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?
Every tool on this hub is live. Tonight: Tonight Observing Score, Stargazing Weather, Sun/Moon Times & Dark Window, Planets Visible Tonight, Jupiter's Moons Tonight, ISS Pass Predictor, Phone Sky Check, What's That Bright Thing?, Tonight's Targets, Tonight's Top 3 Highlights, Golden & Blue Hour Timeline, Moonlight Impact Calculator, Dew Risk Calculator, Jupiter Altitude Today and Comet Watch. Events and 3D: Meteor Shower Simulator, Lunar Eclipse 3D Viewer, Solar Eclipse Times & Local View, Visible from Guyana?, Teacher Page for CSEC, Solar System 3D and Local Sky Sphere. Dark skies: Bortle Map, Contribute Tonight, Milky Way Season Planner, Milky Way Field Guide and Darkest Nights This Month by Moon Phase. Photography: Star Trail Session Planner, Solar Pinhole Camera, Pinhole Optics Calculator, Pinhole Daytime Exposure, Solargraph Install Planner, Sun Path Today, Hour by Hour, NPF / Spot Stars Calculator, Camera Field Framing, Telescope FOV & Plate Scale, Pixel Scale / Sampling Advisor and Equatorial Imaging Pack.