The journey of astronomical telescopes began in the early 17th century when Galileo Galilei crafted his first refracting ...

Jupiter's largest moons, known as the Galilean moons, are Io, Europa, Ganymede, and Callisto. These moons were discovered by Galileo Galilei in 1610 and are significant for their unique ...

About the same diameter as Earth’s moon, the innermost of Jupiter’s four giant moons ... making it the closest pass since NASA’s Galileo probe imaged the volcanic moon in October 2001.

front of Jupiter's Great Red Spot ... Amalthea, however, is tricky to spot even when you have a spacecraft. NASA's Galileo mission imaged Amalthea in 1999. Large impact craters are visible.

Jupiter's moon Io is the most volcanically active body in our Solar System ... especially early in their formation – including our own Moon – we may need to rethink how planets form and evolve. While ...