The sky we are losing are living in a difficult time. For the first time in the history of mankind the technology is readily available to almost everyone, but that facility is us can return against, because the advances at such a speed that does not allow us to think about the consequences of our activities on the natural resources of our planet, on which all depend. We are all aware of the effects of human environmental activities and the advance of global warming. Men pollute, and between that pollute our sky is: produce light pollution. Cities grow, are poorly lit, Heaven ever shines more and accordingly each time we can least enjoy the spectacle that gives us the night sky. Thanks to the technology available today can observe our planet from space, and during a typical night what we can observe is: cities us disconnected from nature, and the firmament that was previously available to all is no longer. We are forgetting to look towards the sky, perhaps because we can almost not see it.

But that is probably the lesser of the evils. Did we say we lighting evil?. Simply because the luminaires are poorly designed, and that means a waste of energy that we cannot afford. We not only lighting the soil, but also to the sides and upwards, we must use energy to illuminate not only the areas that we need but also the unnecessary. To brighten up what we do it is that that light is disseminated in our atmosphere gases and particles from the air and produces a bright sky (skyglow), which could be avoided. And I reiterate, this leads to an excess in the consumption of electricity, which precisely does not spare us. Moreover the ecosystem is altered because excessive artificial light produced in animals, especially birds, disorientation and glare, and causes abnormal behaviors in them.