Astronomy / Space-Data / Astrophysics DSLs Family Index
type: language-family-index family: astronomy-space languages_catalogued: 27 tags: [language-reference, family-index, astronomy-space, fits, ivoa, votable, adql, tap, spice, pds4, asdf, voevent, gcn]
Astronomy / Space-Data / Astrophysics — Family Index
Family overview
Astronomy is, quietly, one of the longest-running open-data communities in science, and its data-interchange standards are correspondingly old, durable, and unusually well-respected. The anchor format is FITS (Flexible Image Transport System), first defined by Wells, Greisen, and Harten in 1981 and still — 45 years later — the universal carrier for astronomical images, spectra, cubes, and tabular catalogs. The current edition is the FITS Standard 4.0, which was approved by the IAU FITS Working Group on 22 July 2016 and finalised in its language-edited form on 13 August 2018; the standard now mandates CHECKSUM/DATASUM keywords for data-integrity verification. FITS’s design — fixed-length 80-character ASCII header cards in 2880-byte blocks, followed by binary-aligned data — was unfashionable even by 1990s standards, but its self-describing, header-readable-without-tooling property has carried it through five generations of computing.
The second major thread is the Virtual Observatory ecosystem, codified by the International Virtual Observatory Alliance (IVOA) starting around 2002. The IVOA stack is layered: VOTable (XML for tables, current Recommendation 1.5 of 2024-02-13) is the wire format; TAP (Table Access Protocol) 1.1 (2019-09-27) is the REST query layer; ADQL (Astronomical Data Query Language) 2.1 (2023-12-15) is an SQL-92-derived dialect with spatial extensions for cone, box, and polygon queries; UWS (Universal Worker Service) is the async-job pattern; SIA, SSA, SLAP, SODA, ConeSearch, ObsCore/ObsTAP, DataLink, SAMP, MOC fill out the rest. Collectively this is one of the most successful open-standards efforts in any scientific domain, and ADQL in particular is a genuinely SQL-class query language used in production against billions of rows in Gaia DR3, SDSS, and Vera Rubin’s LSST archives.
The third thread is time-domain alerting. VOEvent (IVOA, 2006) is the XML format for transient astronomical events — supernovae, GRBs, microlensing, gravitational-wave triggers — and the General Coordinates Network (GCN), formerly the Gamma-Ray Burst Coordinates Network, is NASA’s broadcast infrastructure. GCN historically used the GCN Classic protocols (TCP socket streams) but the modern path is GCN Kafka with notices in JSON, with the GCN Classic VOEvent brokers scheduled for retirement shortly after the LIGO O4 observing run concludes (October 2025). This matters for LIGO/Virgo gravitational-wave alerts and for the Vera Rubin Observatory’s expected 10-million-alerts-per-night LSST stream.
The fourth thread is mission and spacecraft data: PDS4 (NASA’s Planetary Data System 4, current Information Model 1.25.0.0 released December 2025 with Build 16) is the XML-bundle archive standard for planetary missions; NAIF SPICE is the universal spacecraft ephemeris/geometry toolkit; CCSDS XTCE standardises telemetry/command databases across space agencies (cross-link aerospace-defence); and ASDF (Advanced Scientific Data Format) — HDF5-based binary blocks with YAML headers — is the modern attempt at a FITS successor, used in the James Webb Space Telescope pipeline (current standard 1.6.0).
In our deep library
None catalogued. Astronomy/space-data DSLs are file/wire formats and standards rather than general-purpose programming languages; they all sit on top of host languages already catalogued.
Cross-reference:
- scientific — sibling family covering MATLAB / Mathematica / Octave / numerical computation; the analysis layer that consumes FITS/VOTable/ASDF data.
- geospatial — NetCDF is dual-classified here; HDF5 ecosystem and coordinate-system overlap (FITS WCS is in spirit a sibling to OGC CRS).
- api-description — IVOA TAP/SIA/SSA are REST protocols with XML schemas; ObsCore is effectively a domain ontology.
- notation-spec — ADQL has a formal BNF grammar; VOTable and PDS4 use XSD; relevant for parser/spec discussion.
- aerospace-defence — CCSDS family (XTCE, SANA registries, Packet Telemetry) lives there; cross-list because spacecraft science data and spacecraft engineering telemetry share standards.
- python — Astropy (the canonical FITS/VOTable/WCS/ASDF library), astroquery, sunpy, specutils, and the entire AstroPy Project ecosystem are Python-hosted.
