The Extremely Large Telescope (ELT) is an astronomical observatory and the world’s largest optical/near-infrared extremely large telescope now under construction.
Part of the European Southern Observatory (ESO), it is located on top of Cerro Armazones in the Atacama Desert of northern Chile.
The design comprises a reflecting telescope with a 39.3-metre-diameter (126 foot) segmented primary mirror and a 4.2-metre-diameter secondary mirror, and will be supported by adaptive optics, six laser guide star units and multiple large science instruments.
The observatory aims to gather 100 million times more light than the human eye, 13 times more light than the largest optical telescopes existing in 2014, and be able to correct for atmospheric distortions.
It has around 256 times the light gathering area of the Hubble Space Telescope and, according to the ELT’s specifications, would provide images 16 times sharper than those from Hubble.
The ELT is intended to vastly advance astrophysical knowledge by enabling detailed studies of planets around other stars, the first galaxies in the Universe, supermassive black holes, and the nature of the Universe’s dark sector, and to detect water and organic molecules in protoplanetary disks around other stars.
Construction work on the ELT site started in June 2014. The first stone of the telescope was ceremoniously laid on May 26, 2017, initiating the construction of the dome’s main structure and telescope. First light is currently planned for 2024.
The dry atmosphere of the Atacama provides as near perfect observing conditions as it is possible to find on Earth, with some 70 percent of the world’s astronomical infrastructure slated to be located in the region by the 2020s.
The ELT is being funded by the European Southern Observatory, an organization consisting of European and southern hemisphere nations. Construction costs were not available but the ESO has said previously that the ELT would cost around 1 billion euros ($1.12 billion) at 2012 prices. ($1 = 0.8949 euros)
