White House directs NASA to create time standard for the moon

The White House on Tuesday mandated NASA to establish a unified standard of time for the moon and other celestial bodies, as the U.S. seek to set international norms in space amid a growing lunar race among nations and private companies.

The head of the White House Office of Science and Technology Policy (OSTP), according to a memo seen by Reuters, instructed the space agency to work with other parts of the U.S. government to devise a plan by the end of 2026 for setting what it called a Coordinated Lunar Time (LTC).

The differing gravitational force, and potentially other factors, on the moon and on other celestial bodies change how time unfolds relative to how it is perceived on Earth. Among other things, the LTC would provide a time-keeping benchmark for lunar spacecraft and satellites that require extreme precision for their missions.

"The same clock that we have on Earth would move at a different rate on the moon," Kevin Coggins, NASA's space communications and navigation chief, said in an interview.

OSTP chief Arati Prabhakar's memo said that for a person on the moon, an Earth-based clock would appear to lose on average 58.7 microseconds per Earth-day and come with other periodic variations that would further drift moon time from Earth time.

Under its Artemis program, NASA is aiming to send astronaut missions to the moon in the coming years and 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.

An OSTP official said that without a unified lunar time standard it would 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 also could lead to errors in mapping and locating positions on or orbiting the moon, the official said.

"Imagine if the world wasn't syncing their clocks to the same time – how disruptive that might be and how challenging everyday things become," the official said, adding that deployment of atomic clocks on the lunar surface may be needed.

The official also said that as commercial activities expand to the moon, a unified time standard would be essential for coordinating operations, ensuring the reliability of transactions and managing the logistics of lunar commerce.