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Starry Night at CERN – 23 September

The CERN Astronomy Club will host a stargazing event at CERN as part of the “la nuit est belle!” initiative to turn off all public lighting in Greater Geneva

The Milky Way rising above Geneva. (Image: Klaus Barth – CERN’s astronomy club member)

The Milky Way rising above Geneva. (Image: Klaus Barth – CERN’s astronomy club member)

Update on 23.09.2022: Unfortunately, given the unfavourable weather conditions, the public event “La nuit est belle au CERN” organized by the astronomy club is cancelled.


On 23 September, CERN, for the third year running, will join Greater Geneva in turning off its public lighting as part of the “La nuit est belle!” initiative.

The CERN Astronomy Club invites you to the CERN Meyrin site to gaze up at a luminous night’s sky, temporarily untarnished by the effects of light pollution. This free event will last about an hour and will kick off with a presentation briefing guests on the stars and constellations that they will be able to observe over the course of the evening. The remainder of the event will be devoted to stargazing with telescopes and binoculars. Check out the Indico events page for more information and to register your attendance.

The aim of “La nuit est belle!” is to educate the public on the impact of light pollution caused by excessive artificial lighting. The theme of the inaugural event was astronomy and stargazing, the second edition focused on protecting the biodiversity of nocturnal wildlife, and this year’s event will be dedicated to the importance of energy conservation.

More than 150 municipalities on both sides of the French-Swiss border are taking part in the event. Private individuals, shops, and companies are also being encouraged to switch off their lights to maximise the clarity and intensity of the night’s sky.

CERN will play its part in the event by cutting the lights of the Globe, the Esplanade des Particules, site entrances A, B, C and E, the roads, and carparks at both the Meyrin and Prévessin sites, as well as the lights at the LHC and SPS sites. CERN will thus be plunged into darkness for the whole evening and night of 23 September. Pedestrians and cyclists should take care to remain visible, and drivers must stay alert!

CERN also encourages people to act on their own initiative : turn off the lights in the office and at home, enjoy the evening, and look up at the magical night’s sky.

For more information, visit the website: La nuit est belle - Événement du Grand Genève