Simon Marius (Latinized form of Simon Mayr; 10 January 1573 – 5 January 1625) 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...
Marius is a male name, a Roman family name, and a modern given name. The name Marius was used by members of the Roman gens Maria. It is thought to be derived from either the Roman war god Mars or from the Latin root mas or maris meaning "male".
There are 115 known moons of the planet Jupiter as of 9 April 2026. This number does not include a number of meter-sized moonlets thought to be shed from the inner moons, nor hundreds of possible kilometer-sized outer irregular moons that were only...
The Galilean moons (), or Galilean satellites, are the four largest moons of Jupiter. They are, in descending-size order, Ganymede, Callisto, Io, and Europa. They are the most readily visible Solar System objects after Saturn, the dimmest of the...
Ganymede is a natural satellite of Jupiter and is the largest and most massive moon in the Solar System. Like Saturn's largest moon, Titan, it is larger than the planet Mercury, but has somewhat less surface gravity than Mercury, Io, or Earth's Moon...
Io () is the innermost and second smallest of the four Galilean moons of Jupiter. Slightly larger than Earth's Moon, Io is the fourth-largest natural satellite in the Solar System, has the highest density and strongest surface gravity of any natural...
In Greek mythology, Io (; Ancient Greek: Ἰώ [iːɔ̌ː]) was one of the mortal lovers of Zeus. An Argive princess, her descendants included Perseus, Cadmus, Heracles, Minos, Lynceus, Cepheus, Dionysus, and Danaus. The astronomer Simon Marius named a...
Galileo di Vincenzo Bonaiuti de' Galilei (15 February 1564 – 8 January 1642), commonly referred to as Galileo Galilei or mononymously as Galileo, was an Italian astronomer, physicist, engineer and polymath. He was born in Pisa, then part of the...
Europa ( ) or Jupiter II is the smallest and least massive of Jupiter's four Galilean moons. It is observable from Earth with common binoculars and is a planetary-mass moon, slightly smaller and less massive than Earth's Moon. Europa is an icy moon,...
Jupiter is the fifth planet from the Sun, and the largest in the Solar System. It is a gas giant with a mass nearly 2.5 times that of all the other planets in the Solar System combined and slightly less than one-thousandth the mass of the Sun. The...
