The fourth planet from the Sun, Mars, is one of our solar system's most enigmatic celestial bodies. We've known about its existence for thousands of years, but it took until the "Space Age" for humans to figure out just how strange the "Red Planet" is.
It is a dusty, cold, desert world, and it also has its own seasons, polar ice caps, enormous canyons, and gigantic volcanoes. Mars is one of the most studied bodies in our solar system, and it's the only planet where we've sent rovers to roam the alien landscape.
But, even after all this attention, Mars still leaves us with more questions than we've managed to answer.
What are some mind-boggling facts about Mars?
Mars is a very alien world compared to what we are used to here on Earth. The reasons for this are varied, but needless to say, it is not exactly the most inviting place for potential future human Martian colonists.
Roughly the same age as planet Earth, it has had a very different history over its 4.5 billion or so years of existence. We can't definitively say for sure who the first person to "discover" Mars was, as it is one of the few celestial bodies that can be seen in the night sky with the naked eye.
Mars is very bright and has a reddish color, so it stands out and is easily noticed - especially if you live somewhere with little light pollution. The planet Mars has been known since ancient times and was observed for thousands of years by the people of many different cultures.
Let's find out what we know, or we think we know, about our planet's little red sibling.
1. Earth and Mars have similar amounts of land (more or less)
Believe it or not, Mars and Earth have similar amounts of landmass. This, despite the former being only about 15 percent as large as Earth in terms of volume and roughly only 10 percent of Earth's mass.
According to NASA, Earth has a volume of roughly 108.321 1010km3, and Mars 16.318 1010km3. Mar's equatorial radius is 3,396.2 km (or approximately half that of Earth) and masses (very roughly) 0.64169 1024 kg. On the other hand, Earth is about ten times more massive, with a mass of 5.9722 1024 kg.
So, you might ask, how do they have the same amount of land if Mars is so much smaller? Put simply, the vast majority of Earth's surface is covered with water.
Simple when you think about it.
2. Mars has the tallest mountain known in the Solar system
Another amazing fact about Mars is that it has the tallest mountain yet discovered on another planet. Called Olympus Mons ("Mount Olympus" in Latin), this enormous mountain is roughly 16 miles (25 km) tall and 373 miles (600 km) in diameter.
That is astonishingly huge and dwarves any comparable mountain here on Earth. Our tallest (above sea level), Mount Everest, is a paltry 29,032 feet (8,849 meters) by comparison.
Since Mars has no oceans like Earth, however, it might be fairer to compare it to another enormous mountain, such as Mauna Kea in Hawaii, with a height of 32,696 feet (9,966 meters, or 6.2 miles) from the seafloor (but just 13,728 feet of that is above sea level). But Olympus Mons still dwarf Mauna Kea.
Olympus Mons is a presumed long-dead (extinct) shield volcano, which is thought to have been active over a billion years ago. That is so long ago that it predates most, if not all, complex life forms on Earth.
It is important to note that some Mars experts believe it may actually be partially active today, with some evidence of more recent lava flows. However, this is hotly debated.
3. Mars derives its name from the Roman god of war
If you ever wondered why our red neighbor is called Mars, it is because this was the name for the Roman god of war. This is thought to be, quite reasonably, related to Mars' striking blood-red color when seen from Earth.
In fact, the ancient Greeks named the planet "Ares" after their own god of war for the very same reason.
Even more interestingly, this practice is not unique to ancient Europe. Other ancient cultures were also inspired by Mars' color, such as China’s astronomers calling it "The Fire Star". The ancient Egyptians associated the planet with the god Horus and called it "Her Desher" (or "The Red One"). There is currently an ancient river valley on Mars named Her Desher Vallis.
The planet's color is due to the large amounts of iron-rich dust and rock that blankets the planet. This is derived from the large amounts of iron oxide minerals on the planet's surface, from minerals like hematite (Blood Stone), a common iron ore here on Earth.
However, much of the iron sank into the core when the planet was still molten on Earth, while Mars' smaller size and weaker gravity may have allowed more iron to remain near the surface. Scientists are still unsure exactly how the iron oxidized (which turns it red and requires the presence of some form of oxygen).
4. Mars should get its own ring in the future
Saturn and Uranus are two of the more unique planets in our Solar System because of their characteristic orbiting rings. But, it turns out, Mars, not to be outdone, could get its own ring in a few tens of millions of years.
