As an introduction, let’s just say that ESO – the European Southern Observatory – basically builds and operates the most advanced and powerful telescopes observing from our planet. For their 50th anniversary, they had the awesome idea to get one of their followers to tweet their way to the VLT… I came back a few days ago, and it was a beautiful life-changing experience.

Striking a pose on the VLT platform

The Very Large Telescope is located on top of a Chilean mountain, Cerro Paranal, at an altitude of about 2600 meters. Cerro Paranal is in the Atacama Desert, the driest region on Earth, 2 hours away by car from the nearest town. ESO chose the southern hemisphere to install their telescopes because it enables them to observe the center of the Milky Way and the Magellanic Clouds… and they chose Chile because the “seeing”, the quality of the observations is excellent. The atmosphere is very stable, the skies are almost always clear, there is no light pollution whatsoever.

Cerro Paranal is often nicknamed the astronomers’ paradise by those who visit it… and with reason; one of them even told me that if he was not married, he would never want to leave! The conditions up there are harsh, and of course observations last all night long, 365 days a year, but Paranal is nonetheless an amazing place to work and live. ESO did a great job when they built the Residencia,  which is beautifully integrated in the surrounding landscape. From the outside, it looks a bit like the underground lair of a James Bond villain… which may explain why the Residencia was chosen as a filming location for Quantum of Solace!

Cerro Paranal hosts 10 active telescopes. There are four telescopes with an 8.2-meters diameter mirror, named UT-1 through 4 and a.k.a. Antu (The Sun), Kueyen (The Moon), Melipal (The Southern Cross) and Yepun (Venus) in Mapuche language. There are also 2 survey telescopes, VST with a 2.6-meters and VISTA with a 4-meters mirror and 4 “small” ones, with “only” an 1.8-meters mirror (the auxiliary telescopes). Telescopes can be combined for specific observations using a process that is called Interferometry – which makes them even more powerful. The 4 auxiliary telescopes can be moved around to any of the 30 positions available on the platform, which opens an amazing range of observation possibilities. I think the only place where I can say it this here, among spacetweeps… I sure did not expect to be so emotionally moved by these gentle giants.

The telescopes are amazing pieces of technology… powerful, silent, and gorgeous in the chilean light – sunrise, daylight, sunset, darkness, moonlight… The view from and on the VLT platform is always breathtaking. Please check out check out my pictures here if youre not convinced yet!

On my last night at Cerro Paranal, I teamed with Henri Boffin – a renowned ESO astronomer- to image Thor’s Helmet, the NGC 2359 nebula… The observation was streamed live on ESO’s website as part of a six-hours broadcast, which I can only recommend you watch if you’re interested in astronomy. The picture we took is stunning! Mathieu (outreach team), Gabriel (astronomer), Claudio (shift supervisor) and I were also live from the VLT platform a few hours later for a Q&A session…

Credit: ESO/B.Bailleul

If I had to sum up this week in Chile… I had a great time, met a lot of people who are passionate about their work, and learned a lot about astronomy and ESO. And if you’d rather read the longer version, please check out my blog entries for this trip… available in both english or french!

Can you imagine that the mirror for the future E-ELT (European-Extremely Large Telescope) will be 39 meters wide?