Our Interactive Sky Chart is working again after a 2-month hiatus. A number of modifications have been made, notably in the Change Location function, which had ceased to work on some browsers about a year ago.
As before, the Sky Chart comes up in Greenwich, England by default. After you have changed the location, the new location is remembered in a cookie on your computer instead of being stored centrally on the server. So if you use multiple computers, you will have to Change Location on each.
An odd glitch is that when you do a Change Location, the Sky Chart with the corrected location pops up in a new window or tab, leaving the old one in place. That's OK — just close the old window and proceed with the new one.
The Sky Chart has an improved "geocoder" to deduce your location from the name of your city and country (and, for the U.S. and Canada, your state or province). Zip code also works, as before. The new geocoder knows some pretty obscure places, but we're sure it's not perfect.
The time zone is now deduced automatically from your location, whereas before it needed to be set manually. Unfortunately, there is currently no way to override the time zone.
The option to set your latitude and longitude manually doesn't work very well. Instead, we recommend selecting a named location near you. Anything within 50 miles (80 km) will work fine. At the level of resolution of a full-sky chart, a 50-mile error in location is negligible.
As before, Change Location is a popup window, so you must enable popups to use it.
We hope to iron out the remaining problems with the Interactive Sky Chart over the next month. Sorry for the inconvenience.