According to astronomers, Mars' largest and most enigmatic moon, Phobos, will eventually be torn apart by gravitational forces. This will lead to the formation of a debris field that will, eventually, settle down into a stable orbit and form a rocky ring around Mars.
Phobos' orbit puts it a mere 3,700 miles (6,000 kilometers) above the surface of Mars, and it is closer to its planet than any other moon in the solar system. Mars’ gravity is slowly but surely, drawing in Phobos by about 6.6 feet (2 meters) every hundred years. According to NASA, the moon will be pulled apart in 30 to 50 million years.
The ring won't last forever, however. It has been estimated that it should last roughly 100 million years or so before disintegrating and falling to Mar's surface.
You can see the early telltale signs of this moon's impending doom today in a series of large cracks on its surface.
5. Mars has an enormous canyon on its surface too
Mars is also home to an enormous canyon called Valles Marineris ("Mariner Valley" in Latin), apart from having the Solar System's tallest mountain. The canyon, or rather canyon system, runs along the planet's equator and is an awe-inspiring feature to behold.
It runs for around 2,610 miles (4,200 km) and is, in places, roughly 4.4 miles (7 km) deep. That is so big that it would almost span the entire continental United States from the Atlantic Ocean to the Pacific Ocean.
To put that into perspective, the Grand Canyon in Arizona is about 446 km (277 mi) long and 1.8 km (1.1 mi) deep.
Valles Marineris is actually an enormous plate boundary that moves so slowly that little happens over millions of years. Mars has a very primitive form of plate tectonics, and the action of the two plates sliding past each other began splitting the surface some 3.5 billion years ago.
6. Mars appears to be where probes go to die
Another interesting fact about Mars is its uncanny ability to defeat the best engineering humans have to offer. Since around 1960, more than 50 missions have been launched by various nations to the Red Planet, but only about half have successfully landed.
The first mission designed to reach Mars was the Soviet Union's 1M, dubbed Marsnik 1 by the western press, which suffered a launch failure in 1960.
The first successful flyby of Mars was NASA's Mariner 4, which flew by the planet on July 14-15, 1965, sending back photos. Since then, around 55 probes have been sent to Mars or attempted to be sent. Of these, many of the early attempts by the Soviet Union suffered from launch failures, while several other attempts had some kind of technical failure en route, in orbit, or on the surface of the planet. This may have been partly down to the nature of the missions and the push to get there with equipment that wasn't ready.
The more recent attempts have been more successful. NASA had a series of successes with the Phoenix Lander in 2008, the MAVEN orbiter, launched in 2013, the plucky and long-lived Opportunity rover from 2014 to 2018, and the Curiosity rover (launched in 2011). A number of missions had also arrived on Mars more recently — NASA's Perseverance rover and Ingenuity helicopter, the United Arab Emirates' Hope orbiter (a first interplanetary mission for that country), and the China National Space Administration's Tianwen-1 orbiter and lander-rover mission, which was China's first successful mission to the Red Planet.
It seems that any "curse" hanging over the planet was more likely an artifact of the immensely difficult task of getting to another world. Nevertheless, Elon Musk and SpaceX may find some competition in the plans to get a colony up and running by 2050.
7. Bits of Mars have actually reached Earth in the past
Believe it or not, scientists believe they have found proof that little bits of Mars have actually landed on Earth in the past. Called "Martian Meteorites", these are little pieces of rock that have miraculously managed to make it to Earth.
This might sound impossible, but bits of planets are blasted off their surfaces over time as things like large asteroids hit them. These impacts release a massive amount of ejecta that actually throw stuff off into space if the impact is significant enough.
This ejecta can have enough energy to escape the planet's gravity well and travel around the Solar System before being influenced by another planet's center of gravity.
What's more, these kinds of events appear to be quite common. As of 2020, something like 277 meteorites found on Earth is thought to have been derived from Mars. That might sound like a lot, but that is a fraction of 1 percent of all confirmed meteorites found on Earth.
Of the ones thought to be Martian in origin, the largest complete and uncut example is Taoudenni 002. Discovered in Mali in early 2021, it weighs 32 pounds (14.5 kg) and is currently on display at the Maine Mineral & Gem Museum.
Scientists use the study of rocks like this to determine the composition of Mars' surface and perhaps even its old atmosphere.
