ESOcast 43: Seeing Sharp — Special 50th anniversary episode #3

The third special episode of this series -- ESOcast 43 overall -- presents ESO’s flagship facility: the Very Large Telescope (VLT). In this episode we discover the state-of-the-art technology behind this telescope, which has provided astronomers with an unequalled view of the Universe.

To obtain the sharpest images of the sky, the VLT has to cope with two major effects that distort the images of celestial objects. The first one is mirror deformations due to their large sizes. This problem is corrected using a computer-controlled support system — active optics — that ensures that the mirrors keep their desired shapes under all circumstances. The second effect is produced by Earth’s atmosphere, which makes stars appear blurry, even with the largest telescopes. Adaptive optics is a real-time correction of the distortions produced by the atmosphere using computer-controlled mirrors that deform hundreds of times per second to counteract the atmospheric effects.

As one demonstration of its power the VLT’s sensitive infrared cameras, helped by adaptive optics, have been able to peer through the massive dust clouds that block our view to Milky Way’s core. The images, taken over many years, have allowed astronomers to actually watch stars orbiting around the monstrous black hole that lies in the center of our galaxy. It was even possible to detect energetic flares from gas clouds falling into the black hole.

Watch this episode to discover more about why the Very Large Telescope is the planet’s sharpest eye on the sky.

More episodes of the ESOcast are also available.

Find out how to view and contribute subtitles for the ESOcast in multiple languages, or translate this video on dotSUB.



Directed by: Lars Lindberg Christensen
Art Direction, Production Design: Martin Kornmesser
Producer: Herbert Zodet
Written by: Govert Schilling
3D animations and graphics: Martin Kornmesser & Luis Calçada
Editing: Martin Kornmesser
Cinematography: Herbert Zodet & Peter Rixner
Sound engineer: Cristian Larrea
Narration Mastering: Peter Rixner
Host & Lead Scientist: Dr J (Dr Joe Liske, ESO)
Narration: Sara Mendes da Costa
Soundtrack & Sound Effects: movetwo — Axel Kornmesser & Markus Löffler
Proof reading: Anne Rhodes
Executive producer: Lars Lindberg Christensen
Footage and photos: ESO, Stéphane Guisard (, Christoph Malin (, Babak Tafreshi/TWAN, A. Santerne, Martin Kornmesser, J. Dommaget/J. Boulon/J. Doornenbal/W. Schlosser/F.K. Edmondson/A. Blaauw/Rademakers/R. Holder, Mineworks, Daniel Crouch/Rare Books (, Getty Images, Royal Astronomical Society/Science Photo Library, Jay M. Pasachoff, Chris de Coning/South African Library/Warner-Madear, Africana Museum/Warner, Leiden University, G. Brammer, Nick Risinger (, Mauricio Anton/Science Library, José Francisco Salgado (, NASA/Spitzer Science Center/R. Hurt, VISTA/J. Emerson/Digitized Sky Survey 2, MPE/S. Gillessen/M. Schartmann, PIONIER/IPAG.


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About the Video

Release date:10 May 2012, 14:00
Related announcements:ann12033
Duration:09m 21s

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Type:• X - ESOcast



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