What If You Climbed the Highest Mountain in the Solar System?

Climbing the world’s tallest mountains is a daring adventure. But you’re about to make an epic extraterrestrial trek on the biggest mountain in the entire Solar System. How would this journey compare to trekking the tallest peaks on Earth? What kind of special equipment would you need? And what would you see from the top?

Behold Olympus Mons. This massive Martian volcano is 25 km (15.5 mi) high, making it the tallest mountain in the entire Solar System. The base of Olympus Mons covers about the same amount of land as the state of Arizona. And it’s nearly three times taller than Mount Everest. Climbing Everest is a gruelling physical feat.

You need to be in excellent physical shape and spend weeks acclimatizing to low oxygen levels at extreme altitudes. But thousands of people have reached the summit of Everest. Could you be the first to reach the peak of Olympus Mons? Let’s not take for granted that to attempt this climb, you’d have to make an arguably more epic journey first. You’d have to get to Mars.

But assuming that worked, you’d arrive at the base of Olympus Mons. A giant moat would surround the mountain because of the sheer weight of the volcano. Now would be a good time to be a good mountaineer and check the weather. Fierce windstorms would likely be raging all over the planet. But with the thin Martian atmosphere, these winds would not be as strong as on Earth.

And there would be one other bonus. The atmosphere on Mars is almost entirely carbon dioxide. You’d have a spacesuit providing you with a steady supply of oxygen so you could breathe. And that means no need to adjust to the oxygen levels at different altitudes on the mountain. On Everest, you’d have to do this. And you’d have to worry about the so-called “death zone.”

This is the area higher than 7.9 km (4.9 mi), where oxygen levels are critically low. At the peak, you’d only breathe one-third of the amount of oxygen you get at sea level. Your body could begin to break down. But you wouldn’t have to worry about that on Olympus Mons. You could head straight to the peak with a steady supply of oxygen.

It would be best to have a smaller device to convert carbon dioxide into oxygen. Otherwise, your oxygen would be too bulky to carry to the top. Your journey from the base would start with a cliff. And not just any cliff. A nearly vertical cliff as tall as Mount Everest. It could be 7 to 10 km (4 to 6 mi) high, depending on where you are.

If this first leg doesn’t defeat you, the slope would be more gentle from here on. You’d have about 30 hours of non-stop hiking to reach the summit, give or take. That’s if nothing goes wrong on your way. But at least that would be an almost flat journey to the top. Don’t forget that you’d be doing this in a spacesuit that weighs around 38 kg (83 lb).

And that’s taking into account that the surface gravity of Mars is about one-third of Earth’s. Imagine hiking Everest with the same suit. On Earth, it would weigh about 100 kg (220 lb). The suit would have everything essential to your survival. All your oxygen, food and water. And you wouldn’t be able to take it off.

You’d have to eat food you could reach with your mouth inside your helmet. NASA astronauts on spacewalks do this with rice paper-covered fruit and cereal bars. You’d need to eat in one bite. You wouldn’t want crumbs flying around your suit. And you’d need to carry your water inside the suit too. Or at least in a temperature-controlled backpack.

Water would freeze fast with average temperatures on Mars at -62°C (-81°F). You’d also need to wear a thick, fast-absorbing diaper to soak up your urine. But you’d be finally getting close to the summit. You’d pass through thin, wispy clouds of water vapor. This would surprise you since it never rains on Mars.

At the top, you’d encounter a massive collapsed crater 85 km (53 mi) wide. That’s the width of Lake Ontario. With such a thin atmosphere around you, you’d feel like you are standing on an island in space. A rust-colored sea stretching out all around you. You made it. But now you’d have to get down and get to Earth somehow. Ooops, you haven’t figured that part out, have you? Hope you’re ready to spend the next 100 years on Mars.