Here's Why Space Agencies Want To Standardize Moon's Set Time

Topline

It’s about time the Moon got its own time zone, the European Space Agency said on Monday, part of an international push to standardize lunar operations and overcome a fundamental challenge of space exploration, as more nations and private companies race to plot missions and even draw up plans for permanent lunar colonies.

Organizations are working to coordinate a way of telling time on the Moon.

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Key Facts

With dozens of Moon missions planned over the coming decade, Europe’s space agency said there needs to be a synchronized time zone to ease collaboration and ensure precise communication and navigation.

The Moon does not have its own independent time zone and each lunar mission carries Earth’s coordinated universal time, or UTC, with it and remains synchronized with the Earth-based team.

The method—which means different spacecraft are out of sync with one another—works when there are only a few active missions but is “not sustainable” given the expected surge in lunar activity, the ESA said.

Precise timekeeping is vital for navigation and communication and is key for craft to carry out operations efficiently, the agency said.

ESA navigation system engineer Pietro Giordano said there is an “importance and urgency” to figure out a common lunar time that all lunar systems and Moon missions could refer to.

A “joint international effort” has been launched to achieve this aim, Giordano added.

What We Don’t Know

It’s not clear what form a standardized lunar time zone might take and the ESA said many questions must be answered before a system is set up. This includes whether a single organization should be responsible for keeping lunar time, or whether lunar time should be set independently on the Moon or kept in sync with Earth. In the future, it’s possible more granular time zones on the Moon might be desirable, linking time to the Sun’s position as on Earth.

Surprising Fact

Clocks on the Moon, and time itself, run faster than their counterparts on Earth. However, the definition of a second is the same everywhere. The seemingly counterintuitive phenomenon is actually a well-established prediction of Einstein’s general theory of relativity, which outlines gravity’s ability to warp time. As Earth is more massive than the Moon, it has a stronger gravitational field and time there will move more slowly. The ESA estimates clocks on the Moon gain around 56 microseconds, or millionths of a second, per 24 hour period. This rate will also vary based on the clock’s location on the Moon, with those in lunar orbit ticking slower than those on the surface, for example. The time differences add additional layers of complexity to lunar missions. While the disparity may seem small, precision is key for ensuring safe and effective work and the differences will grow over time.

News Peg

There is an active effort among space agencies to settle the issue of lunar time. It has become a pressing problem, particularly given the uptick in space exploration and lunar missions as nations and private companies both vie to establish themselves on or around Earth’s natural satellite. Several crewed missions are even in the works. The ESA said it gathered experts to discuss the issue in November, part of a broader initiative to set common ground covering communication and navigation systems on the Moon. The ESA’s Javier Ventura-Traveset said the scheme is similar to the coordinated time system underpinning the U.S.’s GPS and Europe’s Galileo, adding that there’s a unique opportunity now to agree on a set of standards “before the systems are actually implemented.” Similar discussions are also underway at NASA, which has established the LunaNet initiative to develop standards for lunar communications and navigations as part of the Artemis program to build Moon bases and travel to Mars.

Crucial Quote

It’s important agencies settle the issue of lunar time soon, Patrizia Tavella, head of time at the International Bureau of Weights and Measures in France told Nature. If an official time is not established, Tavella warned different agencies and private companies will develop their own standards, possibly creating a patchwork of different standards in use simultaneously. “This is why we want to raise an alert now, saying let’s work together to take a common decision.”

Here’s Why Space Agencies Want To Standardize Moon’s Set Time