Dwarf planet · Dwarf planet (Kuiper belt)

Pluto

(134340) Pluto

Solar System

Scientific overview

Pluto is a dwarf planet (kuiper belt) in orbit around The Sun, at a mean distance of 5,906.4 million km from the Sun.

Physical characteristics

Mass	0.015 ×10²⁴ kg
Diameter	2,370 km
Radius	1,185 km
Density	2.095 g/cm³
Surface gravity	0.7 m/s²
Escape velocity	1.3 km/s
Rotation period	153.3 h (retrograde)
Mean temperature	-225 °C

Orbit

Distance from Sun	5,906.4 million km (39.481 AU)
Orbital period	247.94 years
Perihelion	4,436.8 million km
Aphelion	7,375.9 million km
Eccentricity	0.244
Orbital inclination	17.2°
Axial tilt	122.5°
Orbital velocity	4.7 km/s

Moons (1)

Charon603.6 km

Exploration

New Horizons2006

Sources

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.
NASA JPLJet Propulsion Laboratory / Solar System Dynamics
Orbital data, ephemerides, and small-body parameters for planets, asteroids, and comets.
IAUInternational Astronomical Union
Official naming, definitions, constellation boundaries, and astronomical nomenclature.

Quick facts

Type: Dwarf planet (Kuiper belt)
System: The Sun
Discovered: 1930 · Clyde Tombaugh
Moons: 5

Provenance & sources

review 2026.1

Asteria Scientific Review Process · verification: sourced · accurate

High evidenceconfirmed
Pluto is a dwarf planet in the Kuiper Belt; under the IAU's 2006 definition (Resolution B5) it is classified as a dwarf planet rather than the ninth planet.
Source: NASA (NSSDCA) — NASA Planetary Fact Sheet · Public domain (US Government work)
- NASA Planetary Fact Sheet, Planetary Fact Sheet
- IAU 2006 General Assembly — Definition of a Planet (Resolution B5) (2006)

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.

DatasetPluto Fact Sheet

NASA Goddard — NSSDCA

Cite (APA / BibTeX)

NASA Goddard — NSSDCA (n.d.). Pluto Fact Sheet. NASA Goddard — NSSDCA. https://nssdc.gsfc.nasa.gov/planetary/factsheet/plutofact.html

@misc{cite:factsheet-dwarf_planet-pluto,
  title        = {Pluto Fact Sheet},
  organization = {NASA Goddard — NSSDCA},
  year         = {n.d.},
  url          = {https://nssdc.gsfc.nasa.gov/planetary/factsheet/plutofact.html},
  note         = {Physical and orbital parameters for Pluto.}
}

Institutional pagePluto — NASA Solar System Exploration

NASA

Cite (APA / BibTeX)

NASA (n.d.). Pluto — NASA Solar System Exploration. NASA. https://science.nasa.gov/

@misc{cite:nasa-dwarf_planet-pluto,
  title        = {Pluto — NASA Solar System Exploration},
  organization = {NASA},
  year         = {n.d.},
  url          = {https://science.nasa.gov/},
  note         = {NASA overview of Pluto.}
}

Standards referenceIAU 2006 General Assembly — Definition of a Planet (Resolution B5)

2006

International Astronomical Union

Cite (APA / BibTeX)

International Astronomical Union (2006). IAU 2006 General Assembly — Definition of a Planet (Resolution B5). International Astronomical Union. https://www.iau.org/

@misc{cite:iau-planet-definition-2006,
  title        = {IAU 2006 General Assembly — Definition of a Planet (Resolution B5)},
  organization = {International Astronomical Union},
  year         = {2006},
  url          = {https://www.iau.org/},
  note         = {Established the 'dwarf planet' category under which Pluto is classified.}
}

Quality & authority

75%

Reviewed

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

Data from the NASA Planetary Fact Sheet & JPL (public domain). See source quality.

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Sources

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.

NASA JPLJet Propulsion Laboratory / Solar System Dynamics

Orbital data, ephemerides, and small-body parameters for planets, asteroids, and comets.

IAUInternational Astronomical Union

Official naming, definitions, constellation boundaries, and astronomical nomenclature.

NASA Goddard — NSSDCA (n.d.). Pluto Fact Sheet. NASA Goddard — NSSDCA. https://nssdc.gsfc.nasa.gov/planetary/factsheet/plutofact.html @misc{cite:factsheet-dwarf_planet-pluto, title = {Pluto Fact Sheet}, organization = {NASA Goddard — NSSDCA}, year = {n.d.}, url = {https://nssdc.gsfc.nasa.gov/planetary/factsheet/plutofact.html}, note = {Physical and orbital parameters for Pluto.} }

NASA (n.d.). Pluto — NASA Solar System Exploration. NASA. https://science.nasa.gov/ @misc{cite:nasa-dwarf_planet-pluto, title = {Pluto — NASA Solar System Exploration}, organization = {NASA}, year = {n.d.}, url = {https://science.nasa.gov/}, note = {NASA overview of Pluto.} }

International Astronomical Union (2006). IAU 2006 General Assembly — Definition of a Planet (Resolution B5). International Astronomical Union. https://www.iau.org/ @misc{cite:iau-planet-definition-2006, title = {IAU 2006 General Assembly — Definition of a Planet (Resolution B5)}, organization = {International Astronomical Union}, year = {2006}, url = {https://www.iau.org/}, note = {Established the 'dwarf planet' category under which Pluto is classified.} }