From 1969 to 1972, 12 NASA astronauts walked on the Moon. After six decades, the agency announced its plans to return to our celestial neighbor and build a permanent base to be used as a waypoint for flights to Mars. This means that walks on the Moon may become as common as they are on Earth.
Assuming that humans have reached the Moon once again, how long would it take for a person to walk around it?
Challenges When Walking Around the Moon
The surface of the Moon is covered in a layer of dust and debris known as regolith, a blanket made of loose fragments of rock, minerals, and other materials that might have been broken down by impacts from meteorites and comets over time. It also has a thin atmosphere of carbon dioxide, helium, and other gases.
In order to walk around the Moon, some factors need to be considered. First, a human would need a space suit that can protect them from radiation, lack of air pressure, and extreme temperatures. A modern NASA space suit weighs 286 pounds (30 kg) by earthly standards and 48 pounds (22 kilograms) by lunar standards. Another element that can affect a person's movement on the lunar surface is the Moon's gravity, only 17% of what we experience on Earth.
This means that the astronauts need less energy to move due to low lunar gravity, but their space suits limit their mobility. The Moon's rugged topography will also make the journey more difficult, especially due to meteorite impact craters that can be several miles deep.
How Long is a Complete Lunar Round Trip?
The circumference of the Moon is about 6,796 miles (10,921 km). This means that if a person were to walk around it, the journey would be equivalent to walking around the Earth 2.6 times. However, the Moon is not a perfect sphere, so the exact length of its circumference can vary. It can be affected by bulges and dips on the lunar surface.
Apollo 11 astronaut Neil Armstrong, the first human to walk on the Moon, spent 21 hours and 36 minutes on its surface. He was mostly inside the lunar module, and his walk on the Moon was 2 hours and 31 minutes. For every subsequent lunar mission, the walks of Apollo astronauts became longer and longer, and the last one lasted a record 22 hours.
According to NASA, Apollo astronauts bounced across the lunar surface at an average speed of 1.4 miles per hour (2.2 kph). They could have moved much faster if their space suits were more flexible. The agency proved this in one of its theoretical calculations made in 2014.
In this study, eight participants used a treadmill aboard a DC-9 aircraft, which flew on special parabolic trajectories on Earth to simulate the gravity of the Moon. They reached a speed of 3 miles per hour (5 kph), which was made possible by swinging their arms as people on Earth do when they run.
This pendulum-like movement created a downward force that partially compensated for the lack of gravity. At this speed, a person could travel the circumference of the Moon in 91 days of non-stop walking.
Check out more news and information on the Lunar Surface in Science Times.
