Time moves faster on the Moon compared to Earth – scientists share exactly how much quicker a day goes on lunar surface
TIME on the Moon is ticking away faster than on Earth, scientists have confirmed – and this has implications for future missions to space.
As the Moon has one-sixth of Earth’s gravity, this impacts the speed at which time moves.
And it seems the cosmic body is ahead of its parent planet by 57 millionths of a second, according to researchers at Nasa’s Jet Propulsion Laboratory.
To put things into perspective, it has moved just 1.1 seconds ahead of us since the last time humans were on the Moon in 1972.
“An atomic clock on the moon will tick at a different rate than a clock on Earth,” explained Kevin Coggins, Nasa‘s top communications and navigation official.
“It makes sense that when you go to another body like the Moon or Mars that each one gets its own heartbeat.”
Millionths of a second may seem insignificant, but the difference is more important than ever as Nasa gears up to resume crewed missions to the Moon.
The agency aims to send astronauts to the satellite by 2026 as part of its Artemis missions, which will examine possible sites for lunar bases.
Nasa wants to use this sustained presence on the Moon as a jumping-off point for expeditions to other destinations in our Solar System, including Mars.
Earlier this year, the Biden administration tasked Nasa and other federal agencies to devise a unified time reference system for the Moon.
However, disagreement is already brewing.
Nasa’s figure is just a step ahead of the 56.02 microseconds calculated by researchers at the US National Institute of Standards and Technology.
Neither result has been peer-reviewed, so the agencies have a ways to go.
A coalition of agencies and international bodies must sign off on the final decision.
To kickstart this process, two key players – the International Bureau of Weights and Measures and the International Astronomical Union – will meet next month.
The development occurs against the backdrop of other discoveries, including a growing body of evidence that Earth’s days are lengthening.
Scientists generally agree the number is somewhere between 1.7 and 1.8 milliseconds per century.
This is a one-minute increase every 3.3 million years – meaning it will take 200 million years before another hour is tacked on.
The length of Earth days has varied throughout history. One billion years ago, a day was only about 19 hours long.
The Moon – our closest neighbour explained
Here's what you need to know...
- The Moon is a natural satellite – a space-faring body that orbits a planet
- It’s Earth’s only natural satellite, and is the fifth biggest in the Solar System
- The Moon measures 2,158 miles across, roughly 0.27 times the diameter of Earth
- Temperatures on the Moon vary wildly. Nasa explains: “Temperatures near the Moon’s equator can spike to 250°F (121°C) in daylight, then plummet after nightfall to -208°F (-133°C). In deep craters near the Moon’s poles, permanent shadows keep the surface even colder — NASA’s Lunar Reconnaissance Orbiter has measured temperatures lower than -410°F (-246°C).”
- Experts assumed the Moon was another planet, until Nicolaus Copernicus outlined his theory about our Solar System in 1543
- It was eventually assigned to a “class” after Galileo discovered four moons orbiting Jupiter in 1610
- The Moon is believed to have formed around 4.51billion years ago
- The strength of its gravitational field is about a sixth of Earth’s gravity
- Earth and the Moon have “synchronous rotation”, which means we always see the same side of the Moon – hence the phrase “dark side of the Moon”
- The Moon’s surface is actually dark, but appears bright in the sky due to its reflective ground
- During a solar eclipse, the Moon covers the Sun almost completely. Both objects appear a similar size in the sky because the Sun is both 400 times larger and farther
- The first spacecraft to reach the Moon was in 1959, as part of the Soviet Union’s Lunar program
- The first manned orbital mission was Nasa’s Apollo 8 in 1968
- And the first manned lunar landing was in 1969, as part of the Apollo 11 mission
A study published last month in Nature found evidence that the planet’s inner core has changed direction and is rotating more slowly.
Researchers believe it has been moving slower than the Earth’s mantle and crust, rather than faster, since 2010.
And while this could affect the length of a day on Earth, it would be imperceptible in one lifetime – amounting to just thousandths of a second.