Astronomers describe the universe as being made mostly of dark energy, dark matter, and a small amount of ordinary matter, plus a tiny contribution from radiation.

Main ingredients

• Dark energy: About two‑thirds to roughly 70% of the universe’s total mass‑energy, acting like a repulsive effect that drives the accelerated expansion of space.

• Dark matter: Around a quarter to just under 30%, an invisible form of matter that interacts via gravity and helps hold galaxies and clusters together.

• Ordinary (baryonic) matter: Only about 5% of the total, made of protons, neutrons, and electrons, forming stars, planets, gas, dust, and everything directly observable.

Minor but important components

• Radiation: Includes photons such as starlight and the cosmic microwave background; it contributes well under 1% of the universe’s mass‑energy today but carries key information about the early universe.

• Antimatter and neutrinos: Present in much smaller amounts in the current universe, but important in particle physics and in processes in the early universe and high‑energy environments like supernovae.

Summary table

Component| Approx. share today| Role in universe
---|---|---
Dark energy| ~68–70%| Drives accelerated expansion of space. 132
Dark matter| ~25–27%| Provides extra gravity, shapes galaxies and large‑scale structure. 135
Ordinary matter| ~5%| Forms stars, planets, gas, dust, and living things. 357
Radiation, etc.| <1%| Includes light and relic radiation, traces early universe conditions. 135