Sky View only displays stars down to magnitude 6.5. Where are fainter stars? Stars fainter than mag = 6.5 are only available for devices with Android versions above 3.0. You have to download the extended star catalog which includes stars down to magnitude 11. From the main menu select "Object Database" and then tap on "Download Catalogs and then Extended Star Catalog" (~25 MB).
The times of events are one or more hours off. Why? Perhaps the time-zone has not been set correctly. Check your location and time-zone through Menu->Set Location. Normally, this should be resolved by tapping on Get Current Location. In case this does not resolve the issue, try to also use the GPS for determining the location or set the time-zone manually (Daylight Savings Time is automatically set when you use the correct time-zone).
Where do the algorithms for computing the astronomical data come from? The calculations in Mobile Observatory are mainly based on the books Astronomical Algorithms and Astronomical Formulae for Calculators by Jean Meeus and provide good precision for computations between 1900 and 2100.
The program always crashes (FC) at the same point. To help, resolve this issue, please either send a message through the Force Close dialog, or send an email to the developer at firstname.lastname@example.org, stating the problem and information about your device and Android version.
How can I find an object in the sky? There are several possibilities. You can either tap on SKY VIEW, look for the object there and then double-tap on it to open a dialog. The other possibility is to use the search-function or one of the object lists. Let's assume you would like to find Jupiter. Select OBJECTS, tap on Jupiter and then on Find Me to start using the orientation sensors of your device. The red arrow points toward Jupiter. You can also use the Search function in the main menu (or through your device's menu button). Then enter Jupiter or simply j into the search field and then tap the button Solar System. Tap on Jupiter in the search results and a pop-up dialog showing some visibility information of Jupiter will appear. To find Jupiter using the orientation sensors of your device, tap on Find Me. Now point your device on the sky and follow the red arrow to find Jupiter.
When is the next Full Moon? Tap on MOON. The list below shows you the dates of the next phases. Tap on the date to set this date. To find out where the Moon will be located, you can switch to OBJECTS, tap on Moon, and select Sky Map. From the dialog select a time, when the Moon is visible.
Which meteor showers are currently visible? Tap on OBJECT DATABASE select Meteor Showers. This will open up a list of all meteor showers that are visible during the year. Tap and select Activity Data. Currently active showers have a light blue background.
What will the sky look like tonight? Tap on TWILIGHT. This shows you in the first column the times of sunset and evening twilight. Tap on the time of either the end of civil (just dark enough to see some stars), nautical (dark enough to see most stars), or astronomical (twilight has ended, it is completely dark) twilight to set this time. Now switch to SKY VIEW via the drop-down menu (top-left) or the Main Menu. This will show you the view of the sky at that time. Another possibility is to tap on TONIGHT'S BEST and there switch to SKY VIEW via the drop-down menu. This will show the sky at 8:30 pm (or late if it is still light) and highlight rewarding objects.
When is the next lunar eclipse visible from my location? Tap on ECLIPSES. This will show you a list of the ten next solar and lunar eclipses. Scroll down the list until you find a lunar eclipse which is visible from your location according to the description. Tap on the event to open a dialog window with more detailed information, list the time of maximum eclipse, or its magnitude. If you would like to be reminded, you can add this eclipse information to your calendar by clicking on Export to Calendar.
When will Venus reach its best evening visibility? Tap on SolarSystem and there select Venus. Switch to the screen EVENTS via the top-left drop-down menu and scroll to the event Max. Evening Elon. (or for other objects Best Evening Visibility). Tap on the event and select Show in Map to display the sky view at the time when Venus is best visible in the evening.
I have some favorite objects. How can I add them to a custom list? There are several possibilities to add an object to the list of favorites. The list of favorites is accessible via the FAVORITES in the Main Menu. Generally, you can tap on a star-symbol to add an object to the favorite list.
Which deep sky objects can I observe tonight with a small telescope? Let's say you want to observe a few nice and relatively bright deep sky objects tonight after it has become completely dark. Select TWILIGHT to set the time when it has become completely dark. Then go back and tap on OBJECTS DATABASE and select in the Deep Sky-objects Messier. This will show you a list of all Messier objects. Tap on Filter to open the filter settings. Check Use Magnitude filter and set as faintest magnitude 8. Then also check Use altitude filter and set as lowest altitude 30°. Now, the object list will show you only objects that are far above the horizon and relatively bright.