Occasionally, you run across a useful, powerful, fun and educational application that just wows you with its strengths, with all the thought that went into it, and with its ease of use. The good feelings are increased even further when you get to download and use it for free, with no restrictions. It’s enough to make you feel a little better about human beings. Stellarium is just such a program, virtually guaranteed to put stars in your eyes… along with galaxies, planets, and more. As per the official wiki,

Stellarium is an open source desktop planetarium for Linux/Unix, Windows and MacOSX. It renders the skies in realtime using OpenGL, which means the skies will look exactly like what you see with your eyes, binoculars, or a small telescope. Stellarium is very simple to use, which is one of its biggest advantages: it can easily be used by beginners. The Stellarium project was started by Fabien Chéreau during the summer of 2001 and uses Sourceforge intensively.

It’s a lot of fun to use, too. I spent some time playing with the numerous configuration options, available through a toolbar at the bottom-left of the screen. I changed the background scene, toggled equatorial and azimuthal grids, looked at constellations with background illustrations, and went forward faster and faster in time (which, by the way, will quickly show you, in a few seconds, how the sky changes seasonally, even daily).

If, however, you are not interested in downloading this excellent program for your computer, there is a nice option for you. The online Neave Planetarium, although simpler in appearance and with less features generally, will still satisfactorily allow you to explore and identify the stars above.

Both applications allow you to input your latitude and longitude (with some limitations). If you are, like I was, ignorant of your latitudinal and longitudinal coördinates, then you can remedy that by inputting your zip code at the U.S. Census page here. Once you have, and you begin to look around at all those stars, you might want to get even more perspective.

Hakan’s Space Balls will give you a strong visual idea of the difference in size between, say, our own star (Sol, with it’s diameter of 1,390,000 km/864,000 miles) and Sirius (with a diameter almost twice that of the sun). As a side note, Antares, a massive red giant, is about 700 times larger than our sun. That really is bigger than one can readily imagine (it would, in place of our sun, swallow the inner four planets).

Scale is an interesting thing. Size and distance, space and time, tell us a lot. One of the best illustrations of such scales is the famous Powers of 10 (official Website). Another, interactive, version is here. The Powers of 10 movie was even parodied on The Simpsons.