Simon Marius was a German astronomer. He was born in Gunzenhausen, near Nuremberg, but spent most of his life in the city of Ansbach. He is best known for being among the first observers of the four largest moons of Jupiter, and his publication of his discovery led to charges of plagiarism.

Ansbach is a city in the German state of Bavaria. It is the capital of the administrative region of Middle Franconia. Ansbach is 40 kilometers southwest of Nuremberg and 140 kilometers north of Munich, on the river Fränkische Rezat, a tributary of the river Main. In 2020, its population was 41,681.