Only 5% of our universe is made of visible matter - everything we can see, from Earth to distant stars, is just a tiny fraction of what exists.
Dark matter neither absorbs, reflects, nor radiates light, making it completely invisible to all forms of electromagnetic radiation we know.
The mystery of dark matter was first proposed by astronomer Fritz Zwicky 80 years ago when studying the unusually fast movement of galaxies in the Coma cluster.
Scientists believe dark matter may consist of unknown particles created during the universe's early phases, possibly including axions and neutrinos.
Galaxy clusters' strong gravitational forces binding thousands of galaxies together suggest the presence of invisible mass - dark matter.
Dark matter makes up approximately 85% of the universe's total mass, or about 30% of its combined mass-energy.
As Newton said, "What we know is a drop, what we don't know is an ocean" - perfectly capturing our current understanding of dark matter.
Gravitational lensing, which creates strange rings around galaxies, might be explained by dark matter's invisible presence.
Current tools and technologies cannot detect dark matter directly, making it one of space's greatest ongoing mysteries.
Scientists study the movement of visible objects within galaxy clusters to estimate how much invisible mass exists in these regions.