References and tools for your collection.

A palynological database in which an entry ideally carries a detailed grain description, LM, SEM and TEM images, images of the plant and flower, and the relevant literature.

Best for

Checking a description against a carefully written one for the same taxon, and seeing the same grain across several imaging modalities at once.

Limits

Coverage is entry-by-entry rather than comprehensive — roughly 4,650 species at last check — and not every taxon carries the full complement of description, images and literature. The electron-microscope images show detail you will not resolve on a light microscope, which makes them easy to over-read when matching your own view.

Coverage

Global, with strong European representation. Modern pollen and spores; roughly 4,650 species across 1,810 genera.

Reuse

Custom licence, not Creative Commons: educational and non-commercial use only, with the photographer and PalDat credited. Commercial use requires written permission.

Imaging

Light microscopy · Light microscopy, hydrated · Scanning electron microscopy · Transmission electron microscopy

Contributing

Free online access to read; a free registration is required to publish data.

In 2021 PalDat absorbed the PONET database, adding more than 2,000 datasets of high-resolution light micrographs of hydrated pollen. That hydrated-LM material is the closest published analogue to what you are actually seeing down the tube, and it is the part of PalDat to reach for first if you are matching against your own light-microscope view.

PalDat's own curated set of links to other palynology sites, collections and projects.

Best for

Finding the regional atlas or specialist collection that no general list will have thought to include.

Limits

A link list maintained by a third party, with no stated review cadence. Expect dead links: at the last check it still listed the University of Arizona's pollen image catalogue, which returns a 404. Treat it as a set of leads to verify, not a vetted index.

Coverage

Global, weighted toward European institutions.

Reuse

Not stated by the maintainer.

Worth mining rather than duplicating. If you are looking for something this library does not yet list, start here before searching generally.

Free online access to the largest pollen and spore collection in the Australasian region, with details on over 15,000 species, searchable or browsable by family.

Best for

Australasian material, where a European or North American atlas will simply not contain the taxon you are looking at.

Limits

Regional by design, and of limited use outside Australasia. The 15,000-species figure counts records with morphological and locality metadata — image coverage is considerably thinner, and it is normal to reach a fully described record that carries no photograph at all. Light microscopy only.

Coverage

Australasia. Over 15,000 species described. The physical collection is held at ANU in Canberra.

Reuse

CC BY-NC-SA 3.0, stated site-wide.

Imaging

Light microscopy

The site is explicitly built for amateurs as well as professionals, which makes it an unusually good starting point. For contributors working on Australian material this is the first place to look, not the last.

An open platform serving two purposes: identifying unknown grains, and acting as a morphological reference collection.

Best for

Focusing through a grain the way you would at the microscope, rather than reading a single fixed-focus photograph.

Limits

Coverage depends on what the community has contributed, so it is uneven across taxa and regions, and it is light microscopy only — no electron micrographs. A crowd-sourced determination is evidence about a grain, not an authority on it. Development also appears to have slowed: at the last check some linked occurrence feeds had not refreshed since 2022, one headline counter on the front page read zero, and the public API is still labelled a preview.

Coverage

Global, community-contributed. Roughly 2,340 species across 2,771 digitised slides at last check.

Reuse

CC BY 4.0 for the Global Pollen Project reference dataset, as stated in its terms.

Imaging

Light microscopy

Contributing

Unknown grains can be uploaded for crowd-sourced identification, mediated by an identification model; once they satisfy it they pass into the master reference collection.

Grains are presented as five-image z-stacks you can focus through, emulating a light microscope. That makes it the closest thing available to comparing your own view against a reference, rather than comparing your view against a photograph of one.

A community-curated database covering fossil pollen among many other palaeoecological proxies, reachable through a map interface, an API, an R package and DOIs.

Best for

Placing a fossil pollen record in its stratigraphic and regional context, and seeing how comparable assemblages have been reported.

Limits

Palaeoecological rather than identification-focused — it will not help you name a grain. Coverage reflects where researchers have worked, which is heavily weighted toward North America and Europe.

Coverage

Global, unevenly. Fossil and sub-fossil material across many proxies.

Reuse

CC BY 4.0, stated in its data use and embargo policy.

Relevant to Clio less for identification than as a precedent: it is a working example of versioned, citable, community-curated records, which is the model Clio is building toward.

The international occurrence infrastructure and taxonomic backbone against which biodiversity records are commonly resolved.

Best for

Checking that the plant name your determination lands on is current, and seeing where the taxon has actually been recorded.

Limits

Not pollen-specific, and the backbone is an aggregation rather than a nomenclatural authority in its own right — for contested names, check a botanical authority as well. Occurrence coverage reflects collection effort, not true distribution.

Coverage

Global, all taxa.

Reuse

Not stated by the maintainer.

Not pollen-specific, but it is the occurrence backbone the Global Pollen Project links against and a useful example of Darwin Core data in practice. Clio has no GBIF publishing connection.

A book-length illustrated treatment of pollen terminology, pairing each term with photographs of real grains showing the feature.

Best for

Learning what a term actually looks like down the tube, rather than what its definition says.

Limits

A terminology reference, not an identification key — it will teach you to describe a grain precisely but will not tell you which taxon it belongs to. Many illustrations are electron micrographs showing detail a light microscope cannot resolve.

Coverage

Global; over 300 terms with more than a thousand images.

Reuse

Not stated by the maintainer.

Imaging

Light microscopy · Scanning electron microscopy · Transmission electron microscopy

Published under a CC BY 4.0 licence, so the full book is legitimately free to download and redistribute — unusual for a reference of this standing, and the single best starting point if you are buying nothing. Its terminology is also browsable through PalDat.

The community's standard glossary, defining roughly two thousand terms and attributing each to the author who introduced it.

Best for

Settling exactly what a term means, and which author's sense of it a source is using, when two references appear to disagree.

Limits

Paywalled on the publisher's site, and it is text rather than an illustrated guide — it defines terms precisely but shows you very little. Copies circulating on university teaching pages are not an official open-access release, so do not rely on one being there.

Coverage

Global; pollen and spore morphology terminology.

Reuse

Not stated by the maintainer.

There is no formal TDWG or machine-readable ontology for pollen morphology. This glossary is the de facto standard by community convention, which is worth knowing if you are trying to map a description onto structured fields.

A published laboratory protocol for extracting pollen from sediment, covering reagents, sequence and the safety regime each step requires.

Best for

Understanding what a full preparation actually involves before deciding whether to attempt it or send the sample to a laboratory.

Limits

Written for a staffed university laboratory operating under UK COSHH requirements. It assumes a fume hood, institutional training and supervision, and it is not adaptable to a home setting — several steps involve hydrofluoric acid.

Coverage

Sediment-based pollen extraction.

Reuse

Not stated by the maintainer.

Read the safety section on this page before the method section. It is unusually explicit about the hazards, including the buddy system and calcium gluconate requirements for hydrofluoric acid work.

The standard identification key for Central European pollen, with keys, plates and comparative tables.

Best for

Working systematically to a determination on Central European material, rather than browsing images and hoping for a match.

Limits

German-language only, and regionally scoped to Central Europe and adjacent areas — of limited use elsewhere. In print and priced accordingly rather than free.

Coverage

Central Europe and adjacent regions. 542 pages, 120 plates.

Reuse

Not stated by the maintainer.

A worked key is a different tool from an image atlas: it forces you through the characters in order, which is exactly the discipline that stops a determination resting on one striking feature.

The long-standing standard textbook of pollen analysis, covering laboratory technique alongside the morphological system used to describe grains.

Best for

Building the underlying method properly, rather than assembling it from separate protocols and glossaries.

Limits

The linked scan is the 1975 third edition and is borrow-only under controlled digital lending, not a free download; the 1989 fourth edition is the one usually cited and is available only in print. Laboratory safety practice has moved on considerably since either, so do not take its procedures as current guidance.

Coverage

General method; Northern European emphasis in its examples.

Reuse

Not stated by the maintainer.

Contributing

A free Internet Archive account is required to borrow the scanned copy.

Erdtman's introductory text, the source of much of the shape and aperture vocabulary still in use.

Best for

Seeing where the descriptive system came from, and why it is built the way it is.

Limits

Published in 1943. Its taxonomy, distribution data and laboratory safety practice are all long out of date, and it should be read for the origin of the concepts rather than as current guidance.

Coverage

General introduction; historical.

Reuse

Not stated by the maintainer.

Freely downloadable in full, unlike most of the classic literature. Useful background, not a working reference.

Kew's published taxonomy, synonymy, distribution and descriptions for the world's vascular plants, built on the World Checklist of Vascular Plants.

Best for

Checking whether the plant name your determination landed on is currently accepted, and what it is a synonym of if not.

Limits

Depth and currency still vary by plant group, and the taxonomy reflects Kew's editorial judgement rather than a multi-institution consensus — for a contested name, compare against World Flora Online. There is no documented public API.

Coverage

Global; vascular plants. Names and distributions refreshed weekly.

Reuse

Dataset metadata published under CC BY; images CC BY, © Trustees of RBG Kew.

A pollen determination ends in a plant name, and a plant name is only useful if it is the accepted one. This is the step most often skipped.

An open, multi-institution consensus taxonomy for all known plants, published as a continuously curated backbone with citable twice-yearly snapshots.

Best for

A name check that reflects agreement across institutions rather than one herbarium's position, and a versioned snapshot you can cite.

Limits

Taxonomic depth depends on whether an active expert network covers the family in question; groups without one may still reflect the 2013 Plant List baseline it was seeded from.

Coverage

Global; all known plants. Citable snapshots cut on 21 June and 21 December each year.

Reuse

Portal content CC BY 4.0; the downloadable taxonomic backbone is released CC0 1.0.

This supersedes The Plant List, which is now offline entirely. If a guide or paper points you at theplantlist.org, it is out of date.

Australia's national biodiversity platform: occurrence records, species profiles and imagery, with name matching against the Australian Plant Census.

Best for

Confirming that a plant you have determined actually occurs where you found it, and resolving Australian plant names against the national authority.

Limits

Australian in scope and in taxonomy — plant names resolve against the Australian Plant Census, so names outside an Australian context are handled less authoritatively here than in POWO or World Flora Online. Occurrence coverage reflects collecting effort, not true distribution.

Coverage

Australia; over 100 million occurrence records across thousands of datasets.

Reuse

CC BY 3.0 Australia.

Paired with APSA, this is the practical Australian workflow: match the grain against the regional atlas, then check the resulting name and its distribution here.

A review of why pollen and spore records characteristically describe plant life at a rank above species, and what drives that limit.

Best for

Understanding why the determination ceiling exists rather than taking it on trust — and having something citable when you record a family-level identification.

Limits

Paywalled, and it is an analysis of the problem rather than a guide to working around it. It will not help you identify a grain.

Coverage

General; palynological taxonomic resolution.

Reuse

Not stated by the maintainer.

The paper attributes conservative genus- and family-level classification to the difficulty of describing very small morphological differences between species with the available terminology. That is the honest reason a species name is usually not on offer.

A global checklist joining expert taxonomic sources across the living world, with accepted names, synonyms and classification.

Best for

Normalising a proposed name across kingdoms and tracing the specialist source from which the treatment came.

Limits

Completeness and update cadence differ among taxonomic groups. The Extended Release is broader but less uniformly scrutinised than the expert-vetted Base Release, and neither identifies a specimen or observation.

Coverage

Global; animals, plants, fungi, prokaryotes and other living groups, with source-dependent coverage.

Reuse

CC BY 4.0 for Catalogue of Life releases unless a contributing source states otherwise.

Prefer the Base Release when you need the most consistently reviewed backbone; use the Extended Release when breadth matters, and retain the release name in your record.

An international taxonomic backbone connected to specimen, survey and citizen-science occurrence records and their source datasets.

Best for

Checking synonymy, geographic plausibility and the provenance of published occurrence evidence.

Limits

The backbone is a synthetic working taxonomy rather than the final authority for disputed names. Occurrence data can contain errors, duplicates and geographic or collecting bias; a point on the map is not proof of identity or true range.

Coverage

Global, all taxa; coverage and record quality vary greatly by region and source.

Reuse

Each occurrence dataset and media item carries its own CC0, CC BY or CC BY-NC licence; check the source record before reuse.

Contributing

Browsing and API access are open. An account is required for mediated downloads and publishing occurs through recognised data publishers, not by adding a record directly to GBIF.

Follow a record back to its dataset and institution. GBIF is most useful when it reveals the evidence chain, not when its map is treated as an answer.

Australia's national biodiversity discovery layer, joining names, descriptions, images, maps, records and specialist sources.

Best for

An Australian first pass: finding the relevant national flora, fauna list, collection record or identification resource and checking regional plausibility.

Limits

It aggregates records of differing quality and taxonomic age. Citizen-science records need source-level scrutiny, sensitive localities may be generalised, and absence from the map does not establish absence in nature.

Coverage

Australia and its territories across the living world, with links to global and regional sources.

Reuse

ALA site material is generally CC BY 3.0 Australia; occurrence records and media retain the licence stated by each provider.

Contributing

Browsing is open. An account is required for contributions and some personalised services.

For Australian observations, use ALA as a route into the specialist source rather than stopping at the aggregated species page.

A professionally operated global observation platform combining photo and sound suggestions with visible community identifications and discussion.

Best for

Generating candidates, finding identifiers who know the group, and seeing which visible characters changed a community determination.

Limits

Computer vision and community consensus are evidence, not authority. Geographic, seasonal and observer biases affect suggestions; 'research grade' describes a platform state rather than independent verification, and difficult taxa still require specialist characters.

Coverage

Global, all observable living groups; strongest where the community and training data are dense.

Reuse

Observation data and media use contributor-selected licences; check each item before reuse. Platform code and exported datasets have separate terms.

Contributing

A free account is required to post observations, add identifications or participate in discussion.

Use it to open an identification, not to close one. Preserve the suggested taxon, identifiers' comments and later changes as part of the determination history.

The world's largest open-access digital library of biodiversity literature and archives, with scientific-name indexing across historic and modern works.

Best for

Finding original species descriptions, monographs, plates, historic observations and the literature behind a taxonomic claim.

Limits

Much of the collection is historical: names, ranges, language and scientific conclusions may be outdated, and optical character recognition can misread names. A digitised page is a source to interpret, not a current determination.

Coverage

Global biodiversity literature from the fifteenth century to the present, with holdings determined by contributing libraries and rights availability.

Reuse

Metadata is CC0. Public-domain works remain public domain; in-copyright items and images carry the rights statement shown on the item.

Its taxonomic name finder is an unusually effective bridge from an accepted name to the literature and illustrations that established or revised it.

A global vascular-plant reference joining accepted names, synonyms, native ranges, descriptions, literature and extensive imagery.

Best for

Checking the accepted global treatment of a vascular-plant name and comparing distribution and available herbarium imagery.

Limits

It is not a universal diagnostic key. Descriptions and images are uneven among taxa, and regional floras can legitimately adopt a different current treatment.

Coverage

Global vascular plants; coverage depth varies by family and region.

Reuse

Kew and contributing-provider terms apply; check the rights statement attached to data and images before reuse.

APC records nationally accepted Australian vascular-plant names; APNI provides the publication, usage and synonym trail behind them.

Best for

Settling the accepted Australian name, then tracing alternative names and the literature in which each usage appeared.

Limits

Neither service identifies an unknown plant or replaces a flora. Taxonomic concepts can change, so retain the service and access date with a determination.

Coverage

Australian native and naturalised vascular plants and their nomenclatural history.

Reuse

Australian National Species List and Australian Government reuse terms apply.

The current national platform for Australian plant descriptions, identification keys, illustrations, distributions and habitat accounts.

Best for

Working from recorded morphology through an Australian key rather than matching a single photograph.

Limits

Authoritative where a group has been treated, but the electronic flora is still expanding and some families or profiles remain incomplete.

Coverage

Australian native and naturalised plants, with treatment depth varying by group.

Reuse

CC BY unless a page, image or contributing source states otherwise.

A detailed regional flora with interactive keys, descriptions, images, maps and herbarium-linked records.

Best for

Identifying New South Wales plants from diagnostic characters and checking local distribution against herbarium evidence.

Limits

Primarily New South Wales. State treatments can differ from the national census, and determinations outside the region need an appropriate local flora.

Coverage

New South Wales vascular plants, including native and naturalised taxa.

Reuse

Botanic Gardens of Sydney citation and reuse terms apply; image rights can differ by contributor.

National descriptions, habitat, distribution and interactive keys for Australian mosses, liverworts and hornworts.

Best for

Moving an Australian bryophyte observation from growth form toward a defensible taxon using field and microscopic characters.

Limits

Some profiles are explicitly partial, and many species cannot be resolved reliably without microscopy and a suitable technical flora.

Coverage

Australian bryophytes; descriptive coverage is still being developed.

Reuse

CC BY unless the profile, image or source states otherwise.

Linked global services for fungal nomenclature, publication details and an accepted-name consensus, including lichenised fungi.

Best for

Separating the publication history of a fungal name from the currently accepted taxonomic treatment.

Limits

A nomenclatural record is not an identification, and a name present in Index Fungorum is not necessarily the accepted one. Visual and ecological evidence is limited.

Coverage

Global fungi, including lichenised fungi, with source-dependent taxonomic depth.

Reuse

Kew and database terms apply; no blanket licence for all linked content is stated.

Australia's current accepted fungal classification connected to the national nomenclatural and bibliographic trail.

Best for

Checking which fungal name Australia currently accepts and tracing the usages and synonyms behind it.

Limits

It is a name service, not an image key. A large proportion of Australia's fungal diversity remains undescribed, so a missing species may reflect a real knowledge gap.

Coverage

Australian fungi; taxonomic and nomenclatural records rather than comprehensive identification media.

Reuse

Australian National Species List and Australian Government reuse terms apply.

The current national destination for accepted Australian lichen names and their nomenclatural records.

Best for

Verifying the accepted Australian name after morphology, microscopy or chemistry has produced a candidate.

Limits

It provides little visual identification help. Many lichens require microscopic structures or chemical characters that a field photograph cannot show.

Coverage

Australian lichens and lichenicolous fungi.

Reuse

Australian National Species List and Australian Government reuse terms apply.

Free specialist family treatments and identification keys progressively replacing the older printed British and Irish lichen flora.

Best for

Working through technical lichen characters with a current specialist treatment rather than relying on colour photographs.

Limits

Regional and still incomplete. The treatments are technical and often require microscopy or chemical tests; the older LGBI2 genus key is acknowledged as outdated.

Coverage

Great Britain and Ireland; family treatments are released progressively.

Reuse

British Lichen Society and individual publication terms apply.

Australian field guides, identification support and mapped observations connecting skilled amateurs, mycologists and public recording platforms.

Best for

Learning the field characters of conspicuous Australian macrofungi and finding an appropriate expert community.

Limits

Strongest for visible macrofungi rather than microfungi. Community identifications still need diagnostic support, and the resource must never be used to infer edibility or safety.

Coverage

Australia, especially conspicuous and target macrofungi.

Reuse

Site, publication and contributed-media terms vary; check the item before reuse.

Contributing

Public participation is routed through Fungimap activities and linked observation platforms; account requirements depend on the activity.

Australia's primary national compilation of accepted animal names, synonyms, classification, distribution and bibliography.

