While we can't directly observe dark matter, its existence is inferred through its gravitational effects on visible matter, such as galaxies and galaxy clusters. It is estimated to make up about 85% of the total matter in the universe.
Here's why it's called "dark":
* No electromagnetic radiation: Dark matter does not interact with light or other forms of electromagnetic radiation, meaning we can't see it directly with telescopes.
* Mysterious nature: Its exact composition is still unknown, though leading theories include weakly interacting massive particles (WIMPs) or axions.
It's important to distinguish between "dark matter" and "dark energy," another mysterious component of the universe that is responsible for accelerating the expansion of the universe.