- bio-fileformats — HDF5 conventions overlap; both communities lean on HDF5 for large multidimensional arrays.
Tier 3 family table — Foundational astronomy formats
| Format | First appeared | Origin | Type | Status (2026) | URL |
|---|---|---|---|---|---|
| FITS (Flexible Image Transport System) | 1981 (Wells/Greisen/Harten); FITS 4.0 approved 22 Jul 2016, language-edited 13 Aug 2018 | IAU FITS Working Group | Self-describing binary container; 2880-byte blocks, 80-char ASCII header cards, HDU (Header-Data Unit) structure; mandatory CHECKSUM/DATASUM since 4.0 | Universal, the de facto astronomical format for 45 years; FITS 4.0 remains current | https://fits.gsfc.nasa.gov/fits_standard.html |
| FITS WCS (World Coordinate System) | Papers I–VII, 2002–2015 | Greisen, Calabretta, et al. | Keyword conventions inside FITS headers for celestial / spectral / time / distortion coordinates | Active, embedded in FITS 4.0 and universally implemented | https://fits.gsfc.nasa.gov/fits_wcs.html |
| CDF (Common Data Format) | 1985 | NASA Goddard Space Flight Center (NSSDC) | Self-describing scientific data format used heavily in planetary/heliospheric (THEMIS, MMS, SDO) | Active (CDF 3.9 era, 2024–25), niche to space-physics community | https://cdf.gsfc.nasa.gov/ |
| NetCDF | 1989 (NetCDF-3); NetCDF-4 (HDF5-backed) 2008 | UCAR/Unidata | Self-describing array-oriented format; cross-listed in geospatial | Very active, atmospheric/oceanographic + some astronomy | https://www.unidata.ucar.edu/software/netcdf/ |
| HDF5 | 1998 | NCSA (now HDF Group) | Hierarchical binary container; powers ASDF, NetCDF-4, many telescope pipelines | Very active | https://www.hdfgroup.org/solutions/hdf5/ |
Tier 3 family table — IVOA Virtual Observatory
| Format | First appeared | Origin | Type | Status (2026) | URL |
|---|---|---|---|---|---|
| VOTable | 1.0 in 2002; 1.5 Recommendation 2024-02-13 | IVOA | XML format for tabular astronomical data; supports inline TABLEDATA, BINARY, and BINARY2 serialisations; carries UCDs (Unified Content Descriptors) and VOUnits | Recommendation 1.5 current; universal IVOA wire format | https://ivoa.net/documents/VOTable/ |
| TAP (Table Access Protocol) | 1.0 in 2010; 1.1 Recommendation 2019-09-27 | IVOA | REST(-ish) service protocol for querying tabular astronomical databases; sync + async; results in VOTable | Recommendation 1.1 current; used by Gaia, SDSS, NED, ESA, NASA archives | https://www.ivoa.net/documents/TAP/ |
| ADQL (Astronomical Data Query Language) | 2.0 in 2008; 2.1 Recommendation 2023-12-15 | IVOA | SQL-92-derived query language with geometric primitives (POINT, CIRCLE, BOX, POLYGON, CONTAINS, INTERSECTS) and ivo_ user-defined-function namespace | Recommendation 2.1 current; the production query layer for billion-row catalogs | https://www.ivoa.net/documents/ADQL/ |
| Cone Search (Simple Cone Search) | 1.03 in 2008 | IVOA | Minimal REST GET ?RA=&DEC=&SR= interface returning a VOTable; the simplest VO service | Recommendation 1.03, ubiquitous on catalog services | https://www.ivoa.net/documents/REC/DAL/ConeSearch-20080222.html |
| SIA (Simple Image Access) | 1.0 in 2009; 2.0 Recommendation 2015 | IVOA | REST protocol for discovering and retrieving astronomical images by sky position | Recommendation 2.0 current | https://www.ivoa.net/documents/SIA/ |
| SSA (Simple Spectral Access) | 1.0 in 2008 (updated 1.1 in 2012) | IVOA | REST protocol for discovering 1D spectra | Recommendation, broadly deployed | https://www.ivoa.net/documents/SSA/ |
| SLAP (Simple Line Access Protocol) | 1.0 in 2010 | IVOA | REST protocol for querying atomic/molecular spectral-line databases | Recommendation, niche but stable | https://www.ivoa.net/documents/SLAP/ |
| SODA (Server-side Operations for Data Access) | 1.0 Recommendation 2017 | IVOA | Server-side cutout / filter / sub-array operations on image and cube data (POS=CIRCLE, BAND=, etc.) | Recommendation | https://www.ivoa.net/documents/SODA/ |
| UWS (Universal Worker Service) | 1.0 in 2010; 1.1 Recommendation 2016 | IVOA | Generic async-job pattern (/jobs/{id}, phase transitions PENDING → EXECUTING → COMPLETED) underlying TAP async and SODA async | Recommendation 1.1, widely used | https://www.ivoa.net/documents/UWS/ |
| DataLink | 1.0 Recommendation 2015; 1.1 in 2023 | IVOA | Discovery protocol for related data products (preview, raw, derived, calibration) | Recommendation 1.1 | https://www.ivoa.net/documents/DataLink/ |
| ObsCore / ObsTAP | 1.0 Recommendation 2011; 1.1 in 2017 | IVOA | Observation-core data model; standardised set of TAP columns for cross-archive observation discovery | Recommendation 1.1, the cross-archive lingua franca | https://www.ivoa.net/documents/ObsCore/ |
| SAMP (Simple Application Messaging Protocol) | 1.3 Recommendation 2012 | IVOA | Desktop hub-and-spokes IPC for inter-app messaging (TopCat ↔ Aladin ↔ DS9 ↔ ESASky) | Recommendation 1.3, ubiquitous in the desktop tool ecosystem | https://www.ivoa.net/documents/SAMP/ |
| MOC (Multi-Order Coverage) | 1.0 Recommendation 2014; 2.0 in 2022 | IVOA | HEALPix-based hierarchical spatial-coverage description; FITS- or JSON-serialised | Recommendation 2.0 (adds time-MOC and space-time-MOC) | https://www.ivoa.net/documents/MOC/ |
Tier 3 family table — Time-domain & alerts
| Format | First appeared | Origin | Type | Status (2026) | URL |
|---|---|---|---|---|---|
| VOEvent | 1.0 in 2006; 2.0 Recommendation 2011 | IVOA | XML format for transient astronomical event reports (GRBs, supernovae, microlensing, GW triggers) | Recommendation 2.0, but transport is migrating off VOEvent-XML brokers onto GCN Kafka + JSON | https://www.ivoa.net/documents/VOEvent/ |
| GCN (General Coordinates Network) Notices | 1992 (as BACODINE/GCN-Classic at GSFC); modernised GCN at gcn.nasa.gov launched 2022 | NASA GSFC | Real-time machine-readable transient alerts in JSON (Kafka), VOEvent-XML (legacy), or plain-text | Active; GCN Classic VOEvent brokers retiring shortly after LIGO O4 (Oct 2025); Kafka + JSON is the forward path; SVOM, Einstein Probe, LIGO/Virgo/KAGRA, Fermi, Swift all publish | https://gcn.nasa.gov/ |
| ATEL (Astronomer’s Telegram) | 1998 | Robert Rutledge / community | Web-based short-form text bulletins; adjacent to GCN; not machine-structured but archived | Active, used for follow-up and slower transients | https://www.astronomerstelegram.org/ |
| MPC (Minor Planet Center) formats | 1947 (MPC); machine formats evolved with electronic publication | IAU MPC at SAO | XML, JSON, and fixed-column ASCII formats for solar-system body astrometry and orbits; MPECs, DOU, ORB records | Active, the IAU clearinghouse for asteroids/comets | https://minorplanetcenter.net/ |
Tier 3 family table — Mission / spacecraft data
| Format | First appeared | Origin | Type | Status (2026) | URL |
|---|---|---|---|---|---|
| PDS4 (Planetary Data System 4) | 2011 (mandated for new NASA planetary missions); Information Model 1.25.0.0 with Build 16 (Dec 2025) | NASA PDS | XML-based archival bundle: label XML + data file + dictionaries; replaces PDS3’s PVL labels | Active, the NASA-mission archive standard | https://pds.nasa.gov/datastandards/about/ |
| SPICE kernels (NAIF) | mid-1980s; SPICE Toolkit N67 era in 2024–25 | NASA NAIF (JPL) | Family of binary/text kernels: SPK (ephemerides), CK (orientation), PCK (planet constants), FK (frames), IK (instrument), LSK (leap-seconds), SCLK (spacecraft clock), DSK (digital shape) | Universal, the de facto spacecraft-geometry toolkit; PDS4-bundled via naif-pds4-bundler | https://naif.jpl.nasa.gov/naif/toolkit.html |
| CCSDS XTCE (XML Telemetric & Command Exchange) | 1.0 in 2008; 1.2 in 2017; current revisions ongoing | CCSDS / OMG | XML schema for spacecraft telemetry packet definitions, command databases, calibration curves; cross-list aerospace-defence | Active (CCSDS 660.0-B-2 and successors), used by ESA EGS-CC, Yamcs, NASA cFS extensions | https://public.ccsds.org/Publications/SeriesB.aspx |
