Atlas of Worlds

Systems comparison

How many moons does each world have in this catalog snapshot?

Recorded on 2026-09-02, Saturn leads the selected catalog with 293 moons.

For individual moons and their measurements, explore the satellite catalog.

Atlas leaves Moon, Titan, and Europa unranked because the catalogs read on 2026-09-02 do not establish subordinate-satellite counts for them.

Known moons ranked comparisonHow many moons does each world have in this catalog snapshot? Bars begin at zero; 9 of 12 worlds are ranked. Earth is Atlas’s default baseline and the reference marker. A bracket joins each shared rank; Atlas does not distinguish order at the stored tolerance. Of the 12 world rows, 2 positive-value bars are shown at a fixed locator minimum and are not proportional below it; use value labels and the table for exact comparison.Earthreference1Saturn293 moons2Jupiter115 moons3Uranus29 moons4Neptune16 moons5Pluto5 moons6Mars2 moons7Earth1 moon8=Mercury0 moons8=Venus0 moons—MoonNot established—TitanNot established—EuropaNot established
Known moons values run from highest to lowest; bars start at zero. Earth is the reference. A bracket means Atlas does not distinguish order at the stored tolerance. Of the 12 world rows, 2 positive-value bars are shown at a fixed locator minimum and are not proportional below it; use value labels and the table for exact comparison.
Values / method / sources

Values and sources

The chart, in inspectable form.

Every row keeps its reference level, resolution state, and source attached. Derived means Atlas calculated the value from published inputs with a registered formula.

Published comparison values. Known moons is shown in moons; differences are measured from Earth. Shared ranks use the stored comparison tolerance.
RankWorldValuevs. EarthReference levelStateEvidence
Saturn293 moons+292 moonsNot applicableSettled
Source passportSettledNASA Jet Propulsion Laboratory Solar System Dynamics

Source passport: Saturn

Published value
293 moons
Primary source
NASA Jet Propulsion Laboratory Solar System Dynamics
Definition
natural satellites recorded by the selected NASA/JPL catalog at the stored Atlas snapshot epoch; JPL's discovery roster is limited to satellites officially recognized by the IAU
Reference level
Not applicable
Epoch
2026-09-02
Resolution state
Settled

Provenance details

Uncertainty
Not stated
Alternatives
No competing admissible value
Value ID
saturn:moon_count:iau_recognized_natural_satellites:jpl_satellite_discovery_circumstances:0
Dataset version
0.1

Sources

  1. Planetary Satellite Discovery CircumstancesNASA Jet Propulsion Laboratory Solar System DynamicsJPL Solar System Dynamics. Planetary Satellite Discovery Circumstances. NASA Jet Propulsion Laboratory. Catalog read 2026-09-02.Locator: Planetary Satellite Discovery Circumstances, Satellites of Saturn: 293Retrieved 2026-09-02 · published Not statedTier A · us-government-work · reuse allowedAtlas retains catalog counts with NASA/JPL credit. The page footer says the data were last updated 2023-May-23, but the roster contains 2026 discovery references and totals 460; Atlas therefore records its 2026-09-02 catalog read as the value snapshot instead of treating the stale footer as an epoch.
Jupiter115 moons+114 moonsNot applicableSettled
Source passportSettledNASA Jet Propulsion Laboratory Solar System Dynamics

Source passport: Jupiter

Published value
115 moons
Primary source
NASA Jet Propulsion Laboratory Solar System Dynamics
Definition
natural satellites recorded by the selected NASA/JPL catalog at the stored Atlas snapshot epoch; JPL's discovery roster is limited to satellites officially recognized by the IAU
Reference level
Not applicable
Epoch
2026-09-02
Resolution state
Settled

Provenance details

Uncertainty
Not stated
Alternatives
No competing admissible value
Value ID
jupiter:moon_count:iau_recognized_natural_satellites:jpl_satellite_discovery_circumstances:0
Dataset version
0.1

