Dark Matter Day



Dark Matter Day (animation)

What is Dark Matter?

There’s more to the universe than stars, planets, asteroids, comets, and space dust. In fact, there’s a lot more to the universe that we can’t yet explain.

Scientists believe that dark matter, which we have so far only detected through its gravity-based effects in space, makes up about a quarter (26.8 percent) of the total mass and energy of the universe, and something that is driving the universe’s accelerating expansion—which scientists call dark energy—accounts for another 68.3 percent. The ordinary matter, like stars and planets and galaxies, makes up just 4.9 percent of the total mass and energy of the universe.

So there’s a BIG part of the universe that we don’t know much about. We’re not sure if dark matter is made up of undiscovered particles, or if it can be explained by tweaking the known laws of physics. Its makeup could teach us much about the history and structure of our universe.

Plan an Event

Want to plan a Dark Matter Day event in your community? We can help! Check out the links below to resources that can help you find and connect with local dark matter experts, plan a program for a particular audience, and promote and share your event with the world.

Begin preparing for Dark Matter Day 2023 by familiarizing yourself with these resources.

Plan an Event

veritas and building
world map

Celebrate Dark Matter Day

On and around October 31st, 2023, the world will celebrate the historic hunt for the unseen—something that scientists refer to as dark matter.

Since 2017, more than 159 global, regional, and local events have been held on and around October 31 by institutions and individuals looking to engage the public in discussions about what we already know about dark matter and the many experiments seeking to solve its mysteries.

Find a Dark Matter Day Event