Best for

Checking the accepted Australian name and taxonomic placement after an animal has been identified from appropriate evidence.

Limits

Australia and its territories only. Coverage depth and update date differ among groups, and image or identification-key support is limited.

Coverage

Australian animals across terrestrial, freshwater and marine groups.

Reuse

Australian Government citation and reuse terms apply.

A current global mammal checklist with accepted species, synonyms, higher classification, ranges and downloadable releases.

Best for

Verifying a mammal name against a release maintained by specialist mammalogists.

Limits

Taxonomy-focused, with limited help identifying an unknown from tracks, photographs, hair or skeletal material. Living and recently extinct mammals are its core scope.

Coverage

Global living and recently extinct mammals.

Reuse

Release and dataset terms are stated with each Mammal Diversity Database download; cite the release used.

High-quality diagnostic image sets and comparison tools for invertebrates, pathogens and other organisms of biosecurity significance.

Best for

Comparing a suspect pest or vector against expert-prepared views of diagnostic structures and close lookalikes.

Limits

Biosecurity-oriented rather than a complete fauna, and its presence in the library does not establish regulatory status. Some identifications still require a diagnostic laboratory.

Coverage

Australia-focused biosecurity taxa with international pest and disease coverage.

Reuse

PaDIL site and contributed-image terms apply; check the item before reuse.

Contributing

Public browsing is open; contributor functions require authorisation.

A global ant reference collection with standardised specimen images, type material, regional lists and taxonomic records.

Best for

Comparing an ant specimen from several standard views and locating type or curated collection material for the candidate taxon.

Limits

Restricted to ants, and many determinations require microscopic characters or a regional key. Image matching alone is especially weak in species-rich genera.

Coverage

Global Formicidae, with uneven digitisation among regions and collections.

Reuse

Specimen data and many images are CC BY; retain the photographer, specimen and collection attribution shown on each record.

The current global authority for accepted spider names, synonyms, literature and brief distributions.

Best for

Checking spider nomenclature and tracing the taxonomic literature after morphology has produced a candidate.

Limits

Spiders only and not a visual key. Geographic detail is brief, and species-level determination commonly requires adult genital morphology.

Coverage

Global Araneae.

Reuse

World Spider Catalog terms apply; API and bulk use are controlled separately.

A guided mobile identification tool using location, date, description, photographs and supported sound recordings with a global bird reference library.

Best for

Generating a short list from a field observation or recording and learning which visible or acoustic features separate candidates.

Limits

Mobile-first, with regional gaps in Sound ID. Photo and sound suggestions are model outputs that require confirmation against field marks, calls, range and season.

Coverage

Global bird reference coverage; assisted features and sound models vary by region.

Reuse

Cornell Lab terms apply; reference media retain contributor and Macaulay Library rights.

Contributing

The app is free; email or account confirmation is required for continued use and contribution-linked features.

Searchable Australian bird profiles using shape, size, colour, habitat, family and state, with calls and conservation context where available.

Best for

Narrowing a photographed Australian bird and checking habitat, range and call against a conservation organisation's account.

Limits

The profile collection is still growing and does not cover every Australian bird. It is a visual aid rather than a complete diagnostic key.

Coverage

Australian birds; profile depth and taxon coverage vary.

Reuse

BirdLife Australia and individual media rights apply; no blanket open-media licence is stated.

A current global reference for living reptile taxonomy, synonyms, distributions, literature and many images.

Best for

Checking a reptile name and distribution, then following the literature and images attached to the taxon.

Limits

It is not a universal diagnostic key. Images can narrow candidates but rarely replace scale counts, measurements, locality-specific literature or examination of the animal.

Coverage

Global living reptiles.

Reuse

Database and contributed-image terms apply; no blanket open-media licence is stated.

A global reference for amphibian names, nomenclatural history, country distributions and taxonomic literature.

Best for

Verifying an amphibian name and tracing its synonymy and original or revising literature.

Limits

Taxonomy-heavy rather than a field or call-identification tool, with limited visual support. Country-level distribution cannot confirm a local observation.

Coverage

Global living amphibians.

Reuse

All rights reserved by the maintainer; citation is required for scholarly use.

An Australian citizen-science app that identifies frogs from georeferenced call recordings reviewed by frog experts.

Best for

Turning a good Australian frog-call recording into a reviewable, expert-checked candidate with date and place attached.

Limits

Australia only and call-based. It cannot identify silent animals or image-only records, and overlapping callers or poor recordings may remain unresolved.

Coverage

Australian frogs and their calls.

Reuse

Australian Museum and FrogID terms apply to records, audio and derived data.

Contributing

A free account and the mobile app are required to submit recordings.

An expert-controlled global register of accepted marine names, synonyms, classification, sources and durable Aphia identifiers.

Best for

Verifying the accepted name and taxonomic placement of a marine organism after diagnostic evidence has produced a candidate.

Limits

Primarily nomenclatural rather than a visual key. Images, distributions and identification tools are uneven among groups, and whole-database redistribution has additional conditions.

Coverage

Global marine taxa, with specialist subregisters for many groups.

Reuse

WoRMS data are broadly available under CC BY with citation; media and some source records carry separate terms.

A global finfish database with names, morphology, photographs, distributions, ecology, references and a substantial set of regional keys.

Best for

Comparing finfish morphology, checking meristic characters and following a regional key or species account.

Limits

Finfishes rather than all aquatic life. Data depth and interactive-key coverage vary, and photographs do not replace counts or examination in difficult groups.

Coverage

Global marine and freshwater finfishes.

Reuse

Database content is CC BY-NC 4.0; images retain separately stated rights.

Authoritative Australian fish accounts, images, distributions, a picture-based family finder and an interactive freshwater-fish key.

Best for

Identifying Australian marine or freshwater fishes and checking the candidate against museum-supported range and diagnostic information.

Limits

Geographically restricted to Australia, and key depth differs among groups. Some identifications still require counts or specialist examination.

Coverage

Australian marine and freshwater fishes.

Reuse

CC BY 3.0 Australia unless a page or image states otherwise.

A global companion to FishBase for aquatic organisms other than finfishes, with species pages, images, maps, ecology and references.

Best for

Finding baseline information and comparison material for marine invertebrates and other non-finfish aquatic groups.

Limits

Coverage and depth are much less complete than the diversity it represents. It is not a consistent diagnostic key, and accepted names should be checked in the relevant specialist register.

Coverage

Global non-finfish marine and freshwater organisms, uneven by group.

Reuse

Database content is CC BY-NC 4.0; images retain separately stated rights.

The world's largest open-access infrastructure for marine biodiversity occurrences, measurements and associated environmental data.

