Alternatives
Products that do what A JSON API for NASA HORIZONS Planetary Ephemeris Tables does
I don't always all-caps, but when I do, it's because every word is an acronym. The NASA HORIZONS[1] system is a telnet service that provides planetary data and ephemeris tables, which are basically coordinate-time plots for celestial bodies. It's pretty archaic and somewhat difficult to use, especially since it just dumps out text tables and you have to parse it to do anything with it. Some projects, e.g. KDE Marble, use it as a data source and typically just consume it with a little procedural code to get what they need. I wanted to provide a full-fledged library for it so that you can…
- 1AOAtlas of Space▲770
Hello HN! Sharing a recent side project of mine, the Atlas of Space, that I built out to explore the Solar System. As a long-time space nerd, I realized recently that I didn't have a good intuition on the scale, speed, and relative orientation of the celestial bodies around us. So over the break I built out a kind of spatial Wikipedia to click around and learn about planets, moons, asteroids, and other bodies orbiting the Sun. The physics is all simulated in the browser using simple Newtonian mechanics. There's a lot left to do from here, including modeling objects in non-Keplerian orbits…
2025 · atlasof.space
- 2
- 3NR
This is a service I've built to provide equirectangular cloud maps of the whole Earth, updated every 3 hours, for free. It's based on infrared and visible light data from EUMETSAT, processed to enhance the clouds and try to reduce the impact of surface temperatures on the final image. I built it because it's surprisingly hard to find these kinds of images in a format that's useful to developers and hobbyists. I was building a 3D ISS tracker and wanted to include live clouds but couldn't find anything good, so I got sidetracked, and here we are.
2023 · github.com
- 4AD
2022 · nasa-apod.portaldocs.dev
- 5MA
Made a little Artemis II tracker for anyone else who is unnecessarily invested in this mission: https://artemis-ii-tracker.com/ For those of us who apparently need a dedicated place to monitor this mission instead of behaving like well-adjusted people.
Apr 2026 · artemis-ii-tracker.com
- 6AAAstro App▲291
I really like Stellarium and SkySafari but I felt like these are primarily geared towards exploring the sky but not so much "here are the long list of things I want to see, when can I see them tonight and where". There's also not really a great option I've found that combines sky object planning + location weather details while still being free so I built this. The UI's heavily inspired by NINAs sky atlas + Robinhood. Right now you can: View the altitude chart of objects and 3D view Create lists of objects of interest View the annual max/min daily altitude of an object to find the best…
2024 · astro.sshh.io
- 7
- 8
- 9
- 10B3
This is a little hobby project that I hope you enjoy. You can see where the International Space Station is now, with live HD video from NASA, on a realistic 3D globe. The positions of the sun and moon are also accurate, though distances aren't to scale. The clouds are also near-realtime; I span that out into a separate project at https://clouds.matteason.co.uk, where the cloud images I create from EUMETSAT data are freely available. I've got more features almost ready to go, like the ability to turn off all UI, toggleable clouds and turning off the day/night cycle I'd love for…
2024 · iss.matteason.co.uk
- 11
- 12
- 13
Hello, I am the creator and maintainer of Stellarium Mobile. I have been working in my free time for about a year on this new project Galaxium, that is more about traveling in the universe rather than looking at the sky from Earth. It is still experimental, and at the moment I am not sure what it will become. Feedback is welcome.
13d ago · galaxium.app
- 14
- 15GC
Hi HN, I’d like to share a project I’ve been working on called GalaxyBrain. It’s a tool for organizing information. Key features: Embeddable dynamic metadata: as you type, metadata is generated in the background. This metadata can be accessed and embedded directly into the page. Light programming concepts built in: you can add custom values (think variables) to any page, then reference those values across different pages to build dynamic relationships. Metadata can be chained together: referencing values on other pages, or by using a formula. Updates to anything flow through the entire…
2025
- 16
- 17AF
There are plenty of Artemis II trackers out there. I looked at a bunch and kept running into the same issues - some had data that didn't look right, it was hard to use on smaller screen, others felt overly complicated for what I actually wanted to know: what's the crew doing, where is Orion, how fast is it going. The best one I found was issinfo.net/artemis, which inspired a lot of the design. So I built my own. The part that was genuinely interesting to me was the data. Turns out anyone can query JPL's Horizons API for full ephemeris data on the Orion spacecraft - position, velocity,…
Apr 2026 · artemis.fyi
- 18
- 19OA
Hey HN! I made Orbit, an iOS app that allows you to see the satellites, planets, and constellations above you in AR, on a 2D map, and on a 3D globe. The app includes more than 15,000 objects tracked by CelesTrack, together with their pass predictions, descriptions, and detailed orbital data. A searchable catalog of all objects is also available, as well as a built-in chatbot designed to answer any space-related questions you might have. This is my first published iOS app, so any feedback is greatly appreciated! App Store: https://apps.apple.com/app/id6772174570
Jul 2026 · nagylukas.github.io
- 20GD
Over the last year, I've worked on aggregating Groundhog data, including predictions, location, and a cute photo. Welcome to GROUNDHOG-DAY.com: The clean and breathable, machine-readable, all-regional data source for Groundhog Day forecasts. Find your fave groundhog, peruse past predictions, or trek the continent-wide Groundhog Map. Includes enterprise-grade API for corporate use cases.
2023 · groundhog-day.com
- 21S1
We just released 1.0 of SpacetimeDB, a database designed for real-time games and applications built in Rust and using WebAssembly stored procedures for running server-side logic.
2025 · github.com
- 22
- 23PA
This is a Python (with Rust backend) library for high accuracy orbit calculation of the entire known catalog of asteroids. It is a full N-Body integrator, including lots of additional physics, such as relativistic effects, non-spherical gravitational fields of planets, masses of large asteroids, and a number of non-gravitational forces such as radiation pressure. The design goal is essentially JPL Horizons on your laptop, but all asteroids at once. I began this project while I worked at Caltech on a NASA mission called NEO Surveyor (which is a space telescope designed to survey Near Earth…
2025 · github.com
- 24OD
Hey HN, I'm excited to share Orbital, a new approach for unifying APIs and Data sources! Rather than relying on glue code to bridge endpoints, Orbital leverages annotations in schemas & API specs to build the integration dynamically. The traditional method of crafting glue code often becomes repetitive and burdensome to maintain in the long run. With Orbital, developers embed tags to their existing API specs (OAP, Protobuf, etc), indicating where data can be sourced, and publish these specs to Orbital (which runs self-hosted). Consumers query these tags with our TaxiQL language, and Orbital…
2023 · github.com
Ranked by how close each launch is in meaning, then by votes. Refine with a description →