plenty of liquid water, breathable air, and plant and animal life. At present, scientists do not think humanity’s level of technology is enough to actually terraform Mars.

They also believe that it’s impossible to make Mars exactly like Earth. However, experts continue to study whether or not it’s possible to make Mars enough like Earth that humans can live on its surface without spacesuits.

Facts About Mars, Terraforming Mars
Photo by Daein Ballard from Wikipedia