Io – that’s perhaps the smallest name of any celestial object known to humans. It is one of the 67 moons of Jupiter and is quite an interesting object hanging out there in the void. In this article on Io facts, we are going to share some of the most mind-blowing information about this interesting Jovian moon. So, sit tight. It is going to be one hell of a read…
Interesting Io Facts: 1-5 | About Io – Discovery, Position
1. Io was discovered on January 8, 1610. The discoverer was Galileo Galilei. It was one of the four Jovian moons that were discovered by Galileo and hence, it is often referred to as the Galilean Moon of Jupiter. The other three moons that were discovered by Galileo are:
2. If we are to compare the volume and mass of the four Galilean moons of Jupiter, they ranking they get is:
- First – Ganymede
- Second – Castillo
- Third – Io
- Fourth – Europa
3. If we are to arrange all 67 moons of Jupiter in order of distance from Jupiter, Io takes the 5th spot. However, if we are to arrange the four Galilean moons in order of distance from Jupiter, Io takes the 1st spot.
4. Actually, Io was not discovered on January 8. It was discovered on January 7, 1610 by Galileo. However, that night, Galileo failed to distinguish between Europa and Io. Things became clear to him on the next night, that is, 8th January. Hence, it is said that the discovery was done on 8th January.
5. Discovery of Io, Europa, Callisto and Ganymede was the first ever discovery of any moon orbiting any other planet but Earth.
Interesting Io Facts: 6-10 | Incorrect Credit, Naming of Io
6. Galileo’s discovery was stunning. It was his discovery of these moons that eventually led people to believe that planets orbit Sun and NOT the solar system orbiting Earth. Galileo gets a lot of credit for this.
7. The truth however is that it was ancient Indian mathematician-astronomer by the name Aryabhata (born 470 CE) who actually told that planets orbit Sun and not the solar system orbiting Earth. His observations and studies are all recorded in his work ‘Aryabhatiya’ – an astronomical treatise. Still, to this day, West refuses to give him the credit he deserves.
8. Nonetheless, coming back to Io, Galileo actually named the Jovian moon as Jupiter I (because it was the first Jovian moon he discovered). The name he gave was used till mid 1800’s when it became clear that using numbers as names will only create a lot of confusion.
9. So, in mid 1800’s the name of Jupiter I was changed to Io. Io comes from Greek mythology where Io was the priestess of Hera – the wife of Zeus. Io was the daughter of Inachus, who was in turn, the King of Argos.
10. According to Greek mythology, Zeus fell in love with Io. However, he was afraid that Hera would catch him with Io. So, to avoid being caught, Zeus turned Io into a cow.