Best for

Checking marine geographic, depth and temporal plausibility and tracing an occurrence back to its survey, collection or monitoring dataset.

Limits

An occurrence aggregator, not an identification key. Coverage follows sampling effort, records can inherit source errors, and sensitive or culturally governed data require CARE as well as FAIR handling.

Coverage

Global marine biodiversity from a network of regional and thematic nodes.

Reuse

Datasets carry CC0, CC BY or CC BY-NC licences; verify and cite every contributing dataset used. OBIS-derived information products are CC0.

A global reference for algal taxonomy, nomenclature, distribution, literature and selected images across marine, freshwater and terrestrial habitats.

Best for

Resolving algal names and checking synonyms and distribution after morphology or sequence evidence has produced a candidate.

Limits

A work in progress reflecting editorial taxonomic opinions. It is not an interactive key, image and verification coverage are uneven, and bulk reuse is controlled.

Coverage

Global algae, including cyanobacteria and diatoms, across marine, freshwater and terrestrial settings.

Reuse

Browser use is open; database, bulk-data and image reuse are subject to AlgaeBase and contributor licensing.

A substantial teaching reference for optical principles, contrast methods, fluorescence, digital imaging and common artefacts.

Best for

Understanding what the microscope and contrast method can resolve before interpreting a feature as biological.

Limits

Vendor-authored teaching material, not a taxonomic key, safety course or substitute for the operating manual and training for a particular instrument.

Coverage

General light and fluorescence microscopy, digital imaging and selected advanced methods.

Reuse

Copyright Nikon Instruments; reading is open but content is not blanket-licensed for reuse.

Imaging

Light microscopy

Structured training modules and simulators for light, electron and cryogenic microscopy, preparation, analysis and image ethics.

Best for

Learning the workflow and vocabulary of an imaging method before entering a supervised facility or documenting a record.

Limits

Simulators and online modules do not replace facility-specific training, risk assessment or supervised competence with a real instrument and specimen.

Coverage

Light microscopy, SEM, TEM, cryo-EM, focused ion beam and associated preparation and analysis topics.

Reuse

CC BY-SA 4.0 unless a module states otherwise.

Imaging

Light microscopy · Scanning electron microscopy · Transmission electron microscopy

A public archive for publication-associated biological image data across scales and modalities, with dataset-level metadata and accessions.

Best for

Finding primary image evidence behind a paper and comparing methods, metadata and source files rather than screenshots.

Limits

A repository rather than an identification key. Taxonomic depth, metadata completeness, file format, licence and dataset size vary by accession.

Coverage

Biological imaging from molecules and cells to organisms across many modalities.

Reuse

Each dataset states its own licence and terms; check the accession before reuse.

Imaging

Light microscopy · Scanning electron microscopy · Transmission electron microscopy

Contributing

Public discovery and download are open; deposition requires an account and controlled data have additional access conditions.

A curated, searchable collection of published imaging datasets using OME standards and structured annotations, often open to reanalysis.

Best for

Exploring a well-annotated image dataset in the browser and understanding how image, phenotype and experiment metadata connect.

Limits

Selective rather than taxonomically comprehensive, with substantial cell, tissue and screening content. Some legacy images have reduced browser functionality.

Coverage

Curated biological imaging studies across organisms, cells, tissues and experimental screens.

Reuse

Dataset rights and citations are stated per study; software and OME components have separate open-source licences.

Imaging

Light microscopy · Scanning electron microscopy · Transmission electron microscopy

An archive of raw two-dimensional electron micrographs, tilt series, tomograms and volume-EM data underlying published work.

Best for

Inspecting primary electron-microscopy evidence and the acquisition context behind a reconstruction or published figure.

Limits

Files can be enormous and require specialist software. Much of the archive is structural cryo-EM rather than an organism-identification atlas.

Coverage

Electron microscopy datasets across structural, cellular and organismal biology.

Reuse

Public EMPIAR datasets are released under CC0; citation of the accession and associated publication remains expected.

Imaging

Scanning electron microscopy · Transmission electron microscopy

An illustrated reference for Nordic phytoplankton, cyanobacteria, diatoms, dinoflagellates, ciliates and related protists.

Best for

Comparing a microalgal or plankton observation with curated regional images and occurrence context tied to current names.

Limits

Nordic emphasis and uneven image coverage. Instrument-specific images may not resemble compound light microscopy, and contributed material varies.

Coverage

Nordic marine and freshwater microalgae, cyanobacteria and protists.

Reuse

Media licences vary by contributor; check each record. API data follow the terms stated by the service.

Imaging

Light microscopy · Scanning electron microscopy · Photography

A large environment for plankton and particle images from ZooScan, UVP, FlowCam, PlanktoScope and related systems, with annotation and machine-assisted classification.

Best for

Comparing instrument-specific plankton images at scale and seeing how experts organise categories within a project.

Limits

Annotations vary by project, machine predictions are not determinations, and only public projects are visible. Instrument appearance may differ markedly from a compound microscope.

Coverage

Global project-contributed plankton and particle imagery, weighted toward oceanographic imaging systems.

Reuse

Project and image licences vary; inspect the project terms before reuse.

Contributing

Visitors can inspect public material; a free account and project permission are needed for annotation and additional data.

Illustrated genus and species accounts with morphology, terminology, ecology, original references and a practical visual identification system.

Best for

Learning which valve characters to measure and comparing a North American diatom against calibrated specialist imagery.

Limits

North American emphasis and explicitly a work in progress. Taxonomic concepts continue to change, and ecological interpretations may not transfer to other regions.

Coverage

North American freshwater and selected other diatoms, expanding by specialist contribution.

Reuse

Content is copyrighted with page-specific citation and reuse conditions.

Imaging

Light microscopy · Scanning electron microscopy

A global nomenclatural backbone for living and fossil marine and freshwater diatoms, with synonyms, types, literature and selected images.

Best for

Validating the name reached through valve morphology or sequence evidence and tracing its type and literature.

Limits

Primarily nomenclature, not a complete visual key. The service reports substantial unchecked and incompletely illustrated content.

Coverage

Global living and fossil diatoms across marine and freshwater habitats.

Reuse

WoRMS/DiatomBase and record-level terms apply; media licences vary.

A rigorously documented independent atlas of living protists with microscopy, scale, morphology and sampling information.

Best for

Comparing the movement and living morphology of a protist against carefully scaled, professionally made micrographs.

Limits

An individually maintained, mainly European resource rather than a peer-reviewed database. Taxonomic coverage is selective and every determination still needs specialist corroboration.

