A new study has made it possible to produce the first detailed map of the distribution of water on the Moon.
The study has been made based on observations made by the SOFIA air observatory (for the acronym of Stratospheric Observatory For Infrared Astronomy), NASA and the DLR (German Aerospace Center). SOFIA was a heavily modified Boeing 747SP aircraft that carried a telescope with an effective diameter of 2.54 meters at altitudes up to about 14 kilometers.
The study was carried out by the team led by Bill Reach, from the NASA Ames Research Center in the United States.
The new map covers about a quarter of the Earth-facing side of the lunar surface below 60 degrees latitude and extends to the Moon’s South Pole, an important area for space exploration. Given the large region covered, the researchers could easily identify how the water relates to features on the Moon’s surface, moving away from sunlight and favoring cold areas.
At the end of 2024, NASA’s VIPER (Volatiles Investigating Polar Exploration Rover) vehicle will land in the region studied by SOFIA, at the top of Mons Mouton, to carry out the first resource mapping mission beyond Earth.
The new study on the quantity and distribution of water on a part of the lunar surface visible from Earth has been based on the tracking of a unique light signature of water. Other investigations in which large areas of the lunar surface have been observed have tracked different wavelengths of light, which do not allow distinguishing water from similar substances, such as hydroxyl. Moon water is present in the ground and could be found in the form of ice crystals, or as water molecules chemically bound to other materials.
Visualization of SOFIA data measuring a signature or “light signature” of water superimposed on a visualization of the Moon as it was at the time of the observations, in February 2022. Darker blue indicates a higher concentration of water . Near the upper left of the study region, a dark blue ridge is visible, where water is especially concentrated on the shadowed side of a steep lunar drop. In the middle of the left zone of the region is the Moretus crater. The inner wall of the upper half of the crater is clearly outlined in dark blue, indicating a greater presence of water on this shadowed surface. (Image: NASA’s Goddard Space Flight Center Scientific Visualization Studio / Ernie Wright)
Rather than determine the absolute amount of water in the region, the researchers compared data obtained around the Moon’s South Pole with a relatively dry reference region near the lunar equator to see how its abundance changes. Water was found in highest concentrations on the shaded slopes of craters and mountains. The phenomenon is well known to skiers on Earth, who know that slopes that receive less direct sun retain snow longer. The pattern observed on the Moon suggests that the Moon’s local geography plays an important role in the amount of water present.
NASA is preparing to send astronauts to the Moon under the Artemis program, and has already identified 13 candidate landing regions near the lunar South Pole. With Artemis, NASA will send the first woman and the first person of color to the Moon, and lunar water could be a critical resource for establishing a long-term human presence. (Fountain: NCYT de Amazings)