About StargazingTime
StargazingTime is a one-page tool that tells you — in five seconds — whether tonight is a good night for stargazing, based on cloud cover, moon phase, light pollution, and astronomical twilight at your exact location.
Background
I'm a one-person web operator running seoulnote.com — a Korean travel-information curation site, currently being expanded into an English-language edition for global readers.
Based on years of content curation and SEO operations work, I started StargazingTime after noticing that existing stargazing tools — while excellent for hobbyist astronomers — are too dense and chart-heavy for everyone else.
The starting point was simple frustration: a camper, a photographer, or a parent who wants to show their kids the Milky Way doesn't want to read a Bortle chart and a transparency forecast. They want one number, in five seconds.
Operating entity
This site is operated by JJ Company (Justin Seo). The same operator runs the following sites:
- 🌏 seoulnote.com — South Korea travel curation
- 📚 incomeflowlab.com — AI side hustles & monetization
- ✦ stargazingtime.com — stargazing forecast (this site)
Operating principles
- Cite every source. Every score is computed from named public data feeds (Open-Meteo / NOAA HRRR, SunCalc, light-pollution map). The source is shown on the page.
- Honest uncertainty. When a data source falls back to a heuristic or a stale cache, the page marks it. We don't round "mock" data to look real.
- Privacy first. GPS coordinates are never stored. We only use them to look up the nearest pre-fetched US city for the weather call.
- Disclaimers up front. Forecasts change. Score is best-effort guidance, not a guarantee.
- Ads stay out of the way. Ads (Google AdSense) appear in fixed slots that don't interrupt the score or the forecast.
Verification process
- Every 30 minutes, a cron job fetches weather for 120 US city centroids from Open-Meteo (which uses NOAA HRRR at 3 km resolution for the US).
- Each fetch is stored in our database with a 60-minute TTL — so user requests never trigger a direct external API call.
- A user request snaps their GPS coordinates to the nearest pre-fetched city (within 200 km radius) and reads the cached payload.
- Moon phase and twilight times are computed locally using SunCalc — no third-party call, identical to NASA Horizons within ±1 minute.
- Bortle (light-pollution) value is a heuristic based on distance from major US population centers — accurate to ±1 class.
- A single 1–10 score is computed locally using a documented weighted formula (Clouds 35% / Moon 25% / Bortle 25% / Humidity 10% / Visibility 5%).
Disclaimer
The information on this site is advisory only and does not replace local conditions on the ground. Cloud cover can change in minutes; the score is a forecast, not a guarantee.
Before driving out to a dark-sky site, double-check the latest forecast and your local weather radar.
Contact
Bug reports, feature requests, partnership inquiries — email justin4905@gmail.com. I usually reply within 1–2 business days.