Not unless it begins a sentence. Like for example: "In the house was a dog." But not if it is in the middle of a sentence. For example: "The cat walked around in the house." If it starts a title, then yes. For example: "In silent night when rest I took" (Anne Bradstreet, Poem).
Earth, as in we live on the planet Earth, is supposed to be capitalized. Earth, as in the dirt we walk on, is not supposed to be capitalized.
Usually, yes a phase of the moon is supposed to be capitalized.
No, it shouldn't be capitalized.
No it shouldn't be capitalized.
Yes, "Hindenburg" should be capitalized as it is a proper noun referring to the German airship LZ 129 Hindenburg.
Yes, America should be capitalized.
no
No, but the names of individual languages are capitalized.
Yes, Siamese would be capitalized.
Yes.
Yes.
No.