VLT – Very Large Telescope

The ESO’s Very Large Telescope is the most advanced system that man can use today from the Earth’s surface

The first step towards optical astronomy was moved by Ruggero Bacone, who studied the properties of a particular type of lens, convex flat lenses.

Bacone noted that the magnification obtainable was determined by the refraction of the image, the direct consequence of the focal length of the lens and the distance of the eye from it; Shortly after similar lenses were successful in the first eyeglass models.

However, for astronomical use one will have to wait 1608, when Dutch Dutchman Hans Lippershey built the first refractive telescope model. The same instrument was perfected by one year from the great Galileo Galilei, who is remembered as the first real revolutionary of optical astronomy.

Since then, it has been made a giant step to say a little. At the beginning of the third millennium, ESO‘s VLT (European Southern Observatory) is surely the first to place ground-based astronomy facilities.

The Very Large Telescope or literally the “Very Large Telescope” is the most advanced system ever available to man from the Earth’s surface.

It consists of eight spotlight telescopes: the 4 main (called with the names of some astronomical objects in the local Mapuche language – Antu the Sun, Kueyen the Moon, Melipal the Southern Cross and Yepun the Venus Planet) are Ritchey-Chrétien Optical Configuration And each of them has a diameter of 8.2 meters (more than the length of a regatta sailing boat!); The other are 4 auxiliary telescopes, movable, if necessary, of 1.8 meters in diameter.

You are wondering why to implant a multiple system rather than a single more powerful telescope?

Well, you could answer with a phrase like “The union is the force”.

Indeed, the above-mentioned telescopes can be combined to form a real giant interferometer: the ESO Very Large Telescope Interferometer (VLTI) allows you to “scrutinize” the cosmos up to 25 times better than the single telescopes that compose it.

To be aware of what one can do with one of these titans, just think that a single exposure of about an hour allows you to display celestial bodies up to thirty-five magnitudes; Bearing in mind that the current apparent magnitude record, held by LBV 1806-20 (a blue super-gigantic light, distant 38,000 light-years from the Sun, which appears extremely weak due to extinction) is 35 m, the comparison is soon made.

The VLT is located at the Paranal Observatory on Cerro Paranal, a tall mountain of 2,635 m, in the Atacama desert in northern Chile. Like other world observers, the place has been chosen for its dryness, abundance of serene nights, high altitude and distance from sources of light pollution. This place also has a particularity: no one has ever seen rain on the Paranal!