When the fireworks stop and the smoke clears, it would be a great weekend to look at our beautiful summer skies. Pocket Universe [App Store] is a US$2.99 app that has been updated to make star finding easier for those that have a new iPhone 3GS.

The app uses the position sensors and the compass to orient your phone to match the real sky. As you turn or tilt the phone, the sky map changes to give you a very accurate picture of where you are pointing, with lots of labels and links to more information. This is one of the first examples of an augmented reality app to hit the platform since the introduction of the 3GS.

If you have an older iPhone or iPod touch running OS 3.0, you can tilt the phone to match where the real sky is, but you'll have to manually set the direction you're facing.

This changes everything for the novice astronomer. I tried the feature and it worked really well, even though I was near a large metal building. As I turned my phone the display of the sky changed very rapidly to keep up with my movement.

Other nice features from the last version are intact. You can tap the 'locate' button to find any object that is above the horizon. Select it and it centers on the map. Tap a pop-up for more info and you get a quick summary of the object. In the new version of the app a further tap gets you a Wikipedia entry.

You also get a list of meteor showers, lunar phases and a very nice 'tonight's sky' feature that tells you right away what's up and worth seeing.

Some things I'd like to see improved: The app could support finger-pointing to an object to identify it in addition to going to the locate menu, and the Virtual Sky feature is buried in an options menu. I'd like to see an onscreen button to turn it on and off.

The 3GS features are similar to a Celestron product called the Sky Scout that is a dedicated astronomical instrument. The Sky Scout has a lot more information, and audio tours of the skies, but it costs $200.00. If you're really serious about the stars and planets I'd give it a look.

Meanwhile, another favorite astronomy app, Distant Suns [App Store] has been updated recently, and is now on sale for US$3.99. It has added features to the wonderful tour guides and now includes more information about the objects displayed, including travel time at light speed to the planets. It also includes some breathtaking images from the Hubble Space Telescope.

This is the International Year of Astronomy, so it's a great time to get outdoors and look up. It's fun to do, and the iPhone apps really make it a more compelling and educational experience.

Here are some screen shots of Pocket Universe in operation:

I've always loved astronomy. There is something about the tremendous size and scope of our observable universe that is inspiring and humbling at the same time. It's why I get excited about the variety of astronomy programs for the iPhone.

The latest is called Pocket Universe [App Store link]. For the $2.99US price, your iPhone or iPod touch gets a star atlas of 10,000 objects, a guide to moon phases, a list of what's up on any particular night including meteor showers and any visible planets, as well as live links to astronomy news.

The app also includes an accurate rendering of the positions of the 4 easily visible moons of Jupiter, but your best bet in seeing a planet this time of year is Saturn which is high in the southeast.

As we move toward summer, more and more people will be heading outdoors. That makes it it is a great time to learn the constellations and be able to understand what you are looking at, as opposed to just wondering what that bright thing is.

A nice feature of the app is auto tilt, so when you are pointing the right direction, you can tilt the phone up to get a view higher in the sky and the star map will follow your tilt. If, as rumored, the iPhone adds some kind of direction finding compass, apps like this can be even more helpful as you turn and tilt, as the map should track your movements exactly.

Pocket Universe has a very clever locate feature, where you can select an object, and there are on-screen directions to take you to the object by superimposing arrows on the screen. This feature didn't always work perfectly. I asked the program to find Saturn. It told me to follow the arrows, but no arrows appeared. It seemed to work fine on other objects I was looking for, and Saturn was properly placed on the sky map.

How does this object compare to some of the competition? Quite well. It's reasonably priced, and with the live links it has some features the others don't have. I also recommend Distant Suns, Starmap, and Star Walk as worthy alternatives.

Here are some screen shots: