1.1 Objectives. These Guidelines are designed to provide a rational system of nomenclature to be adopted by the discoverers of new meteorites which will avoid confusion and ambiguity in published reports on existing meteorites. The Guidelines should also be acceptable for common-place usage in the field or laboratory and will assist the prompt announcement of new meteorites. In addition, the Guidelines are intended to ensure that type specimens of all new meteorites are preserved in collections that make material available for research1.2 Scope. These Guidelines provide a framework for naming objects that are commonly recognized to be meteorites.
a) Meteorites to be named under the Guidelines include objects found on the Earth as well as on other solar system bodies during the course of space exploration.
b) The following types of materials are NOT to be named under these Guidelines: micrometeorites and interplanetary dust particles; xenolithic clasts in other meteorites; artificial meteorites; pseudometeorites; impact craters, tektites, and other impact-produced materials; and, meteoroids or other small bodies in space.
c) Special provisions are made in these Guidelines for highly altered materials that may have a meteoritic origin, designated relict meteorites, which are dominantly (>95%) composed of secondary minerals formed on the body on which the object was found. Examples of such material may include some types of "meteorite shale," "fossil meteorites," and fusion crust.
2.1 Unique names. A unique name shall apply to:2.2 Distinctive names. A meteorite name must clearly distinguish the occurrence to which it refers from other meteorite names, and should convey the geographical location of the fall or find. Names should be as brief as possible, but abbreviations (e.g., St. and Mt.) should be spelled out unless special circumstances warrant their usage in the name.a) the set of all individual bodies recovered from a single observed meteorite fall or meteorite shower. Each individual shall carry the same name as the set;
b) a meteorite find that cannot be related with certainty to other falls or finds recovered from the same vicinity;
c) several meteorite finds, or a fall and one or more subsequent finds, whose geographical relationship and inherent characteristics establish, after careful evaluation of all evidence available, that they belong to a single occurrence (with the exception stated in §4.2 for finds in dense collection areas).
2.3 Precedents. An established meteorite name shall remain unchanged, whether the spelling or name of its locality is subsequently altered or was originally assigned in error, or whether it becomes obsolete with respect to current conventions of transliteration or transcription. Earlier meteorite names that do not conform to these Guidelines will not be changed unless the Committee for Meteorite Nomenclature (hereafter called The Committee) rules that this is necessary to avoid confusion. Changes to the names of meteorite falls or important meteorite finds (e.g., Canyon Diablo; Leoville) should be avoided except under extraordinary circumstances (e.g., §3.3a).
2.4 International usage. Meteorite names should be rendered according to local spelling at the time, but in Roman script, including diacritical marks where appropriate. New Chinese meteorite names will be transcribed according to the Pinyin system.
3.1 Geographic features. A new meteorite shall be named after a nearby geographical locality. Every effort should be made to avoid unnecessary duplication or ambiguity, and to select a permanent feature which appears on widely used maps and is sufficiently close to the recovery site to convey meaningful locality information. Acceptable names include physiographic features such as rivers, mountains, lakes, bays, capes, and islands, political features such as towns, counties, states, and provinces, and sites of human activity such as parks, mines, historical sites†, and railroad stations. Other sites mainly associated with recent human activity, such as buildings, commercial localities, schools, bridges, roads, and golf courses are not generally acceptable names for meteorites. In sparsely populated areas with few place names, less permanent features such as ranches or stations or, in extreme cases, local unofficial names of distinctive quality may be used, provided the latitude and longitude of the recovery site are well determined. The names of large geographic features such as continents, countries, provinces, states, and large counties should be avoided if names that are more specific are available, except as specified in §3.3 and §3.4. In general, the selected feature should be the closest such feature to the site of the recovery. If, for example, the name of the nearest town is already used, the meteorite should not be named for the next nearest town. In such a case, a different geographic feature (e.g., a stream) should be selected, if available (if not, §3.3 applies)."