| OpenSpace asset config | 2017+ | OpenSpace Project (AMNH / NASA / Linköping) | Lua-based scene/asset configuration for the OpenSpace open-source planetarium | Active, niche to planetarium visualisation | https://www.openspaceproject.com/ |
Tier 3 family table — Modern formats / tooling
| Format | First appeared | Origin | Type | Status (2026) | URL |
|---|---|---|---|---|---|
| ASDF (Advanced Scientific Data Format) | 1.0 in 2015 (Greenfield et al., STScI); standard 1.6.0 | STScI / Astropy Project | YAML tree headers + binary block storage; JSON-Schema validation; the JWST and Roman pipeline format; FITS successor candidate | Active, growing adoption; the JWST _asdf extensions are canonical | https://www.asdf-format.org/ |
| Aladin Lite / Aladin Desktop / TopCat / DS9 / JS9 (data-viewer formats) | various 1990s–2010s | CDS Strasbourg / IoA Cambridge / SAO | Desktop and browser viewers that consume FITS, VOTable, MOC, HiPS — not languages themselves but de facto reference implementations | Active, the canonical reference clients for VO standards | https://aladin.cds.unistra.fr/ |
| HiPS (Hierarchical Progressive Surveys) | 1.0 Recommendation 2017 | CDS / IVOA | Tiled HEALPix-based progressive sky-image format (analogous to map tiles for the celestial sphere) | Recommendation, hosts all-sky surveys for Aladin and ESASky | https://www.ivoa.net/documents/HiPS/ |
Notable threads
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FITS’s 45-year reign and why it persists. FITS was designed in 1981 for 9-track magnetic tape on VAX/VMS minicomputers; its 2880-byte block size descends from tape-record alignment. Every modern complaint about it is correct — 80-character header cards waste space, the lack of native compression is awkward, binary tables predate sane variable-length array support, and there’s no good schema-validation story. And yet: every observatory, archive, pipeline, and student tutorial uses it, because the cost of changing the substrate of an entire scientific field over 50 years of accumulated data is effectively infinite. FITS 4.0 (2018) added mandatory checksums but otherwise codifies what’s been deployed for decades. ASDF is the most credible successor candidate (it powers JWST), but FITS will outlive most of us.
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The IVOA as a quietly successful international standards effort. Unlike many standards bodies, the IVOA delivers: ADQL 2.1, TAP 1.1, VOTable 1.5, ObsCore 1.1, SODA 1.0, MOC 2.0, and a coherent registry are not aspirational — they’re deployed across the world’s major observatories (ESO, ESA, NASA, NRAO, CDS, Gaia, SDSS, Vera Rubin). The community runs twice-yearly InterOp meetings, the proposals go through Working Drafts → Proposed Recommendations → Recommendations with real interoperability testing, and (crucially) the reference implementations — TopCat, Aladin, Astropy/astroquery, pyvo, GAVO DaCHS — are open-source and serve as conformance tests. It is, by some measure, the gold standard for science-data interop in any field.
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VOEvent + GCN as the time-domain alert backbone. Multi-messenger astronomy — GW170817, the GRB-supernova connection, IceCube neutrino alerts — depends on machine-readable transient alerts arriving within seconds. VOEvent was the IVOA’s 2006-era XML answer; the GCN (originally BACODINE for gamma-ray burst alerts in the early 1990s) is the NASA broadcast infrastructure. The 2022 modernisation of GCN at gcn.nasa.gov moved the canonical transport to Kafka + JSON, and the legacy GCN Classic VOEvent brokers are scheduled for retirement shortly after LIGO O4 concludes (~Oct 2025). This matters enormously for the Vera Rubin Observatory’s LSST, expected to produce ~10 million transient alerts per night starting from full survey operations — a regime that VOEvent-XML-over-TCP-sockets was never going to handle.
