She flips to a fresh page of her sketchbook, and begins to draw the dipper from memory; she's got the proportions down easily. "The big dipper is a constellation that's visible in the sky all year round, at least in the right parts of the world. If you follow these two stars forward, there's another star, Polaris, that can help you if you get lost, because it's always in the north. But these aren't the ones that are the favorite."

She circles the second star from the end on the handle. "If the night is very, very dark and quiet, you can see that there's not just one star here, but two. One's a lot fainter than the other, and it's hard to see sometimes, to where they used to use it as a vision test. Mizar and Alcor. Out in space, they're a binary star system, they revolve around one another, like they're holding hands and spinning in a circle together up in the sky."