Dark Matter Day

Dark Matter Day is approaching … but don’t be afraid of the dark!

On Tuesday 31 October, the world will celebrate the historic hunt for the unseen - what scientists usually refer to as dark matter. As of 20:00, the Globe of science and innovation at CERN will open its door to the public.

Invisible dark matter makes up most of the universe – but we can only detect it from its gravitational effects. During this event at CERN, learn more about the experiments and theories that seek to provide us with a deeper understanding of this strange matter.

Dark Matter Day falls on Halloween! Why don't you come dressed-up... as dark matter! The best costume will win a prize.

More information and registration available here.
The full programme of #DarkMatterDay at CERN is available here.

The event will be in English with simultaneous interpretation into French and will be webcast.
Discover the worldwide programme of events on www.darkmatterday.com

Want to know more about dark matter? Watch our Facebook live on 31 October: http://cern.ch/go/67pZ

What is dark matter?

Dark matter explains how galaxies spin at a faster-than-expected rate without coming apart. Scientists know from these and other space observations that there is “missing” mass—something we can’t see—that makes up an estimated 85 percent of the total mass of the universe. So a big part of the universe is largely unknown to us.
Finding out what dark matter is made of is a pressing pursuit in physics. We don’t yet know if it’s composed of undiscovered particles or whether it requires some other change in our understanding of the universe’s laws of physics. A host of innovative experiments are searching for the source of dark matter using different types of tools, such as mile-deep detectors, powerful particle beams, and space-based and ground-based telescopes.

Why is there a day dedicated to dark matter?

Revealing dark matter’s true nature will tell us a lot about the origins, evolution, and overall structure in the universe, and will reshape our understanding of physics.
Dark Matter Day events are intended to educate the public about the importance of learning all we can about dark matter to develop a fuller picture of the unseen universe. Focusing more brainpower and scientific resources on dark matter’s mysteries could lead to new ideas and new discoveries.

Who is behind Dark Matter Day?

This first-ever Dark Matter Day campaign was conceived by the Interactions Collaboration, a group of science communicators representing the world’s particle physics laboratories. The collaboration also runs the www.darkmatterday.com website as a resource for people who want to host or attend local Dark Matter Day events.

Type of event


Event Date

31 Oct 2017, 20.00 - 22.00



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