†A historical site is defined as a locality that is well-known for its historical significance, and for which the dominant modern function is the depiction of this history3.2 Duplicate place names. Duplication of a place name previously used for a meteorite from another country, state or province should be avoided. If it cannot be avoided, both names may be amplified as in Edmonton (Kentucky) and Edmonton (Canada).
3.3 Sparse place names. The following rules apply to cases involving insufficient numbers of unique place-names:
(a) Coincidental falls. In the event that a meteorite falls near the same locality as an existing named meteorite, the new fall should not be assigned a letter designation as in §3.3b, or a numeric designation as in §3.3c. If an appropriate, unique name cannot be found for the new fall, then it should receive the suffix (year), as was done for Wethersfield (1982) and Monahans (1998). If there is only one pre-existing meteorite from this location, then the older one should also be given a (year) suffix, e.g., Wethersfield (1971) and Monahans (1938). This is one of the rare situations wherein an existing meteorite fall or an important find may be renamed. If there are multiple existing meteorites with the same name followed by numeric or lettered suffixes, then the fall should still get the year suffix, but the older meteorites do not need to be renamed.
(b) Coincidental finds. Where several meteorites are found near the same locality and alternative place names are not available, each separate meteorite shall bear the name of the locality followed by a parenthesized lower-case letter, e.g. Kress (a) and Kress (b). Letters shall be assigned alphabetically in order of recognition. If an earlier meteorite from the same locality already exists, e.g. Kress, its name does not need to be changed to Kress (a) (although this can be designated as a synonym). In this case, the first new name should be Kress (b).
(c) Dense collection areas. If particularly numerous recoveries are made in one region, as for instance in Antarctica and the Sahara, a generic prefix (conveying geographic information) and a suitable series of numeric suffixes should be applied. New meteorites found within the designated region will be named by combining the prefix with the next available suffix. Proposals to create new nomenclatural regions must be accompanied by maps, aerial photographs, satellite imagery and/or written descriptions that explain the geographic extent of the region. Once approved, the committee may later vote to change the boundaries of the region.
3.4 Meteorites of unknown or poorly known provenance.
(a) Withheld information. Where the source of a new meteorite cannot be determined due to the withholding of geographic information by a collector or other party, the name should be chosen to reflect the smallest geographic feature identifying the collection location with certainty. If the location information is too vague, or is uncertain or disputed, the name Nova followed by the next available three-digit number should be adopted as the permanent name.
(b) Transported meteorites. When the provenance of a new meteorite cannot be determined due to a lack of sufficient historical information, it should be named after the locality where it was first recognized. For meteorites found in institutions such as universities and museums, the name may be either that of the institution, the collection, or the city in which the institution is located. In accordance with §3.6, the names of people, even if part of the official name of the collection, should be avoided.
(c) Meteorites found in large numbers. In cases where many meteorites are found and distributed or sold without careful documentation of provenance, a numbered sequence of generic names should be used as in §3.3c, wherein the prefix reflects the geographic area in which the meteorites were most likely recovered (e.g., Northwest Africa, for meteorites coming from marketplaces in Morocco).
[Abolished Feb 2015]: 3.5 Meteorites from Morocco and surrounding areas. All meteorites found, reported to be found, or purchased in Morocco and adjacent parts of the surrounding countries shall be named according to the following special rules:
(a) Falls. Observed falls will be named the same way as they are in other areas (§3.1-3.3).
(b) Finds and purchased meteorites. These meteorites will all be numbered in a "Northwest Africa" (NWA) series unless they are accompanied by documentation including the date of find, name and address of finder, and reasonable proof of the find location (e.g., a single photograph showing the meteorite in situ, a length-scale, and an active GPS unit displaying the geographic coordinates). If so documented, the meteorites may be given locality-specific names as in §3.1-3.3. If a meteorite bearing a provisional NWA number is later given a formal locality-specific name, the NWA number will become a synonym for the new name.
3.6 Prohibited terms. Neither a person's name, the classification, nor an unofficial directional term (for example North Haig) should be used in a meteorite name. However, the Committee may rule that such practices are permissible in exceptional situations. Names given under this section should not be changed retroactively, even given the eventual resolution of the true provenance.
4.1 Sparse collection areas:a) Level of scrutiny. A reasonable effort should be made to ensure that a new recovery does not belong to a previously named meteorite (see also §2.1).
b) Paired meteorites. If two meteorites previously thought to be separate are subsequently found to be paired after comprehensive studies (preferably of the main masses), one name should be abolished and one retained.
c) Separation of meteorites. If several individuals previously regarded as a single meteorite prove to be distinct, with no reasonable expectation of genetic affinity, then one or all should be renamed in accordance with the provisions of §3. If the original name designates a fall, then every attempt should be made to preserve that name without change.
4.2 Dense collection areas. In areas of dense meteorite concentrations such as those covered under §3.3c and §3.4c, the following guidelines apply:
a) Level of scrutiny. Sequential names comprising a prefix and numeric suffix will be given to new meteorites without checking for possible pairings, although a single (collective) name may be given in cases where fragments fit together or similar-looking fragments are found within a few meters of each other.
b) Pairing groups. Two or more newly discovered meteorites in dense collection areas may be considered paired with each other or with another formally named meteorite if there is overwhelming evidence, including geographic data, that is consistent with the meteorites being part of a single fall. The evidence must be evaluated by the Committee. All approved members of a pairing group will be named with a geographic prefix plus a number in the same way as are unpaired meteorites; special type-specimen requirements will apply to newly paired meteorites (section 7.1f). If two or more numbered meteorites with formal names are subsequently determined to be paired, their names should not be changed. Pairing groups may be referred to collectively by the lowest specimen number, the most widely studied mass number or the largest mass number (e.g., the EET 87711 pairing group).
c) Separation of meteorites. If several individuals previously regarded as a single meteorite prove to be distinct, with no reasonable expectation of genetic affinity, then lettered suffixes in parentheses may be applied, as in section 3.3b (e.g., Place 95035 (b)).
5.1 Synonyms. Synonyms are unofficial names of meteorites, and their use is discouraged. They may be created when:5.2 Discredited names. Meteorite names that are abolished or discredited, or that have been modified through the later addition of a suffix shall not be reused for the naming of subsequent falls or finds.a) popular usage or existing publications have caused confusion through the introduction of alternate names or alternate spellings of the names of approved meteorites.
b) a meteorite name is abolished after a determination of pairing with a second meteorite, or a meteorite name is modified through the addition of a suffix.
Abbreviations for meteorite names with numeric suffixes (i.e., those named under §3.3c and §3.4c; e.g., ALH = Allan Hills) should be unique and different from all unabbreviated meteorite names (disregarding case). Such abbreviations should be used with a space separating the abbreviated prefix and the numeric suffix (e.g., ALH 84001); the exception to this is certain Antarctic meteorites with names approved prior to 1981, which should have an "A" in place of the space (ALHA, BTNA, DRPA, EETA, MBRA, META, OTTA, PGPA, and RKPA; e.g., ALHA77005). Authors should avoid the use of abbreviated meteorite names in titles and abstracts of publications, and should introduce them in text as they would any other abbreviation. A complete list of abbreviations approved by the Nomenclature Committee, demonstrating proper usage, will be maintained by the Editor of the Meteoritical Bulletin.
7.1 New meteorites. All new meteorite names must be approved by the Committee. The minimum information required to name a meteorite, which the Committee should only modify under special circumstances, is:
- The location, preferably as geographic coordinates, of the fall or find;
- The circumstances of the fall or find (narrative);
- The total known mass and number of pieces recovered;
- An authoritative classification;
- The location of the main mass;
- The location of a type specimen. Type specimens must be deposited in institutions that have well-curated meteorite collections and long-standing commitments to such curation. At the time of submission of the meteorite to the Committee, the type specimen must be in the permanent custody of the institution that is the type specimen repository;
- The type specimen mass. The minimum mass of a type specimen should be 20% of the total mass or 20 g, whichever is the lesser amount. For newly paired meteorites from dense collection areas (§4.2b), the minimum required mass shall be whatever is needed to bring the aggregate mass of existing type specimens (if any) to 20% of the aggregate mass of the entire pairing group or 20 g, whichever is less.
