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Why do we have to go to sleep at night, but the other side of the world is having morning? – Braelyn, 12, Ohio

Dear Braelyn,

If I drew a straight line through the Earth to the opposite side of the planet from me, I’d hit a place called Port-aux-Français. That’s an island near Antarctica. Mostly scientists live there.

Right now, it’s 12 PM, or noon, on Friday for me. But those scientists are probably snoozing in their beds. For them, it’s after 12 AM, or midnight, on Saturday. They’re already living in my tomorrow. Weird!

I talked about why that is with my friend David Luftig. He’s a science librarian at Washington State University. Science librarians are experts in two things: science and helping people find information for research and learning.

He told me it’s all because of Earth’s rotation. As the Earth rotates, or spins, the sun shines on one part of the Earth at a time.

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Hello Dr. Universe: I was wondering, how does an eclipse happen? - Susan, 13, San Francisco, CA

Dear Susan,

It just so happens the Great American Eclipse is coming up on Aug. 21, 2017. This solar eclipse will be the only one visible from across the lower 48 states in nearly a hundred years. When it happens, parts of the country will experience darkness for a couple minutes during the day.

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