The download button opens the iTunes App Store, where you
may continue the download process. You must have iTunes installed with an
active iTunes account in order to download and install the software. This
download may not be available in some countries.
NightSkyToolbox is a handy utility for every astrophotographer - information about the current longitude and latitude, Greenwich and local mean sidereal times, Julian date, the polaris local hour angle with the rotated polar finder reticle images and the Field-of-View and resolution calculator for all of your telescopes and cameras...