Free astronomy tools for any latitude: ISS passes, Milky Way planning, Bortle maps, stargazing weather, and star trails, built in Guyana for worldwide use.
Frequently asked questions
Are AstroPhotosGY astronomy tools free?
Yes. Every live tool on this hub is free to use in your browser with no account required. Share a link with lat/lon or date parameters to preserve your setup.
Do these tools only work in Guyana?
No. Tools accept any latitude and longitude. Guyana (~6°N) is our home base and default demo because tropical skies need different Milky Way, trail, and sun-path defaults than mid-latitude Europe or North America.
Why build astronomy tools in Guyana?
At roughly 6°N you see both celestial hemispheres, steep solar arcs, and long Milky Way core windows. Building here forces tropical-first physics that still works worldwide when you change the pin.
How is this different from Stellarium or PhotoPills?
Stellarium and PhotoPills are excellent general tools. AstroPhotosGY focuses on fast, free web workflows: solargraph simulation with real cans, Bortle-style maps, ISS spotting with visibility flags, and stargazing weather for humid nights, plus Learn lessons that teach the same skills.
When is the next lunar or solar eclipse?
Open /tools/eclipse-viewer/ for the next lunar eclipse (contact times, Moon direction, 3D umbra). Open /tools/solar-eclipse-viewer/ for local solar contacts, obscuration, and a Sun disc. Always use ISO 12312-2 eye-safety guidance. There is no separate /sky-events/eclipses/ page; the tools own next-event times.
Which tools are live today?
Live tools include Tonight Observing Score, Stargazing Weather, Bortle & Dark Sky Map, Sun/Moon Dark Window, Milky Way Season Planner, Milky Way Field Guide (PDF), ISS Pass Predictor, Planets Visible Tonight, Lunar Eclipse 3D Viewer, Solar Eclipse Times & Local View, Solar Pinhole Camera, Pinhole Optics Calculator, and Star Trail Session Planner. More calculators are on the roadmap.