8. Mars suffers from some seriously nasty sandstorms
If Mars' barren landscape isn't enough reason not to visit it anytime soon, another hazard on the planet is its power.
The cause for these enormous storms is due to Mars' elliptical orbit around the Sun. This can lead to variations in temperature between the hemispheres that dramatically increase atmospheric circulation — the air currents pick up dust and circulate it around the planet.
These fierce dust storms can cover the whole planet and last up to six months.
One of the latest ones caught on camera occurred in February of 2022. It was so huge that it covered twice the size of the United States and effectively blanketed the entire Southern Hemisphere of Mars. The storm also caused NASA’s Insight lander put itself in a "safe mode" to conserve battery power after dust prevented sunlight from reaching the solar panels. NASA's Ingenuity Mars Helicopter also had to postpone flights until conditions improved.
9. Mars has frozen ice today but it is thought to have once been liquid
One of the essential prerequisites for life is thought to be the presence of water on a planet. While it is best for life as we know it for the water to be in liquid form, the fact that water exists at all is a good sign that life may be present on a planet(or has been present in the past).
In the case of Mars, we know for a fact that the planet has large quantities of ice at its poles. As far as we know, there is little to no possibility that liquid water exists on the planet, as its very thin atmosphere prevents this from physically occurring.
Any water that is present outside of the polar regions of Mars is probably also frozen. Still, NASA probes like the Curiosity Rover are searching the planet for potential locations on the planet that might be suitable for life to exist.
If there is no life on Mars, the large quantities of frozen water will be an excellent resource for any future human colonies and expeditions to the planet in any case.
But, could this frozen ice have been liquid in the past? Scientific opinion is divided and discussions have been raging about this for over a century on this very topic. From early misinterpretations of structures that resemble intelligently-made water canals, several spacecraft have spotted signs of what appear to be ancient river channels, fluvial plains, and other hydrological features that may be evidence of liquid water in the past.
10. Mars has quite a lot of methane in its atmosphere too
Another interesting fact about Mars is the presence of gaseous methane in its atmosphere. Like water, the presence of methane has also been used as an indicator of the potential presence that there was once, or still is, life on a planet.
First detected in the atmosphere by the Mariner 9 probe in 1971, further telescopic observations have since recorded wildly different methane levels over the years. To date, few spacecraft have also been designed to probe for the element in detail.
That being said, the Curiosity Rover has detected spikes in methane in its area, and the source is still very much a mystery.
On Earth, methane tends to be produced primarily as a byproduct of microbial activity and human agriculture.
However, methane can also be produced by geological processes like volcanism. Given the large quantities of volcanoes on the surface of Mars (including the enormous Olympus Mons), this is thought to be a more likely source for the gas.
If we discover that methane is not biologically generated, it is still good news for humans, as methane will be a useful resource for future Mars colonies. In fact, the likes of SpaceX, plan to use it and Mar's abundant water supply to help make resources like fuel.
11. You wouldn't last very long on Mars without a spacesuit
One of the most memorable scenes from the film "Total Recall" is when Arnold Schwarzenegger's character briefly suffers from a severe case of "popping eyes" while exposed to a partial vacuum on the Martian surface. While this scenario is obviously heavily dramatized, the reality is even worse.
The main reason for this is the fact that Mars' atmosphere is pretty thin. So thin, in fact, that if you were ever to find yourself standing on the planet without a spacesuit, your trip would be a concise one.
But, having your insides forcing their way out of your body is only part of the problem. One of the following significant issues is the planet's icy surface. For reference, the planet has an average temperature of -50 degrees Fahrenheit (-45 degrees Celsius) in the mid-latitudes.
This would be a severe problem in and of itself, but things get worse. Mars' atmosphere is famously very thin, with an air pressure of roughly 1 percent of that on Earth.
This would mean it would be next to impossible to breathe. Presume you're not already dead "Total Recall" style.
But, even if you could breathe, you'd likely quickly be asphyxiated, as the composition of Mar's practically non-existent atmosphere would be toxic to you. Mars' atmosphere, for the most part, comprises about 95 percent carbon dioxide, 3 percent nitrogen, 1.6 percent argon, and other trace elements like the aforementioned methane.
And that, Mars fans, is your lot for today.
The planet Mars has fascinated our species for thousands of years and might just be the first extraterrestrial planet that humans may colonize in the future. But, as you can see, there are quite a few differences from our home planet that will need to be overcome before we could ever call Mars a second home.