Coverage

Mainly European freshwater and other free-living protists, selected by the author.

Reuse

Many records are CC BY-NC-SA 3.0; verify the licence shown on the individual item.

Imaging

Light microscopy

Included as the library's independent exception because scale, preparation and living morphology are documented unusually well; that does not turn it into a nomenclatural authority.

A cross-taxon platform joining standard barcode sequences to specimen, voucher, image, collection and taxonomy metadata with identification engines.

Best for

Matching an appropriate barcode marker against specimen-linked references and inspecting the evidence behind the closest records.

Limits

Coverage and label quality are uneven, private records can make a result hard to reproduce, and Barcode Index Numbers are operational clusters rather than formally described species.

Coverage

Global animals, plants, fungi and other groups using supported barcode loci.

Reuse

Record, sequence and media rights vary by contributor and project; check every reference record before reuse.

Contributing

Public search and identification are free. An account is required for workbench, project and submission functions.

General nucleotide and protein sequence-similarity searching across curated and broad public databases, with accession-level results.

Best for

Tracing a query to candidate accessions and publications when no more appropriate specialist identification service covers the marker.

Limits

Similarity is not identity. Broad databases contain submitter-supplied labels, contaminants and uneven curation, and no universal percentage threshold establishes a species.

Coverage

Global public nucleotide and protein sequence collections across all organisms.

Reuse

Public sequence records follow NCBI and source-database policies; cite accessions and the database searched.

Quality-controlled, aligned small- and large-subunit ribosomal RNA reference datasets with taxonomy, browsers and downloads.

Best for

Broad 16S, 18S, 23S or 28S placement using a release that can be recorded and reproduced.

Limits

Reference and Parc subsets have different curation levels; not every record is type-validated, eukaryotic curation is uneven and taxonomy changes between releases.

Coverage

Cellular life across bacterial, archaeal and eukaryotic ribosomal RNA loci.

Reuse

CC BY 4.0; cite SILVA and the exact release used.

Curated fungal nuclear ITS references, expert annotations, reference sequences and DOI-bearing Species Hypotheses with analysis-ready releases.

Best for

Fungal ITS assignment with a versioned reference set and operational hypotheses that can be cited precisely.

Limits

Species Hypotheses are threshold-dependent clusters rather than formal species. ITS resolution differs among clades and underlying public labels can still be imperfect.

Coverage

Global fungi and selected other eukaryotes represented by ITS sequences.

Reuse

CC BY for UNITE releases; retain the release DOI and attribution.

Contributing

Browsing and downloads are open; registration is used for advanced PlutoF curation tools.

An expert-curated 18S ribosomal RNA reference taxonomy for protists with downloadable releases and metabarcoding support.

Best for

Protist-specific 18S assignment using a curated taxonomic framework rather than a broad unfiltered sequence archive.

Limits

A sequence reference rather than morphology; 18S often cannot resolve species, environmental labels can be uncertain and expert coverage varies among clades.

Coverage

Global protists, with selected fungi, animals and plants retained for context.

Reuse

Open releases; cite PR² and record the database version used.

Strain-level bacterial and archaeal taxonomy, morphology, physiology, cultivation, isolation, biosafety and sequence links, including type strains.

Best for

Checking whether a microbial candidate agrees with a documented strain's provenance, morphology, physiology and culture conditions.

Limits

Not a visual identification key. Culture-derived phenotypes can differ from environmental observations, uncultured diversity is underrepresented and record completeness varies.

Coverage

Global bacterial and archaeal strains held by culture collections and represented in the literature.

Reuse

CC BY 4.0 for BacDive data.

Contributing

Browsing is open; some programmatic services require free registration.

A reference for valid publication status, nomenclatural history, synonyms, type strains and literature under the prokaryotic nomenclature code.

Best for

Checking whether a bacterial or archaeal name is validly published and identifying its nomenclatural type strain.

Limits

Nomenclature is not identification and LPSN is not an official universal biological classification. A valid name says nothing about whether the query belongs to that taxon.

Coverage

Global names of Bacteria and Archaea governed by the International Code of Nomenclature of Prokaryotes.

Reuse

Attribution and DSMZ Digital Diversity terms apply; API and downloads require registration.

Whole-genome identification and classification against type-strain genomes using digital DNA–DNA hybridisation, G+C comparison and phylogenomics.

Best for

Testing a bacterial or archaeal genome against type-strain references with a standards-oriented, documented workflow.

Limits

Requires a usable genome, can queue jobs and cannot compensate for missing or problematic type-genome data. Its result still needs sample and contamination scrutiny.

Coverage

Prokaryotic taxa with suitable type-strain genome references.

Reuse

DSMZ service terms apply; cite the TYGS method and references returned with the result.

Contributing

Submission is free and uses an email address to return results; no persistent user account is required.

The authoritative list of accepted mineral names, status, formulae and nomenclatural changes maintained by the IMA commission responsible for mineral naming.

Best for

Checking whether a mineral name is approved, renamed, discredited or otherwise qualified, with the list version retained.

Limits

Not an identification key, occurrence database or image library. An accepted name does not show that a sample belongs to that species.

Coverage

Globally recognised mineral species and IMA nomenclatural status.

Reuse

IMA and CNMNC reuse terms apply; cite and retain the dated list or update used.

Measured Raman, X-ray diffraction, chemistry and related reference data linked to documented mineral samples.

Best for

Comparing laboratory measurements with reference spectra or diffraction data rather than relying on appearance.

Limits

Species and sample coverage are incomplete, and RRUFF is not the mineral-naming authority. The rebuilt service still marks some functions as unfinished.

Coverage

Global mineral reference samples represented by available analytical datasets.

Reuse

RRUFF citation and site terms apply to data and downloads.

Free mineral-species PDFs summarising physical, optical, chemical and crystallographic properties, occurrence and references.

Best for

Checking whether a candidate's measured properties and associations agree with a concise specialist summary.

Limits

Entries are literature summaries rather than live determinations; locality lists are selective and the PDFs are copyrighted.

Coverage

Recognised mineral species, organised in handbook volumes.

Reuse

Copyright Mineralogical Society of America; reading is free but reuse is not blanket-open.

A hierarchical scheme and published reports for consistently naming and describing igneous, sedimentary, metamorphic and superficial materials.

Best for

Turning recorded texture, composition and origin into a reproducible rock-classification term.

Limits

A BGS corporate scheme with some differences from other national or IUGS practice. Classification still requires adequate observation or analysis.

Coverage

Major natural and artificial rock and superficial-deposit classes used by BGS.

Reuse

British Geological Survey copyright and reuse terms apply.

