Review

Planetarium software: a comparative review

A Planetarium package is a sky visualising program, that simulates the movements of the stars, planets and other objects across the night sky. The benefit is obvious, no excursions required. Students and teachers have access to the visible universe on their desktop.

The quality varies widely in terms of what is available, especially in the shareware/freeware category. The older it is, in general the poorer the quality, due to the limited display and processor power that the early versions had to contend with. The basic features these days include: toggles, labels, constellation lines, etc; zooming in and out; animation; set location of observer; limit stars by magnitude; mouse driven; click on object for information, eg. a star's magnitude. A quick straw pole of Australian academics revealed how they considered them useful to:

• give a basic knowledge of the sky: constellations etc (1st yr);
• visualise the sky as a sphere rotating about an axis through the poles (1st yr);
• generate finding charts for observing (4th yr);
• learn how the constellations and planets and the moon move across the sky, using the ability to quickly change the time of observation within the program;
• explore astronomical phenomena
• demonstrate the changing aspect of the night sky in lectures.

What can be learned depends in part on the features provided, but also on the imagination of teacher or student. Whilst no replacement for observations, it can be a cheaper alternative for undergraduate classes.

A rough comparison was done with the following scale used;
*=poor, **=average, ***=good & 1/2 in between.

This was judged on content (information available), manuals and online help, interface (menus, pop-lists, mouse button use), and screen issues (animation speed, toggles). Short comments list the pros and cons of the packages. As one would expect, Windows programs tend to be better than the DOS equivalents as these were written later for machines with better graphic and computational capabilities. However, not all of the Windows programs make the most of what is available to them.

Earth Centred Universe ***
Pros: select & zoom, click on object for information, onscreen angular separation measurements, telescope driver, centering view on object.
Cons: not able to automatically reset time/position after animations, some features disabled in shareware.

Home Planet ***
Pros: satellite tracking, telescope or horizon display, huge object catalogue - linked to displays.
Cons: manual setting of time zone in autoexec.bat, multiple windows a nuisance, no printing facilities.

CyberSky **
Pros: easy to use interface, printing
Cons: content poor, no star labels, no zoom feature.

Mystars! **
Pros: can add locations and comets, extinction effects near horizon included
Cons: constant registration reminder, animation interface awkward, update patch doesn't work.

Planet Watch **
Pros: very simple interface.
Cons: not full sky - ecliptic only with planets motion, prints emphemeris only.

SkyGlobe (Win) ***
Pros: excellent zoom feature (object labels appear as you move in), 'turbo' zoom and pan, printing maps.
Cons: too many buttons - cluttered screen, no information on objects.

Astro * 1/2
Pros: can print or produce gif output, neat button interface, zoom feature.
Cons: no labels for stars.

Starry (Starry Nights) **
Pros: can label objects manually, prints charts, select object to centre, drawing feature with mouse.

Page Maintained By: PhySciCH@mail.usyd.edu.au
Last Update: Monday, 30-Apr-2012 15:41:57 EST
URL: http://science.uniserve.edu.au/newsletter/vol6/pope.html