A giant telescope to tackle the big questions of the universe: Europe’s foremost intergovernmental astronomy organization, the European Southern Observatory (ESO), is building the so-called Extremely Large Telescope – with a primary mirror diameter of 39 meters – in the Atacama Desert (Chile). In the following interview, Roberto Tamai, Program Manager of the entire project, talks to the Aspen Italia website team regarding what the future holds for this initiative.
What purpose does a piece of equipment the size of the Extremely Large Telescope serve? The Extremely Large Telescope is a response to the need for astronomy to always look ahead, tackling the big questions about the origins of the universe and the physical laws that govern it. So what makes the construction of very large ground-based telescopes interesting – as after all, they are nothing more than big “light funnels”, albeit with very sophisticated refocusing features – is the adaptive optics, which enable distortions caused by the Earth’s atmosphere to be corrected.
The Earth-bound journey of millions of years travelled by photons is disturbed in the last few milliseconds by entry into the Earth’s atmosphere, which creates distortion due to the presence of air masses with different temperatures. Just to be clear, this phenomenon is similar to the visual effect – familiar to anyone who drives in summer – produced by the refraction of light as it passes through layers of air of different temperatures and densities. But adaptive optics allow us to compensate, through corrective distortion, for the observation difficulties caused by the atmosphere. Sure, space-based telescopes do not have these problems as they are outside the atmosphere, but the costs involved – not just to build and deploy such telescopes, but also to maintain them – and the small size currently transportable, necessitate the construction of large ground-based telescopes.
When will it be completed and what research will it be used for? The building of the Extremely Large Telescope is a ten-year project, and we have already taken several preparatory steps, as well as getting some contracts underway. The investment envisaged is 1.1 billion euro. We are moving forward both from a funding perspective – pending formal ratification by Brazil of its recent membership of the ESO – and from an infrastructure standpoint, that is, preparing the site and the platform, which will be situated on a 3,000-meter high peak in the Atacama Desert in Chile, where our other telescopes are already located owing to the excellent atmospheric conditions for Earth-based astronomy.
The Extremely Large Telescope will enable us to study the life cycle of solar systems in the universe, focusing particularly on planets that reside in what can be considered habitable zones, that is, not too far away nor too close to their sun. The new telescope will also allow us to perform a spectroscopic analysis on the atmosphere of these planets, with the aim of finding signs of life similar to those present on our world, such as the presence of chlorophyll, for instance.
What sort of ties are there between the ESO and the Italian research industry? The ESO is an intergovernmental organization founded in 1962, initially as an offshoot of CERN, and Italy is one of its member countries. Each member makes a financial contribution in proportion to its GDP, but also receives an industrial and economic return, since the organization seeks to offer every country benefits equivalent to 70% of the amount invested. There are also opportunities for researchers and practitioners from each country, with calls for astronomers and engineers to take part in fellowship programs. But some countries offer even further possibilities: Spain and Portugal, for example, pay their researchers to complete their training at the ESO and return home with enhanced skills.
Having served as Head of Engineering and Deputy Director of the Paranal Observatory in Chile, as well as Head of Technology Division and Chief Engineer at the ESO, Roberto Tamai is now Program Manager for the European Extremely Large Telescope project (or E-ELT).
