An uncle of mine has recently gotten interested in astronomy, so I was looking for an astro-related Christmas present for him, and I found an extremely cool program, which also turns out to be free (and open-source): Stellarium.
When you run it, it displays a full-screen rendering of the sky, and in a very cool and realistic way: In the foreground you can see the ground, e.g. grass, trees, etc.; and the sky is beautifully rendered with colors appropriate to the current time of day where you are, e.g. dark blue with a pink horizon at sunset (the sky is always beautiful in Stellarium-land; be sure to check out the screenshots on the website).
But hey, you want to see what stars would be visible if it weren’t daytime? Click a button, and the atmosphere disappears. You want to see what stars are currently hidden below the horizon? Click another button, and the ground disappears. You want to see the sun and stars move in fast motion? Want to see how the sky looked in 1966 during the heaviest meteor shower ever seen? Want help learning where the constellations are? Where the planets are? Click click click. Want to see close-up photos of all the planets? Of a number of interesting nebulae? They’re all there. Want to see how high the sun is right now in Alaska? Change your location to Alaska. Want to see how the sun never sets when it’s summer at one of the poles? Change your location, and accelerate time, and watch the sun move across the sky without setting.
When you start the program, it defaults to a viewpoint from Paris; to change that, click configuration (the wrench icon at the bottom of the screen), go to Location, and click the map. Also, to zoom in on your general area so it’s easier to click the right spot, hold the mouse over your part of the world and rotate the mouse wheel.
I’ve burned it onto a CD, and I’m going to give it to my uncle. Yes it’s free, but he never would have found it on his own, and also I’m gonna give him a hand with it since he is only moderately computer-savvy.
Merry Christmas!