Why the US wants to create moon standard time

STORY: NASA COMMS: “That’s 5:24 p.m. Central time, but obviously there’s some give and take…”

It comes as no surprise that moon time differs from Earth time.

As the U.S. aims to set international norms amid a growing lunar race, the White House has given NASA a directive: to establish a unified time standard for the moon.

NASA must work with other parts of the U.S. government to set Coordinated Lunar Time, or LTC, by the end of 2026.

That’s according to a memo seen by Reuters from the White House Office of Science and Technology Policy, or OSTP.

Here’s what’s at play.

The differing gravitational force, and potentially other factors, on the moon change how time unfolds relative to how it is perceived on Earth.

The OSTP memo says that for a person on the moon, an Earth-based clock would appear to lose about 58.7 microseconds per Earth-day.

Having a standard time would provide a time-keeping benchmark for lunar spacecraft and satellites that require extreme precision.

Under its Artemis program, NASA is planning more astronaut missions to the moon in coming years.

It aims to 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.

Other countries also have their own lunar ambitions.

China has said it aims to put its first astronauts on the moon by 2030, while India last year became the first country to land a spacecraft near the unexplored lunar south pole.

An OSTP official said that without a unified lunar time standard, it would be challenging to ensure data integrity and synchronized communications between Earth, lunar satellites, bases and astronauts.

Time discrepancies could also lead to errors in mapping and locating positions on or orbiting the moon, the official said.

On Earth, most clocks and time zones are based on Coordinated Universal Time, or UTC.

This internationally recognized standard relies on a vast global network of atomic clocks placed around the world.

They measure changes in the state of atoms and generate an average that ultimately makes up a precise time.

The deployment of atomic clocks on the lunar surface may be needed, according to the OSTP official.

The OSTP memo says that implementing LTC will require international agreements through “existing standards bodies,” and among the 36 nations that have signed a pact called the Artemis Accords, which involve how countries act in space and on the moon.

China and Russia, the two main U.S. rivals in space, have not signed the Accords.