QUESTION:
Pluto is now the eighth planet from the sun.  Is it any warmer now that 
it's closer to the sun?

ANSWER from Marc Buie on May 26, 1996:
Pluto may be slightly warmer now that it's closer to the Sun.  More
importantly, its atmosphere is thicker now that it's closer to the Sun.
As Pluto moves away from the Sun over the next 120 years, the atmosphere
will get thinner and thinner.  If it collapses completely, the surface 
will get much colder.