Once you have selected an object to follow (see Selecting an object for instructions), the Interactive Night Sky Map will locate the object in the sky and provide handy information for viewing it.
The object itself is marked and named in the sky, even at times when it is not visible. The curved line represents the object's apparent path across the sky during the selected date (noon to noon), as seen from the selected location. The solid portion of the line shows the object's movement before the currently shown point in time; the dotted portion shows its movement after that moment. The path line can be switched on or off in the Settings.
Note: The path line always covers a 24-hour period (noon to noon). By far most of the object's apparent movement is caused by the Earth's rotation. However, since the planets and the Moon are in constant motion and the Sun also shifts its apparent position each day in relation to the Earth, their position in the sky changes slightly from one noon to the next. For this reason, the beginning and end of the path line may not join up. While the planets only move very slightly in relation to the stars during 24 hours, some celestial objects, such as the Moon, cover a comparatively large daily distance, causing a clearly visible gap between the beginning and end of the path line. This is not an error but a realistic representation of their actual movement.
The info box on the left shows
- the object's name,
- rise, set, and best viewing times (if applicable),
- its altitude and direction at the selected moment,
- an abbreviation of the general compass direction (N = north, E = East, S = South, W = West),
- a verbal, color-coded indication of the viewing conditions, and
- an icon indicating if the planet is visible to the naked eye or if you need binoculars or a telescope to see it. (Binoculars are displayed if the apparent magnitude is 5-10 mag; a telescope is shown if it is greater than 10. Both magnitude figures are adjusted for atmospheric absorption, based on an extinction coefficient of 0.25.)
Click on the Rise, Best, or Set times to jump to that moment in the animation.
Please see Object visibility for more information about object brightness and viewing conditions.