Questo è un articolo che ho scritto per la rivista del CAI Auronzo "Quota 864 ". He speaks of the Three Peaks, where you could do a Star Party in July 2010.
now live in a world without the night. Our cities are illuminated much more than is really necessary and the result is the stars, the sky which inspired the birth of our culture, it is unknown to most people. We see a few dozen stars in the sky, and no longer know celestial phenomena as the Milky Way, the meteor showers, the zodiacal light, the ' airglow, the Gegenschein.
Fig.1 - The lights of a polluted industrial area and the sky (orange) of the plains. Who has not seen a sky like they knew our grandparents can not even imagine what are the Stars.
Fortunately, there are still places where you can still see the show of the Stars, "almost" as it should be. The Alps, hostile to human settlement, and the real people of the mountains (not prone to the wasteful style of light that exists in the plane) that you are still reluctant places almost untouched.
Fig.2 - Panorama of the horizon south of the Three Peaks. 
Fig.3 - Panorama Three peaks from the south horizon at night and the lights of the plains to 100 km away. One of these is the Three Peaks. From the base of the famous mountains, as well 2300 meters high, you can enjoy a free horizon from the northeast to the northwest, and at night you see southern constellations. Some light from the plains to nearly 100 km away can be seen along the horizon, to remind us that "civilization" is just around the corner. These little lights that filter out over 50 km of mountain ranges are sufficient to take place at the perfection of a time, but not enough to prevent us from enjoying the sight of Heaven. Passing
here one night, you can touch the sky. Moonless nights, the starlight is enough to see. It is not complete darkness. Indeed, the first thing you realize is that we have been made to see with the starlight. Just the patience to wait half an hour.
Down, in the great valley of the Po, which lies beyond the mountains, the lights appear, in this view, even more exaggerated. It is not difficult at night, armed with a compass, recognize the lights of Udine, Veneto, and even those of the Adige Valley.
Luckily these are extinguished within a few degrees from the horizon giving way to the spectacle of the sky.
summer crossed the sky is the Milky Way, the galaxy that is where we are. We see from the inside as a milky band crossing the sky. From a dark sky, like the Three Peaks takes personality and the Milky Way appears as a continuous succession of clouds of stars, nebulae spots and "dark." One of them, in particular, is overhead in summer. It 'called the "sack of coal of the North" because there are two even bigger and famous with this name visible in the southern hemisphere looks like a black hole in the middle of the Milky Way.
We can see many stars, some bright and others gradually weaker, which appear and disappear from view. Astronomers indicate the intensity of the stars with the word "magnitude". Each magnitude more stars are two and a half times less bright. The brightest stars are called "first magnitude". Followed by the others. If the night is calm will easily able to see stars of magnitude up to almost 7. From our city if all goes well you see those of magnitude 4, which are only a few hundred in the whole sky, while here, up to magnitude 7, there are about 10000. To this are added other entertainment. For example, in the nights of August in San Lorenzo horse you can see one of the most famous meteor showers. The dark sky can see them well and these nights if you can see hundreds, but any meteors in one night there (usually half a dozen per night).
The majestic mountains in the north are: black shadows against the sky and reassuring. The sky to the north is just the natural, yet it is not dark. The sky is not a natural fact it is quite dark.
But the artificial lights are often much brighter and ruin it. Amateur astronomers use a scale to describe the quality of the sky. 1 The degree of this scale (that scale Bortle by the name of the person who first proposed) is the perfect sky. Unfortunately, the Three Peaks are no longer in grade 1 because of the plain to 100 km away!. A sky
"Bortle 1" is located in the great deserts and there are amateurs who go to Namibia to see it. In a sky like that there are other shows: the zodiacal light, and the zodiacal band Gegenschein is a thin band of light that travels across the sky along the constellations (we imagine that the ancients saw the constellations of the zodiac highlighted by this light). The light source in the dust that is present in the plane of the solar system among the planets. The zodiacal light itself is the most intense that you can see in the morning or before dusk after dusk of the evening, in the form of a cone that extends from the direction of the sun in the direction of the zodiac. The light then continues weaker doing all around the sky, and it's called "zodiacal band." In the opposite direction to the Sun swells a little and called Gegenschein.
The three peaks are not perfect enough to see all these phenomena. In fact a sky Bortle class 2 or 3 (depending on climatic conditions). The zodiacal band is no longer visible, However, the zodiacal light, in the favorable season (spring and autumn sunrise to sunset) is visible and is also visible with a little 'attention to the Gegenschein.
Another phenomenon typical of unpolluted skies is the airglow. This is the natural brightness of the atmosphere, which becomes a glow on the horizon but which is distinguished by light pollution in the first case because the horizon is dark and the maximum intensity of this light is about ten degrees above the horizon . Three Peaks to the south horizon is broken by the plain, and less than the airglow climatic conditions will not be visible, but is visible in the directions north (Moving from the side of the refuge Locatelli).
Fig.4 - The Milky Way rising behind one of the Three Peaks. The mountain is illuminated by the lights of a car that was coming up, otherwise it would be completely black. 
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