A: It's about as bright as dusk or dawn before the sun rises
B: pluto is so far away the molecules have just frozen
C: Plutos atmosphere is 100,000x thinner than earths, so basically a vaccumn
From a standpoint of realism, Arnold taking off his helmet in outer space should have resulted in his death and Miss Frizzle's arrest (or death, if one or more angry parents decided to take things into their own hands).
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