Reviewed in the April, 1999 edition of Sky & Telescope.
|Calculates and displays the positions of Jupiter's four main (Galilean) moons - Io, Europa, Ganymede and Callisto for any date and time|
|Provides timezone support based on a PC's time, date and timezone settings and takes account of Daylight Savings Time|
|Displays side-on view as it would be seen through one of three optical configurations (Binoculars, Astronomical Telescope, Star Diagonal) and plan view of Jovian system|
|Displays the selected Date, Time and optical configuration|
|Calculates the Longitude of Jupiter's Central Meridian for both equatorial (System I) and non-equatorial (System II) zones and displays these figures|
|Displays the numerical distances of the four moons (in Jupiter radii) from Jupiter - both East-West and North-South distances are given|
|Calculates and displays satellite tracks for a specified month and year and can provide a printout of the tracks|
|Calculates and displays the Great Red Spot Transit times for the specified month and year and can provide a printout of the transit times|
|Animates Jovian system using a user-specified interval|
|Provides real-time option which updates positions and figures (based on system clock)|
|Allows magnification of the side-view display|
|Provides a Northern/Southern Hemisphere switch|
|NOTE: The JupSat95 window can be moved around the screen by clicking on the JupSat95 title, holding the left mouse button down and dragging the window across the desktop.|
Across the top of the screen is the menu bar.
Below this is the graphic side-on view of the Jovian system. The satellite and Jovian disks are drawn to scale, as are the satellites' distances from Jupiter (within screen resolution limits).
At the bottom right of the screen is the plan view of Jupiter and its satellites (again drawn to scale). Each satellite is represented by a different colour in both graphics windows: (Io - White; Europa - Yellow; Ganymede - Red; Callisto - Blue).
Three panels sit at the bottom left of the screen. The top-left panel shows the date and time for which the calculations were performed along with the optical configuration represented in the side-on view.
The top right panel shows the Longitudes of Jupiter's Central Meridian for the equatorial (System I) and non-equatorial (System II) zones.
The bottom panel displays data for Jupiter's satellites. This consists of each satellite's distance from Jupiter (north-south and east-west distances, measured in multiples of Jupiter's radius) and the angle of Inferior Conjunction for each satellite. Inferior Conjunction occurs at zero (0) degrees, i.e. when a satellite is directly behind Jupiter. The angles are measured westward from this point, going to 90 degrees West, 180 degrees West (when the satellite is immediately in front of Jupiter, to 270 degrees West and finally back to zero. In addition, the compass directions relating to the optical configuration chosen are shown at the top left of this panel.
|Increase the magnification in the side-view window|
|Decrease the magnification in the side-view window|
|Start Jovian system animation|
|Stop any currently running animation|
|Put the application into realtime mode - uses the system clock|
|Display satellite tracks for the selected month and year|
|Set display for Northern Hemisphere|
|Set display for Southern Hemisphere|
|Display JupSat95 Help. This calls up the help file in the default web browser|
|Display About window. Contains application version number, copyright and contact details|
|Print the satellite tracks or GRS transit times for the current month and year|
|Display the Great Red Spot transit times for the selected month and year|
|Set the Tracks or GRS transit times window to Local Time|
|Set the Tracks or GRS transit times window to Universal Time|
|Display the Great Red Spot longitude window|
Calculations for any date and time can be performed (both Julian and Gregorian Calendars). Once any component of the date/time has been entered, the display updates automatically. The Now button resets the date and time to that of your PC's system clock.
Supports different timezones using the date, time and timezone settings on your PC, was added in V1.11. (Previously, positions were calculated only for GMT). Daylight Savings Time is taken account of. The Satellite Tracks and Great Red Spot transit times can be calculated for either Universal Time (GMT) or Local Time (time on your PC).
Three optical configurations are provided by the application - the view as seen through binoculars, as astronomical telescope and a star-diagonal. Both the side-view and plan-view displays update when a different optical configuration is chosen. The default is that through binoculars.
The view through an Astronimical Telescope is now the default view.
Using, and , the side-view display can be magnified and reduced to give a closer / more remote view of Jupiter and its satellites. Magnification can be performed at any stage, including during animations.
