Scientists may have found a way to “listen” to the moon on future Artemis missions using invisible laser fiber optic cables

Moonquake sensing may enter a new stage as fiber optic technology is adapted to the lunar surface. The Moon is generally considered stationary and unchanging, but it continues to experience internal vibrations caused by tidal interactions with the Earth, meteorite impacts, and extreme temperatures. Instruments have detected thousands of seismic events since the Apollo missions, but their limited placement has left gaps in understanding how these motions behave throughout the moon’s interior. Recent related work Los Alamos National Laboratory Explore whether fiber optic cables could provide a broader, more continuous way to detect these vibrations. Combined with ongoing NASA-led lunar exploration efforts, this approach could contribute to safer and more informed mission planning.

Apollo missions and first direct recording Lunar seismicity

Seismic experiments conducted by the Apollo missions directly measured moonquakes for the first time. Equipment was set up at different landing sites and experiments were conducted between 1969 and 1977, which revealed that the moon, despite having no plates, had several different vibrations.Different types of seismic activity on the moon are caused by many different factors, including the Earth’s gravity, the moon’s expansion and contraction due to temperature changes, and the impact of space debris. Although the information gathered during this period was valuable, the limited number of devices meant that a complete picture of global seismic activity was not obtained.

What is fiber optic sensing using distributed acoustic sensing

Fiber optic sensing relies on a method called distributed acoustic sensing, in which laser pulses travel through a cable and are reflected in response to small disturbances. Each vibration along the cable slightly changes the returned signal, allowing movement along the entire length rather than a single point to be detected.This turns a single cable into a long string of virtual sensors. Instead of deploying multiple separate instruments on the lunar surface, a single extension cable can capture seismic activity over long distances. This concept reduces system complexity while increasing the scope of data collected from a given area.

Fiber optic cables in lunar conditions

Fiber optic cables offer a different approach to solving this problem. On Earth, fiber optic cables are often buried underground to prevent interference from outside sources. On the Moon, however, there is no atmosphere and therefore no weather-related interference to place these cables on the lunar surface. Fiber optic cables placed on a simulated lunar surface, such as crushed basalt, were tested to evaluate their performance in detecting vibrations. Fiber optic cables could be used to detect seismic activity on the lunar surface, according to research published in scientific journals such as Icarus and Earth and Space Sciences.

Technical considerations and limitations

The process of designing such systems is a balance of sensitivity and quality. While thicker cables made from fiber optics can provide a clearer, more powerful signal, they also make the system heavier. In space exploration missions, the cost of launch systems is a major issue and is tightly controlled.