At 2,400 meters altitude, above the ##sea of clouds##, the sky at Teide is one of the purest in Europe. Teide National Park is certified as a Starlight Reserve and Starlight Tourism Destination, making it one of the rare sites in Europe to hold both labels. On clear nights, the Milky Way is easily visible to the naked eye, some shooting stars can be observed during meteor showers, and Jupiter can reveal its moons with simple binoculars. The Instituto de Astrofísica de Canarias operates several of the world's most important observatories there, including at Izaña.
Three main factors explain the exceptional quality of the site. The altitude (2,400 m at the Parador, 3,718 m at the summit) places the observer above the thermal inversion layer, often situated between 1,000 and 1,800 m. Light pollution is very low thanks to the Canary Islands Sky Law (1988), which strictly limits nighttime lighting. Finally, the geographical position allows observation of a very large portion of the constellations in the northern hemisphere, as well as a portion of the southern sky.
With the naked eye: the Milky Way as a dense band of light, the Orion nebula under good conditions, and the Andromeda galaxy as a diffuse patch visible in very dark skies. With a 150 mm telescope (often provided by excursions): the rings of Saturn, the cloud bands of Jupiter and its Galilean moons, the craters of the Moon in detail, as well as star clusters like the Pleiades. During meteor showers such as the Perseids (mid-August), it is possible to observe several dozen shooting stars per hour under good conditions.