At 2,400 meters, above the sea of clouds, the Teide sky rivals the best observation sites in Europe. Teide National Park is certified as a Starlight Tourism Destination, and the Cumbres de Tenerife form a Starlight Reserve, a dual accreditation that is uncommon in Europe. 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 observatories there among the most important in the world, notably at Izaña.
Three reasons make Teide so reliable for astronomy. The altitude (2,400 m at the Parador, 3,718 m at the summit) places the observer above the thermal inversion layer, often located between 1,000 and 1,800 m. Light pollution is very low thanks to the Canary Islands Sky Law (1988), which heavily restricts nighttime lighting. Finally, the geographic position allows observation of a very large portion of constellations in the northern hemisphere, as well as a portion of the southern sky.
With the naked eye: the Milky Way as a dense luminous band, the Orion Nebula in good conditions, and the Andromeda galaxy as a diffuse patch visible in very dark skies. With a 150 mm telescope (often provided by excursions): Saturn's rings, Jupiter's cloud bands and its Galilean moons, the Moon's craters in detail, as well as star clusters like the Pleiades. During meteor showers like the Perseids (mid-August), it is possible to observe several dozen shooting stars per hour in good conditions.