China unveils world’s first timekeeping software for moon

  Chinese researchers have released the world’s first software for lunar timekeeping, a tool designed to support precise navigation and landings as a new global race to the moon gathers pace. 

Clocks tick faster on the moon than on Earth due to weaker gravity – by about 56 millionths of a second per day. The effect is tiny but accumulates over time, making Earth time increasingly unreliable for lunar operations. 

To address this, a team from the Purple Mountain Observatory in Nanjing built a model that accounts for both the moon’s weaker gravity and its motion through space, allowing events on the moon to be accurately synchronised with clocks used on Earth. 

The researchers reported that their method remained accurate to within a few tens of nanoseconds even over 1,000 years. 

They also packaged the model into ready-to-use software, enabling users to compare lunar and Earth time in a single step instead of relying on complex calculations. The team said the goal was to make lunar timekeeping practical as missions to the moon become more frequent. 

The team named the software LTE440, short for Lunar Time Ephemeris. They noted that it was an early step and would need to be extended to support real-time navigation and future lunar clock networks. 

In the past, the fact that clocks tick differently on the moon and on Earth mattered little because lunar missions were rare. Engineers simply used Earth time and applied corrections for each mission when needed. 

WAM