The International Date Line is an imaginary line on Earth's surface that runs roughly along the 180th meridian in the Pacific Ocean, where the calendar date changes by one day. When you cross it traveling west, you move to the next day, and when traveling east, you move back one day.

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Antarctica is the largest desert on Earth, covering about 5.5 million square miles. It is classified as a desert because it receives very little precipitation, mostly in the form of snow.

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Vatican City is the smallest country in the world, covering only about 0.17 square miles (0.44 square kilometers). It is an independent city-state located entirely within Rome, Italy.

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The Nile River in Africa is the longest river in the world, stretching approximately 4,130 miles (6,650 kilometers) from its source to the Mediterranean Sea.

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We have time zones because the Earth rotates, causing the sun to be at different positions in the sky at the same moment in different locations. Time zones divide the world into regions so each area can set its clocks based on the sun's position in that location.

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