BOOM! The European Extremely Large Telescope (E-ELT) project starts with a blast!

7 July 2014 by Aprajita Verma

Image of the blast at Cerro Armazones, the site of the E-ELT (Credit: ESO)

On Thursday 19th June 2014 at ~18:45 BST, an explosion high in the Atacama desert in Northern Chile marked the beginning of construction of what will be the largest optical & infrared telescope in the World. The European Extremely Large Telescope (E-ELT), built by the European Southern Observatory (ESO), will be sited at a high and dry peak on Cerro Armazones, some 20 km away from ESO's Paranal Observatory. By the completion of the levelling work, the 3060m peak would have been reduced by 40m, some million tonnes of rock removed to create a 300m by 150m plateau on which the E-ELT will be built.

This enormous telescope will have a primary mirror of 39m in diameter, just short of half a football pitch, housed in a dome that's as large as a football stadium! This huge collecting area is larger than the area of all the 2m and above optical/infrared professional telescopes currently in operation combined. The large mirror means that the telescope will collect enough light to detect the faintest objects in our Universe. It also means that we will be able to observe astronomical objects in exquisite detail, the E-ELT will provide images 16 times sharper than the Hubble Space Telescope. The E-ELT will address numerous key areas of research including studying the first galaxies that formed after the Big Bang, directly measuring the expansion of the Universe and studying and characterising extra-solar planets.

The sub-department of Astrophysics is heavily involved in this project, both in the science the telescope will deliver (Professor Isobel Hook & myself) and in the instrumentation that converts the light the telescope collects into digitised data to enable scientific analysis. One of the first instruments on the telescope is called HARMONI and Oxford's Professor Niranjan Thatte is leading the European consortium who are designing and constructing it. HARMONI is a very powerful and versatile instrument that takes images of the sky but for every pixel in that image we also get a spectrum where the light is split up by wavelength. The resultant data allows us to perform scientific studies over a very wide range of astrophysical questions. For example, we will be able to determine how stars and gas move in different environments in the Milky Way but also track this motion in galaxies, from those nearby to those that reside in the very young Universe. This gives us important information on the interplay of stars, gas and chemistry in these objects and key constraints on the formation and history of the galaxies we observe.

We are also involved in research and development for a possible Multi-object Spectrograph for the E-ELT that can take spectra of may objects over the full E-ELT field in one shot. Prof Gavin Dalton leads Oxford's work on this ambitious instrument that will address many open questions by making large spectroscopic surveys of the sky. This includes understanding how galaxies formed, built-up and evolved by looking observing galaxies through all cosmic time and making a census of stars in nearby galaxies (so called "stellar archaeology").

The Oxford instrumentation group also contributes to the challenging R&D for the ELT Planetary Camera & Spectrograph (Oxford lead Dr Matthias Tecza). This instrument will make use of the E-ELT's superb sensitivity and resolution to observe faint exoplanets lying close (and possibly within the habitable zone) to their parent stars. As the planets are a million to a billion times fainter than the parent stars, the challenge is in achieving observations with high contrast. We will be able to tell whether the planets are gas giants (like Jupiter) or rocky (like the Earth), and also study their atmospheres. These observations lead to the tantalising possibility of detecting "signs of life" on extra terrestrial planets.

These are very exciting times for members of Oxford Astrophysics and the challenging E-ELT project that will create the World's Biggest Eye on the Sky!!

The E-ELT blast was reported on in the Oxford Science Blog by Pete Wilton

Further information & videos of the E-ELT blast can be found at

Further information on the UK involvement in the E-ELT at

Further information on the overall E-ELT project

Categories: E-ELT | exoplanets | galaxies | Instruments | technology | telescopes