On the Moon, certain regions have never experienced sunlight. There are parts of some craters on the Moon that have never seen the light of day and will never do so, primarily in the polar regions. These areas feature deposits of water ice, according to spacecraft observations. And at that location space agencies intend to send humans, landers, and rovers in the near future.
But why is it that those places never receive sunlight? Everything depends on how the Moon is tilted. Think of the Earth. With a tilt of 23.5 degrees with regard to the orbital plane, there are periods when the Northern Hemisphere is oriented toward the Sun (as it is now during the Boreal Summer), away from the Sun (during the Austral Summer), or receives equal amounts of light from both the Sun and the Earth (during the fall and spring). For the Moon, however, this is not the case.
It tilts 1.5 degrees with respect to the Earth’s orbit around the Sun. The Moon appears to be pointing straight up. This indicates that the Sun’s rays always strike the Moon almost perpendicularly, regardless of the Moon’s velocity around the Earth. As a result, there is plenty of light in the equatorial regions, yet it is relatively simple to generate deep shadows at the poles. In the lunar polar regions, it is always late afternoon during the dead of winter.
There wouldn’t be a mountain there to make the night last forever. The shadow would spin together with the Moon. But things would be different if there was a crater with a rim. Never getting sunlight would be the bottom and a portion of the wall. Always, the Sun would be hidden by the rim.
There is water in those craters
Cold traps are the names given to areas that experience constant darkness. It will soon be clear why it’s happening. These shaded locations are always below -160 °C (-260 °F) in temperature. Ice that formed there is permanent. Ice behaves like a rock at those temperatures, even in an environment without an atmosphere. For a billion years, it will remain in place.
These cold traps exist at both poles, however 60% of the South Pole’s are located south of 80 degrees latitude. This explains why space agencies have shown such a keen interest in the area. In a few days, Russia’s Luna 25 hopes to arrive there. Then, a few days later, India’s Chandrayaan-3.
With the Chang’e-7 lander and rover set to arrive in 2026 and a personal mission from Jeff Bezos’ Blue Origin, automatic missions will also originate from China. There is also Artemis 3. At this time, a mission to return humans to the Moon is planned for December 2025.
Artemis 3 might end up being a new mission with no landing there because SpaceX’s Starship blew up in the air, damaged the launch pad, and caused significant delays.
Where does the water on the Moon come from?
On the Moon, there are several sources of water; it’s not just ice in the frigid traps. Some are found in hydrated minerals and even in glass beads that were created as a result of the Moon colliding with other, smaller bodies in the Solar System.
On the surface of the Moon, water can be found everywhere if we are only thinking about the individual water molecules and not as a potential source of building materials for a future settlement. Although the dark craters have plenty of ice, the sunny areas also have water molecules in the dust particles.
The source cannot be identified with certainty until more investigation is done. Volcanic activity from long ago has contributed to it. The interaction between the lunar soil and the plasma in the solar wind may lead to the formation of water, however comets and frozen micrometeorites are also thought to be important participants.