{"id":23168,"library":"skyfield-data","title":"Skyfield Data","description":"A data package for the Skyfield astronomy library, providing essential ephemeris files (e.g., de421.bsp) and Earth orientation data (finals2000A.all) that automatically expire and can be refreshed. Current version 7.0.0 requires Python >=2.6, !=3.0-3.7; supports Python 3.11, 3.12. Releases are irregular, driven by data file updates.","status":"active","version":"7.0.0","language":"python","source_language":"en","source_url":"https://github.com/brunobord/skyfield-data","tags":["astronomy","ephemeris","skyfield","data"],"install":[{"cmd":"pip install skyfield-data","lang":"bash","label":"Install from PyPI"}],"dependencies":[{"reason":"Data files are used by Skyfield's loader and timescale computations.","package":"skyfield","optional":false}],"imports":[{"note":"","wrong":"","symbol":"get_skyfield_data_path","correct":"from skyfield_data import get_skyfield_data_path"}],"quickstart":{"code":"from skyfield.api import load\nfrom skyfield_data import get_skyfield_data_path\n\n# Use the data path provided by skyfield-data\nload_data = load(get_skyfield_data_path())\n# Load an ephemeris (de421.bsp is included)\nplanets = load_data('de421.bsp')\nprint('Ephemeris loaded successfully')","lang":"python","description":"This snippet imports Skyfield's loader and the data path from skyfield-data, then loads the included de421.bsp file."},"warnings":[{"fix":"Ensure your Skyfield timescale initialization does not rely on deltat files; upgrade skyfield-data to 3.0.0+ and let Skyfield use the IERS data automatically.","message":"Version 3.0.0 switched from using deltat.data/deltat.preds to finals2000A.all for timescale computations. Existing code using old file paths will break.","severity":"breaking","affected_versions":">=3.0.0"},{"fix":"Remove any manual loading of deltat files; upgrade to skyfield>=1.31 and skyfield-data>=2.0.0.","message":"Version 2.0.0 removed deltat.data and deltat.preds files; Skyfield 1.31+ no longer uses them. Code that accesses these files directly will fail after upgrade.","severity":"deprecated","affected_versions":">=2.0.0"},{"fix":"Call get_skyfield_data_path() with expire=True to force a refresh, or catch the warning and re-download using the included download script.","message":"Data files have expiration dates. If a file is expired, get_skyfield_data_path() will raise a UserWarning. Code that uses the path without checking may silently use stale data.","severity":"gotcha","affected_versions":">=0.1.0"},{"fix":"Use load_data('de430.bsp') after downloading the file manually, or point the loader to a custom directory.","message":"The included de421.bsp is a simplified ephemeris; for high-precision work, you must download a larger JPL ephemeris separately (e.g., de430.bsp).","severity":"gotcha","affected_versions":"all"}],"env_vars":null,"last_verified":"2026-05-01T00:00:00.000Z","next_check":"2026-07-30T00:00:00.000Z","problems":[{"fix":"Run 'pip install skyfield-data' and use 'from skyfield_data import get_skyfield_data_path'","cause":"Package not installed or imported incorrectly.","error":"ModuleNotFoundError: No module named 'skyfield_data'"},{"fix":"Run the download script: 'python -m skyfield_data.download' or pass expire=True to get_skyfield_data_path()","cause":"Data file is older than its expiration date.","error":"UserWarning: The file ... has expired"}],"ecosystem":"pypi","meta_description":null,"install_score":null,"install_tag":null,"quickstart_score":null,"quickstart_tag":null}