Astronomer maia mitchell discovered a comet in 1847 and went on to become the first professional female astronomer in the united states. identify the essential appositive. astronomer professional female comet maria mitchell

D). Maria Mitchell.

Explanation:

An appositive is illustrated as the noun words or phrase that defines another noun it follows. It functions to rename or explain the noun or pronoun by proposing additional information about it.  

In the given statement, the essential appositive would be 'Maria Mitchell' as it renames the noun 'astronomer' right beside it by adding further information about the astronomer. Thus, option D is the correct answer as the other options do not define or elaborate a noun.