SAN FRANCISCO — NASA is once again preparing new missions to the moon in 2024, and Einstein’s theory of relativity is influencing the plans.
“We are closer than ever to returning humans to the moon,” said Catherine Koener, Associate Administrator for Exploration Systems at NASA. “The Artemis II crew will be the first humans to see the far side of the moon in more than half a century.”
However, precision is a crucial part of space exploration. Time is an important part of this. But time works differently on the moon.
“Clocks don’t run at the same speed on the moon as they do on Earth,” says Gerald McKeegan, an astronomer at the Chabot Space & Science Center. “General relativity says that if you are in an area or on a planet or a moon where gravity is weaker, your clock runs faster.”
It doesn’t run much faster, but the small difference makes an impact.
“If you’re on the moon, your clock runs about 56 microseconds per day faster than on Earth. That’s not much, it amounts to 2/100ths of a second over the course of a year,” McKeegan said. . “It doesn’t sound like much, but when you’re talking about things like navigation signals that require very precise timing, you have to take that into account.”
With that understanding, the White House has directed NASA to work in coordination with the Departments of Commerce, Defense, State and Transportation on a strategy to establish and implement a lunar time standard by December 31, 2026.
“NASA has the Artemis mission, which is a mission to go back to the moon. They plan to first do an orbital mission to go around the moon and then eventually land at the south pole of the moon,” McKeegan said . “The reason they set that goal is because Artemis is expected to land on the moon in 2026.”
Over the next decade, the US won’t be the only entity with missions to the moon. Establishing a uniform time standard will be fundamental as this chapter of space exploration unfolds, the White House memo said.
“Under an international agreement, no country can own the moon. The moon is available to all countries and missions to the moon are theoretically done for the benefit of all humanity,” McKeegan said.
The last manned mission to the moon was Apollo 17 in 1972. Earlier in 2024, a major milestone occurred when Odysseus landed on the moon’s surface. It was the first time in more than fifty years that a US-built spacecraft landed on the moon. However, one of the spacecraft’s legs became stuck in a depression and the lander tipped over.
It collected data until the power went out. Scientists still considered the mission a major success.
