Pluto Is Sublime. It's Also the Pits.

Astronomers are still getting data back from the New Horizons space probe from July's Pluto flyby, and some new ones are a bit ... odd. I mean, they're all odd -- Pluto is a really strange place -- but this one has a new feature. The shot above shows hundreds of pits in Sputnik Planum, the "atrium and ventricle" of the famous heart-shaped region. This huge area is probably a depression on the surface filled with frozen nitrogen, which may have flowed into the lowlands like a glacier, smoothing...