There's an app for that...

I won't try to hide my delight in Apple products. I have an all-Apple home (well, I run Windows XP in Parallels for those applications that insist...) that includes devices large and small. I have been enthusiastic over the iPod Touch from the beginning, but I find the iPad – which is fundamentally a large iPod Touch – has had a significant impact on my computing behavior. It has superb resolution, fast networking for a wireless device, and plenty of  inexpensive applications – or "apps."

My latest acquisition was Gas Giants from Software Bisque. It is a simple concept: provide simulated views of Jupiter and Saturn, based on time and telescope. I would argue that for $2.99 you can't afford to not have it. True, you can get the same information from a PC planetarium program, such as TheSkyX, but Gas Giants provides nearly instant access on a very portable device, either iPod or iPad.

Ignoring for a minute both the educational and aesthetic appeal, this app has practical observing value. I can't think how many times I wished I had printed out the moon alignments or Red Spot position in advance. Indeed, Gas Giants does a wonderful job of showing moon shadows and their eclipsing. Needless to say, one wants to be wary of exposing eyes to the screen brightness; a little red plastic film, found in auto parts stores for fixing tail lights, over the screen will do the job.

For $2.99 it is an attractive and powerful piece of software. It occasionally abruptly crashes for no apparent reason, but this is not unusual for new iOS software and is only a minor inconvenience, as the application can be restarted almost immediately. I don't doubt that Software Bisque will fix it in coming releases. The quality of the simulated graphics is breathtaking.

I like this world of inexpensive and very focused software that iOS is enabling. In contrast, I have been trying to figure out which level of The Sky I might want to buy; the price ranges from $99 to over $300 – too much money to take the plunge to see if I it does what I need it to do. $2.99 is another story. I would be very pleased to see a similar app for Lunar viewing.