Buzz
The Red Planet has long been a subject of human fascination. For over a hundred years, we've been eager to unravel the mysteries of Mars and the hypothetical creatures we once believed inhabited its surface. When NASA debunked the idea of life scurrying across its rust-colored landscapes, it led to an even more exciting possibility: that we ourselves might one day be the ones to call Mars our home.
Mytour interviewed Kirby Runyon, a research scientist at Johns Hopkins University Applied Physics Laboratory, and Tanya Harrison, the science strategy director for Planet Labs, to discover more about the potential future home of humanity.
1. A year on Mars is just shy of two Earth years.
Mars takes 687 Earth days to complete a full orbit around the sun. A day on Mars, referred to as a sol, is 24.6 hours long, which could be troublesome for the circadian rhythms of astronauts (though still much less extreme than a day on Venus, which lasts a staggering 5832 hours).
2. Mars is cooler than it seems.
Mars may appear scorching hot, resembling a desert like New Mexico with its hazy skies and reddish iron oxide soil. However, it’s actually quite cold, with the hottest sol reaching only 70°F, and the coldest sol plummeting to a brisk -225°F. The planet experiences enormous dust storms; in 2018, one storm became so massive that it covered the entire planet for more than a month.
3. Mars is significantly smaller than Earth.
When compared to Earth, Mars resembles a small Styrofoam ball. Its diameter is just over half that of Earth’s, and its mass is only one-tenth of ours. The gravity on Mars will pose a major challenge for future settlers, at just 38 percent of Earth's gravity. (For instance, a person who weighs 100 pounds on Earth would only weigh 38 pounds on Mars.)
4. The atmosphere of Mars is primarily carbon dioxide.
You wouldn’t want to inhale the air on Mars unless you're aiming for suffocation: its atmosphere is composed of 95.32 percent carbon dioxide, with trace amounts of nitrogen and argon. (In contrast, Earth's atmosphere is mainly nitrogen and oxygen.) If you attempt to breathe on Mars, the tears on your eyes, saliva in your mouth, and water in your lungs would instantly vaporize. While you wouldn’t die immediately, it would likely feel unbearable.
5. Mars has two moons that have more intriguing names than our own.
Mars' moons are named Phobos and Deimos, which mean Fear and Dread, respectively. Shaped like potatoes, they don’t exactly light up the Martian sky. From the surface of Mars, Phobos would appear about one-third the size of Earth’s moon, while Deimos would seem more like a bright star.
Future Martians will have to enjoy Phobos while they can. The tidal forces from Mars are slowly destroying it, and in 50 million years, this large potato-shaped moon will disintegrate.
In the meantime, Phobos is one of the key waypoints NASA envisions for its mission to Mars. Human exploration of the Red Planet will be a monumental challenge, and before landing on Mars (and figuring out how to launch back into space and return to Earth), it’s much more feasible to land on Phobos for some reconnaissance, then take off and head back home. Plus, during the journey to Phobos [PDF], astronauts can bring along equipment needed for future Martian settlement, easing the process for the next crew of explorers.
6. Mars boasts the tallest mountain in the solar system.
NASAEarth’s highest mountain, Mount Everest, stands at 29,029 feet. On Mars, Olympus Mons towers above at over 72,000 feet, making it the tallest mountain by far in the entire solar system.
Olympus Mons isn’t the only remarkable feature of Mars: adventurous mountaineers might also be interested in NASA’s trail map for exploring the famous Face on Mars. For those who prefer canyons, Valles Marineris is a must-see. It’s as large as North America and reaches depths of four miles. (The only place deeper is Earth’s Atlantic Ocean.) When Earth’s ice caps finish melting, you might want to check out the ones on Mars as well. (With a telescope, you can spot them easily—they’re the planet’s most distinctive features visible from your backyard.)
7. The concept of Martians has existed for over a century.
This idea emerged partly due to fictional works like H.G. Wells' 1897 novel War of the Worlds, where Martians invade England, and partly because of the astronomer Percival Lowell, who wrote extensively about the canals he believed to have observed through his telescope, speculating that they were necessary for the survival of Martians due to Mars’ declining conditions.
While we can easily dismiss such ideas today, Lowell played a major role in making space science popular, and his legacy includes the Lowell Observatory in Flagstaff, Arizona—one of the oldest observatories in the United States and the location where Clyde Tombaugh discovered Pluto.
8. If Martians exist, they would likely be microscopic organisms.
Modern scientists are working diligently to uncover Mars' intricate geological history to figure out if life could still exist there or if it ever existed. According to Runyon, “We believe that Mars was most conducive to life around to 3.8 billion years ago.” This period marks the end of the Noachian and the beginning of the Hesperian epochs. It’s possible that Mars once had a global ocean, followed by cycles of wet and dry periods, with vast crater lakes replacing the ocean. Wherever there’s water, life has a good chance of thriving.
"Finding life on Mars—whether extinct or current—would be fascinating," says Runyon. "But what’s even more intriguing is whether life emerged independently on Mars, separate from Earth." It’s possible that meteorite impacts on Earth ejected life-bearing rocks into space, which then landed on Mars. "A second emergence of life on Mars isn’t just a geological matter. It’s a biogeochemical one. We know that Mars could support life, but we still haven’t answered whether it ever had or currently has life."
9. NASA is deeply involved with Mars exploration.
Mars has seen no shortage of missions in recent years. Currently orbiting the planet are the Mars Reconnaissance Orbiter, which captures detailed images and scans the surface; MAVEN, which focuses on Mars' atmosphere; Mars Express, the European Space Agency's inaugural Mars mission; MOM, the Indian Space Research Organization's first Mars mission; the ExoMars Trace Gas Orbiter from ESA, which is on the hunt for methane in the atmosphere; and Odyssey, which studies water and ice on Mars while acting as a communication relay for surface vehicles.
On the Martian surface, Curiosity and Perseverance, both NASA missions, are actively exploring the planet’s geology. Perseverance, which landed in February 2021, is also investigating the Jezero Crater for signs of ancient life. Meanwhile, the InSight mission is analyzing the interior of Mars.
10. Mars is undergoing changes, but the reasons remain a mystery.
"Most people don't realize how active Mars is," Harrison tells Mytour. "Other planets aren’t just lifeless, frozen worlds stuck in time. Things are actually happening on Mars right now." Data from the HiRISE and Context Camera instruments on the Mars Reconnaissance Orbiter have captured phenomena such as avalanches, sand dune erosion [PDF], and recurring slope lineae (flowing Martian saltwater).
Things are moving, but the reasons remain unclear. "A lot of material has been eroded," says Harrison. "We have vast regions on Mars that appear to have been buried and then unearthed. That’s a lot of material. The big question is, where did it all go? And what forces caused this erosion?"
11. To truly understand Mars, we’ll need to go there ourselves.
To gain a deeper understanding of Mars' processes and history, we must send geologists in spacesuits. "You can’t replace human intuition with a rover," Harrison explains. "Looking at a picture on a screen is nothing like being physically present, observing the surroundings, examining stratigraphic columns, and interacting with the rocks. Once humans land, it’ll be like the leap from what we knew from Viking and Mars Global Surveyor to the breakthrough from Mars Global Surveyor to Mars Reconnaissance Orbiter. Our understanding of Mars' past will undergo a major shift, and we'll discover that much of what we thought we knew was incorrect."
