Answer:
The similarities are that the sun and moon both gave a peice of themself, so they will not be lonely.
The difference is that a girl climbed a mountian and threatened the sun, while the moon offered his willingly.
When Harry opens his blanket, Ginny notices the holes spell something out: “Dad. Help. Godric’s Hollow. 31/10/81.” Harry then realizes that Albus has sent him a message telling where he is in time.
