SkyGazer for the iPhone and iPod touch from Carina Software is a guide to the night sky and shows all the stars one can see with the naked eye plus all the planets and 220 of the best known star clusters, nebulae and galaxies. The strength of the app is the enormous amount of additional detail for major objects, including NASA spacecraft imagery.

At first glance, SkyGazer appears to be just another planetarium program that shows the night sky from various places and times.

Looking West from Denver tonight, end of dusk

However, touching an object of interest, a star or planet or whole constellation for example, brings up a wealth of detail. In the case of constellations, one need merely press "info" at the bottom to bring up a detailed data. For example, the origin and mythology of all the constellations is provided with a touch of the description button.

History, Mythology of Constellation Bootes

In the case of the planets, there is a wealth of technical data, diagrams, and beautiful photos from NASA spacecraft and the Hubble telescope that give one a great feel for almost being there, floating in space.

Any planetarium program for the iPhone has access to the horsepower to do the coordinate transformations and display the night sky. However, the strength of this program is the supporting astronomical information. One can learn a lot about observational astronomy if one just sits back and does some reading.

Saturn's rings and close in moons

A search function is nicely set up in categories, so if, for example, you're looking for Venus, just touch Search, touch planets, then Venus, and you can either find it and show it in the sky (or see that it's below the horizon) or read more details.

The only thing I could wish for is a way to change the time of night right on the display. As it stands, one must go into settings and select a fixed date and time. Its easy to do, and the settings are extensive, but changing the time right on the display with a small slider would be a nice addition.

Read all about Jupiter or just look at a great photo

This is quality software, has a great look and feel, and provides a textbook's worth of information for US$2.99. Anyone who is casually interested in learning the night sky can't wrong for that price. For more advanced amateurs, SkyGazer has a big brother version, SkyVoyager, with a much larger catalog of stars and more capability. Both can control a telescope via Wi-Fi to serial converter if it's one of the computer controlled GoTo versions.

Sky Gazer offers a lot for just US$2.99. It requires iPhone OS 2.2 or later. You'll literally be in heaven.