Astronomical Tools

Before you head outside to see tonight’s sky, check out our interactive astronomical tools to see what’s up. For a quick glance at the sky, use our most popular software by far, the Interactive Sky Chart, and create a customized, naked-eye sky map. (Need help? Click here.) Then plan your night with the almanac — find out when the Sun sets, when twilight begins, when the Moon is up, and when the five brightest planets rise and set. This tool will even alert you when stars and planets pass close to each other in a conjunction.

Interested in finding the International Space Station, mapping Mars, or telling apart Jupiter’s moons? Wondering what eyepieces and accessories will really pay off in resolving and imaging power for your telescope? Forget what phase the Moon is in tonight? Each of our javascript apps below is designed to make skygazing a little easier — and more fun!

How to Link to S&T’s Interactive Sky Chart

Numerous webmasters have asked us how to link to Sky & Telescope's Interactive Sky Chart so that the Java applet will open with a particular observing location already specified. This could be handy, for example, if the members of an astronomy club want to get a chart of the sky over their observatory via a…

System Requirements for the Interactive Sky Chart

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…