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What Time Is It in Space?

Scientists plan to figure out what time it is on the Moon!

Earth and the Moon are in space and a talk bubble shows the Moon asking Earth for the time.

NASA/JPL-Caltech/ESA; Photo illustration Encyclopædia Britannica, Inc.

What time is it on the Moon? Scientists say there is no set time on the Moon, and that could make things confusing when astronauts spend more time there.

On Earth, people have agreed on the time. For example, we all know when it’s 10 in the morning. Earth also has time zones for different parts of the planet. When it’s 10 a.m. in New York, it’s 9 a.m. in Texas. And it’s 4 p.m. in France. 

So, how do people work out the time in space? When astronauts go to space, they decide what time it is based on the time on Earth. For example, if they launched into space from Texas and it’s 9 a.m. in Texas, then it’s 9 a.m. in space, too!

But that won’t always work. Many trips to the Moon have been planned by people from different parts of the world. If people from different countries work together on the Moon, they will need to agree on what time it is. Why? Think about how hard it would be to get through a day if everyone at home or at school thought it was a different time! 

It won’t be easy to set a Moon time. First, nations will need to agree to one. Second, time doesn’t work the same way on the Moon that it does on Earth. If you put a clock on the Moon, it would go a tiny bit faster than it would on Earth. This has to do with the Moon’s distance from Earth’s gravity. But scientists will work on these problems together.

If it sounds tough to come up with a Moon time, here’s another question to think about. What time is it on Mars?

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Fun Fact

NASA, © dikobrazik/; Photo illustration Encyclopædia Britannica, Inc.

On Earth, one day lasts for 24 hours, from one sunrise to the next. 

On the Moon, one day lasts for almost 30 Earth days!

Why We Have Time Zones

In the United States, there are many time zones. When it’s 7 p.m. in New York, it’s 4 p.m. in California and 3 p.m. in most of Alaska. Everyone agrees about what time it is. But it wasn’t always like that!

For most of history, people used the Sun’s place in the sky to figure out what time it was. It was an easy way to get an idea of the time. But it wasn’t easy to get an exact time. A person in one town might say it was 3 p.m. while someone in the next town might say it was 3:20 p.m. This was okay if people stayed close to home. 

But it became a problem as people started traveling more. It was especially hard for railroad companies to do business. A company might say a train was leaving at 2 p.m., but what did that mean? So, in the 1880s, railroad companies created four time zones across the United States. 

It took a while, but in 1918, the U.S. government passed the Standard Time Act. This law created the time zones the U.S. has today. And it let everyone know what time it was.

The map below shows how time zones work. Click on Houston, Texas, the home of NASA. Then click on any black dot to see the time in any other part of the world when it’s Friday at 10:30 a.m. in Houston.

© Encyclopædia Britannica, Inc.

Hello, Moon!

NASA Scientific Visualization Studio

The video shows the Moon and how it moves during a whole year. The Moon is orbiting Earth. That means it’s moving on a path around Earth. What is it like on the Moon? Could we ever live there?

Learn more at Britannica School!

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Part of speech:



: of or relating to the Moon

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