Magma ocean
large area of molten rock on the surface of a planet
Magma oceans are vast fields of surface magma that exist during periods of a planet's or some natural satellite's accretion when the celestial body is completely or partly molten.
In the early Solar System, magma oceans were formed by the melting of planetesimals and planetary impacts. Small planetesimals are melted by the heat provided by the radioactive decay of aluminium-26. As planets grew larger, the energy was then supplied from giant impacts with other planetary bodies. Magma oceans are integral parts of planetary formation as they facilitate the formation of a core through metal segregation and an atmosphere and hydrosphere through degassing. Evidence exists to support the existence of magma oceans on both the Earth and the Moon. Magma oceans may survive for millions to tens of millions of years, interspersed by relatively mild conditions.
Magma ocean heat sources
The sources of the energy required for the formation of magma oceans in the early solar system were the radioactive decay of aluminium-26, accretionary impacts, and core formation. The abundance and short half life of aluminium-26 allowed it to function as one of the sources of heat for the melting of planetesimals. With aluminium-26 as a heat source, planetesimals that had accreted within 2 Ma after the formation of the first solids in the solar system could melt.
Begin with the source’s own compact description: “Magma ocean” is large area of molten rock on the surface of a planet. The dossier treats that line as a proposition to test through Magma, ocean and large, not as a finished interpretation.
Why this record matters
The phrase “large area of molten rock on the surface of a planet” supplies a clear boundary for inquiry. It also exposes the unanswered questions: who defined that boundary, when it became stable and which sources sit outside it.
Vocabulary and entity names are the principal evidence signals here, because they determine the precision of every later search. The source revision retrieved here is dated Jun 21, 2026. The linked authority identifier is Q12034896. None of the 0 selected statements returned an explicit reference.
A concise general-reference account can conceal disagreements about scope, terminology or the weight assigned to individual sources. The source lead contains qualifying language; that uncertainty should survive quotation, summary and reuse. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Use the entry as an orientation point, then follow its citations and revision history. Names, dates and institutional relationships should be checked against the original record.
- Subject orientation
- Search vocabulary
- Locating named sources
The closest primary source, responsible institution and strongest cited specialist reference.
Three-step research path
- Establish the record: confirm the title “Magma ocean”, its source revision and the description used here.
- Expand the search: follow Magma ocean primary sources, Magma ocean archive and Magma research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “Magma ocean”?
- What terminology or title could unlock a more precise catalogue search?
- Which cited source is closest to the event, object or claim?
Search terms from this dossier
This entry incorporates text from “Magma ocean” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.