"The iPad as a High-End Telescope Controller: a Case Study"

Astronomy Techology Today,
March-April 2011

Read the story in ATT!

SkySafari 4 Features

Please Note: SkySafari is now owned and supported by Simulation Curriculum Corporation. This page contains legacy information for owners of older versions of the app. For the latest information on SkySafari for iOS, go to

The following features are shared by all three versions of SkySafari 4:

  • Precision Graphics - SkySafari accurately shows the sky from any location on Earth, at any time up to 100 years in the past or future. And SkySafari Plus and Pro are precise astronomical calculators, computing the positions of solar system objects to sub-arcsecond precision with the latest JPL planetary ephemerides.

  • Compass & Gyro Support - If you have an iPhone/iPad with a compass, or an iPod Touch with a gyroscope, SkySafari can help you identify stars and planets by holding your phone next to them. Tap the Compass button (or tilt your phone up at the sky) to activate the compass - now, as you move the phone around, the sky chart follows your motion. Search for any object in the sky, and follow the arrow on screen to find it!

  • Educational Content - SkySafari is a complete astronomy handbook that fits in your pocket! It contains hundreds of images from NASA space missions, the Hubble Space Telescope, and the world's foremost amateur and professional astro-photographers. It provides extensive on-line help, including an illustrated guide to basic astronomical concepts. Unlike other stargazing apps, which just give you Wikipedia links, our object descriptions are carefully researched and fact-checked - and you can use them anywhere, without needing internet access!

  • SkyWeek - SkySafari 4 includes SkyWeek - the mobile version of Sky & Telescope Magazine's super-popular "Sky at a Glance" column. SkyWeek features interactive sky charts for each day of the week, and links to more articles on S&T's website. SkyWeek shows you all major sky events: eclipses, conjunctions, good meteor showers — miss nothing!

  • Night Vision - SkySafari 4 has a "Night" button to preserve your dark adaptation as you're exploring the night sky.

  • Time Flow - The Time Flow feature lets you animate the night sky using simple VCR controls - follow the motion of the stars and planets as SkySafari compresses days, months, and years into a few seconds.

  • Customizable Horizon - You can select from a simple transparent, translucent, or opaque horizon, or you can choose a photo-realistic horizon panorama. If you're handy with photoshop, you can even create and import a horizon panorama of your own backyard! You can show and hide daylight, and enjoy colorful sunsets with realistic horizon and sun glow effects.

Animate the rising and setting skies with interchangeable
horizon panoramas and natural skyglow effects.
You can even add your own backyard!

SkySafari predicts elipses, conjunctions, transits,
and occultations hundreds of years in the past or future.

SkySafari gives you more than facts and figures.
You also get history, mythology, science...

SkySafari is the only iOS app which correctly
reproduces both solar and lunar eclipses correctly.

Telescope Control

SkySafari Plus and Pro can control the following GoTo telescopes, using either a wired serial connection, or wirelessly - using the Wi-Fi capability built into your iPhone/iPad/iPod Touch.

  • Meade LX-200 Classic and GPS
  • Meade LX-90, ETX, LXD, LX-400 ACF with AutoStar #497 controllers
  • Meade Magellan I and II
  • Celestron Ultima 2000
  • Celestron NexStar 4/5/8, 5i/8i, GPS, SLT, SE
  • Celestron CG5, CGE, CGEM, CPC
  • Orion Sirius, Atlas, SkyView Pro, SkyQuest XTg
  • SkyWatcher mounts with SynScan controllers
  • iOptron SmartStar/MiniTower mounts with 8402A controllers. 8402G not supported.
  • iOptron iEQ30/iEQ45 mounts with 8406/8407 controllers.
  • iOptron SmartEQ/ZEQ25 mounts with 8407/8408 controllers.
  • Takahashi Temma 2
  • Vixen StarBook (see note below)
  • StellarCAT ServoCAT, Wildcard Argo Navis, Sky Commander, Losmandy DSC
  • Astro-Physics GTO, Losmandy Gemini, Vixen SkySensor 2000
  • Tangent Instruments BBox, JMI NGC-MAX, Celestron AstroMaster, Lumicon SkyVector, Takahashi Super Navigator, Dave Ek Box
  • Orion Intelliscope, Orion SkyWizard

To control your telescope, you will also need a hardware solution to relay commands from your iPhone/iPad/iPod Touch to the serial port on your telescope. Southern Stars offers two such solutions:

  • SkyWire - the world's first Apple-approved serial accessory for plug-and-play wired telescope communication.
  • SkyFi - for wireless telescope control in the field, using the Wi-Fi capability built into your iPhone/iPad/iPod Touch.

Vixen StarBook users please note:The Vixen StarBook controller uses an ethernet interface, which is also physically incompatible with SkyFi. However, you can use an Apple AirPort Express (or other wireless router) to control the StarBook from SkySafari. This document from Vixen explains how.

The telescope control interface with Night Vision turned on.
Compare to the image at bottom right of this page.

SkySafari Pro's Moon map has 8x the resolution of any
other version. Every named surface feature is labelled!

With over 100,000 double stars in SkySafari Pro's database,
you can chart the view looking back from Alpha Centauri!

Enter your telescope equipment into SkySafari,
and it can automatically compute the field of view.

iPad Support

SkySafari is a "universal" app that runs natively on the iPad, as well as the iPhone and iPod Touch. It works almost identically on both devices. In a few places, the user interface has been rearranged to fit the larger iPad screen, but the app's features and functionality remain unchanged.

Here are a few screen shots of SkySafari running on the iPad. You may need to make your browser window wider to see them completely:

SkySafari's Object Info on the iPad gives you the facts and figures,
along side encyclopedic descriptions and a gallery of images.

SkySafari Plus and Pro's telescope control interface on the iPad.

Animate gorgeous sunsets with interchangeable horizon
panoramas and natural skyglow effects.

Orbit the planets with SkySafari Plus and Pro.
Tour Jupiter's moons like the Galileo probe!