Functions and FeaturesFor those not familiar with astronomy "planetarium-type" programs this rates as one of the best for amateur astronomers. Starry Night Deluxe allows the user to display the day or night time sky not only from any location on or around the earth but from anywhere in the solar system and beyond. The sky is presented to you in "real time" but can also be fast forwarded or backed up minutes, hours or even centuries to simulate astronomical events at any time during history (or the future).Starry Night Deluxe will install a "star catalog" up to a certain star brightness on your hard drive however if you leave the SND CDROM in your player it will refer to a much larger catalog listing enabling you to view fainter and fainter stars. Especially interesting is the ability to display multiple windows or views of a particular "event" from multiple locations in real time ...for instance being able to view a total solar eclipse from the path of totality, from the moon (looking towards the earth) and also from the Sun itself. Other features include plotting of orbits and inputting of new astronomical orbit data.There is a whole host of options and customizations available, one of which is the darkness of the sky (eg. light pollution). Other options include field of view, location of viewer and many, many others. Custom star charts can also be printed (black stars) on white background, with names and labeling.