Mobile Observatory Free

Wolfgang Zima

Contains ads

About this app

Mobile Observatory Free is the perfect tool for anybody interested in the sky's wonders, from the occasional sky gazer to the passionate amateur astronomer.

If you want the ad-free version, please visit
https://play.google.com/store/apps/details?id=com.zima.mobileobservatorypro

Do you want to know if the next lunar eclipse is visible from your location or when the next bright comet is visible? Would you like to be notified by your smart phone next time, Jupiter and the Moon meet in the sky? Do you want to know what the blazing bright object in the evening sky is? Do you want to be always up-to-date which celestial events that are visible from your location? Then this app is a must-have for you!

Mobile Observatory does not only include a live, zoomable sky map which tells you what sky object you are looking at but provides you with loads of detailed extra information on stars, planets, deep sky objects, meteor showers, asteroids, lunar and solar eclipses as well as detailed ephemeris of all included sky objects and an interactive top-down view of the Solar System. All that in just one app!

Mobile Observatory Free is the free version of the successful astronomy app Mobile Observatory Pro, which is available for purchase on Google Play.

The key features of MO Free are as follows:
- Photo-realistic display of the night and day sky with correctly illuminated landscape. Its the only app on Android which renders the sky physically correct, taking into account atmospheric scattering. Only the real sky is more beautiful...
- 30.000 stars to magnitude 7
- 3D-view of the Solar System
- Automatically created calendar of celestial events
- Map of the Earth showing day and night
- Automatic calculation of interesting celestial events for your location
- Daily notifications of current celestial events
- 1000 minor planets
- All 88 constellations
- Messier and Caldwell catalogs (220 Deep Sky objects)
- ... and much much more...

Mobile Observatory displays the current view of the sky, the times of rise and set of any object, current positions, and apparent views of the planets, twilight times, moon phases, celestial events (such as conjunctions and eclipses), a 3D-view of the Solar System and much more. Use Live Mode to point your device to the sky and find out what you are looking at using the orientation sensors or get daily notifications of celestial events.

Mobile Observatory currently includes data for the Sun, Moon, seven planets + Pluto, a built-in star catalog of more than 30000 stars (to magnitude 7), the Messier catalog (110 objects), and the Caldwell catalog (110 objects). The orientation sensors of your device can be used to use Mobile Observatory as a guide to the sky via Live Mode.

Ratings and reviews

I love this app. So many free features and a comprehensive format. I also get notifications for events like meteor showers or the best time to view various planets. When I was in school the curriculum did not include anything but very basic astronomy. Now I find I want to know everything! I've discovered something about myself , it's in the stars.

Used version 2 for as long as I can remember. Seems like I paid for an upgrade at some point but I can't be certain. Version 3 ads are too intrusive and, because the app uses my location data, I can't be certain of that data not being passed along to the same in app ads. I wanted to try 3 to find out if I would buy the pro version but I guess I'll be sticking with the previous version for now.

Technically a comprehensive and useful app, but the ads were a bit too demanding when I first installed it in Jan 2022, esp. when you had to watch totally irrelevant ads while waiting to download satellite data. Now in Jan 2026, the ads are shorter, so I gave five stars. Let's see if there are any feature updates!

What’s new

- Several bugs fixed