What Time Is It On The Moon?
By John Oncea, Editor
In this new era of space exploration seamless communication is becoming increasingly important. This will require the creation of a lunar time zone.
It’s 11:37 a.m. on Wednesday, April 10 as I write this from my office in Erie, PA. In Antarctica, it’s Wednesday, April 10, 12:37 p.m. at Carlini Base.
It’s also Thursday, April 11, 1:37 a.m. at Dumont d'Urville Station; Wednesday, April 10, 12:37 p.m. at Palmer Station; and Wednesday, April 10, 9:37 p.m. at Vostok Station.
It’s 3:37 a.m. in both Neumayer-Station III and Mario Zucchelli Station, but it’s Wednesday in the former and Thursday in the latter.
Confused? Well, because the South Pole is located in Antarctica, the continent sits on every line of longitude and is theoretically located in every time zone. However, choosing an appropriate time zone is difficult because areas south of the Antarctic Circle experience extreme day-night cycles near the times of the June and December solstices.
So, for practical purposes time zones are usually based on territorial claims; however, many stations use the time of the country that owns them or the time zone of their supply. For example, South Pole, McMurdo, and Scott Base run on New Zealand time zone because of the U.S. base in Christchurch while Palmer runs on the Brazilian Time Zone because of the port that supplies it. In most areas south of 80 degrees latitude, Coordinated Universal Time (UTC) is assumed despite the limited presence of clocks.
While the telling of time in Antarctica can be a bit convoluted, at least there is time. On the Moon, there is no time. That’s something the Biden administration is calling on NASA to fix, calling for the creation of a lunar standard time.
Where Things Currently Stand
As things stand now there is no universal timekeeping system on the Moon. Each lunar mission uses UTC, — the standard against which the Earth’s clocks are set. However, defining lunar time is not straightforward because while the concept of a “second” remains the same everywhere, the general theory of relativity dictates that clocks tick slower in stronger gravitational fields.
The Earth’s gravitation pull is stronger than the Moon’s so time on the Moon moves 58.7 microseconds (millionths of a second) faster each day than on Earth, according to Phys.org. As we prepare for future lunar missions there’s a push to establish a Coordinated Lunar Time (LTC) — a standard time reference for lunar spacecraft and satellites that require precise timing for their missions. This effort will benefit all spacefaring nations by ensuring safety, accuracy, and interoperability across international partners as we explore the cosmos.
Take the upcoming Artemis program and its mission to land the first woman and person of color on the Moon, explore the lunar surface, and lay the groundwork for sending astronauts to Mars. As of right now, 36 nations across the globe are taking part making it of the utmost importance to produce a way for all participants to communicate in the same time.
It’s easy to imagine a future in which timekeeping gets messier and messier as we explore more of the solar system, deploy space stations, and increase the number of spacecraft orbiting Earth. And while you’re imagining that future, think about the political struggles that most certainly will occur when trying to establish a UTC. We can’t agree on the future of daylight saving time, consider the arguments that will come with trying to coordinate time when multiple celestial bodies have their time standards.
”I hope that this is the beginning of a collaboration, Michelle Hanlon, executive director of the Center for Air and Space Law at the University of Mississippi told NPR. “When we think about the geopolitical circumstances down here on Earth, it doesn't look particularly hopeful.
“It’s been very hard for us to find agreements here on Earth and even agreements about things in space. We all agree that space should be exclusively for peaceful purposes. We all agree that we have free access and freedom of exploration and use. But as we get to the moon, we realized, wait a minute, we might be on top of each other.”
Hanlon adds all spacefaring nations are looking at exploring the Moon’s south which will lead to conflict because we all want to get to the same resources. Agreeing on LTC “could be the first stage of agreement and collaboration,” said Hanlon. “Let’s all agree on how we're going to tell time on the moon and how it’s going to be keyed off.”
NASA’s Task
As noted earlier, NASA has been tasked to create a lunar time zone by the end of 2026 as “part of a broader effort to ‘establish time standards at and around celestial bodies other than Earth,’” writes Space.com, referencing an April 2 memo by the White House Office of Science and Technology Policy (OSTP). It was not immediately clear whether the moon would have multiple time zones, as Earth does.
Earth time is measured by atomic clocks staggered around the globe and the same approach may be used on the Moon. “An atomic clock on the moon will tick at a different rate than a clock on Earth,” Kevin Coggins, manager of NASA’s Space Communications and Navigation Program said. “It makes sense that when you go to another body, like the moon or Mars, that each one gets its own heartbeat.”
NASA is consulting with subject matter experts throughout the international community to determine an approach to provide recommendations to the International Astronomical Union for lunar reference frame and time systems. According to NPR, “The LTC would not be like a regular time zone on Earth. On Earth, those zones are set using UTC, which reflects a weighted average measurement of hundreds of extremely precise atomic clocks placed around the globe.” Because of the 56-microsecond difference between the Earth and the Moon, atomic clocks would run at a different rate.
“Similar to how UTC is determined, the memo suggests ‘an ensemble of clocks’ deployed to the moon might be used to set the new time standard, NPR writes. “The memo also notes the creation of the LTC would require international agreements.”