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Hi, I'm Bianca with another NASA fact.

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How do you tell time and space?

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With a watch?

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You could, but space travel will require more accurate clocks,

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which can test Einstein's theories about space and time.

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So how can we make better clocks?

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Anything that repeats itself regularly can be used to tell time.

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Cesium atoms emit light waves that repeat their cycle about 9 billion times every second.

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Every 9 billionths of a second is one tick on an atomic clock.

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Wow!

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Scientists have built laser-cooled atomic clocks that are much more precise because of the lower temperatures.

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If cold is better, then cold and slower moving is even better than that.

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NASA plans to install a laser-cooled atomic clock on the International Space Station.

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This will lead to even better navigation in space.

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To learn more about atomic clocks, visit our website.

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Until next time, I'm Bianca with another cool NASA fact.