Wonder, marvel, prodigy, miracle, phenomenon can all mean something that causes astonishment or admiration.
Wonder applies specifically to whatever excites surprise, astonishment, or amazement (as by its perfection, its greatness, or its inexplicableness).
Marvel applies to something that excites surprise or astonishment especially by its extraordinariness, its strangeness, or its curiousness.
Prodigy may name some extraordinary or abnormal fact or circumstance in nature seen as an omen or portent or apply to something that makes one marvel because of its oddness or unusualness especially in degree of some quality (as skill, endurance, size, or achievement).
Miracle applies to something that is accomplished or occurs which seems to those who are witnesses or have undergone the experience to exceed human powers and to require a supernatural or superhuman explanation.
In its nonreligious sense miracle retains its implication of wonder in its insistence on the fact that the person or thing so designated is beyond ordinary human comprehension or capacity to do or produce; only occasionally does it suggest a supernatural or superhuman agent or agency.
Phenomenon in its more popular sense, which is somewhat contrary in meaning to phenomenon as used by scientists and philosophers (compare phenomenal under MATERIAL ), implies something exceptional or extraordinary; it applies to a person, animal, or thing that is regarded as a prodigy or marvel or occasionally merely as an oddity.