Cosmological concept · Cosmology

Dark Matter

Cosmology & UniverseStrong Evidence

Definition

An unseen form of matter, detected only through its gravity, that outweighs ordinary matter roughly five to one.

Scientific overview

Dark matter does not emit or absorb light, but its gravity is required to explain the rotation of galaxies, the motions of galaxy clusters, gravitational lensing, and the pattern of the cosmic microwave background. It makes up about 27% of the Universe.

Evidence

Flat galaxy rotation curves (Rubin)
Cluster dynamics (Zwicky, 1933)
Gravitational lensing, e.g. the Bullet Cluster
The CMB power spectrum

Current measurements

Fraction of the Universe

≈ 27%

Planck Collaboration

Open questions

What is dark matter made of (WIMPs, axions, something else)?
Why has no particle been detected directly?
Could modified gravity explain the observations instead?

Rests on

General Relativity

Related discoveries & objects

Evidence for Dark Matter

Measured by

Planck

Euclid

Related scientists

Vera Rubin

Fritz Zwicky

Dark Matter Halo

Knowledge connections

Required byStructure Formation
Required byThe Present Universe
Related toDark Matter Halo
Part of modelThe Lambda-CDM Model
Depends onGeneral Relativity
Related toEvidence for Dark Matter
Studied byVera Rubin
Studied byFritz Zwicky
Measured byPlanck
Measured byEuclid
Related toThe Standard Model (overview)
Related toThe Lambda-CDM Model
Related toModified Newtonian Dynamics (MOND)
Related toPrimordial Black Hole
Required byDark Matter Halo
Associated withGravitational Lensing
Associated withGalaxy Rotation Curves
Associated withThe Coma Cluster
Associated withMatter Density (Ωm)
Associated withAmplitude of Fluctuations (σ8)
Associated withGalactic Rotation

Sources & references

Facts on this topic will be cited from these primary and reference sources.

NASANational Aeronautics and Space Administration
Mission data, planetary science, space telescopes, and public-domain imagery.
Most NASA-produced imagery is in the public domain; individual items are checked for usage terms before publication.
Planck CollaborationESA Planck mission / Planck Collaboration
Cosmic microwave background maps and the cosmological parameters of the ΛCDM model.
ESAEuropean Space Agency
European missions, observatories, and space science imagery.

Quick facts

Type: Cosmological concept
Field: Cosmology
Consensus: Strong Evidence
Part of model: The Lambda-CDM Model

Scientific consensus

Strong Evidence

Strongly supported by multiple independent observations; some details remain open.

Quality & authority

63%

Reviewed

Completeness: Complete
Source coverage: Complete
Citation coverage: Complete
Relationship coverage: Complete
Review coverage: Complete
Image coverage: None

Curated from authoritative sources. See source quality.

Provenance & sources

review 2026.1

Asteria Scientific Review Process · verification: sourced · accurate

Moderate evidencelikely
Dark matter is unseen mass whose gravitational effects are inferred from galaxy rotation curves, gravitational lensing, and the cosmic microwave background; it constitutes most of the matter in the universe, although its physical nature is unknown.
Source: ESA — Planck Collaboration
- Planck 2018 results. VI. Cosmological parameters, Astronomy & Astrophysics 641, A6 (2020)doi:10.1051/0004-6361/201833910
Limitation: The gravitational evidence for dark matter's existence is strong, but its underlying nature is unknown — so this is rated moderate, not high, and is not overstated.

Reviewed by the internal Asteria Scientific Review Process — not an external institutional review. See the evidence framework and authority dashboard.

Scientific citations

Real, source-backed references — primary papers first, then datasets and institutional sources. Formatted through the citation engine; nothing is fabricated.

Peer-reviewed paperRotation of the Andromeda Nebula from a Spectroscopic Survey of Emission Regions

Vera C. Rubin & W. Kent Ford Jr. · The Astrophysical Journal 159, 379 · 1970

The Astrophysical Journal · doi:10.1086/150317

Cite (APA / BibTeX)

Vera C. Rubin & W. Kent Ford Jr. (1970). Rotation of the Andromeda Nebula from a Spectroscopic Survey of Emission Regions. The Astrophysical Journal 159, 379. The Astrophysical Journal. https://doi.org/10.1086/150317

@misc{cite:rubin-ford-1970,
  title        = {Rotation of the Andromeda Nebula from a Spectroscopic Survey of Emission Regions},
  author       = {Vera C. Rubin and W. Kent Ford Jr.},
  organization = {The Astrophysical Journal},
  howpublished = {The Astrophysical Journal 159, 379},
  year         = {1970},
  doi          = {10.1086/150317},
  url          = {https://doi.org/10.1086/150317},
  note         = {Andromeda rotation curve — evidence for dark matter.}
}

Institutional pageDark Matter — NASA Universe

NASA

Cite (APA / BibTeX)

NASA (n.d.). Dark Matter — NASA Universe. NASA. https://science.nasa.gov/

@misc{cite:nasa-cosmo-dark-matter,
  title        = {Dark Matter — NASA Universe},
  organization = {NASA},
  year         = {n.d.},
  url          = {https://science.nasa.gov/},
  note         = {NASA science overview: Dark Matter.}
}

Loading…

Sources & references

Facts on this topic will be cited from these primary and reference sources.

NASANational Aeronautics and Space Administration

Mission data, planetary science, space telescopes, and public-domain imagery.

Most NASA-produced imagery is in the public domain; individual items are checked for usage terms before publication.

Planck CollaborationESA Planck mission / Planck Collaboration

Cosmic microwave background maps and the cosmological parameters of the ΛCDM model.

ESAEuropean Space Agency

European missions, observatories, and space science imagery.

Vera C. Rubin & W. Kent Ford Jr. (1970). Rotation of the Andromeda Nebula from a Spectroscopic Survey of Emission Regions. The Astrophysical Journal 159, 379. The Astrophysical Journal. https://doi.org/10.1086/150317 @misc{cite:rubin-ford-1970, title = {Rotation of the Andromeda Nebula from a Spectroscopic Survey of Emission Regions}, author = {Vera C. Rubin and W. Kent Ford Jr.}, organization = {The Astrophysical Journal}, howpublished = {The Astrophysical Journal 159, 379}, year = {1970}, doi = {10.1086/150317}, url = {https://doi.org/10.1086/150317}, note = {Andromeda rotation curve — evidence for dark matter.} }

NASA (n.d.). Dark Matter — NASA Universe. NASA. https://science.nasa.gov/ @misc{cite:nasa-cosmo-dark-matter, title = {Dark Matter — NASA Universe}, organization = {NASA}, year = {n.d.}, url = {https://science.nasa.gov/}, note = {NASA science overview: Dark Matter.} }

Dark Matter

Definition

Scientific overview

Evidence

Current measurements

Open questions

Rests on

Related discoveries & objects

Measured by

Related scientists

Related topics

Knowledge connections

Sources & references

Dark Matter

Definition

Scientific overview

Evidence

Current measurements

Open questions

Rests on

Related discoveries & objects

Measured by

Related scientists

Related topics

Knowledge connections

Sources & references