The sky, wherever you are.

A free planetarium, open in any browser, on any device.
A community of astronomers, astrophiles and curious minds building it together.
One shared photo and one clear night at a time.
Enter the WebPlanetarium!
Join the community - it's free

Free. Non-profit. For everyone.

WebPlanetarium.org was created with a single goal: to allow anyone, anywhere, to view a faithful reproduction of the starry sky directly in their web browser. There is no need to install anything, as it is a standard website accessible online.

Whether you are a scientist, a longtime astronomy enthusiast, a student, or simply someone who noticed a bright point of light in the sky and became curious, you will find a valuable tool here for your celestial observations.

The planetarium is completely free: simply register to access exclusive features. Registration also allows you to join a growing community of sky enthusiasts, with the opportunity to share images and access many other upcoming features.

This is a non-profit project: created and maintained in his spare time by an Italian astronomy enthusiast as a labor of love for the sky, and to share it with anyone who wishes to look up.

A sky built by the people who look at it

Here's what makes it different: the astronomical photos you upload don't end up relegated to a private album. Link your image to the specific star, galaxy, planet, comet, or asteroid it depicts: from that moment on, the photo will live inside the planetarium itself, right within that object's information panel, visible to anyone viewing it, anywhere in the world. Your own little corner of a celestial atlas built collectively - one photo at a time.

A user photo shown inside an object's info panel
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What you'll find inside

Explore the whole sky

Over 41,000 stars, the full Messier and NGC catalogues, major asterisms, and every Planet, the Sun and the Moon - rendered in 9 different sky projections, from a classic star map to a full-dome fisheye view.

A living Solar System

Comets and Asteroids move along their real orbits, about 100 of the brightest artificial satellites are tracked live, and a monthly Events Calendar puts every conjunction, opposition and eclipse one click away.

A sky that feels real

Physically based twilight, atmosphere, sun glow and horizon haze; animated meteor showers with realistic density; stars that blink, glow and shine in their true colours.

Find anything, instantly

One unified Search across stars, deep-sky objects, comets and asteroids; keyboard and gesture micro-adjustment for pinpoint accuracy; a responsive, touch-friendly layout that works as well on a phone as on a desktop.

Share and belong

Free registration unlocks reserved features and allow own settings saving. You can also create personal photo galleries tied to real sky objects, publish your profile and save Sceneries and Screenshots you can share with a single link.

From phone to dome

From a phone in your pocket to a full planetarium dome: gyroscope sky-tracking on mobile, a dedicated Projector View for dual-screen rendering, and fisheye/polar/ortho projections built specifically for Dome setups.
If you'd like the full technical rundown, check the Help page or the latest Changelog.

Standing on the shoulders of giants

The state of the art would not have been possible without drawing on these sources:

  • Its core is based on Virtualsky, a project made by Stuart Lowe when he was working for Las Cumbres Observatory
  • The star data are obtained from the Hipparcos catalogue by European Space Agency (ESA) and the HYG Database by David Nash
  • NGC data have been retrieved from the excellent OpenNGC by Mattia Verga
  • Asteroids and Comets position are fetched from JPL Horizons System by NASA
  • Recent Comet list are retrieved from Comet Observation database (COBS) maintained by Crni Vrh Observatory in Slovenia
  • Side panel images are linked to the Aladin Sky Atlas public API from Strasbourg astronomical Data Center (CDS)
  • The photographic Milky Way background is taken from European Southern Observatory (ESO) / S. Brunier
To all these people and organisations goes my deepest gratitude.
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