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






It democratized rhythm. It proved that a mouse and a monitor could replace a studio full of outboard gear. For the tens of thousands of electronic musicians who started their journey in a dorm room with a pirated copy of Cubase 5.0 and the LM4 Mark II, those blue buttons and punchy kicks are the soundtrack of their youth.
Are you trying to to run on a modern 64-bit operating system?
The Mark II version transformed the simple drum player into a more comprehensive module with advanced sound manipulation:
A clinical, powerful, and forward-thinking instrument that traded sex appeal for pure function. If you ever meet an old-school producer who still raves about "the LM-4," ask them to show you the filter envelope on the kick drum. They will talk for an hour.
The LM4 Mark II proved to a skeptical industry that software could handle the rigorous timing demands of drum sequencing without lagging or crashing. It helped establish the VSTi (VST Instrument) standard as a viable replacement for expensive MIDI rack modules. For many producers working in the early 2000s, the LM4 Mark II was their very first introduction to the world of software-based drum layering.
You could stack up to 16 samples on a single pad. You could set velocity ranges so a soft hit triggers a delicate sidestick, while a hard hit triggers a rimshot. You could also enable "Random" layer selection—primitive round-robin—to avoid the "machine-gun effect" where repeated snare hits sounded identical. This was deeply humanizing.
To help find solutions for your vintage setup or modern equivalents, let me know: Are you trying to on a modern system?
In the mid-to-late 1990s, the world of music production stood at a crossroads. On one side, there was the hardware studio—racks of samplers, drum machines, and synthesizers connected by a spaghetti of MIDI cables. On the other side, the promise of the "DAW" (Digital Audio Workstation) was just beginning to flicker to life. While Cubase had already established itself as a powerful MIDI sequencer, audio recording was still a separate, expensive affair.
The is a landmark in the evolution of virtual instruments, serving as a successor to one of the first widely adopted VST rhythm boxes. Released in 2002 , this 32-bit drum module was designed to offer a balance between intuitive handling and high-performance sample-accurate timing. It significantly expanded upon the original LM-4 by introducing a massive library of high-quality sounds and more advanced sample-shaping tools. Key Features and Specifications LM4 Mark II
The LM-4 MkII was eventually discontinued when Steinberg pivoted to (released 2003). Groove Agent offered a more modern, stylized interface with built-in beats and a focus on acoustic kits. It was commercially more appealing, but many hardcore users felt Groove Agent was a step back in terms of raw sound design power. Groove Agent was a pattern-based drum machine; the LM-4 was a modular drum synthesis lab.
Before the LM4 Mark II, producing realistic drums on a computer required expensive hardware samplers connected via bulky SCSI cables and complex MIDI mapping. The LM4 Mark II proved that a computer's CPU could handle high-quality, low-latency audio sampling internally.
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 steinberg lm4 mark ii
Point your camera and explore the sky
Real-time aurora and solar activity dashboard It democratized rhythm
Personalized recommendations for your location
Massive astronomical database at your fingertips Are you trying to to run on a modern 64-bit operating system
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.
It democratized rhythm. It proved that a mouse and a monitor could replace a studio full of outboard gear. For the tens of thousands of electronic musicians who started their journey in a dorm room with a pirated copy of Cubase 5.0 and the LM4 Mark II, those blue buttons and punchy kicks are the soundtrack of their youth.
Are you trying to to run on a modern 64-bit operating system?
The Mark II version transformed the simple drum player into a more comprehensive module with advanced sound manipulation:
A clinical, powerful, and forward-thinking instrument that traded sex appeal for pure function. If you ever meet an old-school producer who still raves about "the LM-4," ask them to show you the filter envelope on the kick drum. They will talk for an hour.
The LM4 Mark II proved to a skeptical industry that software could handle the rigorous timing demands of drum sequencing without lagging or crashing. It helped establish the VSTi (VST Instrument) standard as a viable replacement for expensive MIDI rack modules. For many producers working in the early 2000s, the LM4 Mark II was their very first introduction to the world of software-based drum layering.
You could stack up to 16 samples on a single pad. You could set velocity ranges so a soft hit triggers a delicate sidestick, while a hard hit triggers a rimshot. You could also enable "Random" layer selection—primitive round-robin—to avoid the "machine-gun effect" where repeated snare hits sounded identical. This was deeply humanizing.
To help find solutions for your vintage setup or modern equivalents, let me know: Are you trying to on a modern system?
In the mid-to-late 1990s, the world of music production stood at a crossroads. On one side, there was the hardware studio—racks of samplers, drum machines, and synthesizers connected by a spaghetti of MIDI cables. On the other side, the promise of the "DAW" (Digital Audio Workstation) was just beginning to flicker to life. While Cubase had already established itself as a powerful MIDI sequencer, audio recording was still a separate, expensive affair.
The is a landmark in the evolution of virtual instruments, serving as a successor to one of the first widely adopted VST rhythm boxes. Released in 2002 , this 32-bit drum module was designed to offer a balance between intuitive handling and high-performance sample-accurate timing. It significantly expanded upon the original LM-4 by introducing a massive library of high-quality sounds and more advanced sample-shaping tools. Key Features and Specifications LM4 Mark II
The LM-4 MkII was eventually discontinued when Steinberg pivoted to (released 2003). Groove Agent offered a more modern, stylized interface with built-in beats and a focus on acoustic kits. It was commercially more appealing, but many hardcore users felt Groove Agent was a step back in terms of raw sound design power. Groove Agent was a pattern-based drum machine; the LM-4 was a modular drum synthesis lab.
Before the LM4 Mark II, producing realistic drums on a computer required expensive hardware samplers connected via bulky SCSI cables and complex MIDI mapping. The LM4 Mark II proved that a computer's CPU could handle high-quality, low-latency audio sampling internally.