The White House wants Nasa to figure out how to tell time on the moon.
A memo Tuesday’s dispatch from the head of the US Office of Science and Technology Policy (OSTP) asked the space agency to work with other US agencies and international agencies to establish a moon-centric time reference system. Nasa has until the end of 2026 to set up what is called Coordinated Lunar Time (LTC).
It is not quite a time zone like that on Earth, but a whole time reference for the moon. Because there is less gravity on the moon, time there moves a little faster – 58.7 microseconds each day – compared to Earth. Among other things, LTC will provide a timekeeping benchmark for lunar spacecraft and satellites that require extreme precision for their missions.
“An atomic clock on the moon will tick at a different rate than a clock on Earth,” said Kevin Coggins, NASA’s top communications and navigation officer. “It makes sense that when you go to another body, like the moon or Mars, each one gets its own heartbeat.”
Nasa has plans to send astronaut missions to the lunar surface starting in September 2026 through its Artemis program, which will also eventually establish a scientific lunar base that could help set the stage for future missions to Mars. Dozens of companies, spacecraft and countries are involved in the effort.
Without a unified lunar time standard, an OSTP official told Reuters, it will be challenging to ensure that data transfers between spacecraft are secure and that communications between Earth, lunar satellites, bases and astronauts are synchronized.
Discrepancies in time can also lead to errors in mapping and tracking positions on or orbiting the moon, the official said.
“Imagine if the world doesn’t synchronize their clocks to the same time, how disruptive it can be and how challenging everyday things become,” the official said.
Clocks and time zones on Earth operate on Universal Coordinated Time (UTC), which is internationally recognized. It relies on a large global network of atomic clocks placed in different locations around the world. They measure changes in the state of atoms and generate an average that ultimately constitutes a precise time.
The development of LTC may require placing atomic clocks on the moon.
Defining how to implement LTC will require international agreements, the memo said, by “existing standards bodies” and among the 36 nations that signed an agreement called the Artemis Accords that covers how countries in space and on the moon act. China and Russia, the two main US competitors in space, have not signed the Artemis agreements.
UTC may affect how LTC is implemented, the official said. The UN’s International Telecommunication Union defines UTC as an international standard.
The International Space Station, which is in low Earth orbit, will continue to use Coordinated Universal Time. But just where the new space age kicks in is something Nasa has to figure out. Even Earth’s time speeds up and slows down, requiring leap seconds.
Unlike on Earth, the moon will not have daylight savings time, Coggins said.