Sources

  1. Planetary Satellite Discovery CircumstancesNASA Jet Propulsion Laboratory Solar System DynamicsJPL Solar System Dynamics. Planetary Satellite Discovery Circumstances. NASA Jet Propulsion Laboratory. Catalog read 2026-09-02.Locator: Planetary Satellite Discovery Circumstances, Satellites of Jupiter: 115Retrieved 2026-09-02 · published Not statedTier A · us-government-work · reuse allowedAtlas retains catalog counts with NASA/JPL credit. The page footer says the data were last updated 2023-May-23, but the roster contains 2026 discovery references and totals 460; Atlas therefore records its 2026-09-02 catalog read as the value snapshot instead of treating the stale footer as an epoch.
Uranus29 moons+28 moonsNot applicableSettled
Source passportSettledNASA Jet Propulsion Laboratory Solar System Dynamics

Source passport: Uranus

Published value
29 moons
Primary source
NASA Jet Propulsion Laboratory Solar System Dynamics
Definition
natural satellites recorded by the selected NASA/JPL catalog at the stored Atlas snapshot epoch; JPL's discovery roster is limited to satellites officially recognized by the IAU
Reference level
Not applicable
Epoch
2026-09-02
Resolution state
Settled

Provenance details

Uncertainty
Not stated
Alternatives
No competing admissible value
Value ID
uranus:moon_count:iau_recognized_natural_satellites:jpl_satellite_discovery_circumstances:0
Dataset version
0.1

Sources

  1. Planetary Satellite Discovery CircumstancesNASA Jet Propulsion Laboratory Solar System DynamicsJPL Solar System Dynamics. Planetary Satellite Discovery Circumstances. NASA Jet Propulsion Laboratory. Catalog read 2026-09-02.Locator: Planetary Satellite Discovery Circumstances, Satellites of Uranus: 29Retrieved 2026-09-02 · published Not statedTier A · us-government-work · reuse allowedAtlas retains catalog counts with NASA/JPL credit. The page footer says the data were last updated 2023-May-23, but the roster contains 2026 discovery references and totals 460; Atlas therefore records its 2026-09-02 catalog read as the value snapshot instead of treating the stale footer as an epoch.
Neptune16 moons+15 moonsNot applicableSettled
Source passportSettledNASA Jet Propulsion Laboratory Solar System Dynamics

Source passport: Neptune

Published value
16 moons
Primary source
NASA Jet Propulsion Laboratory Solar System Dynamics
Definition
natural satellites recorded by the selected NASA/JPL catalog at the stored Atlas snapshot epoch; JPL's discovery roster is limited to satellites officially recognized by the IAU
Reference level
Not applicable
Epoch
2026-09-02
Resolution state
Settled

Provenance details

Uncertainty
Not stated
Alternatives
No competing admissible value
Value ID
neptune:moon_count:iau_recognized_natural_satellites:jpl_satellite_discovery_circumstances:0
Dataset version
0.1

Sources

  1. Planetary Satellite Discovery CircumstancesNASA Jet Propulsion Laboratory Solar System DynamicsJPL Solar System Dynamics. Planetary Satellite Discovery Circumstances. NASA Jet Propulsion Laboratory. Catalog read 2026-09-02.Locator: Planetary Satellite Discovery Circumstances, Satellites of Neptune: 16Retrieved 2026-09-02 · published Not statedTier A · us-government-work · reuse allowedAtlas retains catalog counts with NASA/JPL credit. The page footer says the data were last updated 2023-May-23, but the roster contains 2026 discovery references and totals 460; Atlas therefore records its 2026-09-02 catalog read as the value snapshot instead of treating the stale footer as an epoch.
Pluto5 moons+4 moonsNot applicableSettled
Source passportSettledNASA Jet Propulsion Laboratory Solar System Dynamics

Source passport: Pluto

Published value
5 moons
Primary source
NASA Jet Propulsion Laboratory Solar System Dynamics
Definition
natural satellites recorded by the selected NASA/JPL catalog at the stored Atlas snapshot epoch; JPL's discovery roster is limited to satellites officially recognized by the IAU
Reference level
Not applicable
Epoch
2026-09-02
Resolution state
Settled

