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Sky Map
The universe in your pocket!
The universe in your pocket!

Sky Map's posts

Got the jitters?

When Sky Map was created 7 years ago the innovation that made it possible was the G1 phone having a built-in compass. The iPhone at that time had an accelerometer, but no compass. An accelerometer will tell you which way down is, but you need a compass to determine direction.

The problem with a compass though is it's very susceptible to interference. This is what makes Sky Map so jittery sometimes. We try to filter out the interference, but the more we smooth it out, the less responsive the map is.

Fast forward a a year or two and phones started to be equipped with gyroscopes. The gyroscope is great because it gives you a nice smooth reading of the motion of the phone. You still need the compass and accelerometer to 'anchor' your position, but the gyroscope's motion sensing can be used to smooth out all the noise from the other two sensors. However, we never got around to upgrading Sky Map to take advantage of it.

That's about to change - we have an alpha build that uses the gyro (strictly speaking it uses Android's rotation vector sensor which does all of the hard work for us). Before releasing it widely we want to get a good sense of how it performs on a range of devices including, if possible, phones that lack gyros.

If you want to help us out (and, hopefully, get a sneak preview of the new smoothness) please email us at and we'll add you to the alpha channel whitelist.

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1.8.3 is starting to roll out.

The most important change is that it uses Google Play Services to check the Location permission on Android 6 devices and guides the user to enabling it if they wish.  Previously it would fail almost silently (erroneously telling the user the phone wasn't capable of autolocation).  Details on the "why" here:

Unfortunately this adds a few bytes to the app (to say the least), but we'll probably be using Play Services more in the future so we hope it's worth it.

Apart from that we've amped up the default sensor damping to reduce the jitters.  If you're upgrading you'll need to go into settings/sensors and change the damping to a higher level.  Clean installs just get the new setting.  This is just a stopgap - using the gyro and eliminating our old sensor code is the Right Thing To Do.

And of course we've fixed a few bugs.  And by popular demand Cassiopeia is now a "W" shape again.

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Eclipse happening tonight:

Even if you can't be there in person you can see it in Sky Map.

Update going out today! It's mostly UI tweaks from feedback on 1.8.0 but we've also restored the constellation labels we dropped in the last version.

One thing we've learned recently is that over 10% of devices don't have a compass. This is something that wasn't the case when we last updated the app 4 years ago. Obviously users with these devices are disappointed as Sky Map is unable to track the sky as the device moves. Rather than completely exclude these devices (which is possible in the Play Store), we've added a dialog that warns the user that auto-mode isn't supported on their device and drops them into manual mode. We're interested to hear feedback on whether this is the right thing to do.

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Where's Taurus?  Not in Sky Map.

It would have been a surprise if last week's launch had been totally without a hitch.  We managed to "lose" a few constellation labels.  The constellations are there, but the labels are not.  The latest build in the beta channel restores them (and more besides).

To paraphrase Douglas Adams: "The App's installs had
dropped  by  nearly a twelfth since the
last update, and only Dirk and The Great Zaganza knew why."

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Hey Folks,
I just wanted to let you know that we're close to our first release of Sky Map in 4 years.

If you want to become a beta tester then sign up at:

Once done you should be able to download the beta version from the Play Store (and/or you'll get a notification saying it's available).

It's taken quite a lot of effort just to bring the code into a buildable state, so the first releases will be quite modest and just fix the most painful issues.  We do have plans for some new features though so stay tuned.  There are going to be 3 almost simultaneous releases targetted at different versions of Android (your phone will pick the right one).  On phones running Kitkat or better you'll get:

* Twice as many stars
* Some data fixes
* Menus are back! No longer will you have to find the secret incantation on your phone to bring up the old-fashioned menu.
* Arabic translations

Let us know on if you have any issues!

John & Kevin on behalf of the Sky Map Devs.

If you've tried to play with the Sky Map code in the past and been frustrated with trying to build it, please give it another try.  We've updated the code on github and it should build much more reliably now (especially the data regeneration).  Again, let us know if you have problems.

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Another way you can advance astronomy using a smart phone!

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Do you remember how your fascination with the night sky began? As a kid, I remember using a book to identify stars and planets. I would pick a map based on the current month, then attempt to orient it with what I saw in the sky.  Finding a planet meant finding the right constellation, then following the directions explaining where to find it for the next few years. Sadly, I was always worried about what I would do when the instructions expired!

The idea for Sky Map came from those experiences. We wanted to create an app that could identify objects in the night sky without flipping through a book or having data that could expire. We were able to do that because of the new technology present in the first generation of Android devices. The phone’s sensors could detect the screen’s orientation and Sky Map would calculate the view of the sky for your exact location. No paper required!

Wouldn’t it be great to take the idea of no paper required one step further?  Maybe, no hands required? Enter… Google Glass. Our team is really excited to launch Sky Map for Glass which represents the next step in exploring the stars. Now you don't even have to hold your phone, you simply have to look at the object that you want to identify. Just like the previous version, you can search for planets, stars, and constellations. Through the elegance and simplicity of Glass, your hands are free to take notes, or operate your telescope, or point out the Big Dipper… you decide.

We hope you enjoy Sky Map for Glass, which you can download here:
Please tell us of your adventures as you explore the stars. We can’t wait to hear from you!

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Remote control Meade LXD-75 with Android (SkyMap)

Check out this awesome video of Sky Map being used to control a telescope.

Hey folks! If you follow us on Twitter too, note that we've changed our username from googleskymap@ to skymapdevs@. We've also just updated the Market with Google-free text and images.
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