The Extremely Large Telescope
Written by
Robert Simpson ShareThis

The European Southern Observatory (ESO) is planning on building a massive – and I do mean massive –
telescope in the next decade. The European Extremely Large Telescope (E-ELT) is a 42-meter telescope in its final planning stages. Weighing in at 5,000 tonnes, and made up of 984 individual mirrors, it will be able to image the discs of extrasolar
planets and resolve individual
stars in
galaxies beyond the
Local Group! By 2018 ESO hope to be using this gargantuan scope to stare so deep into
space that they can actually see the
Universe expanding!
The E-ELT is currently scheduled for completion around 2018 and when built it will be four times larger than anything currently looking at the sky in optical wavelengths and 100 times more powerful than the Hubble Space Telescope – despite being a ground-based observatory.
With advanced
adaptive optics systems, the E-ELT will use up to 6 laser guide stars to analyse the twinkling caused by the motion of the atmosphere. Computer systems move the 984 individual mirrored panels up to a thousand times a second to cancel out this blurring effect in real time. The result is an image almost as crisp as if the telescope were in space.
This combination of incredible technological power and gigantic size mean that that the E-ELT will be able to not only detect the presence of planets around other stars but also begin to make images of them.
It could potentially make a direct image of a Super Earth (a rocky planet just a few times larger than Earth). It would be capable of observing planets around stars within 15-30 light years of the Earth – there are almost 400 stars within that distance!