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Emerald Observatory for iPad

By Emerald Sequoia LLC

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Emerald Observatory displays a wealth of astronomical information all on one screen, in a unique but understandable format. Information includes:

- 12- and 24-hour ordinary clock time
- Times of rise and set for the Sun, the Moon, and the 5 classical planets
- Times of the beginning and ending of twilight
- Heliocentric orrery (display of the planets in orbit around the Sun)
- Altitude and azimuth for the same bodies (one body at a time)
- Current phase and apparent orientation and relative size of the moon
- Current regions of day and night on a world map
- The Equation of Time, solar time, UTC time, and sidereal time
- Month, day, year, and leap-year indicator
- Daily alarm (delivered as local notification on iOS 4+ if app is not running)
- Eclipse simulator
- Displayed times are synchronized via NTP to "atomic clock" standard
- Uses iPad location, or the latitude and longitude may be set manually

A setting is available to allow the display to stay on continuously.

Tap on the display to move forward by a month, day, year, hour, or minute. A detailed manual for the operation of Emerald Observatory can be found at the "Emerald Sequoia LLC Web Site" listed below, at

If you are having any trouble with the application whatsoever, please see our FAQ on the support page listed below and then contact us through that page if your problem is not resolved. We take pride in responding promptly to all support email requests but we can't fix it if you don't report it (and we have no way to respond to Customer Reviews on iTunes).

(NTP requires Internet access. Like all apps Emerald Observatory can not change the device's internal clock.)

What's New in Version 1.4

iOS 7 support

iPad Screenshots

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Customer Reviews

Elegant NIST Synchronized Timepiece

I stumbled across this app looking for one to provide the National Institute of Standards and Technology (NIST) time. This app does synchronize with the NIST atomic clock time via the web. It is so much more. If you enjoy having a spatial sense of where you are relative to the other planets in the solar system, like to know sunrise and sunset times, what planets are visible in the sky, when the next solar and lunar eclipse will occur, or want a better understanding of different time references, then you will enjoy this app. On top of these items, it is the most beautiful time piece I have seen.

I've been using this for years…

…As a functional orrery and ephemeris, and only just now thought to review it. Basically, it's a great app. If you're in any way interested in planetary positions, times of rise and set, and lunar motion and phases, look no further. You've found the app you need.

Beyond that, it's a beautiful timepiece — a clock you'll be pleased to display on your iPad.

Elegant Symbiosis

The beauty of the Emerald Observatory and Emerald Chronometer apps are only surpassed by their elegant symbiosis in conveying precise time and place information. To say that Bill Arnett and Steve Pucci have done a truly outstanding job would be a huge understatement of the enormous development effort they have undertaken to produce such valuable applications. Well done!

Emerald Observatory for iPad
View in iTunes
  • $0.99
  • Category: Utilities
  • Updated:
  • Version: 1.4
  • Size: 19.7 MB
  • Languages: English, Dutch, French, German, Italian, Japanese, Simplified Chinese, Spanish
  • Seller:

Compatibility: Requires iOS 7.0 or later. Compatible with iPad.

Customer Ratings

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