This applet has been developed using Java 1.1.0 library, Netscape's LiveConnect, ECMAScript (also known as Javascript), and related technologies.

Some browsers don't offer full support for these technologies in their default configurations. If you have trouble getting the Sky Chart to appear, or if you have trouble printing, please read the instructions below.

For help using the applet once it's launched in your Web browser, see Sky Chart Help. For tips on using the applet to explore the night sky from any location on Earth on any date from 1600 to 2400, see Fun with S&T's Interactive Sky Chart.

Before reading any further, make sure you know which operating system and Web browser you have. On a PC, our Sky Chart supports only Windows 98 or higher. On a Macintosh, our Sky Chart works on OS X and OS 9.1, but the functionality may vary depending on exactly which version and browser you're running.

If you use Internet Explorer on a PC, choose Help > About Internet Explorer from your browser's top menu. If you use Netscape Navigator, choose Help > About Navigator. In either case, the window that pops up will tell you which version of the browser you have.

On a Mac, here's how to find out which version of Mac OS you're running. Click on the Apple icon in the upper left corner of your screen. Then select "About this computer." In the pop-up screen, you should see something like "OS 9.1" (for Operating System version 9.1).

As explained on the next page, our Sky Chart is known to work on a Mac running OS X and Netscape 7; it may run with partial functionality in Internet Explorer and/or on other versions of Mac OS. If you have Netscape on your Mac, open the program and click the Apple icon in the upper left corner of your screen. Then select "About Communicator" to find out which version you're running.