The Law of the Sky is 30 years old

"Gamma-rays and Comet Dust" (Rayos Gamma y polvo de cometa). Crédito: Daniel López. Esta imagen, en la que se ven los telescopios MAGIC, en el Observatorio del Roque de los Muchachos (Garafía, La Palma), y la lluvia de estrellas de las Perseidas, fue sele
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The exceptional quality of the Canary sky for astronomical observations is protected by what is known as the “Law of the Sky” which the Spanish Government passed on October 31st 1988 after a proposal by the Canary Parliament. This sets the rules for four basic aspects: firstly light pollution, by regulating the outside lighting on the Island of La Palma and the part of Tenerife in a direct line of sight from La Palma; secondly the pollution by radio and electrical signals, by setting maximum levels of electromagnetic radiation in order to avoid interference with the apparatus and working of the observatories; thirdly atmospheric pollution, by controlling activities which could degrade the atmosphere in the  surroundings of the astrophysical installations; and fourthly airline routes, by regulating the air traffic over the observatories which could affect scientific studies.

Since the Law came into force 30 years ago there have been modifications in the public lighting systems of many municipalities in the Islands, which has succeeded in slowing down the otherwise unstoppable advance of light pollution. Furthermore the Law of the Sky in the Canaries has been an impulse for other ideas and similar projects in other autonomous regions. Among these activities we can pick out “Starlight” an international declaration in defence of the night sky and the right of humanity to enjoy the viewing of the universe. In addition, in regions such as Catalonia, the Balearic Islands, and Andalucía, with motives which include astronomy and the environment, projects have been initiated against light pollution. Furthermore in La Palma, declared the first “Starlight Reservation” in the world, with one of the best skies for observing the universe, a large number of projects is under way to develop “astrotourism”, tourism based on the observations of the stars.

“Protect your sky”

To commemorate the 30th anniversary of the Law of the Sky the IAC and the Canary Island Observatories are organizing a number of activities which start on Monday October 1st, with a campaign entitled “30 years, 30 images”. During the whole month the social networks of the IAC will publish, under the hashtag #30cielos, 30 photographs taken from the islands which have been given recognition by NASA in the series Astronomy Picture of the Day (APOD). There is a plan to invite anyone who wants to do so to record a 10 second video in which they explain what it has meant to them to enjoy the skies of the Canaries. All of this information will be available shortly on the social networks of the IAC.

This anniversary has given rise to the creation of a new section of the blog of the IAC “Vía Láctea s/n” which starts from today with the text “The inspiring beauty of the night sky” by Federico de la Paz, a staff member of the IAC working in the Technical Office for Protection of the Quality of the Sky. This office was created by the IAC to facilitate the application of the Law of the Sky, giving advice, and support to those who want to comply with the law.

The IAC will also participate in other activities organized to celebrate this anniversary. Among them is a session of the project “Night Light” which will be celebrated during this week in La Palma, with the participation of the Cabildo of La Palma, dedicated to astrotourism and the control of light pollution. There will also be a seminar “The environmental print of artificial lighting, Protection and evaluation of the Night Sky” organized on October 4th in La Laguna (Tenerife) by the Observatory Foundation of Renewable Energies and Energy Efficiency and the Starlight Foundation. We will offer information on each of these activities.

Contact at the IAC:

Technical Office for the protection of the Quality of the Sky (OTPC)

  • Francisco Javier Díaz Castro (fdc [at] (fdc[at]iac[dot]es))
  • Federico de la Paz (fpaz [at] (fpaz[at]iac[dot]es))       

Phone: 922605365