Your Android observatory with real-time sky view, AR, telescope control, and the only astronomy app that computes your local horizon from topographic data.
Recommended for new users. Start with the freemium app and unlock premium later with a subscription or one-time purchase.
Prefer paying once up front? Get Mobile Observatory Pro on Google Play. The same lifetime premium access is also available later inside Mobile Observatory.
Everything you need for astronomy, in your pocket
Point your phone and identify stars, planets, and constellations live
Explore planets, moons, and comets in an interactive orrery
ISS passes, Starlink trains, and 10,000+ satellites in real-time
2,500+ nebulae, galaxies, and star clusters with photos and details
50+ event types including eclipses, conjunctions, occultations, transits, and more
Aurora alerts, solar flares, ISS passes, and event reminders
Aurora forecast, Kp-index, solar flares, and NASA SDO images
Phases, eclipses, lunar features, sunspot data, and rise/set times
Real terrain profiles from NASA data for precise rise/set times
Auto-generated session plans based on your equipment and location
Connect your GoTo telescope and slew to any object with a single tap
Hipparcos, SAO, and extended catalogs with detailed star data
See Mobile Observatory in action
From first launch to expert observer
Point your phone at the sky and see stars, planets, and the Sun's path over your real 3D terrain.
Browse upcoming conjunctions, eclipses, ISS passes, and thousands of celestial objects with detailed data.
Generate optimized observing plans, control your telescope, and log your observations like a pro.
Scroll through real app screens — tap to enlarge






If you're looking for a solid starting point for a flipbook on CodePen, 1. The Cleanest Modern Version (CSS Variables)
It relies heavily on jQuery. In modern web development, importing the heavy jQuery library just for a flipbook effect is generally discouraged due to performance costs. 3. Modern Vanilla JS and Canvas Libraries
Digital flipbooks bridge the gap between traditional print media and modern web interactive experiences. Whether you are building an online magazine, an interactive restaurant menu, or a digital photo album, a realistic page-turning effect elevates user engagement.
We are seeing a shift from jQuery-based flipbooks to and Web Components . Because jQuery is becoming legacy code, modern "flipbook codepen" searches often exclude jQuery by using querySelectorAll and custom events.
var pages = ["img/cover.jpg", "img/page1.jpg", "img/page2.jpg"];
Individual elements layered sequentially. JavaScript or CSS classes dynamically toggle their visibility and rotation states. 3 Popular Methods Found on CodePen
.book touch-action: pan-y pinch-zoom; /* allow vertical scrolling but not horizontal pan interfering */ .page -webkit-user-select: none; user-select: none;
// invoke custom drawing routine per page (adds rich illustrations) if(story.draw) story.draw(ctx, w, h); else // fallback cute icon ctx.font = `$Math.floor(w * 0.2)px "Segoe UI Emoji"`; ctx.fillStyle = '#ab8e64'; ctx.fillText("📖", w*0.7, h*0.7);
When a panel is "open," its z-index is lowered to 1 so the pages underneath can be seen and interacted with.
A highly configurable React component for creating beautiful page-flip books. Key Features: Designed for AI agents with JSON-based configuration and built upon the react-pageflip library. Use Case: The go-to choice for React developers needing a seamless and configurable flipbook component.
<div class="flipbook"> <div class="page hard">Cover</div> <div class="page"> <div class="front">Page 1</div> <div class="back">Page 2</div> </div> <div class="page"> <div class="front">Page 3</div> <div class="back">Page 4</div> </div> <div class="page hard">Back</div> </div>
// optional corner fold effect ctx.beginPath(); ctx.moveTo(w-20, h); ctx.lineTo(w, h-20); ctx.lineTo(w, h); ctx.fillStyle = '#e9d9bf'; ctx.fill(); ctx.beginPath(); ctx.moveTo(w-20, h); ctx.lineTo(w, h-20); ctx.lineTo(w-18, h-18); ctx.fillStyle = '#cfb280'; ctx.fill();
To change page thickness (the "stack" visual), look for box-shadow on the .page element.
Tools for astronomers, astrophotographers, and anyone who looks up
Explore the solar system in an interactive 3D view
Track the ISS, Starlink, and thousands more flipbook codepen
Point your camera and explore the sky
Real-time aurora and solar activity dashboard If you're looking for a solid starting point
Personalized recommendations for your location
Massive astronomical database at your fingertips Individual elements layered sequentially
Plan your observing sessions in advance
Detailed Sun and Moon information
Fresh 5-star feedback from astronomers around the world
"The update to version 4 brings several interesting graphical and functional improvements. It's incredibly realistic; the horizon profile at your observation location allows for more precise calculations of star rises and sets. The 3D view has been significantly improved, with updated graphics for the well-rendered planets, and every astronomical event is faithfully reproduced. A full 5 stars for this beautiful app, an indispensable tool for both amateur and professional astronomers."
"If you're wondering which special objects are in the constellation you're looking at right now, and when they can best be observed, then this app is exactly right for you. I've tried just about every astronomy app out there. My conclusion: by far the most valuable app for amateur astronomers who want to explore the night sky themselves with their own telescope."
"This app is simply fantastic and keeps getting better. It offers a huge variety of features, making it the most professional app in the Play Store."
"Version 4 is amazing: intelligently programmed, very well organized. Thank you for this excellent work!"
New users should begin with the freemium app, then unlock premium inside the app when they are ready. If you prefer buying up front, Mobile Observatory Pro remains available as the classic paid edition.
Recommended for all new users
Classic paid edition for users who prefer a separate upfront purchase
The story behind Mobile Observatory
Creator of Mobile Observatory
Wolfgang Zima spent years as a professional astronomer before finding his way into software development. After completing his PhD in Astronomy at the University of Vienna, he worked as a postdoctoral researcher at the Institute for Astronomy at KU Leuven in Belgium for five years. It was there that he discovered a passion for scientific software — writing tools for analyzing spectra of pulsating stars and building a CCD image simulator for ESA's PLATO mission, a space telescope searching for Earth-like exoplanets.
Mobile Observatory started almost by accident: when his Nokia phone broke on a mountain biking trip in late 2010, Wolfgang got his first Android phone and was surprised that no good astronomy apps existed. So he built one. First released in January 2011, Mobile Observatory has since grown into one of the most comprehensive astronomy apps for Android and has been continuously improved for well over a decade.
Wolfgang lives in Freiburg, Germany, where he works as a Senior Mobile Developer at sevdesk. He continues to develop Mobile Observatory with the same enthusiasm as on day one — now with the help of modern AI tools that let him bring new features to life faster than ever.
If you're looking for a solid starting point for a flipbook on CodePen, 1. The Cleanest Modern Version (CSS Variables)
It relies heavily on jQuery. In modern web development, importing the heavy jQuery library just for a flipbook effect is generally discouraged due to performance costs. 3. Modern Vanilla JS and Canvas Libraries
Digital flipbooks bridge the gap between traditional print media and modern web interactive experiences. Whether you are building an online magazine, an interactive restaurant menu, or a digital photo album, a realistic page-turning effect elevates user engagement.
We are seeing a shift from jQuery-based flipbooks to and Web Components . Because jQuery is becoming legacy code, modern "flipbook codepen" searches often exclude jQuery by using querySelectorAll and custom events.
var pages = ["img/cover.jpg", "img/page1.jpg", "img/page2.jpg"];
Individual elements layered sequentially. JavaScript or CSS classes dynamically toggle their visibility and rotation states. 3 Popular Methods Found on CodePen
.book touch-action: pan-y pinch-zoom; /* allow vertical scrolling but not horizontal pan interfering */ .page -webkit-user-select: none; user-select: none;
// invoke custom drawing routine per page (adds rich illustrations) if(story.draw) story.draw(ctx, w, h); else // fallback cute icon ctx.font = `$Math.floor(w * 0.2)px "Segoe UI Emoji"`; ctx.fillStyle = '#ab8e64'; ctx.fillText("📖", w*0.7, h*0.7);
When a panel is "open," its z-index is lowered to 1 so the pages underneath can be seen and interacted with.
A highly configurable React component for creating beautiful page-flip books. Key Features: Designed for AI agents with JSON-based configuration and built upon the react-pageflip library. Use Case: The go-to choice for React developers needing a seamless and configurable flipbook component.
<div class="flipbook"> <div class="page hard">Cover</div> <div class="page"> <div class="front">Page 1</div> <div class="back">Page 2</div> </div> <div class="page"> <div class="front">Page 3</div> <div class="back">Page 4</div> </div> <div class="page hard">Back</div> </div>
// optional corner fold effect ctx.beginPath(); ctx.moveTo(w-20, h); ctx.lineTo(w, h-20); ctx.lineTo(w, h); ctx.fillStyle = '#e9d9bf'; ctx.fill(); ctx.beginPath(); ctx.moveTo(w-20, h); ctx.lineTo(w, h-20); ctx.lineTo(w-18, h-18); ctx.fillStyle = '#cfb280'; ctx.fill();
To change page thickness (the "stack" visual), look for box-shadow on the .page element.