STEVE INSKEEP, HOST:
NPR West, where you are, is in a different time zone than Studio 31 here in Washington, where I am now with our crew. But what time is it on the moon? I'd never really wondered that question before, but scientists like Brice Dellandrea are trying to figure this out.
BRICE DELLANDREA: Counting time is not straightforward. We are used to count time like 24 hours a day, 60 minutes per hour, 60 seconds per minute. But it's not absolute. It's what we are used to experience on Earth, but it's not happening like that out of Earth
INSKEEP: At this time, Dellandrea is with the European Space Agency, where they're thinking about giving the moon its own time zone.
A MARTÍNEZ, HOST:
Yeah, that might be easier said than done. For one thing, a day on the moon is equal to 28 days on Earth, and clocks run slightly faster on the moon because gravity is different there.
INSKEEP: Which matters to space crews coordinating complex missions with scientists on Earth. The tiniest discrepancy can throw off calculations of space and distance and could mean life or death for astronauts on the moon.
DELLANDREA: The oxygen and the gas is what you have. I mean, you cannot wait for someone to come and get you. You have to go back to your base. So if you make a mistake on the positioning and you miss your spot, it can become very dangerous.
MARTÍNEZ: Space historian and author Andrew Chaikin says it's not a new problem.
ANDREW CHAIKIN: The astronauts who went to the moon on the Apollo missions - they set their watches to Houston time because that's where Mission Control was. But really, what they referred to was something called Mission Elapsed Time, which was the time that had elapsed from the moment that their rocket lifted off the Earth. And that was the common language.
INSKEEP: International missions today often use Coordinated Universal Time, the time, the standard that most countries use to set their clocks. But as space exploration missions grow more sophisticated, the clock will need to be even more precise.
MARTÍNEZ: Brice Dellandrea estimates about a hundred scientists are working on a lunar time zone, so it could take a lot of time - years, in fact, actually - to figure all that out.
(SOUNDBITE OF PINK FLOYD SONG, "TIME") Transcript provided by NPR, Copyright NPR.