WEBVTT

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(MUSIC)

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Joan Cartan-Hansen, Host: We
measure a day by how long it

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takes for the Earth to turn
once on its axis, and a year

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by how long it takes the Earth
to revolve around the Sun.

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A day on Earth is about 24
hours and a year is about 365

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days.

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But how long is a day or a
year on the other planets in

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our solar system?

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A day on Mercury lasts 1,407
Earth hours but a year is only

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88 Earth days.

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That's because Mercury rotates
slowly on its axis but

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revolves quickly around the
Sun because it is so close to

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the Sun.

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A day on Mars is only 37
minutes longer than a day on

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Earth.

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But a year on Mars is much
longer at 687 Earth days.

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A day on Jupiter is the
shortest in the solar system

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at only 10 hours.

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And a year on Neptune is the
longest at 60,190 earth days.

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So, the length of a day
depends upon where you are in

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the solar system.

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For more information about the
planets, check out the Science

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Trek website.

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You'll find it at Science Trek
dot org.