Harnessing Lunar Shadows for Precision Navigation

Researchers from the National Institute of Standards and Technology (NIST) have unveiled a novel proposal to establish a high-precision navigation system on the Moon. By installing ultrastable lasers within the Moon's permanently shadowed craters, scientists hope to create a lunar equivalent of GPS, enabling astronauts and autonomous rovers to navigate the lunar terrain with greater autonomy.


The Advantage of Permanent Darkness

Permanently shadowed regions near the lunar south pole offer extreme conditions that are typically difficult to replicate on Earth. These areas receive no direct sunlight, resulting in temperatures lower than those found on Pluto—dipping to approximately minus 370 degrees Fahrenheit (-223 degrees Celsius).


While these regions have long been studied for their potential ice reserves, the research team suggests they are also perfect natural laboratories for advanced laser technology. The study focuses on the use of silicon optical cavities, which are devices designed to stabilize laser light frequency. Typically, these systems require sophisticated cryogenic cooling and vibration isolation to prevent thermal expansion. The Moon’s naturally cold, vacuum-sealed, and low-vibration environment provides these conditions automatically.


«As soon as I understood what the permanently shadowed regions can offer, I felt that this would be the most ideal environment for a super-stable laser,» stated Jun Ye, the lead author of the research.

Building a Lunar Positioning Network

As NASA’s Artemis program aims for long-term lunar habitation, the reliance on Earth-based tracking systems is becoming less feasible, particularly in the challenging environment of the lunar south pole. The researchers propose that these crater-based lasers could serve several vital functions:

  • Master Timing References: Acting as the foundation for future communication networks and lunar satellites.
  • Precision Navigation: Providing signals that spacecraft can use to calculate their exact positions without needing constant input from Earth.
  • Optical Atomic Clocks: Forming the core of the first optical atomic clock network on a surface other than Earth.

By locking light into a highly precise frequency, these systems could provide the necessary timing infrastructure to support complex lunar exploration. The findings, which represent a significant leap in space-based positioning technology, were recently published in the journal Proceedings of the National Academy of Sciences.