Redshift Review -- Astronomy on your iPhone!

After loading Redshift onto my iPod touch, I was a little miffed! The app has a gigantic amount of cool astronomy stuff under the hood to write about, and I figured it would take me until 2011 to finish doing a proper review. I hunkered down with grim resolve, and found quickly that hours were flying by in fascination and fun. This app has plenty to draw both hard core astronomy buffs and casual star-gazers as well!

I used my PC iTunes to download the app, even though it isn't all that huge at around 80MB. This speaks well for an app that features 3-D simulations, and high-quality graphics. It ran without issue on my iPod touch 4G (using the 4.1 iOS version). You can grab it here in the App store.

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Before getting to the meat of the review, wanted to do a quick comparison with my favorite astronomy app called Star Walk and say up front, that both of these applications are very well done. I am not recommending either one over the other. My general impression is that SW is more suited for the casual sky watcher, whereas RS is probably better designed for the more serious astronomy buff. Either app does a fine job of bringing the universe to your iPhone, iPad or iPod touch. Here is a brief list of comparison points:

Star Walk vs. Redshift:

 --SW lacks a single unified app (requires Solar Walk for 3-D simulations)

 --RS does not have any gyro support function to calibrate views to the real sky (though both apps support devices with a compass).

 --SW lacks virtual tour feature

 --RS lacks POD feature (picture of the day)

 --SW lacks objects like asteroids, and comets in the database

 --RS has more sound options (forest sounds, crickets, music, etc.)

 --SW includes ephemeris data summary for moon and planets at startup

 --RS does not currently have a feature for tracking satellites (Earth's manmade ones or other planets' natural satellites)

 --SW is around 20-30MB larger in size

 --RS has an enhanced viewing experience, and many configurable options (SW is somewhat easier to use)

 --Both apps are excellent tools for viewing the sky

 --RS is probably more suited to hard-core astronomy geeks

 --SW is $2.99, and RS is $9.99


RS Main Features:

- More than 100,000 stars, 500 fascinating Deep Sky objects, 30 biggest asteroids, 10 famous comets visiting our planet, all major and dwarf planets, as well as Earth’s Moon

- Comprehensive astronomical data for all celestial objects: name (as referred to in various catalogues), distance, type, luminosity, size, rise and set times

- Integrated display of information gathered from Wikipedia

- “Follow Sky“ mode: watch the current sky view and immediately identify a bright star or planet in front of you

- Breathtaking 3-D flights to the Moon, planets and stars

- “Observatory“ option: presents you many fascinating objects shining on the Earth’s sky

- “Day/Night” mode and realistic simulation of dawn

- “Night Vision” mode for observations during the night

- "Time travel“: Create night sky views for any location at any time in the past or in the future

- Location: Choose automatic search via GPS or select manually on the Earth’s globe

- Select from several background sound effects

- Select panoramic views as your individual horizon

Redshift starts up and prompts you to set location services for your geographic locale automatically, and runs a nifty animation zooming into that spot on a 3-D globe. It is obviously important to be able to accurately depict the night sky in your area, so you can set your location manually as well. To pan and zoom around the heavens require the typical swipe, pinch, and multi-touch gestures you would use for any map or reference app. A small section of the night sky is depicted on-screen, and as you pan across the sky, constellations will appear in semi-transparent relief. My 4G touch does not have a compass, and as mentioned perviously, there isn't a similar function as in Star Walk--which ingeniously uses the camera/gyro--allowing you to sync up the app with objects overhead. This is a somewhat minor point, as it is simple to get your bearings using the compass point indicators on the horizon guide. You could after all use these apps to help you navigate even without an internal compass (considering you knew your approximate location, and could see celestial objects).

The app has a monstrous amount of settings and features, so I will try to summarize some of the coolest. First up is the virtual tour. I play with the free PC app called Celestia, which also does 3-D cosmos tours. RS has very similar features. The cool thing is that you can even leap frog from object to object going further out into interstellar space. Pretty cool, and when traveling across the galaxy, the stars zoom by you and appear to keep their relative positions intact. You simply tap the rocket ship button at the top to engage.

The RS head-up display provides a dearth of information (besides date/time) that can be useful for star gazers. A guage at the top indicates the azimuth (in degrees, minutes, and seconds), and altitude (also in deg, min, sec notation). You can select the date/time panel at the base of screen to quickly fast-forward or reverse time passage. This is especially helpful to view an event (say the passage of the Hale-Bopp comet in 97). A target indicator will help you to focus in on the object, and the date/time will automatically be set to that period.

The deep sky imagery and 3-D planet sims available in RS are of superior quality (note the detail showing the Martian Ice cap above). The 3-D trip feature which can also be used to quickly get a close-up view of an object like a distant star or galaxy, or take a virtual tour of in-system objects like planets (and then a distant star in serial fashion). SW does not have this feature, though you can easily zoom up on an object. 3-D planet sims are provided by a separate sister application to Star Walk called Solar Walk, which is a more immersive esperience for viewing Solar System objects. It would be cool (like in Celestia), if you could create your own 3-D tour scripts or macros in RS (maybe you can and I did not locate that feature).

Redshift let's you customize the sky settings in just about every way imaginable! You can turn on/off the eliptic and on-screen guides, filter the density of on-screen labels that appear. Simulate Day/Night, and change the earth-bound scenery surrounding the horizon, and much more. The sound can be turned off, set to forest sounds, crickets or "space" music. The RS team needs to work on the space music selection a bit, as IMHO, Star Walk clearly has the more ethereal and engaging sound track (though lacks the nature selections). Both apps feature a night-viewing mode that changes the display to a red lens or light-suppressive view.

RS has other useful features that are worthy of note. The Observatory tool gives you shortcuts to many common objects, and a comprehensive search tool (the magnifying glass icon) to quickly filter and find objects of interest. After finding an object, selecting the "i" or "W" buttons in the upper-center part of the display will get you more technical data (from the database internally or a re-direct to Wikipedia). The W button on at least one object took me to a broken link, but then I'm sure not every star in the universe has it's own wiki page (yet). You can, of course, simply tap on an on-screen object to select it for more in-depth info/investigation.

So what is the verdict? Redshift is a great application for pocket astronomy, and I give it a top-notch rating. The app performed well, and the graphics and features are very well-designed. The interface is a bit clunky in a few spots (for some menu options, etc.), but still good overall. Star Walk is still my personal favorite. Many features in SW only require a tap or swipe to activate or control, and you get more information on many objects locally in the app. The SW interface is slicker and cleaner. Solar Walk, the solar system viewer app (also by SW designers) edges out the 3-D animation features in Redshift by a hair, though I do like being able to take trips across the galaxy in RS. I am not really an astronomy buff, though I am a passive fan of it, but one aspect of using RS was really cool (IMHO): After travelling out to view an enlarged view of the Andromeda galaxy, I noted that I could pan round and view other stars, yet I did not note any recognizable constellations (makes sense--you cannot do this at all with SW). I am curious to know how the app interpolates the positions of the stars, or if it's accurate to scale? Very cool to be able to view the surrounding star positions as if you were really out there! Anyway, you can grab Redshift at the link below. I highly recommend it...

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Nate Adcock is a system and integration engineer with experience managing and administering a variety of computing environments. He has worked extensively with mobile gadgets of all shapes and sizes for many years. He is also a former military weather forecaster. Nate is a regular contributor for the and blogs and helps manage both websites. Read more from Nate at or e-mail him at