I’ve recently gotten into astronomy and astrophotography since I got an 8″ telescope for my birthday in 2010. Since then I have found that my Android phone is a must have tool! This is a list my favorite and most useful Android apps for astronomy. All of the ones mentioned here are free or have a free version. I suggest donating or upgrading on all of them if you like them to help compensate the programmers for their hard work.

UPDATED with new app (see end of post for the new addition).

Before Heading Out:

Before going out for the night, you have to check the weather and the skies. There are several apps I like to use for this. Droid Clear Sky is one such app. It gives a simple familiar cloud cover forecast using data from Clear Dark Skies. It is also Open Source so go check out the code if you like.

Another app for checking if it will be a good night to go stargazing which has a lot of other information as well is Astro Panel. It gives much more information than DroidSky such as humidity and transparency among other stats.

My favorite app by far for forecasting cloud cover has to be Where Its Cloudy by Aquila Systems. This app is fast and very accurate, showing you live updates of data from NOAA satellites showing visible and infrared (of course use the infrared at night) maps of water vapor (clouds).

You also should check out the Skyweek app which let’s you know dates and times of interesting astronomical events. When is Io being eclipsed by Jupiter? The Skyweek app will let you know.

SpaceWx is a great program that collects and displays tons of current information from several sources such as Rice University and NOAA among many others. Topics include graphs of everything from solar wind to current air temperatures. My favorite part is the link to the NOAA Aurora predictions (in the magnetosphere section). It isn’t often we see auroras in the Carolinas, but I would hate to miss the chance.

Neat Stuff in the Sky:

A fun past time is satellite spotting. The best time for this is at dawn or twilight, but with the help of a few apps you can always be aware of what satellites are overhead and whether or not they are visible.

Droid Sat is a great augmented reality satellite tracking app. Use it as a window to the sky and visually track a few satellites and the ISS (international Space Station) as they cross the sky. One of my favorite things about this app is that it is open source. I’ve been wanting to check the code out pretty badly, but I know I won’t have time to play with it.

Satellite AR is another great augmented reality app which gives you tons of potentially visible satellites to track. Also, clicking on each satellite can load a webpage about that particular satellite or piece of space junk.

Heavens Above is another great app for satellite and space junk spotting. It has a nice widget and the ability to alarm you for possible sightings.

Iridium Flares, reflections off the Iridium satellite phone satellites, are by far the most frequent and easiest satellites to spot. Two great apps that will help you spot them are Iridium Flare Forecast and Iridium Flares.

Iridium Flare Forecast is nice because it allows you to automatically scan your location based of your wireless cell tower location, or GPS and allows you to add a flyby event to your calendar.

Iridium Flares is good because it shows you a google map overlay with expected flybys and can be set up to scan and alarm you when flybys occur. It also has a night mode to make sure not to ruin you night vision.

Meteor Shower Calender is a neat little app that helps you catch shooting stars! It will alarm you when meteor showers are visible or at their peak, giving you plenty of time to plan ahead and spot at least a few meteors.

When You Finally Get Outside:

Once you get out into the night and begin looking at the skies, there are a couple of must-have apps I always use for setting up the scope or identifying things in the sky.

A good red flashlight is invaluable, and instead of carrying around a separate device, why not use you phone? The Astronomy Flashlight is great because it doesn’t require any permissions. There are several choices for red flashlights, but others often ask for shady permissions such as making phone calls or reading you address book. The AstronomyFlashlight is simple and has several options. Pick from red, grey or white colored screen, and adjust the brightness of this choice using an on-screen slider.

I also like the use of a level for leveling out my telescope. One that I have found useful (though it does not have a night mode) is Spirit Level Plus. It is simple and effective and does all I need it to.

To calculate the magnification of my scope using different eyepieces, I use Telescope Calculator by Skyworks.

For polar aligning, I like to use PolarFinder (SigmaFinder for residents of the Southern Hemisphere)

You can use also the polar finding portion of Astro Tools. It will also show you the hour angle of Polaris and what to look for in the sky. This app is another that can use the orientation sensor and shows a nice star chart. It seems a bit unfinished as of yet but it seems to be coming along well.

Star Odyssey is a neat app that gives you more than just the names of stars, but other facts as well. Stars can be sorted by distance, name or brightness. And you can even filter for stars with planets.

Of course no list would be complete without mentioning Google Sky Map. This app allows you to use your phone as a window to the heavens. It labels the stars you are pointing at, and has a great search function. The night mode makes it easy to seek out and identify objects in the sky without blinding yourself.

A completely mind blowing and beautiful app is The Invisible Universe which again uses orientation sensors in your phone to show you things in the sky, but displays results of Gamma ray, Xray, far infrared and other telescope findings. These different frequency ranges allow us to see amazing details the visible spectrum just cannot provide such as stars forming in thick gas clouds and much more. This app is truly artful and a must have for anyone even slightly interested in science.

Miscellaneous Useful Apps:

And finally, here few additional apps I like to use to help find my way around the sky and to troubleshoot sensor readings when my google sky map, or other readings don’t match up with the sky.

GPS Status is a really great app that can help diagnose GPS issues.

Sensor List is a simple direct output of all the sensors on your phone. This is invaluable for verifying your sensors are working correctly, which is a requirement of many of the apps. Mentioned in this list.

New Compass (AD) is a good app for testing the compass sensor in the phone, as well as just to get my bearings.

Sun Surveyor Lite is a neat app that shows the sun’s orientation and angle throughout the day.

UPDATED: I just found another great app called SkEye. Basically you strap your phone to your telescope and align it with a known celestial object. From then on, your phone acts as an accurate guide to everything your scope is pointing to (PUSHTO guide). This is far more useful than any other sky mapping app out there.

Of course, there are many other apps out there, and many I have not yet tried. These are the ones I have tried and use repeatedly. If you enjoy using these apps, be sure to pop for the paid or upgraded versions of them if they are available!