Official Lunar Time Zone Coming Soon

As humanity prepares to send astronauts back to the Moon and then onto Mars; an initiative is underway to establish an official time zone for the Moon, with the aim of facilitating reference for all lunar systems, including robotic missions and human surface stays.

Leading this effort is the European Space Agency, which contends that a universal lunar reference time is crucial for accurate timekeeping.

Currently astronauts aboard the International Space Station utilize Coordinated Universal Time (UTC) or Greenwich Mean Time (GMT) as they orbit the Earth every 90 minutes, witnessing 16 sunrises and sunsets within a day while deep space missions synchronize their on-board chronometers with Earth time using antennas on Earth.

“Of course, the agreed time system will also have to be practical for astronauts" - Bernhard Hufenbach, ESA’s Directorate of Human and Robotic Exploration Moonlight Management Team

The establishment of a universally accepted "time zone" is crucial for spacefaring humans and their Earth-based counterparts, including ground support and mission control, as it would provide a common reference point for guidance and navigation during humanity's return to the lunar surface.

NASA's Gateway station, a versatile space outpost expected to orbit the Moon, is slated to house astronauts who will rely on timely communication and accurate information for their mission. This underscores the importance of implementing a reliable lunar reference time system.

Do Clock Work On The Moon?

Clocks function differently on the Moon than on Earth because of the Moon's strong gravitational field, causing them to run faster than Earth time, which is determined by the rotation of the planet on its own axis. The rate of this difference in time depends on the Moon's position and results in a gain of roughly 56 microseconds per day. Additionally, the Moon's surface progresses at a different speed than its rotation, resulting in a lunar day lasting 29.5 Earth days.

"This will be quite a challenge on a planetary surface where in the equatorial region each day is 29.5 days long, including freezing fortnight-long lunar nights, with the whole of Earth just a small blue circle in the dark sky. But having established a working time system for the moon, we can go on to do the same for other planetary destinations.” - Bernhard Hufenbach, ESA’s Directorate of Human and Robotic Exploration Moonlight Management Team

ESA has reported that an international partnership is in progress to determine which organization will be responsible for establishing and maintaining the lunar time standard.

Future Lunar Communication and Navigation Network

The European Space Agency (ESA) is currently developing a lunar communications and navigation service through its Moonlight programme. The primary purpose of this service is to enable future lunar missions to establish communication links with Earth and navigate around the moon and on its surface, allowing them to focus on their core tasks. To achieve this, a shared common timescale is essential for the successful linking of missions and facilitating position fixes.

In addition to Moonlight, NASA is sponsoring its own equivalent service called the Lunar Communications Relay and Navigation System, which will also orbit the moon. To ensure interoperability and maximum efficiency, both systems should employ the same timescale. This will enable them to work seamlessly with other crewed and uncrewed missions that they are designed to support.