Stellarium: The Open Source Planetarium
I want to show you a really good software, it is called Stellarium.
It’s very useful if you want to watch the sky. You can easily find out what you can see from your position. You can select whether you watch with the naked eye, binoculars or a telescope. It’s also a nice tool to learn the constellations, stars, planets, moons and improve your orientation skills.
You can decide what you want to be shown (planets, nebulas, etc.) and you can zoom in to get a closer look to see the moons of the planets for example.
It is open source and available for Linux, Mac OSX and Windows. The official homepage is: http://stellarium.org/
I made a few Screenshots to show some of the features: