Occasionally, when the ‘seeing’ is good, I pull out my big gun optics pointing them toward the Jovian Moon system. There are many more moons around Jupiter than are on this image. These four however are the easy ones. The little 12 inch diameter optic I used for glass here is not up to the task unless I do much longer tracking time exposures. A 12 inch light gathering ability makes it faster than catching the same image with a smaller aperture. I have also found that higher resolutions cameras give you higher resolution images lol. This is an effective 4800mm focal length.
The year was 1609 and a fellow by the name of Galileo Galilei pointed a primitive Duch made gadget up at the massive Planet. Looking through the pieces of glass mounted like a skeletonized tube. Galileo was important in the early development of the telescope as he taught himself to grind glass to build his own instruments. He notices that 4 “stars” were circling Jupiter. Humm. That single observation set in motion the Brilliant mathematical mind that man possessed. He was obsessed with the new telescope working tirelessly to improve the state of the art. In 1609, he was observing an 20X view that the human eye could achieve. That is similar to a 24 power rifle scope. I can’t imaging observing this with less than a 1200 mm focal length and a 6 or so inch aperture. Let alone a rifle scope. Better than naked eye though in use before the improvements by Galilei lol.
Jupiter and Main Moons with a bit of intentionally blank space … Excuse the text…
Galileo Galilei has made Many Contributions to science but one of the biggies was the discovery of 4 moons/satellites orbiting the bright Planet Jupiter. Galileo observed that the “stars” moved along with Jupiter in the sky. Seemly carried along with the bigger/brighter star. The moons were all lined up like ducks in a row. Just a week ago in 1610, he was gazing through an “astronomic instrument” . He had noticed those “stars moved apparently around” Jupiter. Several noted historically famous astronomers were enjoying the new fangled contraption. We call it a telescope. They failed to receive credit because Galileo’s work was more precise and accurate, he got the glory.
This arrangement is the worlds largest clock “on the wall” literally. Those moons move like clockwork. Galileo discovered this phenomena. Jupiter Moon time schedules in the form of books remained in use for hundreds of years. By looking at where the moons of Jupiter emerge or disappear. You can literally tell a good accurate time for use in navigation on ships. This works on Land too with Lewis and Clark using Jupiter and it’s moons to tell the exact time. They were in a sea of grass but the sextant works every bit as well there. You need to know the exact time to properly use a sextant to determine your position on the globe.
In this photo, I timed it for Europe just emerging from behind Jupiters shadow at that precise moment of time. Then I could have taken a sextant to give me Latitude and longitude. The sextant is used to measure angles between the horizon and astronomic objects.