A very large community resource for mineral, rock, meteorite and locality discovery, associations, photographs and references.

Best for

Generating candidates from habit and associations and finding locality-specific literature or comparable photographs.

Limits

Community-curated rather than a nomenclatural authority. Corroborate names with IMA and occurrences with surveys or literature; photographs alone do not identify a specimen.

Coverage

Global minerals, rocks, meteorites and collecting localities, uneven by contributor activity.

Reuse

Database and media terms are mixed; check the individual record or image before reuse.

Contributing

Browsing is open; an account is required for contributions and some tools.

Included as the geological community exception because its moderation, locality depth and evidence links are unusually useful; it remains a discovery source, not the final authority.

The official database of meteorite names, approval status, classification, find locality, initial description and type repository.

Best for

Checking an official meteorite name and following its classification and repository information.

Limits

Provisional, doubtful and early classifications need care; classifications can change and mass or collection details can be incomplete. It does not authenticate a newly found stone.

Coverage

Officially named meteorites and related nomenclatural records worldwide.

Reuse

Meteoritical Society and Lunar and Planetary Institute citation and use terms apply.

The global standard chart for chronostratigraphic units, boundary ages and Global Boundary Stratotype Sections and Points.

Best for

Recording a geological age against a named, dated chart version and translating between hierarchy levels.

Limits

Version-specific and global in scale. It does not supply local rock-unit names, field correlations or the evidence assigning a specimen to an age.

Coverage

Global geological time scale.

Reuse

International Commission on Stratigraphy chart reuse terms apply; retain the chart version.

The primary national source for Australian geological unit names, status, hierarchy, age and references.

Best for

Checking the current or historical name of an Australian stratigraphic unit and its documented relationships.

Limits

Australia only. Older legacy records vary in detail and need interpretation through the cited maps and publications.

Coverage

Australian lithostratigraphic and related named geological units.

Reuse

Geoscience Australia attribution and website terms apply.

A research aggregation linking geological maps, stratigraphic columns, harmonised unit names and fossil occurrences through web tools and an API.

Best for

Placing a field observation in broad map and stratigraphic context and finding the original geological source to consult.

Limits

An academic aggregator rather than a naming authority. Global coverage is uneven and the original map, survey or publication should be cited for a record.

Coverage

Global with strongest depth where map and column sources have been integrated.

Reuse

Macrostrat data are generally CC BY 4.0 while source-provider terms remain attached.

A global, literature-linked research database of fossil occurrences, taxonomy, stratigraphy and analytical data.

Best for

Checking the published occurrence and stratigraphic context of a fossil candidate and tracing the source literature.

Limits

Contributor-driven and taxonomically dynamic. It is not a museum specimen catalogue or final taxonomic authority, and coverage follows the entered literature.

Coverage

Global fossil occurrences and palaeobiological literature, uneven by group and region.

Reuse

CC BY 4.0 for database content; cite the database and contributing references.

Contributing

Public search, API and downloads are open; contribution requires an approved account.

Primary museum records and research datasets spanning palaeontology, mineralogy and other natural-history collections, often with stable identifiers and media.

Best for

Finding a documented museum specimen or dataset to compare and citing its holding institution and stable record.

Limits

Represents Natural History Museum holdings and digitisation, not all collections. Records and historical identifications can be incomplete or revised.

Coverage

Natural History Museum collections and published datasets across natural-history disciplines.

Reuse

Licence is stated per dataset; core collection data are commonly CC0 while media and research datasets may differ.

Integrated access to global geochemical, petrological and geochronological observations from publications and repositories, including PetDB.

Best for

Comparing composition or age data with source-linked analyses and locating relevant published datasets.

Limits

A heterogeneous aggregation with geographic and material biases. Contributor-assigned rock names are not independently validated identities.

Coverage

Global Earth-material geochemistry, petrology and geochronology, source-dependent.

Reuse

Dataset-specific licences and citations apply; retain the original dataset attribution.

Contributing

Search is open; submission uses an EarthChem or GeoPass workflow and account.

Australian sample-linked geochemistry and geochronology, including U–Pb, Ar–Ar, fission-track and elemental data.

Best for

Finding Australian analytical data where samples, methods, laboratories and provenance remain connected.

Limits

Australia-heavy and contributor-supplied. Inspect laboratory methods, quality assurance and original attribution before comparison.

Coverage

Predominantly Australian geological samples and analytical datasets.

Reuse

Public data are CC BY 4.0 unless a dataset states otherwise.

Contributing

Public discovery is open; a free account is required for contribution and full workspace tools.

A registry for persistent International Generic Sample Numbers, sample descriptions, provenance, relationships and links to datasets and publications.

Best for

Checking whether an Earth or extraterrestrial sample has a persistent identifier and tracing related samples, datasets and papers.

Limits

A metadata and identifier registry, not proof of identity, legal custody, physical availability or analytical quality.

Coverage

Global Earth, environmental and extraterrestrial physical samples registered through participating allocating agents.

Reuse

SESAR² metadata and site terms apply; linked datasets retain their own licences.

Contributing

Public search is open; ORCID-linked registration is required to create or edit sample records.

Certified, recommended and published values for rock, mineral, glass, solution and other analytical reference materials.

Best for

Documenting calibration and quality assurance against an appropriate reference material and comparing published values.

Limits

Reference materials only, not field specimens. Users must distinguish certified, recommended and compiled values and retain database and material versions.

Coverage

International geochemical, environmental and selected biological analytical reference materials.

Reuse

International Association of Geoanalysts and database citation terms apply.

The primary non-Solar-System name resolver, joining identifiers, ICRS coordinates, object types, measurements and bibliography.

Best for

Resolving alternate designations and checking coordinates, object type and literature for a fixed astronomical source.

Limits

A heterogeneous literature meta-compilation rather than a catalogue, and it excludes Solar-System objects. Measurements from different sources and epochs are not automatically comparable.

Coverage

Galactic and extragalactic objects outside the Solar System.

Reuse

SIMBAD database content is ODbL; linked measurements and publications retain source terms.

Position and field searching across published astronomical catalogues, with catalogue documentation, tables and machine-access formats.

Best for

Cross-matching a field or source against the specific catalogue appropriate to the measurement and retaining its release and ReadMe.

Limits

Catalogues have different epochs, selection functions, uncertainties and quality flags. Coverage is not exhaustive and source-catalogue reuse terms vary.

Coverage

Global astronomical catalogues across wavelengths and object types.

Reuse

Reuse terms are set by each source catalogue; cite the catalogue and VizieR record.

