Construction begins on European Extremely Large Telescope in Chilean desert

Construction work on the European Extremely Large Telescope, in Chile got underway yesterday. On completion, the telescope will be the world's largest optical telescope, about five times larger than the top observatory instruments in use today.

Artist's impression of the European Extremely Large Telescope

According to backers of the ELT, the size of the telescope could potentially transform our understanding of the universe. The main mirror of the ELT will measure some 39 meters (43 yards) across.

Located on a 3,000 meter-high mountain in the middle of the Atacama desert, it will become operational in 2024.

Its other capabilities will include refining astronomers' burgeoning discoveries of planets orbiting other stars. It will also have the ability to find more smaller planets, image larger ones, and possibly characterise their atmospheres, a key step in detecting the presence of life.

"What is being raised here is more than a telescope. Here we see one of the greatest examples of the possibilities of science," said Chilean president Michelle  Bachelet in a speech to mark the beginning of construction at the site.

According to commentators, the dry weather conditions of the Atacama provide possibly the best conditions for astronomical observations on earth. The region is set to be home to some 70 per cent of the world's astronomical infrastructure by the 2020s.

They add, from 2024, the European Southern Observatory involving 16 nations should have the best lens yet to find habitable extraterrestrial planets.

The ground-breaking ceremony for the 39-metre diameter lens took place yesterday on atop Cerro Armazones, a mountain rising to 3,000 meters.

The Extra Large Telescope (ELT) had been conceived by the European Southern Observatory (ESO), a consortium that includes Brazil, Germany, France and Britain, which will also have four smaller lenses.

The main mirror will be made up of 800 hexagonal sections, each with a diameter of 1.4 meters, designed for an exact fit. The mirror will be protected by an 80-metre dome.