SiderealLab

What it does

SiderealLab helps you measure Earth’s rotation speed based on your location and observation time. Built for astronomy education, it includes sidereal time input, visualizations, and exportable reports.

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  SiderealLab iOS Distributed NOW2025 · apps.apple.com · ▲2

  Measure the Earth rotation locally

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  Atlas of Space2025 · atlasof.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…

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  EarthGuessr2025 · earthguessr.com · ▲192

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  Beautiful 3D ISS tracker with live video and near-realtime clouds2024 · iss.matteason.co.uk · ▲139

  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…

• IB
  I built a space travel calculator using Vanilla JavaScriptJan 2026 · cosmic-odometer.vercel.app · ▲54

  I built this because measuring my age in years felt boring—I wanted to see the kilometers. The first version only used Earth's orbital speed (~30km/s), but the number moved too slowly. To get the "existential dread" feeling, I switched to using the Milky Way's velocity relative to the CMB (~600km/s). The math takes some liberties (using scalar sum instead of vector) to make the speed feel "fast," but it gets the point across. Under the hood, it's a single HTML file with zero dependencies. No React, no build step. The main challenge was the canvas starfield—I had to pre-allocate the…

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  ThereDec 2025 · thereapp.site · ▲129

  🪐 Your cosmic compass through the galaxy

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• IV
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  We built Tapflow for devs, designers, PMs, and tech folks who’ve been sitting on internal docs, templates, and systems — but never productized them. Upload a PDF, notes, or workshop deck, and Tapflow drafts a structured product (with chapters, teaser and pricing plans). It’s good for AI kits, onboarding guides, design systems, and frameworks. You can sell through Stripe, LemonSqueezy, or PayPal. Real-time collaboration is in early beta. No site builder, no LMS — clean design and just focused tools to ship. Fully bootstrapped and just launched on PH today →…

  Work · 2025 · tapflow.ai

• C9
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