An interactive sky atlas for survey imagery, SIMBAD and VizieR overlays, catalogue cross-matching and local FITS/WCS inspection.

Best for

Visually checking a solved field against survey imagery and catalogue sources while retaining their identifiers.

Limits

HiPS layers are often resampled visualisations rather than original calibrated files. Authority and reuse conditions remain with each upstream archive.

Coverage

All-sky and targeted survey layers and catalogues supplied through CDS and partner archives.

Reuse

Aladin Desktop and Lite software are GPLv3; displayed data retain provider terms.

The reference archive for Gaia positions, proper motions, parallaxes, broad-band photometry, variability and released spectra.

Best for

Checking astrometric identity and epoch-dependent position against a named Gaia data release.

Limits

Crowding, zero-points, selection effects and release-specific source identifiers matter. The live archive warned of instability during DR4 preparation at the last check.

Coverage

All-sky stellar and other source data within Gaia's observing and processing limits.

Reuse

Gaia data are publicly accessible; cite the applicable release and follow ESA and Gaia acknowledgement guidance.

Contributing

Public access is available without payment; registration is optional but recommended for sustained or saved queries.

A cross-identification and synthesis service for galaxies, quasars and other extragalactic objects, including redshifts, distances, spectral energy distributions and literature.

Best for

Resolving an extragalactic source and tracing the measurements and publications behind its identifiers and redshift.

Limits

Extragalactic only and updated in releases rather than continuously. Legacy APIs cannot see data ingested after January 2026; use the current APIs.

Coverage

Extragalactic objects and associated measurements and literature.

Reuse

No blanket open licence is stated; cite NED and the original data sources.

A moderated living index of variable-star identities, coordinates, AUIDs, variability types, periods, magnitude ranges and references.

Best for

Checking a variable-star designation and the current classification and period evidence attached to it.

Limits

An index rather than a light-curve archive or formal publication. Crowded fields, blends and incomplete literature can remain, and records are revised.

Coverage

Known and candidate variable stars worldwide.

Reuse

AAVSO citation and data-use guidance apply.

Contributing

Public search is open; an AAVSO account is required for submissions and revisions.

A long-baseline archive of visual and instrumental variable-star photometry with bandpass, uncertainty and observer provenance.

Best for

Comparing a time series with historical observations and inspecting the filters, errors and observer metadata behind each point.

Limits

Instruments, filters and error practices are heterogeneous; visual observations have intrinsically larger scatter. Time and quality flags need careful interpretation.

Coverage

International variable-star photometry contributed by professional and amateur observers.

Reuse

AAVSO data-use and citation guidelines apply.

Contributing

Search and export are open; submission requires an account and observer code.

The official clearing house for designations, astrometric observations, orbital records and circulars for minor planets, comets and outer natural satellites.

Best for

Checking an official designation and the observation and orbit record for a Solar-System small body.

Limits

Preliminary designations and orbits evolve as observations arrive. A short arc or catalogue entry does not prove a secure identification.

Coverage

Minor planets, comets and outer natural satellites.

Reuse

No blanket database licence is stated; use MPC citation and data-use guidance.

Contributing

Public access is open; astrometric submission uses MPC and ADES workflows and usually requires an observatory code.

Observer- and time-specific ephemerides for Solar-System bodies, including coordinates, rates, light-time, visibility and frame choices.

Best for

Testing whether a moving object should have occupied the measured position at the recorded time and observing site.

Limits

Observer centre, time scale, refraction and coordinate-frame defaults must be checked. Coverage has object-specific bounds and the service is best-effort.

Coverage

Solar-System objects represented in JPL ephemeris and small-body services.

Reuse

NASA and JPL terms apply; cite Horizons and retain the query parameters and solution date.

The official IAU mechanism for reporting and naming astronomical transients, with discovery and classification reports, coordinates, photometry and spectra.

Best for

Checking whether a transient has an official designation and whether it is merely reported, classified or confirmed.

Limits

A named candidate is not necessarily classified or confirmed. Proprietary periods exist and the service discourages bulk scraping of search pages.

Coverage

Reported extragalactic and other astronomical transients within TNS scope.

Reuse

TNS and source-report terms apply; cite the discovery and classification reports used.

Contributing

Public search is open; reporting requires an approved account or group, and API automation requires bot credentials.

Time-matched, registered multiwavelength solar imagery and event overlays from major solar missions.

Best for

Comparing a solar observation with the same time and wavelength context across SDO, SOHO, STEREO, Hinode, Solar Orbiter and other sources.

Limits

Primarily a visualisation service using derived products. Retrieve original calibrated files from the mission archive for measurement.

Coverage

Solar imagery and event annotations from participating spacecraft and observatories.

Reuse

Open-source service; imagery remains subject to the source mission's terms and acknowledgement guidance.

Original and calibrated FITS images, spectra and time series from Hubble, Webb, TESS, Kepler, GALEX, Pan-STARRS and related collections.

Best for

Retrieving the mission-calibrated product and provenance behind a comparison image, spectrum or light curve.

Limits

Primarily ultraviolet, optical and near-infrared; active-mission data can be embargoed, and calibration and product meanings remain mission-specific.

Coverage

NASA and partner space-telescope missions curated by MAST.

Reuse

Most public holdings are public domain; some high-level products are CC BY 4.0 and DSS/GSC products have separate restrictions.

Contributing

Public data are available anonymously; an account is required for protected data and some workspace functions.

An accessible all-sky discovery and download interface for ESA and selected partner images, spectra and catalogues.

Best for

Finding which mission has relevant data at a sky position before moving to the mission archive and documentation.

Limits

A discovery interface rather than the final authority for calibration or provenance. Return to the named source mission for quantitative use.

Coverage

All-sky and targeted holdings from ESA and partner missions across wavelengths.

Reuse

Reuse terms follow the contributing mission and product.

A blind plate-solving service that identifies an unknown star field and returns standards-based WCS metadata and object annotations.

Best for

Turning an astrophotograph with no reliable coordinates into a testable sky position and plate solution.

Limits

The shared queue has no solve guarantee; sparse, distorted or poor-signal fields can fail. WCS still needs residual validation and is not photometric calibration.

Coverage

Stellar fields that can be matched to the service's index files.

Reuse

Anonymous uploads are public and default to CC BY 3.0; sign in to control visibility and licensing. The software distribution is GPLv3 overall.

Contributing

Anonymous solving is available, but private or sensitive images should be uploaded only through an account with visibility set deliberately.

Check image privacy before uploading: the anonymous path is public. A plate solution should be retained with scale, rotation, parity and residuals rather than copied as a target name only.