Space & Physics

9 Phenomena NASA Astronauts Will Encounter at Moon’s South Pole

Out-of-this-world phenomena NASA astronauts will experience at the Moon’s south polar region.

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Sep 11, 2024 - 23:00

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9 Phenomena NASA Astronauts Will Encounter at Moon’s South Pole

In the foreground is a figure kneeling on a light grey surface, examining or holding something that is sifting through their gloved left hand. The person is wearing a spacesuit and a big, boxy backpack. A reflective visor that catches and reflects bright light, possibly from the Sun, draws the viewers eye. The background is black. In the distance, mechanical equipment or structures are visible, including a small and simple vehicle.

An artist’s rendering of an Artemis astronaut working on the Moon’s surface.

Credits:
NASA

NASA’s Artemis campaign will send the first woman and the first person of color to the Moon’s south polar region, marking humanity’s first return to the lunar surface in more than 50 years.

Here are some out-of-this-world phenomena Artemis astronauts will experience:

1. A Hovering Sun and Giant Shadows

This visualization shows the motions of Earth and the Sun as viewed from the South Pole of the Moon.
NASA’s Goddard Space Flight Center

Near the Moon’s South Pole, astronauts will see dramatic shadows that are 25 to 50 times longer than the objects casting them. Why? Because the Sun strikes the surface there at a low angle, hanging just a few degrees above the horizon. As a result, astronauts won’t see the Sun rise and set. Instead, they’ll watch it hover near the horizon as it moves horizontally across the sky.

2. Sticky, Razor-Sharp Dust …

A gray triangular fragment with jagged edges sits in the middle of a darker gray backdrop. The fragment’s uneven surface has small granules scattered across it.

This dust particle came from a lunar regolith sample brought to Earth in 1969 by Apollo 11 astronauts. The particle is about 25 microns across, less than the width of an average human hair. The image was taken with a scanning electron microscope.

The lunar dust, called regolith, that coats the Moon’s surface looks fine and soft like baking powder. But looks can be deceiving. Lunar regolith is formed when meteoroids hit the Moon’s surface, melting and shattering rocks into tiny, sharp pieces. The Moon doesn’t have moving water or wind to smooth out the regolith grains, so they stay sharp and scratchy, posing a risk to astronauts and their equipment.

3. … That’s Charged with Static Electricity

A person wears a bulky spacesuit that is shadowed on the bottom half. His suit and face are covered in dark smudges. He wears a headset with a microphone and his shoulder displays the American flag. Behind him, is a small space with controls and dim lights.

Astronaut Eugene Cernan, commander of Apollo 17, inside the lunar module on the Moon after his second moonwalk of the mission in 1972. His spacesuit and face are covered in lunar dust.

Because the Moon has no atmosphere to speak of, its surface is exposed to plasma and radiation from the Sun. As a result, static electricity builds up on the surface, as it does when you shuffle your feet against a carpeted floor. When you then touch something, you transfer that charge via a small shock. On the Moon, this transfer can short-circuit electronics. Moon dust also can make its way into astronaut living quarters, as the static electricity causes it to easily stick to spacesuits. NASA has developed methods to keep the dust at bay using resistant textiles, filters, and a shield that employs an electric field to remove dust from surfaces.

4. A New Sense of Lightness

In 1972, Apollo 16 astronaut Charles Duke hammered a core tube into the Moon’s surface until it met a rock and wouldn’t go any farther. Then the hammer flew from his hand. He made four attempts to pick it up by bending down and leaning to reach for it. He gave up and returned to the rover to get tongs to finally pick up the hammer successfully.
NASA’s Johnson Space Center

Artemis moonwalkers will have a bounce to their step as they traverse the lunar surface. This is because gravity won’t pull them down as forcefully as it does on Earth. The Moon is only a quarter of Earth’s size, with six times less gravity. Simple activities, like swinging a rock hammer to chip off samples, will feel different. While a hammer will feel lighter to hold, its inertia won’t change, leading to a strange sensation for astronauts. Lower gravity has perks, too. Astronauts won’t be weighed down by their hefty spacesuits as much as they would be on Earth. Plus, bouncing on the Moon is just plain fun.

