Phobos

natural satellite of Mars
Thing moon_of_mars Q7547
Phobos
NASA / JPL-Caltech / University of Arizona · Public Domain · Wikimedia
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Summary

Phobos is a moon of Mars[1]. Phobos draws 17,513 Wikipedia views per month (moon of mars category, ranking #1 of 2).[2]

Key Facts

  • Discoverer or inventor: Asaph Hall[3]
  • Site of astronomical discovery: United States Naval Observatory[4]
  • Named after: Phobos[5]
  • Commons category: Phobos (moon)[6]
  • Parent astronomical body: Mars[7]
  • Time of discovery or invention: August 18, 1877[8], August 17, 1877[9]
  • IPA transcription: ˈfoːbɔs[10]
  • Topic's main category: Category:Phobos (moon)[11]
  • Commons gallery: Phobos[12]
  • Orbital eccentricity: 0.0151[13]
  • Apparent magnitude: 11.8[14]
  • Described by source: Otto's encyclopedia[15]
  • Topic has template: Template:GeoTemplate/phobos[16]
  • Orbital inclination: 26.04 degree[17]
  • Density: 1.876 gram per cubic centimetre[18]
  • Mass: 10.66 exagram[19]
  • Orbital period: 0.3189 day[20]
  • Semi-major axis of an orbit: 9377.1 km[21]
  • Volume as quantity: 5695 cubic kilometre[22]
  • Apoapsis: 9517.58 km[23]
  • Periapsis: 9234.42 km[24]
  • Diameter: 22.5 km[25]
  • Albedo: 0.071[26]
  • On focus list of Wikimedia project: Wikipedia:Vital articles/Level/4[27]
  • Surface gravity: 0.0057 metres per second squared[28]

Body

Influence

Things named for Phobos include Phobos Ridge[29], a ridge[30].

Why It Matters

Phobos has Wikipedia articles in 30 language editions, a strong signal of global cultural recognition.[31] Phobos is known by 29 alternative names across languages and contexts.[32]

Entities named for Phobos include Phobos Ridge[29], a ridge[30].

References

Programmatic citations — every numbered marker resolves to a verifiable graph row below.

Direct Wikidata claims

  1. [3] ↑ . A Short History of Astronomy. wikidata.org.
  2. [4] ↑ . wikidata.org.
  3. [5] ↑ . wikidata.org.
  4. [6] ↑ . wikidata.org.
  5. [7] ↑ . wikidata.org.
  6. [8] ↑ . iopscience.iop.org. iopscience.iop.org. Provenance: wikidata.org.
  7. [9] ↑ . A Short History of Astronomy. wikidata.org.
  8. [10] ↑ . wikidata.org.
  9. [11] ↑ . wikidata.org.
  10. [12] ↑ . wikidata.org.
  11. [13] ↑ . wikidata.org.
  12. [14] ↑ . wikidata.org.
  13. [15] ↑ . wikidata.org.
  14. [16] ↑ . wikidata.org.
  15. [17] ↑ . wikidata.org.
  16. [18] ↑ . wikidata.org.
  17. [19] ↑ . ssd.jpl.nasa.gov. Retrieved . ssd.jpl.nasa.gov. Provenance: wikidata.org.
  18. [20] ↑ . wikidata.org.
  19. [21] ↑ . wikidata.org.
  20. [22] ↑ . wikidata.org.
  21. [23] ↑ . wikidata.org.
  22. [24] ↑ . wikidata.org.
  23. [25] ↑ . wikidata.org.
  24. [26] ↑ . wikidata.org.
  25. [27] ↑ . wikidata.org.
  26. [28] ↑ . wikidata.org.

Inverse relationships (entities pointing at this one)

  1. [29] ↑ . wikidata.org. → on this site

Inline context (facts about related entities)

  1. [30] ↑ . Wikidata. wikidata.org. → on this site

Class ancestry

  1. [1] ↑ . Wikidata. wikidata.org.

Aggregate / graph-position facts

  1. [2] ↑ . Wikimedia Foundation. dumps.wikimedia.org.
  2. [31] ↑ . Wikidata sitelinks. wikidata.org.
  3. [32] ↑ . Wikidata aliases. wikidata.org.

📑 Cite this page

Use these citations when quoting this entity in research, articles, AI prompts, or wherever provenance matters. We aggregate Wikidata + Wikipedia + authoritative open-data sources; the stitched, scored, cross-referenced view is what 4ort.xyz contributes.

APA 4ort.xyz Knowledge Graph. (2026). Phobos. Retrieved October 17, 2026, from https://4ort.xyz/entity/phobos
MLA “Phobos.” 4ort.xyz Knowledge Graph, 4ort.xyz, 17 Oct. 2026, https://4ort.xyz/entity/phobos.
BibTeX @misc{4ortxyz_phobos_2026, author = {{4ort.xyz Knowledge Graph}}, title = {{Phobos}}, year = {2026}, url = {https://4ort.xyz/entity/phobos}, note = {Accessed: 2026-10-17}}
LLM prompt According to 4ort.xyz Knowledge Graph (aggregator of Wikidata, Wikipedia, and authoritative open-data sources): Phobos — https://4ort.xyz/entity/phobos (retrieved 2026-10-17)

Canonical URL: https://4ort.xyz/entity/phobos · Last refreshed:

Edit History

Rolling log of changes to this entity's Wikidata record. Values shown reflect the current state of each edited property — follow the history link to see the precise diff for any edit.

  1. 6d ago · ~2026-54193-84 · 2026-10-12 view diff on Wikidata ↗
    Fandom article id → thesolarsystem:Phobos
    Sitelink count → 116
    Wikipedia languages → ['af', 'an', 'ar', 'as', 'ast', 'az', 'azb', 'ba', 'ban', 'bar', 'be', 'be_x_old
    Claims rich → —
    "/* wbsetclaim-create:2||1 */ Fandom article id: thesolarsystem:Phobos"
  2. 12w ago · Kirilloparma · 2026-07-25 view diff on Wikidata ↗
    Apoapsis → {'unit': 'Q828224', 'amount': '+9517.58'}
    P14470 → Locations/Phobos
    Periapsis → {'unit': 'Q828224', 'amount': '+9234.42'}
    "/* wbsetclaim-create:1||1 */ P14470: Locations/Phobos, Adding missing [[P:P14470|P14470]] and [[P:P9675|P9675]] qualifier based on [[P:P5247|P5247]]"
  3. 18w ago · FearlessSeamus · 2026-06-12 view diff on Wikidata ↗
    Aliases → —
    Topic's main category → Category:Phobos (moon)
    Apparent magnitude → {'amount': '+11.8'}
    Mass → {'unit': 'Q2655272', 'amount': '+10.66'}
    + 20 other properties edited (see Wikidata diff for full list)
    "/* wbsetclaim-create:2||1 */ Volume as quantity: 5,695±32 cubic kilometre"
Live feed via Wikidata EventStreams. New edits appear within minutes of being made on Wikidata.