Stella Sky

Stella Sky is a planetarium for iPhone and iPad. Hold your device up and the sky follows it: every star you can see and many more, the planets with their real phases and moons, the constellations, the Moon exactly as it looks tonight. Accurate, realistic, and yours for a single purchase. No ads, no subscription, no account.

TONIGHT Open the app and see what the night holds: sunset, full darkness and dawn; the Moon's phase and hours; which planets are up and when, and where to look; meteor showers at their peak, the Moon passing a planet, planets at opposition. Tap anything to point the sky at it.

POINT AND SEE Sensors mode turns the sky with your phone, using true north from the compass and your location. Or drag and pinch to look around by hand, with a field of view from the whole sky down to a telescope's.

PLANETS UP CLOSE Zoom into Jupiter's bands and its four big moons, Saturn's rings, the craters and maria of the Moon, all lit by the Sun as they are at this moment. Open any body in a 3D view you can turn around.

GUIDED TOURS The rocky planets and the giants at their true relative size. The solar system in motion, with the planets where they are right now and the clock in your hands. The Kuiper belt beyond Neptune: Pluto, Eris, Sedna and the icy worlds. Worlds around other stars: TRAPPIST-1, Proxima b, 51 Pegasi b and more, each with its habitable zone and a button to find its star in your sky.

ANY TIME Run the clock at any speed, forward or back, or jump to any date. Watch the planets wander, the Moon change, the sky turn through the seasons. The daytime sky is simulated with real atmospheric scattering, so Venus and the Moon show through it when they should.

NIGHT MODE Everything turns red, sky and interface, to keep your eyes adapted to the dark.

ACCURATE BY CONSTRUCTION 118,000 stars from the Hipparcos catalog with official IAU names; planetary positions from astronomy-engine, good to better than an arcminute; rise and set times with refraction; orbital elements for minor bodies from NASA's JPL; exoplanet data from the NASA Exoplanet Archive.

PRIVATE AND OFFLINE Everything is on the device: catalogs, maps, tours. Your location and sensors are used only to compute the sky above you and never leave your phone. No network, no analytics, no server.