Hoshizora Dome — a free 3D planetarium in your browser
See tonight's sky in 3D for wherever you are. Hold your phone up to identify stars and constellations, overlay the sky on your camera, and zoom in on Saturn's rings. Nothing to install, no account.
Start with the sky above you right now, or jump to any date and place.
Open the 3D night sky →What you can do
- Real-time 3D sky — about 41,000 stars, the 88 constellations, the Milky Way, the Moon and all eight planets, calculated for your location and time.
- Point your phone at the sky — the view follows your phone's direction, so you can find out what that bright star is. Compass north is automatically corrected to true north.
- AR camera mode (phones and tablets) — constellation lines and names on top of your camera view. Stars below the horizon fade away naturally.
- Planet close-ups — zoom in to see Saturn's ring tilt, Jupiter's four Galilean moons and the phases of Venus as they really are on that date.
- Meteor showers — simulate the shower from its radiant and see when the radiant is highest.
- Tonight's sky score — combines cloud forecasts and moonlight into a 0–100 "how good is tonight" score.
- Birthday sky — create a card of the night sky on the day you were born, and share any view with a link.
How to use it
- Choose a place
Allow location access, or tap a spot on the globe (the "場所" button). Any city in the world works. - Look around
Drag to look around and pinch to zoom. On a phone, tap "かざす" and hold the phone up to the sky. - Change the time
Use the date and time box at the bottom to see the sky at any moment, past or future. "いま" returns to the present. - Search
Type a name in the search box at the top (Japanese or common English names such as Saturn, Sirius, Orion) to fly to it.
Frequently asked questions
Is it really free?
Yes. Hoshizora Dome is free to use, with no sign-up. The site is supported by ads on article pages.
Does it work outside Japan?
Yes. Positions are calculated for any latitude and longitude, in both hemispheres. Only the interface text is in Japanese for now.
How accurate is it?
Stars and constellations are accurate for naked-eye and binocular use. Planet positions come from NASA JPL's approximate orbital elements and are accurate to a small fraction of the Moon's diameter. See our data and methods page (Japanese).
Do you collect my location or camera images?
No. Your location and camera feed are used only inside your device to draw the sky. Only an approximate latitude/longitude is sent to the weather provider (Open-Meteo) when you open the sky score.