About StarGlobe

StarGlobe is a free, interactive star map that runs entirely in your web browser. Point your device at the sky and see the names of stars, constellations, and planets overlaid on the real heavens in real time. No downloads, no accounts, no paywalls — just open starglobe.online and start exploring.

Our Mission

Astronomy belongs to everyone. The night sky is the oldest shared heritage of humankind, and we believe that understanding it should not require expensive equipment or specialized knowledge. StarGlobe was created to make the universe accessible to every curious person on the planet — whether you are a student learning the constellations for the first time, a parent pointing out planets to your children, or an experienced observer planning a night under the stars.

What You Can Explore

• 88 constellations — every constellation recognized by the International Astronomical Union, with lines and labels drawn directly on the celestial sphere.
• 700+ stars — sourced from the Hipparcos catalog, rendered with accurate positions, magnitudes, and color indices so the sky on your screen matches the real sky above you.
• Planets — Mercury, Venus, Mars, Jupiter, and Saturn are computed in real time using astronomical algorithms and displayed at their true positions.
• The Sun and Moon — track sunrise, sunset, moonrise, and moonset. See the current phase of the Moon and the Sun's position along the ecliptic.
• The Milky Way — a soft, realistic band of our home galaxy stretches across the globe, helping you orient yourself in the deep sky.
• The ecliptic and celestial grid — optional reference lines for understanding how the sky is organized.

Key Features

• Real-time sky — the map updates continuously to show exactly what is above your horizon right now.
• Device orientation — on mobile, tilt and rotate your phone to point at the sky. StarGlobe uses your device sensors to align the virtual globe with the real one.
• Geolocation — your coordinates are used to compute the correct horizon, so the stars you see on screen are the ones visible from your location.
• Works offline — once loaded, StarGlobe functions without an internet connection. Take it into the field.
• Night mode — a red-tinted interface preserves your dark adaptation while observing.
• No installation required — runs in any modern browser on desktop, tablet, or phone. Also available as a native Android app.

Technology

StarGlobe is built with performance and accuracy in mind. Here is what powers it under the hood:

• WebGL2 — hardware-accelerated 3D rendering draws thousands of stars, constellation lines, and the Milky Way at smooth frame rates on any device with a GPU.
• Vanilla JavaScript — no frameworks, no heavy dependencies. The entire application loads fast and runs lean.
• Meeus algorithms — planetary positions, solar coordinates, lunar phases, and sidereal time are computed using the well-established algorithms from Jean Meeus's Astronomical Algorithms.
• Hipparcos catalog — star positions and magnitudes are derived from the ESA Hipparcos mission, one of the most precise astrometric datasets ever produced.
• Device Orientation API — on supported devices, sensor data is used to align the star map with the physical sky in real time.
• Geolocation API — your latitude and longitude determine which part of the celestial sphere is above your local horizon.

Open and Free

StarGlobe is and will remain free to use. There are no premium tiers, no locked features, and no mandatory sign-ups. The project is driven by a love of astronomy and a commitment to open access.

Have a question or idea? Visit the contact page or read more on the blog.