Andalusian discovery of David Bowie

During the total solar eclipse, scientists will use telescopes to study the solar corona, monitor space weather and measure wavelengths of light that are usually obscured by the Sun’s bright glare. Incidentally, thanks to international cooperation, state-of-the-art telescopes have been installed in Andalucía, on the peaks of the Sierra Nevada.

In the early 1970s, researchers at the Max Planck Institute for Astronomy in Germany decided to build a world-class astronomical observatory to collect scientific data. Such a facility had to be located precisely in places where the sky is rarely overcast, in order to ensure more effective observation of the stars. The Germans carried out numerous, meticulous measurements of sky conditions in various locations across Europe and North Africa. Ultimately, the Sierra de los Filabres mountain range (subrange of the Sierra Nevada located in Almería province) was deemed the ideal site for the project.

In 1973, an agreement was signed between Germany and Spain regarding the construction of the Calar Alto Observatory (also known as Centro Astronómico Hispano en Andalucía’). The observatory’s name refers to the Calar Alto mountain in the Sierra de los Filabres, which stands at an altitude of 2,168 metres. It is here that the dry atmosphere reduces the limitations imposed by atmospheric water vapour on the transmission of light through the atmosphere, whilst the low number of cloudy nights significantly enhances the effectiveness of observations throughout the year.

Scientific work at Calar Alto began in 1975 using a 1.23-metre reflector telescope. As part of a German-Spanish collaboration in the field of astronomy, a further several telescopes were brought into operation.

The year 1976 is particularly noteworthy in the history of the observatory’s telescopes. It was then that the Calar Alto Observatory acquired its historic Schmidt telescope, transferred from the Hamburg Observatory in Bergedorf.

The telescope is named after the Estonian optician Bernhard Woldemar Schmidt, who in 1930 invented the catadioptric astrophotographic telescope, designed to provide a wide field of view with minimal aberrations. On the Calar Alto, the Schmidt telescope was installed to map the northern hemisphere sky, conduct wide-angle surveys and search for quasars (extremely bright and distant astronomical objects, short for quasi-stellar radio source).

Ten years later, the largest equatorial-mounted telescope in continental Europe was installed on the Calar Alto. Built by J. Zeiss and completed in the mid-1980s, the 3.5-metre telescope was first put into operation in March 1984. Following a full cycle of testing, it was made available to scientific observers at the Calar Alto Observatory in July 1986.

Nowadays, the Calar Alto telescopes are used for a wide range of observations — from objects in the Solar System to cosmology, including the search for exoplanets, planets located outside our solar system.

In 1993, the observatory in Almería gained particular renown. It played a pioneering role in recording the historic collisions between Comet Shoemaker–Levy 9 and Jupiter in July 1994 (Jupiter, thanks to its enormous mass and gravitational pull, was able to capture Comet Shoemaker–Levy 9, which was facing inevitable disintegration). The Calar Alto Observatory managed to capture some of the very first ground-based images of the collisions in the near-infrared spectrum.

In February 2008, in the main belt between Jupiter and Mars, Felix Hormuth at the Calar Alto Observatory discovered asteroid 342843. It was named after the British singer David Bowie. It is worth noting that the German astronomer discovered numerous asteroids during his time in the highlands of Almería. For example, asteroid 18610 Arthurdent was named after the character in Douglas Adams's radio play and book The Hitchhiker's Guide to the Galaxy. Furthermore, it was Hormuth who, in 2003, discovered a minor planet and named it 189202 Calar Alto in honour of the observatory’s location.