Mobile Observatory - Astronomy

Wolfgang Zima

In-app purchases

About this app

Mobile Observatory — the astronomy app with real topographic horizon data. All features included.

See exactly when and where celestial objects rise above your local hills and mountains. Mobile Observatory uses NASA elevation data to compute your actual horizon profile — making it the only astronomy app that shows true rise and set times for your exact location. Perfect for astrophotographers planning the ideal shot of the Moon rising behind a mountain ridge.

★ WHAT MAKES THIS APP UNIQUE ★

REAL TOPOGRAPHIC HORIZON
Other apps assume a flat horizon. Mobile Observatory downloads NASA SRTM elevation data and renders a photorealistic 3D terrain profile for any location on Earth. All rise and set times are computed against your actual landscape — not a theoretical flat line. Astrophotographers and serious observers rely on this for precision planning.

PHOTOREALISTIC SKY RENDERING
The only Android app simulating true Rayleigh and Mie atmospheric scattering. Watch the sky transition from deep blue to golden hour to astronomical twilight — exactly as it appears in reality. Stunning time-lapse animations show celestial motion across a physically accurate sky.

★ NEVER MISS AN EVENT ★

• Aurora alerts when geomagnetic activity spikes at your location
• Solar flare notifications from real-time GOES X-ray satellite data
• ISS visibility alerts with brightness and trajectory predictions
• Daily astronomical event reminders — conjunctions, eclipses, meteor showers
• Push events directly to your calendar

★ INTELLIGENT OBSERVING PLANNER ★

The built-in Observing Plan Generator creates personalized target lists based on your equipment (naked eye, binoculars, or telescope), location, date, light pollution level, and minimum altitude. One tap generates the best objects for tonight — no experience required.

★ DAILY UPDATED CATALOGS ★

• 60,000+ minor planets with daily orbital element updates
• 1,000+ comets with observed light curves from the Minor Planet Center
• All active satellites including ISS and Starlink with pass predictions
• Real-time solar images and X-ray flux data from NASA SDO and GOES
• Variable star light curves and eclipsing binary predictions

★ TELESCOPE CONTROL ★

Connect directly to your computerized telescope via LX200, NexStar, or INDI protocol. Browse objects in the app and send GoTo commands — seamlessly integrated with the Observing Plan Generator.

★ COMPREHENSIVE FEATURE SET ★

• Photorealistic sky view with 45,000 stars (2.5 million with download)
• Augmented reality mode with live camera overlay
• Interactive 3D Solar System and VR/Cardboard support
• Complete deep sky catalogs: Messier, NGC, Caldwell, Hidden Treasures
• Solar and lunar eclipse predictions with worldwide visibility maps
• Galilean moon positions and Saturn moon tracking
• Live space weather dashboard with aurora forecast
• Home screen widgets and night mode

★ ALL FEATURES INCLUDED ★

This is the complete version of Mobile Observatory with every feature unlocked — satellite tracking, deep sky catalogs, push notifications, telescope control, the Observing Plan Generator, and much more. No in-app purchases required.

Trusted by astronomers, astrophotographers, and stargazers since 2011. Continuously updated with new features and data.

Learn more at https://zima.co

Ratings and reviews

This app is one of the first ones I ever thought worthy of paying for, and it's been on every phone and tablet I've used for years. The recent rewrite the app went through has squashed some longstanding bugs and made things work with a little more polish, which is wonderful. Yes, there's a learning curve to it but it has way more information that most people will ever need.

I've used this app for so many years, but something happened in the recent updates. Moving around in the sky is no longer possible. Swiping across the screen moves the view a fraction of a degree, if at all. It has become entirely useless! Yes, I do have a budget phone, but any other app works flawlessly. No, disabling the horizon/landscape doesn't help. No, it's not the sensitivity setting. After deleting all data, it works. Once. After that, it no longer works at all. Help investigating this.

Very good, complete and capable astronomy app. My only two minor niggles are the on-screen controls are at times a bit small for a phone screen and there's no way to turn off diurnal motion, which means the chart drifts when zoomed in. But that's about it. However there's been no update (as far as I can tell) in 2+ years. Is the developer still active?

What’s new

Version 4.2.0

🆕 Telescope Control (Beta)
🆕 Observing Plan Generator
🆕 Draw Your Horizon
🆕 Saved Sky View Scenes
🆕 Observing Lists & My Observations
🆕 My Equipment & Optical Tools
🆕 Backup & Restore
🆕 Equipment Overlay in Sky View
🆕 Double Stars & Variable Star Light Curves
🆕 Eclipsing Binary Predictions
🆕 Comet Brightness Curves
🆕 3D Topographic Landscape
🆕 Selenographic Ephemeris
🆕 In-App Language Selection
🔧 Bug fixes and improvements