Most people visit a planetarium only once in a blue moon, but they see and marvel at a starry night sky much more often. But those with little knowledge of astronomy probably don’t know what exactly they’re looking at.

That's why it's worth installing Sky Map, a free app that turns any Android smartphone into a pocket planetarium. With the sky map in hand, it's no longer difficult to identify stars, planets, and nebulae.

You can enter the name of a planet, star or constellation in a full-text search, then move your smartphone around the night sky until a search circle with an arrow direction indicator points you in the right direction.

The map can be zoomed in and out, and it automatically moves with the user, provided your phone has a compass (most do). The map can also be moved manually. This is useful if you want to explore areas of the night sky far from your own location.

Speaking of location, the app gets the phone’s location from its GPS data. Alternatively, your can also enter the location manually by longitude and latitude or place name.

The application was originally developed by a Google project team in cooperation with Carnegie Mellon University. However, since 2012 Sky Map has been an open-source project maintained by volunteers.

 - dpa