Reference Io is Jupiter's fifth moon and its third-largest. It is the most volcanically active body in the solar system.
Reference The Orion Constellation — named after the hunter in Greek mythology — is found on the celestial equator and is a prominent constellation in the night sky.
The bull is hard to miss as it charges through the northern winter sky. It's one of the most prominent and visible of all of the constellations.
Astronomer Giovanni Cassini discovered four of Saturn's moons, determined the distance from Earth to Mars and made successful measurements of longitude.
This large constellation contains the most stars with known planets. It is the 15th largest constellation overall.