[sgrove]

> Pluto's average surface temperature is seven degrees warmer.

What about the temperature in Pluto's shaded regions (if there are any)?

[exhilaration]

Maybe Pluto's atmosphere keeps the temperature warmer? I assume it's too far from the sun to have any unshaded versus shaded regions.

[sp332]

The average "temperature" of empty space is 3K, due to heating by background radiation. That's a big enough difference to have a warmer sun-facing side and a cold, shaded side.