Stellarium

you don't have a telescope at home but you want to enjoy the sky and stars, Stellarium is a fine choice to get into this enjoyable hobby. Stellarium is a really good application, enjoyed by both those who like astronomy and those who don't known the first thing about stars. It combines a powerful database and a photo-realistic visual engine. Stellarium is a complete virtual planetarium with more than 120k stars, planets and constellations; plus a fully customizable navsystem to select any place you want to look at the sky from.