From our vantage point on Earth, the moon looks small. But if you were to hop in a spaceship, don a spacesuit and go on an epic lunar hike, how long would it take to walk all the way around it?
The answer depends on myriad factors, including how fast you can go, how much time every day you spend walking, and what detours you’ll need to take to avoid dangerous topography.
Such a trip around the moon could take longer than a year, but in reality, there are a lot more challenges to overcome.
A total of 12 humans have stepped foot on the lunar surface, all of whom were part of the Apollo missions between 1969 and 1972, according to NASA. The footage that was beamed back to Earth showed how challenging (and, apparently, fun) it was to walk — or more accurately, bounce — around in the moon’s low gravity, which is one-sixth the gravity of Earth.
However, research from NASA has since suggested that it is possible for humans to maneuver much faster on the moon than the Apollo astronauts did. Theoretically, walking the circumference of the moon could be done faster than previously predicted.
Picking up the pace
During the Apollo missions, astronauts bounced around the surface at a casual 1.4 mph (2.2 km/h), according to NASA. This slow speed was mainly due to their clunky, pressurized spacesuits that were not designed with mobility in mind. If the “moonwalkers” had sported sleeker suits, they might have found it a lot easier to move and, as a result, picked up the pace
In 2014, a NASA study published in the Journal of Experimental Biology tested how fast humans could walk and run in simulated lunar gravity. To do this, the team got eight participants (three of which were astronauts) to use a treadmill onboard a DC-9 aircraft, which flew special parabolic trajectories on Earth to simulate gravity on the moon for up to 20 seconds at a time.
This experiment revealed that the participants were able to walk up to 3.1 mph (5 km/h) before breaking into a run. This is not only more than double the walking speed managed by the Apollo astronauts but also fairly close to the 4.5 mph (7.2 km/h) average maximum walking speed on Earth, according to the researchers.
The participants pulled off these fast speeds because they were able to freely swing their arms, similar to how humans run on Earth. This pendulum motion created a downward force, which partially compensated for a lack of gravity. One of the reasons the Apollo astronauts were so slow on the lunar surface was because they couldn’t do this properly due their chunky suits.
At this new hypothetical max speed, it would take about 91 days to walk the 6,786-mile (10,921 km) circumference of the moon. For context, it would take around 334 days to walk nonstop (i.e., not stopping to sleep or eat) around the 24,901-mile (40,075 km) circumference of Earth at this speed, although it is impossible to do so because of the oceans.
Obviously, it’s not possible to walk nonstop for 91 days, so the actual walk around the moon would take much longer.