Larger type specimens are recommended (but not required) for meteorites larger than 400 g:
Mass Recommended type specimen 400 g - 10 kg at least 5% of total mass > 10 kg at least 500 g 7.2 Numbering systems. The Committee must approve all new prefixes, abbreviations, and proposed numbering schemes for meteorites in dense collection areas.
7.3 Pairing issues. Proposals to pair or separate meteorites that would result in the abolition or creation of meteorite names under §4 must be reviewed and approved by the Committee.
7.4 Announcements. Information about all new meteorites, paired and separated meteorites, name changes to existing meteorites, synonyms, and abbreviations will be published at least once per year in the Meteoritical Bulletin in Meteoritics and Planetary Science.
7.5 Authoritative information. The authority for existing meteorite names shall be the current edition of the Catalogue of Meteorites of the Natural History Museum, London, supplemented by published appendices to the Catalogue and by ensuing numbers of the Meteoritical Bulletin. However, the Committee may overrule priority for a particular name if strict application of this or other sections contradicts the general objectives of these Guidelines.
7.6 Provisional names. New numbers may be assigned to meteorites in dense collection areas with approved numbering systems prior to analysis and classification. Allocation of numbers will be coordinated by the Editor of the Meteoritical Bulletin. Names assigned in this way will be considered provisional until the Committee grants formal approval.
Assignment of provisional names requires the following minimum information:
- The mass of the specimen;
- A physical description (e.g., crusted stone, broken fragment, etc.);
- An approximate (visual) classification (e.g., stone, iron, chondrite, achondrite, etc.);
- An account of how the specimen was obtained (e.g., place and date of find and/or purchase);
- The coordinates where the specimen was found, or in the case of a meteorite with unknown find location, a description of where it may have been found.
A list of provisional names will be maintained by the Editor of the Meteoritical Bulletin. The names of meteorites on this list remain provisional even if printed as an appendix in future editions of the Catalogue of Meteorites, and should not be used in publications.
7.7 Relict meteorite names. A special type of name should be assigned to relict meteorites (see §1.2c for definition). The documentation required for these names must include a description of the material, the location and date of the find, the approximate mass or size, the location of the main mass, and the type of meteoritic material it is suspected to represent. The name must conform to all applicable parts of §2-§6 above, and must be approved by the Nomenclature Committee prior to publication. Relict meteorite names may be converted to formal meteorite names by a second vote of the Committee, subject to the requirements of §7.1.
Although application of these Guidelines should in the future decrease the risk of confusion, authors are nevertheless encouraged to cite catalogue numbers from established collections in their publications on meteorites, and curators are urged to catalogue individual masses separately.
9.1 Definition. "Meteorite" shall be defined according to Rubin and Grossman (2009) [MAPS 45, 114-122].
9.2 Sample returns. When a meteorite is collected on another celestial body and returned to Earth, it is subject to all of the same nomenclatural rules as meteorites collected on Earth (§1-8).
9.3 Remote observations. Meteorites may be observed in situ on other celestial bodies by manned or robotic missions. In these cases, a special set of nomenclatural guidelines should be applied:
9.3.1 Such objects should be named according to the same principles as meteorites collected on Earth (§1-7).
9.3.2 The criteria for acceptance of a new meteorite listed in section §7.1 shall be replaced as follows:
a. The location of the meteorite, preferably using an appropriate coordinate scheme;
b. The circumstances of the find;
c. The estimated mass and number of pieces observed;
d. Evidence that establishes the likelihood that the object is a meteorite;
e. A visual (or better) classification.