…continuedSky Chart Help
Go to the Interactive Sky Chart by clicking on Tonight's Sky in the dropdown menu, then on Interactive Sky Chart. The applet may take several minutes to download, especially if you have a slow connection.
If you haven't previously set your default observing location, the chart will open with the location set to Greenwich, England. Set the location by clicking on the "Change Location" button. (Pop-ups need to be enabled for our site for this button to work.) Enter your observing location in only one of the three sections available for this purpose: USA or Canada, World by City, or Worldwide by Latitude & Longitude. Then click the corresponding SUBMIT button. (If you run into trouble at this stage, see the more detailed instructions in How to Change Your Location and Time Zone.) Once you've set the location, it'll be remembered in a cookie on your computer.
The time zone is set automatically from your location, and the default time is 9:00 p.m. You can change the time by clicking the arrows next to the hour shown or you can set both date and time by clicking on "Change" in the Date & Time section. If daylight saving time is currently active in your area, check the small box to the right of the words Daylight Saving Time. Then click the SUBMIT button.
The Interactive Sky Chart should now appear on your screen, showing the sky visible tonight from your location at your specified local time:
The All-Sky Chart's center represents the part of the sky directly overhead. Its circular edge represents the horizon all around you, as if you were standing in an open field and turning around in a complete circle. Compass directions are labeled around the horizon/edge.
A star that's plotted on the map halfway from the edge to the center, therefore, can be found about halfway up the sky halfway from horizontal to straight up.
The Selected View shows about as much sky as you can take in at once with your unaided eyes; the field of view is about 50 degrees wide by 40 degrees tall. Compass directions are abbreviated along the bottom, and two markers partway up the right edge of the window indicate your viewing altitude, from 0 degrees at the horizon to 90 degrees overhead.
If you cannot see the bottom or part of the side of the sky chart, resize your desktop to 800 x 600 pixels (or larger). To do this on a PC running Windows 95 or higher, go to the taskbar at the bottom of your screen and click Start > Settings > Control Panel > Display. On the Display Properties screen, click the Settings tab and move the Screen Area bar until it says "800 by 600 pixels." Then click OK. You'll get a pop-up window that says, "Windows will now resize your desktop;" click OK. Once your display is reset to the new size, another pop-up window will ask, "You resized your desktop, do you want to keep this setting?" Click OK again.