Science
What is Dark matter?
Dark matter is an invisible form of matter that doesn't emit or reflect light but makes up about 27% of the universe. We know it exists because its gravity holds galaxies together and bends light, even though we can't see it directly.
See it, don’t just read it.
Watch a 2-minute lesson with voice + animation that explains dark matter.
Key things to understand
- 1It doesn't interact with light, so it's invisible to telescopes.
- 2We infer it from gravity — galaxies spin too fast to hold together without extra unseen mass.
- 3It outweighs ordinary matter roughly 5 to 1.
- 4Its true nature is still one of the biggest open questions in physics.
Frequently asked questions
- How do we know dark matter exists?
- Galaxies rotate faster than their visible mass allows, and light bends around invisible mass — both point to unseen matter.
- What is dark matter made of?
- Unknown — it isn't ordinary atoms; leading candidates are as-yet-undiscovered particles.
- Is dark matter the same as dark energy?
- No — dark matter pulls things together via gravity; dark energy pushes the universe to expand faster.