Unique Boy names

I'm 20 weeks along. We just found out we're having another boy. We were really hoping for a girl this time and had a name already picked out for her. We didn't pick any for a boy because none of them sound right to us. But as fate would have it were having a boy and a terrible time finding the perfect name. We like different unique names. We were thinking of something space/astrology related or something just unique. We're don't like plain old school names. Any ideas or thoughts? Thanks so much!