On this day in On this day in 1573 - January 20th - German astronomer Simon Marius was born.

Marius claimed he had seen Jupiter's moons before Galileo. Galileo's documentation was more extensive and published first, so he got the credit. However, the suggestions Marius made for naming the four large moons were eventually adopted.

Mona Evans
For news, activities, pictures and more, sign up to the Astronomy Newsletter!