About azmth

Data sources

• CelesTrak general perturbations (GP) orbital data, maintained by Dr. T.S. Kelso. azmth refreshes its catalog every 2 hours, matching CelesTrak's update cadence.
• CelesTrak SATCAT for operator and country attribution.
• NASA Visible Earth for the Blue Marble Earth textures (public domain).
• NASA 3D Resources for most of the 3D models shown in the True Scale view (public domain): the ISS, Hubble, GOES, TDRS, Terra, Aqua, Landsat, Sentinel-6, Suomi NPP, Chandra, Fermi, Swift, the Solar Dynamics Observatory, Hinode, SORCE, Cluster II, GRACE, OCO-2, Aura, ICESat-2, Jason, CYGNSS, RADARSAT-1, the SSL-1300 communications bus, and the generic 3U CubeSat.
• Our own models, built in Blender from published dimensions and photographs where no agency model exists and we could not license a suitable one: Meteosat Second Generation, Amazon's Kuiper, and the Soyuz and Progress ferries in Earth orbit; ESA's Mars Express and the UAE's Hope in orbit at Mars; and the Sojourner and Zhurong rovers on the ground there. The four Mars ones are labelled approximate wherever the app credits them, and where a model stands in for a satellite rather than depicting it, the True Scale view labels the shape as approximate too.
• Community 3D models for the Tiangong station (by w29572227) and GPS satellites (by ABC Almaty), both via Sketchfab under the Creative Commons Attribution (CC-BY) licence.
• CelesTrak SupGP for SpaceX-published ephemerides of just-launched Starlink batches, tracked ahead of official cataloging and labeled provisional.
• astronomy-engine for the positions of the Moon and bright planets in the sighting identifier (MIT licensed, accurate to about one arcminute).
• GeoNames for the city database used in manual location entry.

Methodology

Satellite positions are computed in your browser using the SGP4/SDP4 orbital propagation models via the satellite.js library, from each object's latest general perturbations elements. The catalog is baked into the site and refreshed every 2 hours by an automated pipeline, so the app makes no live calls to CelesTrak when you use it. Orbit classification (LEO, MEO, GEO, HEO) uses standard altitude bands derived from each satellite's elements; characteristics like sun-synchronous or Molniya orbits are derived from inclination, period, and eccentricity.

Accuracy

Pass predictions are typically accurate to within about 30 seconds for satellites with fresh orbital elements. Accuracy degrades for objects with stale elements or rapidly decaying orbits. Visibility labels (visible, daytime, in shadow) are geometric estimates and do not yet model per-satellite brightness. Satellite dimensions shown in the True Scale view are documented values for well-known satellites and clearly labelled class-level estimates for the rest.

azmth Luna

The Moon half of azmth: an interactive 3D Moon at azmth.space/moon with the real terminator and libration, every verified landing and impact site, the lunar orbiters we track live, and a catalog of landmark Moon missions with sourced facts and photos. Its data and credits:

• NASA SVS CGI Moon Kit for the Moon colour and terrain maps, built from Lunar Reconnaissance Orbiter camera (LROC) and laser altimeter (LOLA) data (public domain).
• NASA/JPL Horizons for the lunar orbiter ephemerides, refreshed twice daily. A probe whose ephemeris lapses shows as no data, never a guessed position; Queqiao-2, which has no published ephemeris at all, is drawn only as an approximate orbit from the one public orbit determination (an amateur radio Doppler fit, September 2024).
• astronomy-engine for the Sun and Earth geometry that drives the terminator, phase, and libration (MIT licensed).
• Mission photo credits appear with each image across the mission catalog; landing coordinates come from the sources cited on each mission page.
• Orbiter 3D models: LRO and the ARTEMIS probes are official NASA 3D Resources models (public domain). Danuri and the Chandrayaan-2 orbiter we built ourselves in Blender from their agencies' published dimensions and imagery; both are labelled approximate in the app.
• Sounds (the replay ambient and UI chimes) are our own.

azmth Mars

The Mars half of azmth: an interactive 3D Mars at azmth.space/mars with the real day and night line and the axial tilt that gives Mars its seasons, every place human hardware has reached, the orbiters and both moons positioned live, and one clock you can speed up or run back to 1960 to watch the whole Mars programme arrive. Its data and credits:

• The mission catalogue: 110 Mars missions and 13 explainers at azmth.space/mars/missions, every claim carrying its source and the date it was last checked. Where it mattered the research went to the Russian, Chinese and Japanese sources themselves rather than to English summaries of them.
• USGS Astrogeology and NASA MOLA for the surface: the Viking colour mosaic for what Mars looks like, Mars Orbiter Laser Altimeter data for the terrain (both public domain).
• NASA/JPL Horizons for the orbiter and moon ephemerides, refreshed twice daily. A probe whose ephemeris lapses shows as no data, never a guessed position; Tianwen-1, which has no published ephemeris at all, is drawn as an approximate orbit and labelled as one.
• PDS Small Bodies Node for the measured shape models of Phobos and Deimos (P. C. Thomas), so both moons are drawn as the irregular bodies they are instead of as spheres.
• astronomy-engine for the Sun and Mars geometry that drives the terminator, the sub-solar point, and the season (MIT licensed).
• Spacecraft and rover 3D models: the Mars Reconnaissance Orbiter, 2001 Mars Odyssey, the ExoMars Trace Gas Orbiter, Perseverance and Ingenuity are official NASA 3D Resources models (public domain). Curiosity and the twin Mars Exploration Rover, which drove as Spirit and Opportunity, come from NASA's Eyes on the Solar System model set, because NASA 3D Resources publishes no glTF of either. Mars Express, Hope, Sojourner and Zhurong we built ourselves in Blender from published dimensions and photographs, because no agency publishes a model of them we could use; all four are approximate and are labelled so wherever the app credits them. Every rover in the site view stands at true size, its mesh measured against the published figures. Phobos and Deimos need no model: their shapes come straight from the PDS measurements above.
• Rover traverses and site imagery: the path each rover drove and every flight Ingenuity made, from NASA's MMGIS layers, the Analyst's Notebook at Washington University in St. Louis, Pathfinder telemetry in the Planetary Data System and the published Tianwen-1 NaTeCam positions (CNSA/GRAS, CC BY 4.0), drawn over HiRISE and CTX pictures of the ground itself (NASA/JPL/University of Arizona and NASA/JPL-Caltech/MSSS).
• Mission photo credits: every image is self-hosted, and its caption carries the credit as a link to the page the picture came from.
• Free data: the places, the catalogue, and the live orbiter and moon positions are published as CSV and JSON at azmth.space/mars/data under CC BY 4.0. The vocabulary a Mars page assumes (the sol, solar longitude, the areoid) is defined at azmth.space/mars/glossary.

Contact

Feedback and corrections: hello@azmth.space. If azmth is useful to you, you can support it at buymeacoffee.com/langguesser.