The video shown above is of Jupiter. I took it about 4 months ago when the skies in Singapore had lower levels of haze. Well you can see Jupiter, the big bright sphere, and its 4 moons- Io, Europa, Ganymede and Callisto quite clearly. Just for one's knowledge, each moon is about the size of the Earth. I think you get the "big picture" of Jupiter now!
My view in this post will be about these 4 moons and their historical significance to science.
Just about 399 years ago, Galileo Galilei observed these moons with his home made telescope. He thought that they were 3 stars in line near Jupiter. After frequent observations, he saw a 4rth star and soon realized that the "stars" kept changing orientation but never really moved out of the vicinity of Jupiter. This led him to conclude that those celestial objects were not stars but celestial bodies orbiting Jupiter, just like our luna.
This was a really big moment for Galileo Galilei. He had been a believer in the Copernican system, which involved heliocentricism, and this discovery meant a breakthrough as he had just proven geocentricism wrong. The discovery of the moons meant not everything orbited around the Earth, putting an end to the enforced beliefs of geocentricism.
I believe that after this discovery, a true scientific revolution began. Let me explain. Imagine if we humans were not educated and were told that Earth was in the centre of the universe and everything revolved around us. We would feel as if we were the most important beings because everything revolves around us. This would hinder our ability to ask questions and discover new ideas because we would feel as if those questions were too small for our presence in the self-centered universe. Thus, we would never develop.
However, due to Galilei's discovery, we now know just how small and insignificant we are, being a tiny planet in the universe, helplessly revolving around the Sun. This seems, in a way, demoralising. Nevertheless, this is what brought about the scientific revolution. Because we knew we were insignificant in the universe, we became humble and bothered to experiment and question, looking far beyond our own reaches. Because we knew we were insignificant, we advanced to where we are now.
Just imagine if Galilei was too lazy or maybe too tired that evening. Just imagine if he did not search for those moons. If this would have happened, ignorance would have been the next most abundant element after hydrogen! We humans would probably still be stuck with our primordial beliefs. So, every time I go for my astronomy sessions, I always silently offer my gratitude to the stark and beautiful Jupiter and its moons as they indirectly created modern science.
If you have read this post, do remember the remarkable story behind Jupiter the next time you see a really big, bright, white star-like object in the night sky.