21 Lutetia
main-belt asteroid
21 Lutetia is a large M-type asteroid in the main asteroid belt. It measures about 100 kilometers in diameter (120 km along its major axis). It was discovered in 1852 by Hermann Goldschmidt, and is named after Lutetia, the Latin name of the city of Paris.
Lutetia has an irregular shape and is heavily cratered, with the largest impact crater reaching 45 km in diameter. The surface is geologically heterogeneous and is intersected by a system of grooves and scarps, which are thought to be fractures. It has a high overall bulk density, suggesting that it is made of metal-rich rock.
The Rosetta probe passed within 3,162 km (1,965 mi) of Lutetia in July 2010. It was the largest asteroid visited by a spacecraft until Dawn arrived at Vesta in July 2011, and it is currently the 3rd largest asteroid to have ever been imaged in high quality by a spacecraft (after Vesta and Ceres).
Discovery and exploration
Lutetia was discovered on 15 November 1852, by Hermann Goldschmidt from the balcony of his apartment in Paris. A preliminary orbit for the asteroid was computed in November–December 1852 by German astronomer Georg Rümker and others.
This brief starts where responsible research should: with the source description of “21 Lutetia” as main-belt asteroid. Everything that follows is an evidence route, not borrowed authority.
Why this record matters
The subject matters to the general reference register because the source frames it as main-belt asteroid. Its deeper value depends on whether names, dates, institutions and citations support that framing.
Named sources, stable identifiers and responsible institutions provide the strongest route from overview to verifiable evidence. The source revision retrieved here is dated Sep 21, 2026. The linked authority identifier is Q107556. None of the 0 selected statements returned an explicit reference. The first chronological checks are 1852, 2010 and 2011.
A concise general-reference account can conceal disagreements about scope, terminology or the weight assigned to individual sources. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. 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
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The closest primary source, responsible institution and strongest cited specialist reference.
Three-step research path
- Establish the record: confirm the title “21 Lutetia”, its source revision and the description used here.
- Expand the search: follow 21 Lutetia primary sources, 21 Lutetia archive and Lutetia 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
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This entry incorporates text from “21 Lutetia” 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.