Eagle Nebula and the Pillars of Creation


Situated in the heart of the summer Milky Way, this nebula represents the best proof that the galaxy is still alive and in continuous evolution. This enormous expanse of ionized gas is heated and made visible by the numerous hot, young stars born within. You can notice dark columns inside, called the Pillars of Creation. They aren’t zones lacking gas; in fact, they are anything but. There inside, hidden from view, those columns of dense, cold gasand dust are giving birth to new stars and probably planetary systems. Subjected to their own gravitational pull, those dense clouds of gas and dust begin a slow gravitational collapse which breaks them into many smaller clouds from which the single stars will be born. 

The compression increases the heat in the central area, where a protostar is formed: an aggregate of gas, much more extensive than the star will be, and which only emits gravitational energy. The rotation of the gas, for the principle of preserving the angular momentum, increases little by little as it compresses, until a disc forms around the embryo star from which planets can also originate. It will take from 100 thousand to tens of millions of years to transform the protostar into an actual star, the necessary time for the compression of the collapsed gas to exceed, in its nuclear region, the threshold of the 18 million degrees necessary to light the thermonuclear motor.

Although our life is too short to see the Universe evolve, nothing remains unchanged. The entire Universe changes; stars are born, they evolve and go out. The great expanses of shine, move, dissolve; galaxies move, collide and change their shape. Nowhere, therefore, do appearances deceive as in this case: the sky seems the same to us for decades, even millennia, but we’re admiring just a frame of a movie that goes too slowly to appear to be moving. But, we can reconstruct it by looking around us into undefined space, gathering frames of events that are passing through various evolutionary stages and then doing a huge editing job to transform everything into the greatest time-lapse movie ever created by the human hand.

Comments

Post a Comment

Popular posts from this blog

The magnificent Milky Way

Image
The grandeur of the summer Milky Way (winter for southern hemisphere) across almost the entire sky can be seen very well in this 30 seconds shot taken from the Atacama desert. The view is similar with the naked eye in a very dark sky, even though the contrasts are not nearly as sharp and our eyes can’t see the real colors which, instead, any camera can emphasize.  There is an impenetrable wall of stars in front of us; this is the only thing that comes to our mind. How is it possible for them to be so compressed together? How can they avoid colliding with each other?  We’re in a place unknown to us and our experience, where space is compressed and makes us see objects as though they were all at the same distance.  The truth is that we are observing a crack tens of thousands of light years deep and objects that emit immense amounts of energy. The result? That on an average that sea of stars has the same density as the place where the Sun is: the stars all seem to be united
Read more

Inside the M33 galaxy

Image
At almost 3 million light years from here, in the Triangulum Constellation, we find the second closest galaxy after Andromeda. It’s a splendid spiral seen face-on, which is usually very evanescent but rich with splendid objects.  In this long exposure image (a little over nine and a half hours) carried out with a 25cm f4.8 Newtonian telescope and a color camera CCD (ST-2000XCM) you can have the spectacular confirmation of the nature of those spiral nebulae. What seemed like a dim nebulosity is actually the light of billions of stars and thousands of nebulae, some of which are dozens of times larger than the magnificent Orion Nebula.  Going beyond magnitude 22, a brightness 2 million 300 thousand times dimmer than what can be perceived by the naked eye, this image even shows the great clouds of blue stars, born only a few million years ago, and a background sky constituted by millions of tiny stars. If the astronomers of the past had had the same optical and technological
Read more