A star wheel for your own latitude. Set the date and time and it turns to show exactly which stars and constellations are above your horizon — the bright disc is the sky you can see right now.
How to use the star wheel
Set your location. Search a place or tap My location — your latitude decides how much of the southern sky the wheel shows and where your horizon sits.
Set the date and time, or tap Now. The wheel turns to that moment's sky.
Turn the rim to travel in time. Grab the outer month / hour ring and turn it — the whole sky wheels forward or back through the night, just like turning a real planisphere. (On arrival it drifts on its own until you touch it.)
The living sky. The Sun, the Moon at its real phase, and the visible planets (Mercury, Venus, Mars, Jupiter, Saturn) ride the gold dashed ecliptic at their true positions for your chosen moment — the one thing a printed star wheel can never show.
Read the bright disc. Everything inside the glowing horizon oval is above your horizon — the stars and constellations you could actually see. The dimmed area is below the horizon, out of sight.
Find your bearings.N · E · S · W are marked on the horizon. Hold the wheel up and turn it so the direction you're facing is at the bottom; the stars there match what's in front of you.
Zoom the wheel. Pinch, scroll, or use the ＋ / － buttons to magnify the star wheel in place; when zoomed, drag to pan around. ⟳ resets it.
Aim, then dive. Tap a spot in the visible sky to drop a teal target there, then press Dive into Deep Sky to open the real photographed sky at that point with our constellation lines over it. (Double-tap does both at once — and the more you've zoomed the wheel, the tighter the dive.)
The golden ruler. With the wheel un-zoomed, drag around the pole to line the ruler up with any star; its hour (right ascension) reads off the inner blue scale, and the dashed arcs inside the horizon are dusk (civil) and full-dark (astronomical) twilight.
The centre is the pole. Everything wheels once a day around Polaris (near the centre in the north). Nudge the time forward and watch the sky turn.
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Location
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DateTime
Star & constellation data rendered with the same catalogue as the live sky. Positions from real astronomy. Zoom the wheel, aim a target, and dive into Deep Sky imagery.
The parts & the whole
The little wheel above keeps it simple. A traditional planisphere carries far more on its face — three coordinate rings and a printed overlay. Here it is recreated in full: hover or tap a part to light it up and read what it does.
Locating the North Star — Polaris
The one star that never moves. Watch the Big Dipper point the way — with Cassiopeia as a back-up.