{"categories":[{"label":"Astronomy","url":"https://skillfed.io/packages/category/scientific-engineering-astronomy"}],"enrichment":{"capability":"Loads and queries JPL ephemeris files (SPK format) to compute positions and velocities of planets and Solar System bodies at specified Julian dates.","skillfed_tags":["astronomy","ephemeris","orbital-mechanics"],"use_cases":["Compute heliocentric or geocentric positions of planets for mission planning or trajectory analysis.","Extract a subset of a large ephemeris file covering only a specific date range to reduce download size.","Inspect the contents and metadata of an SPK file from the command line without writing code.","Build custom astronomical calculations that require raw Solar System body coordinates in kilometers.","Fetch ephemeris data on-demand from remote JPL servers, downloading only the blocks needed for your date range."],"what_it_does":"jplephem is a low-level library for reading and querying binary Satellite Planet Kernel (SPK) files produced by NASA's Jet Propulsion Laboratory. It loads ephemeris data\u2014precomputed positions and velocities of planets, moons, and other Solar System bodies\u2014and allows you to compute their coordinates at any Julian date within the file's coverage range. The package supports three SPK data types: Chebyshev polynomial representations (Types 2 and 3) and discrete position/velocity pairs with linear interpolation (Type 9).\n\nThe library is designed for astronomers and space mission planners who need raw three-dimensional vectors in the Solar System's reference frame. It includes command-line tools to inspect ephemeris file contents, extract date ranges, and filter by target body codes. Most users working in Python astronomy will want to layer this with a higher-level package like Skyfield, which converts the raw vectors into traditional astronomical measurements such as right ascension and declination.","worth_installing":"Yes, if you need raw JPL ephemeris data in Python and are comfortable managing external SPK files. The package is stable, has no known vulnerabilities, and installs with minimal friction. However, most astronomy workflows will benefit from using a higher-level library like Skyfield instead, which wraps jplephem and provides more intuitive coordinate transformations."},"id":"jplephem","links":{"html":"https://skillfed.io/packages/jplephem","md":"https://skillfed.io/packages/jplephem.md","pypi":"https://pypi.org/project/jplephem/"},"maintenance":{"status":"aging"},"meta":{"latest_release":"2026-01-23","license_spdx":null,"license_treatment":"permissive","name":"jplephem","python_support":"unspecified","summary":"Use a JPL ephemeris to predict planet positions."},"popularity":{"monthly_downloads":819201,"position":4977,"tier":"top_5000"},"security":{"n_vulnerabilities":0},"version":"2.24"}