Uploaded December 2025 | Updated September 2026, 2 weeks ago

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The light gathered by ESO’s Extremely Large Telescope (ELT) will be captured by house-sized instruments, which need to be cooled down to detect faint signals from the cosmos. How do we cool these huge systems to as low as -270 ºC? Our engineers are hard at work at it.

Discover more about ESO’s ELT at: elt.eso.org

Watch our ELT playlist here: youtube.com/watch?v=FuMvka1-dA4&list=PLSZ2Jv0bEZHy7el0mIrOMRKkhCw8pemaZ

Credits: ESO
Directed by: Angelos Tsaousis.
Editing: Angelos Tsaousis.
Written by: Bárbara Ferreira.
Music: Jon Kennedy – Pick up sticks.
Footage and photos: ESO, Luis Calçada, Angelos Tsaousis, Jose Porte.
Web and technical support: Raquel Yumi Shida.
Acknowledgements: Matteo Accardo, Veronika Wimmer.

This video is available for downloaded in various formats on: eso.org/public/videos/eltu_cryogenics