Drawing of Galileo demonstrating his telescope to a group of observers

Notices where this attachment appears

1. AkaSci 🛰️ (akasci@fosstodon.org)'s status on Monday, 08-Jan-2024 09:04:37 UTC AkaSci 🛰️

   OTD on Jan 7, 1610, Galileo Galilei, using a telescope of his own design, discovered 3 moons of Jupiter - Callisto, Europa and Io. He discovered Ganymede 6 days later.

   He observed 3 "stars" around Jupiter, whose positions changed in observations on subsequent nights. On Jan 10, Galileo noted that one of them had disappeared. Within a few days, he concluded that they were "moons" orbiting Jupiter, a discovery that was anathema to the Church at that time.
   1/n