NASA and its international partners have big plans when it comes to the Moon—plans that will require the careful synching of Earth-based clocks with those on the Moon. The White House wants NASA to develop a solution to support the Artemis program, but to also maintain the United States’ leading position in the global space race.
The plan, first reported by Reuters, is for the U.S. space agency to develop Coordinated Lunar Time (LTC) by the end of 2026. Coordinating time systems on Earth is a relatively easy task, but due to relativity, it’s considerably more challenging once the Moon becomes involved.
Due to Einsteinian relativity, time passes differently on the Moon than it does on Earth. The same can be said for space in general. Time—or at least its perception—would slow down significantly if you were near a black hole because of the object’s intense gravitational pull. The difference between how time passes on the Moon versus the Earth is very slight, but it adds up.
The White House’s direction is not without precedent. Last year, ESA opened applications for companies to help it develop a standardized Moon clock. NASA launched its Deep Space Atomic Clock (DSAC) in 2019, to allow spacecraft to better navigate independent from communiques from Earth.

Courtney Milan writes books about carriages, corsets, and smartwatches. Her books have received starred reviews in Publishers Weekly, Library Journal, and Booklist. She is a New York Times and a USA Today Bestseller.
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Before she started writing romance, Courtney got a graduate degree in theoretical physical chemistry from UC Berkeley. After that, just to shake things up, she went to law school at the University of Michigan and graduated summa cum laude. Then she did a handful of clerkships. She was a law professor for a while. She now writes full-time.
Courtney is represented by Kristin Nelson of the Nelson Literary Agency.