A group of researchers in China has designed the world’s first lunar timekeeping software to help synchronize our clocks with the Moon.
As the global race to build a human habitat on the Moon heats up, there are several ongoing attempts to establish a universal lunar time that future missions can rely on. China, however, claims to be the first to set its lunar clocks and has made its new tool publicly available for use.
Researchers from the Purple Mountain Observatory in China released LTE440, short for Lunar Time Ephemeris, in a recently published paper in Astronomy & Astrophysics. The software accounts for the Moon’s weaker gravity and its motion through space to synchronize lunar clocks with Earth time.
How lunar time works
Time passes differently on the Moon than it does on Earth. Einstein’s theory of general relativity revealed that the flow of time is affected by gravity and motion, and time runs slower in stronger gravitational fields.
The Moon has much weaker gravity than Earth, resulting in a slight time difference between the two bodies. A clock on the Moon gains 58 microseconds every 24 hours. It doesn’t sound like much, but that difference adds up over time, resulting in a wider gap that could affect navigation and communications on the Moon.
Currently, missions to the Moon communicate with Earth using coordinated universal time (UTC), which is tied to an ensemble of atomic clocks. Future trips to the Moon are expected to ramp up in the near future, and so a new timekeeping method is needed to ensure better accuracy.
The new software relies on precise data about the Moon’s motion to track any changes in the time difference between Earth and its natural satellite. The researchers then fed those calculations into automated software that allows users to compare the time difference between Earth and the Moon at any given moment.
LTE440 essentially automates the complex calculations behind determining time discrepancies between Earth and the Moon. The researchers behind the tool claim it remains accurate 1,000 years into the future, eliminating the need for manual calculations when preparing for a lunar mission years in advance.
Watching the clock
NASA is preparing to launch its Artemis 2 mission as early as February, with Artemis 3—featuring the first lunar landing since Apollo—scheduled for 2028. The space agency plans to establish a sustainable human presence on the lunar surface. China has similar plans, aiming to land its first crew of astronauts on the Moon by 2030.
The White House has already tasked NASA to develop a Coordinated Lunar Time by the end of this year. In 2025, Congresswoman Jennifer McClellan advanced the Celestial Time Standardization Act out of the House Science, Space and Technology Committee to establish a time standard for the Moon and other celestial bodies.
The idea is for a standard lunar time to be adopted globally, not just among international space agencies but for commercial partners as well. “I want to be sure that the United States generally, and NASA specifically, is the leader in creating that time standard,” McClellan told Gizmodo in a 2024 interview. “So this bill will help make sure that we’re taking the lead by having NASA, on behalf of the U.S., lead development of a celestial time standard.”
NASA may have missed the lead, but its efforts are still ongoing. Similarly, the European Space Agency opened applications for companies to help it develop a standardized Moon clock.
Ideally, all those different entities can develop a globally applicable lunar clock that can be used among international partners. China’s publicly available software is a good first step, but there’s still more work to be done as the new space race heats up.
English (US) ·