Provenance details

Uncertainty
Not stated
Alternatives
No competing admissible value
Value ID
pluto:moon_count:iau_recognized_natural_satellites:jpl_satellite_discovery_circumstances:0
Dataset version
0.1

Sources

  1. Planetary Satellite Discovery CircumstancesNASA Jet Propulsion Laboratory Solar System DynamicsJPL Solar System Dynamics. Planetary Satellite Discovery Circumstances. NASA Jet Propulsion Laboratory. Catalog read 2026-09-02.Locator: Planetary Satellite Discovery Circumstances, Satellites of Dwarf Planet Pluto: 5Retrieved 2026-09-02 · published Not statedTier A · us-government-work · reuse allowedAtlas retains catalog counts with NASA/JPL credit. The page footer says the data were last updated 2023-May-23, but the roster contains 2026 discovery references and totals 460; Atlas therefore records its 2026-09-02 catalog read as the value snapshot instead of treating the stale footer as an epoch.
Mars2 moons+1 moonNot applicableSettled
Source passportSettledNASA Jet Propulsion Laboratory Solar System Dynamics

Source passport: Mars

Published value
2 moons
Primary source
NASA Jet Propulsion Laboratory Solar System Dynamics
Definition
natural satellites recorded by the selected NASA/JPL catalog at the stored Atlas snapshot epoch; JPL's discovery roster is limited to satellites officially recognized by the IAU
Reference level
Not applicable
Epoch
2026-09-02
Resolution state
Settled

Provenance details

Uncertainty
Not stated
Alternatives
No competing admissible value
Value ID
mars:moon_count:iau_recognized_natural_satellites:jpl_satellite_discovery_circumstances:0
Dataset version
0.1

Sources

  1. Planetary Satellite Discovery CircumstancesNASA Jet Propulsion Laboratory Solar System DynamicsJPL Solar System Dynamics. Planetary Satellite Discovery Circumstances. NASA Jet Propulsion Laboratory. Catalog read 2026-09-02.Locator: Planetary Satellite Discovery Circumstances, Satellites of Mars: 2Retrieved 2026-09-02 · published Not statedTier A · us-government-work · reuse allowedAtlas retains catalog counts with NASA/JPL credit. The page footer says the data were last updated 2023-May-23, but the roster contains 2026 discovery references and totals 460; Atlas therefore records its 2026-09-02 catalog read as the value snapshot instead of treating the stale footer as an epoch.
EarthDefault baselineReference1 moon0 moonsNot applicableSettled
Source passportSettledNASA Goddard Space Flight Center National Space Science Data Center

Source passport: Earth

Published value
1 moon
Primary source
NASA Goddard Space Flight Center National Space Science Data Center
Definition
natural satellites recorded by the selected NASA/JPL catalog at the stored Atlas snapshot epoch; JPL's discovery roster is limited to satellites officially recognized by the IAU
Reference level
Not applicable
Epoch
2026-09-02
Resolution state
Settled

Provenance details

Uncertainty
Not stated
Alternatives
No competing admissible value
Value ID
earth:moon_count:iau_recognized_natural_satellites:nasa_nssdc_earth_fact_sheet_archive:0
Dataset version
0.1

Sources

  1. Earth Fact Sheet (2024-11-16 NASA NSSDC archive capture)NASA Goddard Space Flight Center National Space Science Data CenterNASA NSSDC. Earth Fact Sheet. Archived 2024-11-16; retrieved 2026-09-02.Locator: Earth Fact Sheet, Bulk parameters, Number of natural satellites: 1Retrieved 2026-09-02 · published Not statedTier B · us-government-work · reuse allowedThe live NSSDC host was unavailable during review, so Atlas cites a dated, immutable capture transparently. Each candidate locator transcribes the cited field's label, value, and unit.
Mercury0 moons−1 moonNot applicableSettled
Source passportSettledNASA Goddard Space Flight Center National Space Science Data Center

