The current director of the Institute of Astrophysics of the Canary Islands (IAC), Rafael Rebolo, was a “young researcher with a newly achieved position in the center” when its founder Francisco Sánchez managed to convince Spain of the need to have regulations for the protection of the heaven. Now, more than 30 years later, he defends the past and future relevance of his article.
What is special about this law?
It protects an exceptional natural resource of the Canary Islands, especially of La Palma. For people it may be strange to think that the sky is a natural resource with economic importance, but it is and a lot. It allows 3% of the GDP of La Palma to be from the astrophysics sector. If we continue to protect it, we will reach 5% or even, if we are lucky enough to bring the world’s great unique projects such as the TMT, 6% of the island’s GDP would depend on that resource. It is the essence that protects this law, the possibility that the scientific value of the sky is perpetuated in La Palma, but also in Tenerife and throughout the Canary Islands.
Why was La Palma chosen?
It has natural conditions very similar to the sky of Tenerife but the artificial pollution of the Island in the 80s was much lower than in La Palma, and now it still is. In Tenerife, being a sky with exceptional conditions as well, its capacity to carry out exceptional science is more limited. That luminous veil that light pollution gives makes it pointless to install telescopes with a diameter greater than two meters to carry out research on the Universe. It would be appreciated if the contamination were controlled so as not to go further and, therefore, to continue having nighttime research capabilities here in Tenerife, but we also understand that it is much more difficult to limit it with such a large population and such a high level of tourist activity. on the island.
Is that why Izaña has focused on daytime observation?
Yes, traditionally it has been for this reason that we have installed solar telescopes in Tenerife and concentrated night observation with small telescopes. Tenerife has a sky that still allows exceptional astrophysical research. We do what we can do in Tenerife and the most demanding large facilities are taken to La Palma.
Where does the need to protect the sky come from?
The vision of the director of the IAC was very clear. On La Palma the conditions are exceptional and he knew that in the future it would host the largest and most important facilities for investigating the Universe from the surface of the planet. But for that to happen, that natural resource could not be lost.
Was it easy to convince the institutions?
At first it was a pioneering work that had to be consolidated over time. If the site is exceptional, the data will prove it, but the measurements have to be made year after year to demonstrate that it is maintained over time. The first measurements began in the 1970s and are still being carried out. The database we have is unquestionable. There may be comparable or better sites in the world, but all things being equal, being more protected allows for more quality. For example, in China there are places with 5,000 meters that are a real disaster and that is why I try to convince them to consider collaboration. In the world it is clear that the Canary Islands, Hawaii and the summit of the Atacama desert are the best locations for astronomical observation.
I understand that these measures and the law itself serve to convince the world of the quality of the island sky…
Yes, because the data series is unquestionable but, in addition, there are international teams that have their own data series to compare ours.
It is a pioneer standard in the world. Has it replicated?
It has been inspiring others in other territories and there are many regulations that protect certain sky reserves that are extraordinarily dark. What does not exist is a national standard that regulates something like this in another country. Chile, for example, also wanted to protect this natural resource because investments there are much higher than those in the Canary Islands.
Does it influence when attracting scientific projects?
Yes, yes, clearly. The good may have a value today that can be degraded tomorrow. What the law ensures is that this natural resource is protected and any institution that wants to make an investment of 2,500 million feels safer if there is a law that guarantees that this activity will be allowed over time.
Is the protection of the sky related to the rapid success of the astrophysics of the Islands?
It has allowed us to have state-of-the-art facilities that we have built ourselves, such as the Gran Telescopio Canarias, which is recognized as one of the best in the world right now. But before that, after the creation of the observatories, countries like the United Kingdom, Italy or Germany brought their best facilities here, with the advantage that they allowed our teams to use them. This served so that we were forming technological training at the same time that we were already using the best means available in the world. Obviously, the quality of the sky and its protection have been vital.
