The house and senate can only pass amendments to the constitution if

The House and Senate can only pass amendments to the Constitution if "the amendment receives a two-thirds vote."

The Constitution gives that an amendment might be proposed either by the Congress with a two-thirds majority vote in both the House of Representatives and the Senate or by an established tradition called for by two-thirds of the State legislatures. None of the 27 changes to the Constitution have been proposed by sacred tradition. The Congress proposes a revision as a joint resolution.

the answer would be in this answer. someone already asked the question.  

a. the moon was locked into orbit by the earths gravity as it was passing by and capture hypothesis i think