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March is Women's History Month!

Astronomy's Little Secret: The Hidden Art Of 'Moonsweeping'

A few nights ago, (Wednesday, I think, around midnight), I was by my window looking up, and there, hanging in the sky, I saw the moon. Not all of it, just what the almanac used to call "a crescent" — what my mom called a "toenail moon." The whole moon, I knew, was up there, hidden in shadow. The crescent part was facing the sun. That's the part you can see at the beginning of each month, my second grade teacher, Mrs. Elkins taught us, using a flashlight and a tennis ball to demonstrate the phases of the moon. Scotty Miller, I remember, got to hold the tennis ball. Mrs. Elkins, we believed, was infallible.

And yet, Mrs. Elkins never mentioned moon sweepers. I'm not sure why, since, as I say, she knew everything. Maybe she didn't think we were ready. Maybe they are a secret. They are a grandpa, a father and a boy. Their job, every month, is to produce the moon I saw this week in the sky. The "sunshine explanation" is, it seems, a cover story. Here, from the folks at Pixar, is the real deal.

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Robert Krulwich works on radio, podcasts, video, the blogosphere. He has been called "the most inventive network reporter in television" by TV Guide.