Dark matter is a mysterious substance that makes up about 27% of the universe's total mass and energy. It doesn't emit, absorb, or reflect light, which is why it's invisible and "dark" in terms of traditional observations. Scientists infer its existence by observing its gravitational effects on visible matter, such as stars and galaxies.

Dark matter plays a crucial role in the formation and evolution of galaxies, as its gravitational pull helps to bind galaxies together. However, its exact nature remains one of the biggest mysteries in modern astrophysics. Various theories propose that dark matter could consist of undiscovered subatomic particles or even be a manifestation of a new kind of fundamental force beyond the known four fundamental forces of nature.

Efforts to detect dark matter directly have so far been unsuccessful, but researchers continue to investigate its properties and search for experimental evidence that could help unravel its mysteries.