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SPICE as the universal spacecraft-ephemeris tool. NAIF SPICE (NASA’s Navigation and Ancillary Information Facility, JPL) is not a language so much as a toolkit + a family of kernel formats (SPK, CK, PCK, FK, IK, LSK, SCLK, DSK), but it is the universal answer to “where was this spacecraft at this UTC instant, and what was it pointing at?” Every NASA planetary mission, ESA’s BepiColombo and JUICE, and JAXA’s MMX use SPICE; the PDS4 archive bundles SPICE kernels via the
naif-pds4-bundlertool. The longevity matters: SPK files written for Voyager 2 in the 1980s still read correctly in 2026, which is a different kind of standards stability than software people usually mean. -
ASDF as the modern HDF5-based successor. ASDF (Advanced Scientific Data Format) was developed at STScI for JWST and Roman; it combines YAML metadata trees (human-readable, JSON-Schema-validatable) with binary data blocks for arrays, and supports references between blocks. The current standard is 1.6.0. ASDF natively serialises Astropy objects (WCS, models, units, tables) through
asdf-astropy. It is the most credible long-term FITS successor — but FITS has 45 years of inertia and ASDF is currently used in parallel with FITS rather than replacing it. -
PDS4 as NASA’s mission-archive standard. PDS4 replaced PDS3 (which used the PVL — Parameter Value Language — labels) starting in 2011. Every NASA planetary mission since (MAVEN, OSIRIS-REx, Mars 2020, Lucy, Europa Clipper) archives to PDS4. The Information Model is at 1.25.0.0 with Build 16 (December 2025). The XML-bundle approach is verbose but archive-grade — labels are machine-readable, schema-validated, and disconnected from any single piece of analysis software, which is the long-term-archive property you want when data has to be readable in 2075.
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ADQL as a real SQL-class query language for astronomy. Many “domain SQL dialects” are toys; ADQL is not. It extends SQL-92 with geometric primitives (
POINT,CIRCLE,BOX,POLYGON,CONTAINS,INTERSECTS,DISTANCE), supports spatial indexing (HEALPix, Q3C, pgSphere on the backend), and runs in production against Gaia DR3’s ~1.8 billion sources, SDSS-V, NED, and the upcoming LSST catalogs. Theivo_UDF namespace (per the 2024 Catalogue of ADQL UDFs Endorsed Note) handles HEALPix, distance metrics, and unit conversions. For a domain query language, ADQL is the realised version of what XQuery wanted to be for XML — a respected, deployed, multi-implementation standard rather than a single-vendor extension.
Citations
- FITS Standard 4.0 (NASA GSFC, IAU FITS WG, 13 Aug 2018): https://fits.gsfc.nasa.gov/fits_standard.html
- FITS Standard 4.0 PDF (fits_standard40aa-le.pdf): https://fits.gsfc.nasa.gov/standard40/fits_standard40aa-le.pdf
- FITS WCS papers and conventions: https://fits.gsfc.nasa.gov/fits_wcs.html
- IVOA documents index: https://www.ivoa.net/documents/
- VOTable 1.5 Recommendation (2024-02-13): https://ivoa.net/documents/VOTable/
- TAP 1.1 Recommendation (2019-09-27): https://www.ivoa.net/documents/TAP/
- ADQL 2.1 Recommendation (2023-12-15): https://www.ivoa.net/documents/ADQL/
- IVOA ADQL UDF Catalogue 1.2 (2024-08-07): https://www.ivoa.net/documents/udf-catalogue/
- ObsCore / ObsTAP 1.1: https://www.ivoa.net/documents/ObsCore/
- SODA / SIA / SSA / SLAP / DataLink / UWS / SAMP / MOC: https://www.ivoa.net/documents/
- VOEvent 2.0: https://www.ivoa.net/documents/VOEvent/
- General Coordinates Network (GCN): https://gcn.nasa.gov/
- GCN Classic VOEvent retirement notice (post-LIGO O4, Oct 2025): https://gcn.nasa.gov/news
- NAIF SPICE Toolkit: https://naif.jpl.nasa.gov/naif/toolkit.html
- PDS4 data standards portal: https://pds.nasa.gov/datastandards/about/
- PDS4 current Information Model 1.25.0.0 (Build 16, Dec 2025): https://pds.nasa.gov/datastandards/documents/current-version.shtml
- ASDF Standard (asdf-format.org): https://www.asdf-format.org/
- asdf-astropy extension: https://asdf-astropy.readthedocs.io/
- Astropy Project: https://www.astropy.org/
- CCSDS publications (XTCE 660.0-B-2 and successors): https://public.ccsds.org/Publications/SeriesB.aspx
- Minor Planet Center (IAU): https://minorplanetcenter.net/
- HiPS (Hierarchical Progressive Surveys): https://www.ivoa.net/documents/HiPS/
- CDF (NASA GSFC): https://cdf.gsfc.nasa.gov/