5. A Waxing Crescent … Earth?

This animated image shows a person with chin-length hair wearing a patterned dress with a white cardigan on top. The person is holding a stick with a white sphere on top. The person turns counterclockwise to show light hitting different sides of the sphere. The light is coming from the left. A small box to the left of the person shows a closeup view of the sphere. Moon phases are identified at the top of the image as they're displayed on the sphere.

This animated image features a person holding a stick with a sphere on top that represents the Moon. The person is demonstrating an activity that helps people learn about the phases of the Moon by acting them out.

NASA’s Jet Propulsion Laboratory

When Artemis astronauts look at the sky from the Moon, they’ll see their home planet shining back at them. Just like Earthlings see different phases of the Moon throughout a month, astronauts will see an ever-shifting Earth. Earth phases occur opposite to Moon phases: When Earth experiences a new Moon, a full Earth is visible from the Moon.

6. An Itty-Bitty Horizon

In the foreground, a grey surface stretches halfway up the photo. A small, blue and white sphere is peaking over the horizon of the grey surface, suspended against a black sky. The lower part of the sphere is shadowed.

A view from the Apollo 11 spacecraft in July 1969 shows Earth rising above the Moon’s horizon.

NASA

Because the Moon is smaller than Earth, its horizon will look shorter and closer. To someone standing on a level Earth surface, the horizon is 3 miles away, but to astronauts on the Moon, it’ll be only 1.5 miles away, making their surroundings seem confined.

7. Out-of-This-World Temperatures

Two circular images of the Moon’s South Pole are shown side to side over a plain black backdrop. The images are mostly orange throughout, with greens, blues, and purples representing various cooler temperatures based on a key, which sits between them. The key is in Kelvin and starts at 60, spanning to 360. Both images are covered in craters which resemble blue and purple splotches. There are numbers representing degrees along the outer rim of each circle.

This graphic shows maximum summer and winter temperatures near the lunar South Pole. Purple, blue, and green identify cold regions, while yellow to red signify warmer ones. The graphic incorporates 10 years of data from NASA’s LRO (Lunar Reconnaissance Orbiter), which has been orbiting the Moon since 2009.
NASA/LRO Diviner Seasonal Polar Data

Because sunlight at the Moon’s South Pole skims the surface horizontally, it brushes crater rims, but doesn’t always reach their floors. Some deep craters haven’t seen the light of day for billions of years, so temperatures there can dip to minus 334 F. That’s nearly three times colder than the lowest temperature recorded in Antarctica. At the other extreme, areas in direct sunlight, such as crater rims, can reach temperatures of 130 F.

8. An Inky-Black Sky

An animated view of Earth emerging below the horizon as seen from the Moon’s South Pole. This visual was created using a digital elevation map from LRO’s laser altimeter, LOLA.

NASA’s Scientific Visualization Studio

The Moon, unlike Earth, doesn’t have a thick atmosphere to scatter blue light, so the daytime sky is black. Astronauts will see a stark contrast between the dark sky and the bright ground.

9. A Rugged Terrain

An overhead view of the Moon, beginning with a natural color from a distance and changing to color-coded elevation as the camera comes closer. The visual captures the rugged terrain of the lunar South Pole area. It includes a color key and animated scale bar. This visual was created using a digital elevation map from NASA LRO’s laser altimeter, LOLA.

NASA’s Scientific Visualization Studio

Artemis moonwalkers will find a rugged landscape that takes skill to traverse. The Moon has mountains, valleys, and canyons, but its most notable feature for astronauts on the surface may be its millions of craters. Near the South Pole, gaping craters and long shadows will make it difficult for astronauts to navigate. But, with training and special gear, astronauts will be prepared to meet the challenge.

By Avery Truman

NASA’s Goddard Space Flight Center, Greenbelt, Md.