- 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 relative apparent 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
- 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, or minute. As a lifelong lover of astronomy, this app is the most elegant thing I've ever seen. To be able to see the positions of our naked-eye-visible planetary neighbors at any time in history, complete with a brilliant representation of their rise and set times...this apps is beautiful, informative, AND AMAZING.
When I saw the Emerald name I expected a high quality app with superb graphics and attention to detail, but this observatory exceeded my expectations.
The layout contains a wealth of information about the sun, moon, and planets arranged in a pleasing and compelling fashion. It iss fun to press the set button and see how time affects all the different dials and displays.
It all makes for a spectacular dock display - FAR better than a simple clock. If any of the ancient founders of this science could see this, I have no doubt this would be right on their home screen.
One of my best iPad purchase to date, well worth the $1 from the Apple iTunes App Store