Misc: what has only one surface?

Questions

A heavenly body moving under the attraction of the Sun and consisting of a nucleus and a tail is a(n) _______.?

Does Uranus have an aurora?

From 1979 until 2000 the most distant planet from the earth was ________.?

If you're in the northern hemisphere, Polaris, the North Star, can be found by looking which direction?

Name the largest planet in the solar system.?