Source passport: Mercury

Published value
0 moons
Primary source
NASA Goddard Space Flight Center National Space Science Data Center
Definition
natural satellites recorded by the selected NASA/JPL catalog at the stored Atlas snapshot epoch; JPL's discovery roster is limited to satellites officially recognized by the IAU
Reference level
Not applicable
Epoch
2026-09-02
Resolution state
Settled

Provenance details

Uncertainty
Not stated
Alternatives
No competing admissible value
Value ID
mercury:moon_count:iau_recognized_natural_satellites:nasa_nssdc_mercury_fact_sheet_archive:0
Dataset version
0.1

Sources

  1. Mercury Fact Sheet (2024-02-04 NASA NSSDC archive capture)NASA Goddard Space Flight Center National Space Science Data CenterNASA NSSDC. Mercury Fact Sheet. Archived 2024-02-04; retrieved 2026-09-02.Locator: Mercury/Earth comparison table, Number of natural satellites: Mercury 0; Earth 1Retrieved 2026-09-02 · published Not statedTier B · us-government-work · reuse allowedThe live NSSDC host was unavailable during review, so Atlas cites a dated, immutable capture transparently. Each candidate locator transcribes the cited field's label, value, and unit.
Venus0 moons−1 moonNot applicableSettled
Source passportSettledNASA Goddard Space Flight Center National Space Science Data Center

Source passport: Venus

Published value
0 moons
Primary source
NASA Goddard Space Flight Center National Space Science Data Center
Definition
natural satellites recorded by the selected NASA/JPL catalog at the stored Atlas snapshot epoch; JPL's discovery roster is limited to satellites officially recognized by the IAU
Reference level
Not applicable
Epoch
2026-09-02
Resolution state
Settled

Provenance details

Uncertainty
Not stated
Alternatives
No competing admissible value
Value ID
venus:moon_count:iau_recognized_natural_satellites:nasa_nssdc_venus_fact_sheet_archive:0
Dataset version
0.1

Sources

  1. Venus Fact Sheet (2024-02-04 NASA NSSDC archive capture)NASA Goddard Space Flight Center National Space Science Data CenterNASA NSSDC. Venus Fact Sheet. Archived 2024-02-04; retrieved 2026-09-02.Locator: Venus/Earth comparison table, Number of natural satellites: Venus 0; Earth 1Retrieved 2026-09-02 · published Not statedTier B · us-government-work · reuse allowedThe live NSSDC host was unavailable during review, so Atlas cites a dated, immutable capture transparently. Each candidate locator transcribes the cited field's label, value, and unit.
—MoonNot established—Not applicableNot established
Source passportNot establishedNo admissible source

Source passport: Moon

Canonical value
Not established
Canonical source
No admissible source
Definition
natural satellites recorded by the selected NASA/JPL catalog at the stored Atlas snapshot epoch; JPL's discovery roster is limited to satellites officially recognized by the IAU
Reference level
Not applicable
Epoch
Not tied to a stated epoch
Resolution state
Not established

Provenance details

Uncertainty
Not stated
Alternatives
No competing admissible value
Value ID
moon:moon_count:iau_recognized_natural_satellites:unknown:0
Dataset version
0.1

Related context sources

No source is available for the canonical value or related context.

—TitanNot established—Not applicableNot established
Source passportNot establishedNo admissible source

Source passport: Titan

Canonical value
Not established
Canonical source
No admissible source
Definition
natural satellites recorded by the selected NASA/JPL catalog at the stored Atlas snapshot epoch; JPL's discovery roster is limited to satellites officially recognized by the IAU
Reference level
Not applicable
Epoch
Not tied to a stated epoch
Resolution state
Not established

Provenance details

Uncertainty
Not stated
Alternatives
No competing admissible value
Value ID
titan:moon_count:iau_recognized_natural_satellites:unknown:0
Dataset version
0.1

Related context sources

No source is available for the canonical value or related context.

