Simon Marius

Who was Simon Marius?

Simon

Marius (in Latin; German Simon Mayr) (January 10, 1573 – December 26,

1624) was a German astronomer. He was born in Gunzenhausen, but most of

his lifetime he spent in the city of Ansbach. In 1614 Marius published

his work Mundus Iovialis describing the planet Jupiter and its moons.

Here he claimed to have discovered the planet's four major moons some

days before Galileo. This led to a dispute with Galileo, who showed

that Marius provided only one observation as early as Galileo's, and it

matched Galileo's diagram for the same date, as published in 1610. It

is considered possible that Marius discovered the moons independently,

but at least some days later than Galileo; if so, he is the only person

known to have observed the moons in the period before Galileo published

his observations. Regardless of priority, the mythological names by

which these satellites are known today (Io, Europa, Ganymede and

Callisto) are those given them by Marius. Simon Marius also claimed to

be the...