“One small step for man, one giant leap for mankind” – when A.SAmerican astronaut Neil Armstrong Become the first person to step on The surface of the moon On July 21, 1969, it was 10:56 PM in Houston, 5:56 AM in Paris, 7:56 AM in Moscow, and 1:56 PM in Tokyo. But what time is it on the moon?
More than five decades later, he showed up European Space Agency (ESA In English abbreviation) to answer this question. This week, it was announced that space organizations around the world are studying the best way to build a Common reference time for the moonAn idea was already floated in November 2022 at a meeting in the Netherlands.
“Now, a joint international effort to achieve exactly that has been launched,” said Pietro Giordano, navigation systems engineer at the European Space Agency. But the time set by clocks on Earth cannot be applied outside the planet.
Euronews interviewed Francisco Diego, an astronomer at University College London, in order to better understand how time is measured in space.
What is the equivalent of an hour on the moon?
in Landthe time is measured relative to rotation that determine what we know as day and night. A complete rotation of the Earth on its axis takes 24 hours a day, and a circle around the Sun, 365 days, determines the year.
But the lunar cycle It doesn’t work the same way.
“While the moon rotates at the same time as it describes its orbit, the lunar day lasts 29 and a half Earth days. That is why, on the moon, we observe sunrise and sunset in a period of 14 days,” explains Francisco Diego.
And this astronomer adds: “The determination of this time will also be important, and it will be carried out according to the height of the sun above the horizon.”
The question does not arise except in determining the length of the days. Watches are another challenge.
According to the European Space Agency, Clocks run faster on the moon: gain about 56 microseconds or millionths of a second per day. That’s because they work slower in stronger gravitational fields, like Earth’s.
How can time be measured on the moon?
The European Space Agency proposes an international agreement on a frame of reference “similar to the role it plays on Earth International Terrestrial Reference Frame, allowing for the consistent measurement of precise distances between points across our planet. “
Francisco Diego believed that some kind of measurement should be followed along the lines of longitude or time zones on Earth.
The astronomer explained: “It must be based on the central meridian of the moon, which I believe is a zero latitude, the latitude that corresponds to the vertical line that appears when the moon is in its waning or waxing phase.” “From there the time difference will be measured in degrees, but based on the altitude of the sun, so that people can know solar time at that moment,” he explains.
What time is it on the International Space Station?
Those who already know how they should look at the clock, calculate and organize time in space are International Space Station astronauts.
However, although they are in an orbit of 354 kilometers above the Earth’s surface, they follow a time zone of the Earth, namely Coordinated Universal Time (UTC) or Greenwich Meridian, halfway between Houston and Moscow.
This has disadvantages. “The International Space Station has 90 minutes a day,” Diego points out. They see sunrise and sunset 16 times a day for 24 hours.
But it is by far the most practical measure found for maintaining communications with Earth.
Who will decide the lunar time?
In 1884, at the insistence of the United States of America, an international conference was convened in Washington, D.C., to discuss and decide on “the meridian as the common zero of longitude and the standard for calculating time throughout the world.”
The result was GMTbroadcast at the Royal Observatory in London, UK. It has become the international standard for zero degrees of longitude.
The European Space Agency also wants an international agreement on how to measure lunar time.
“These are very dangerous missions that require a lot of help from all countries and we have to go as united humanity, exploring space with the same rules,” says Francisco Diego.
The astronomer believes that this kind of agreement should be included in The Space Treaty of 1967 Signed by the member states of the United Nations. It includes provisions on how to conduct lunar exploration.
Why is it urgent to set the time on the moon now?
The moon is once again at the center of the space exploration efforts of the European Space Agency, which is planning to do so Dozens of missions over the next decadeincluding Building rules on the moon.
There is a need to keep the extension Communication between the moon and the earth in all of these missions […] There will be a need to agree on Greenwich Mean Time, ”explains Diego.
“But on the other hand, when we already have many missions from different countries in orbit around the Moon, communication with Earth will take a back seat and become more independent. And here the lunar time will be very important.”
“Once we have established an operational time system for the Moon, we can continue to do the same for other planetary destinations,” said the European Space Agency.
Charlotte Whitmore is a contributor at Mediarunsearch.co.uk, covering a broad range of topics including news, politics, business, technology, sport, entertainment, and lifestyle. She focuses on delivering clear, balanced reporting and practical information that helps readers stay informed about current events and emerging developments. Her work highlights stories that matter to everyday audiences, with an emphasis on accuracy, relevance, and accessible journalism that keeps readers connected to the issues shaping the UK and beyond.