—EuropaNot established—Not applicableNot established
Source passportNot establishedNo admissible source

Source passport: Europa

Canonical value
Not established
Canonical source
No admissible source
Definition
natural satellites recorded by the selected NASA/JPL catalog at the stored Atlas snapshot epoch; JPL's discovery roster is limited to satellites officially recognized by the IAU
Reference level
Not applicable
Epoch
Not tied to a stated epoch
Resolution state
Not established

Provenance details

Uncertainty
Not stated
Alternatives
No competing admissible value
Value ID
europa:moon_count:iau_recognized_natural_satellites:unknown:0
Dataset version
0.1

Related context sources

No source is available for the canonical value or related context.

Why the result changes

Why this order?

Moon counts are catalog snapshots, not permanent properties. Atlas freezes one reading date so every ranked count belongs to the same comparison.

Counts describe the selected catalogs when Atlas read them, not a continuously updated total. Recognition can change between snapshots.

Recorded on 2026-09-02, the leading systems are Saturn, Jupiter, then Uranus.

Definition and evidence

What this comparison means.

Definitions

  • natural satellites recorded by the selected NASA/JPL catalog at the stored Atlas snapshot epoch; JPL's discovery roster is limited to satellites officially recognized by the IAU

JPL's roster covers satellites of planets and Pluto but excludes Earth; Atlas uses NASA fact-sheet rows for Earth, Mercury, and Venus. Moon, Titan, and Europa remain unranked because the selected catalogs do not establish subordinate-satellite counts. Unconfirmed candidates, ring particles, moonlets, arcs, and temporary captures are outside this count.

Resolution states

Settled
Admissible values agree.
Derived
Calculated from published inputs.
Contested
Admissible values disagree.
Not established
No admissible value fits the definition.

Identity marks—not to scale

  • Mercury
  • Venus
  • Earth
  • Mars
  • Jupiter
  • Saturn
  • Uranus
  • Neptune
  • Moon
  • Titan
  • Europa
  • Pluto

Credit: Blue Marble, March 2014 — NASA/GSFC; Europa full disk, Galileo — NASA/JPL; Full Moon — NASA/GSFC; High-resolution Jupiter globe — NASA/JPL/University of Arizona; Mars global mosaic — NASA/USGS; Mercury globe — NASA/JHUAPL/Carnegie Institution of Washington; Neptune, Voyager 2 — NASA/JPL; Pluto color view — NASA/JHUAPL/SwRI; Saturn, Cassini — NASA/JPL/Space Science Institute; Titan natural-color composite, Cassini — NASA/JPL/Space Science Institute; Uranus, Voyager 2 — NASA/JPL-Caltech; Venus radar-data globe — NASA/JPL

Dataset 0.1 · source records retrieved 2026-09-02 · canonical page /worlds/moons/

Sources used by this comparison

  1. Planetary Satellite Discovery CircumstancesNASA Jet Propulsion Laboratory Solar System DynamicsTier A
  2. Earth Fact Sheet (2024-11-16 NASA NSSDC archive capture)NASA Goddard Space Flight Center National Space Science Data CenterTier B
  3. Mercury Fact Sheet (2024-02-04 NASA NSSDC archive capture)NASA Goddard Space Flight Center National Space Science Data CenterTier B
  4. Venus Fact Sheet (2024-02-04 NASA NSSDC archive capture)NASA Goddard Space Flight Center National Space Science Data CenterTier B

Keep and reuse

Link, cite, download, or present this comparison.

The link and citation track meaningful view settings. The CSV is one stable, reference-independent table with no reference-derived comparison column.

https://yalethom.as/worlds/moons/

Cite this view

Yale Thomas. Atlas of Worlds. “How many moons does each world have in this catalog snapshot?” View: default. Dataset 0.1. https://yalethom.as/worlds/moons/. Accessed [the date you viewed this page].

Without JavaScript, Atlas leaves a bracketed instruction so you can supply the date you viewed the page.

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Includes stable body, role, definition, value, provenance, version, attribution, and license fields in display order.

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