Chuck Bednar for redOrbit.com – Your Universe Online
Deposits of lunar hydrogen appear to be more abundant on crater slopes in the moon’s southern hemisphere, NASA officials revealed on Wednesday, and the discovery could potentially make it easier to harness the element and reduce the cost of space travel.
It could cost thousands of dollars to launch a single bottle of water from the Earth to the moon, the US space agency explained, but the recent discovery of hydrogen-bearing molecules (which could include actual H2O) on the moon has led some to believe that they could be mined.
Lunar water – coming to stores near you!
Assuming it is abundant enough, lunar water could be used for drinking, or its components could be used to manufacture other elements successful for a mission’s success, such as rocket fuel and breathable air. Such a possibility would make space travel more accessible.
Now, NASA has revealed that observations made by its Lunar Reconnaissance Orbiter (LRO) spacecraft indicate that these hydrogen deposits could be more abundant on pole-facing slopes than on equator-facing slopes. In fact, according to NASA’s Goddard Space Flight Center, the former contains an average of 23 parts-per-million-by-weight (ppmw) more hydrogen.
This marks the first time that a widespread geochemical difference in the hydrogen abundance of pole-facing slopes (PFS) and equator-facing slopes (EFS) has ever been detected. It is equal to a one-percent difference in the neutron signal detected by one of the LRO’s instruments, the Lunar Exploration Neutron Detector (LEND).
The hydrogen-bearing material is described as easily vaporized (volatile) and could be in the form of water molecules or hydroxyl molecules (one oxygen atom bound to one hydrogen atom), loosely bound to the lunar surface, the agency explained.
Just like earth
In research published online last October in the journal Icarus, lead author Timothy McClanahan from Goddard and his colleagues explained that the discrepancy between PFS and EFS may have been caused by a phenomenon similar to that in which the Sun mobilizes and redistributes frozen water from warmer places to colder regions on the Earth’s surface.
“Here in the northern hemisphere, if you go outside on a sunny day after a snowfall, you’ll notice that there’s more snow on north-facing slopes because they lose water at slower rates than the more sunlit south-facing slopes,” he explained. “We think a similar phenomenon is happening with the volatiles on the moon – PFS don’t get as much sunlight as EFS, so this easily vaporized material stays longer and possibly accumulates to a greater extent on PFS.”
McClanahan’s team observed the increased PFS hydrogen abundance in the topography of the moon’s southern hemisphere, starting at between 50 degrees and 60 degrees south latitude. The slopes located closer to the lunar South Pole show a larger difference in concentration, and the element was detected in higher amounts on the larger PFS, roughly 45 ppmw near the poles.
Smaller slopes provided less detectable signals than broader ones, and the result suggests that PFS have greater hydrogen concentrations than their surrounding regions, the researchers said. In addition, the LEND measurements over the larger EFS were similar to their surrounding area, which would suggest that they have hydrogen concentrations equal to their surroundings. More hydrogen may be found on PFS in northern hemisphere craters as well, the study authors said, but more data needs to be collected and analyzed before they can say for certain.
“There are different possible sources for the hydrogen on the moon,” according to NASA. Impacts from comets or asteroids may have brought the hydrogen to the lunar surface, or molecules bearing the element may have been created as the result of interaction with the solar wind.
Currently, it is unclear if there is enough hydrogen to economically mine. McClanahan said that the amounts his team is detecting “are still drier than the driest desert on Earth.” However, PFS slopes that are smaller in size may have higher concentrations of the element, and indications are that the most hydrogen will be found in the permanently shaded regions of the moon.
—–
Follow redOrbit on Twitter, Facebook, Instagram and Pinterest.
Comments