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The astronomical quality of the skies of La Palma is defined by their cleanliness and transparency, and by the high number of hours of useful observation. Moreover, the atmosphere is characterised by an absence of turbulence and by being highly laminar, features that are closely related to the climate and the geographic features: it is close to the Equator, but far from tropical storms and the Roque de los Muchachos Observatory is above 2,400 metres above sea level, above what is known as the sea of clouds which, in turn, is a natural barrier to air pollution. The prevailing Trade Winds, which drive the creation of the sea of clouds, together with the existing cold marine currents, determine the climate of the island, dividing the troposphere into two very different stable areas, without turbulence.

 

The Sky Act

 

The Sky Act, adopted in 1988, protects La Palma from light, air and radio-electric pollution and from any pollution that could be caused by air traffic. To enforce these regulations, the IAC has the Technical Office for Protecting the Quality of the Sky – OTPC (from the initials in Spanish).

 

“Light pollution is a general term that indicates the sum of all the adverse effects of artificial light.

One of the most harmful aspects for astronomy is the glow or reflection of light in the night sky produced by the reflection and dissemination of artificial light in the gases and particles of the air due to the use of unsuitable bulbs that send the light straight out into the sky, or outside of the area targeted for lighting and/or by excess lighting.

Any lighting installation that falls under the Sky Act must meet a set of basic standards.

The most immediate benefits are: energy saving, road safety, environmental improvements and the enjoyment of the star-studded sky”. (www.iac.es).