Using Fiber-Optic Cables to Detect Moonquakes

Why It Matters

Surface‑deployed fiber optics could dramatically lower the cost and complexity of lunar seismic networks, accelerating scientific discovery and mission safety. The same technology may reduce monitoring expenses for Earth‑based environmental applications.

Key Takeaways

• Fiber-optic cables can detect lunar seismic events without burial
• Surface deployment reduces weight and installation complexity for missions
• Stiffer, thicker fibers improve signal strength on the Moon
• Data can map debris spread from landings and impacts
• Technology may lower seismic monitoring costs on Earth

Pulse Analysis

The Moon’s interior remains a mystery, despite the handful of seismometers left by the Apollo program in the 1970s. Traditional instruments are heavy, require precise placement, and need extensive support infrastructure, making them impractical for the next wave of crewed and robotic missions. Researchers at Los Alamos National Laboratory therefore turned to distributed acoustic sensing (DAS) – a technique that turns ordinary fiber‑optic cables into dense arrays of vibration sensors. If these fibers can operate on the lunar surface, they could provide continuous, kilometre‑scale seismic coverage with far less mass and cost.

Two recent studies tested the concept in a simulated regolith environment. In the first experiment, fibers were placed at various burial depths and exposed to real earthquakes; signal clarity proved virtually unchanged, indicating that the Moon’s near‑vacuum eliminates the wind‑induced noise that forces Earth‑based installations underground. The follow‑up work focused on cable geometry, finding that stiffer, thicker fibers with continuous ground contact transmit stronger strain signals, while still remaining lightweight enough for launch. These findings validate unburied DAS as a viable lunar seismic platform.

Beyond mapping moonquakes, surface‑deployed fibers could monitor ejecta clouds from lander thrusters, quantify impact‑generated debris, and even aid in locating subsurface water reservoirs. The ability to lay kilometers of cable from a rover or lander without astronaut intervention promises a dramatic reduction in mission risk and expense. On Earth, the same unburied DAS approach is already reshaping fields from groundwater monitoring to Arctic ice tracking, suggesting a cross‑planetary technology transfer that could lower monitoring costs while expanding observational reach.