Why is it in the news?

• The US White House has directed NASA to establish a time standard for the Moon, known as Coordinated Lunar Time (LTC), to coordinate activities on the lunar surface among international bodies and private companies.

More about the news

• Time on the Moon flows differently than on Earth due to Einstein’s Theory of General Relativity, with an Earth-based clock appearing to lose an average of 58.7 microseconds per Earth Day on the Moon.
• This discrepancy in time can create issues for spacecraft docking, data transfer, communication, and navigation, especially as multiple spacecraft operate simultaneously on the lunar surface.
• Currently, each lunar mission uses its own timescale linked to Coordinated Universal Time (UTC), but a unified lunar time standard is needed as more countries plan lunar missions and long-term human outposts on the Moon.
• Establishing a lunar time standard may involve deploying atomic clocks on the lunar surface to set a time standard, similar to how atomic clocks are used on Earth to track time accurately. At least three atomic clocks may be needed at different lunar locations to account for variations in the Moon’s rotation and gravity caused by mascons (mass concentrations) beneath its crust.
• The output from these clocks can be synthesized to provide the Moon with its own independent time, which can be tied back to UTC for seamless operations from Earth.