Program code and documentation ©2006 multiCherry.com
The program displays- in real time- the lines between the light (day) and dark (night) sides of the earth. This dividing line is known as the terminator. The parts of the earth that are crossing the terminator are where sunrises and sunsets occur.
As the program runs in real-time, you can watch different parts of the earth move from night to day (and vice versa).
You can choose between close-up views of the sunrise (night-to-day) and sunset (day-to-night) halves of the terminator. Sunrise (the part of the earth moving out of the shadow) is shown in yellow, moving across the landscape. Sunset (the parts of the earth moving into shadow) is shown in blue.
Latitude is how far north or south of the equator (from 0 to 90 degrees) a place is. You can choose which latitude you want the view centred on. Either click the map (you may find navigation easier if you zoom out first) to centre on that latitude, or enter a value from +90 degrees (the North Pole) to -90 degrees (the South Pole).
Note that areas within the Arctic and Antarctic circles may be in permanent daylight or night during winter or summer, so it's impossible to show sunrise and sunset in such cases.
Sunrise Tracker requires a recent browser which includes support for the latest web facilities (see 'Browser compatibility' below).
In addition, you must also have Javascript enabled in your browser. You may find the following searches useful for this:-
Please note that some people consider Javascript to be a potential security hole, particularly with Internet Explorer. If this is the case, and you only wish to use this site, please remember to turn off Javascript again once you are finished using it.
The program requires (at least)
It might also work with Safari 1.2.4+, Netscape 7.1+, Mozilla 1.4+ and Opera 8.02+, but it hasn't been tested with them yet.
MultiCherry.com recommends Firefox for Windows users. Get it here!
The sunrise and sunset are accurate to within a few minutes at present. It is hoped to improve this in the near future by tweaking the formulae used.
If you have any problems with the site, or you simply want to contact us, our email address is webmaster@multicherry.`com. (Remember to remove the spam-filtering apostrophe).