NASA has been tasked with determining a standard time zone for the moon, but it’s more complicated than you might think.
The United States government has tasked its space agency, NASA, with establishing a standard time zone for the moon, which will be known as Coordinated Lunar Time (CLT).
In a memo issued on April 2, the US Office of Science and Technology Policy (OSTP) stated: “Federal agencies will develop celestial time standardisation with an initial focus on the lunar surface and missions operating in Cislunar space [the area within the moon’s orbit], with sufficient traceability to support missions to other celestial bodies.” “Traceability” means that CLT can be kept in sync with time zones on Earth.
Why does the moon need its own time zone?
In layman’s terms, we need a reliable “lunar time” earth-syncing system because lower gravity on the moon causes time to move slightly faster there than on Earth – by just 58.7 microseconds (there are 1 million microseconds in a single second) faster within every 24 Earth hours.
This is not science fiction, even though it is a main feature of Hollywood blockbusters such as Interstellar. Known as “gravitational time dilation”, the passage of time is impacted by gravity.
Although small, these time discrepancies can cause issues with syncing satellites and space stations in lunar orbit.
An unnamed OSTP official told Reuters: “Imagine if the world wasn’t syncing their clocks to the same time – how disruptive that might be and how challenging everyday things become.”
How would we tell time on the moon?
Earth uses UTC or Coordinated Universal Time to sync time zones around the world. UTC is determined by more than 400 atomic clocks that are maintained in national “time laboratories” in about 30 countries around the world. An atomic clock uses the vibrations of atoms to achieve extreme precision in keeping track of time.
Similar atomic clocks would be placed on the moon to get an accurate time reading.
Known as Positioning, Navigation and Timing (PNT), this precision-timing system allows communications systems to measure and keep accurate timing. The Ordnance Survey, the British organisation that has been producing maps since 1791, explains that PNT has three core elements:
