6) There is a whitish spot that moves along with the starry background, and therefore it is not a cloud or part of the planet.
Anyone who has seen the Milky Way on a clear night knows that its appearance at first glance is similar to that of a "cloud" that extends across the entire sky (depending on the time of year and geographic location). Assuming an initial lack of knowledge of what the Milky Way is, an observer could initially identify it as a cloud, but after vast experience comparing "fixed stars" and "non-fixed" stars (Sun, Moon, "wandering" objects), the observer will come to the conclusion that that whitish spot "moves" in the same way as the fixed stars during the year, and therefore is not a cloud of the many that are seen in the sky, but also can determine, in the second instance, that since it behaves in the same way as the "fixed stars" it is located much further away than the "non-fixed" stars.
Preliminary conclusion: Discovery of the Milky Way. Although verifying what that "whitish spot" really is is beyond the scope of observation, its continued observation allows us to determine that it is located at a great distance (due to its behavior equivalent to that of fixed stars), but it also allows us to verify that in the surroundings of this "stain» there are a greater number of stars, indicating at least that this whitish spot has "something" to do with the fact that that region of space is more starry.
7) There are other bright points in the sky that move differently from the rest of the "fixed" stars and can be followed in time.
Although Venus and Mercury were already discussed in the “Daytime Astronomy” experiments, this exercise includes the discovery of all the planets. The “wandering” planets are simply characterized by moving differently than the rest of the “fixed” stars during the night, and that is why a thorough examination of these objects (which are also characterized by not “flickering” in contrast to the stars) reveals that there are 5 in total that can be observed with the naked eye, and that each of them requires more or less time to perceive that it is moving relative to the background of stars. Just as some objects make their movement evident after a short time (Mercury and Venus), others require several months to notice that they are moving (Jupiter and Saturn). Likewise, if these follow-ups are extensive (for 2, 3 or more years) it will also be possible to notice that this movement is not constant, but suffers certain “setbacks” and then “advances”.
Preliminary conclusion: Discovery of the planets and their movement. Planets have historically been studied by ancient cultures because they stand out against the background of "fixed" stars. Their greater luminosity and lack of "flicker" makes them easier to locate, but discriminating their movement is a task that requires a lot of observation time. In the case of discovering "setbacks" and "advances" in the movement of a planet (e.g. Mars), this attests to nothing less than the phenomenon of retrograde movement, which only happens on the outer planets.
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