Clicking the icon brings up a small dialog box into which the user can enter an increment value (in minutes) which determines the time between each successive calculation. Pressing the ENTER key causes the satellites to be plotted in the two display windows continuously, thus providing an animation effect. (All numerical data is updated continuously as well.) The bigger the increment the faster the satellites will appear to orbit Jupiter. Animation continues until is clicked.
The ESC key can be used to escape from the interval window without any changes taking place.
The animation begins from the time and date currently in the time and date controls onscreen.
|Clicking produces a satellite track diagram for the selected month and year. Each satellite track is drawn in a different colour. (Io - white; Europa - Yellow; Ganymede - Red; Callisto - Blue).
Satellite tracks can be displayed, starting at 00:00:00 in either Universal Time or Local Time. The current time setting is indicated by one of two icons: for Universal Time and for Local Time. The mode can be toggled by clicking on whichever time icon is currently displayed. The diagram is automatically updated when the mode is changed.
Satellite tracks are displayed in a manner which reflects the optical configuration selected on the main screen. In magazines, the tracks are printed to conform to a view through an astronomical telescope or Star Diagonal (East at right). JupSat95 can display the tracks as they would appear through Binoculars (East at left).
Dates for every second day in the month are printed down the left of the diagram. Days are shown against alternate black and dark-grey backgrounds.
The diagram can be printed (and on colour printers is colour coded). Alternate light and dark shading is used on the printout to show successive days. Each track is labelled with the appropriate satellite name. The diagram is headed with the month and year that the printout covers and dates run down the left side of the diagram.
Printouts include the optical configuration for which the tracks diagram is to be used and the time mode (UT or Local).
On screens with resolutions of 640x480 or 800x600, the Tracks window is placed modally over the main JupSat95 window (at the right) and it must be closed before any other operations can be performed on the main application screen.
On screens with a resolution of 1024x768 and above, the Tracks window is placed to one side of the main application (which side depends on the position of JupSat95 on the screen) but operations can be performed on the main application screen. Most noteable is the immediate update of the Tracks window when the month or year is changed on the main screen.
The tracks diagram (if it is visible) is updated whenever the month/year changes during an animation run. This ensures that the Tracks diagram is always correct for the month and year combination on the main screen.
JupSat95 also updates the tracks diagram (if it is visible) whenever the Now button is pressed.
|Clicking produces a table of GRS transit times for the selected month and year. This is an entirely new feature in JupSat95 V1.11.
The table can be produced for either Universal Time or Local Time. As with the Tracks window, the current time setting is indicated by one of two icons: for Universal Time and for Local Time. The mode can be toggled by clicking on whichever time icon is currently displayed. The table is automatically updated when the mode is changed.
The Great Red Spot's longitude changes over time and will need to be updated at some stage. Clicking the icon will bring up the GRS longitude editing window. Any change made is retained for future runs of the application. Pressing ENTER recomputes the transit times for the new longitude. Pressing ESC closes the window without effecting any changes. Jovian System II longitudes are used within the calculations.
Dates for every day in the month are printed down the left of the diagram. Days are shown against alternate black and dark-grey backgrounds.
The table can be printed. Alternate light and dark shading is used on the printout to show successive days. The printout is headed with the month and year, the time mode (UT or Local) and the Great Red Spot longitude used for the calculations.
On screens with resolutions of 640x480 or 800x600, the GRS Transits window is placed modally over the main JupSat95 window (at the right) and it must be closed before any other operations can be performed on the main application screen.
On screens with a resolution of 1024x768 and above, the GRS Transits window is placed to one side of the main application (which side depends on the position of JupSat95 on the screen) but operations can be performed on the main application screen. Most noteable is the immediate update of the transit times when the month or year is changed on the main screen.
If the GRS Transits window is visible during an animation run, the transit times are automatically updated to reflect any change in the month or year. This ensures that the GRS Transit times are always correct for the month and year combination on the main screen.
V1.11 updates the GRS Transit times window (if it is visible) whenever the Now button is pressed.
V1.12 introduced a Northern/Southern Hemisphere switch on the main JupSat95 Toolbar. The Northern hemisphere is represented by the icon and the Southern by . Clicking the icons toggles between one and the other. The compass and satellite views are updated accordingly. My thanks to Geoff Hitchcox in New Zealand for this suggesttion.
Colour applies particularly to the satellites as drawn in the display windows and their numerical information.
On screen, Io is white; Europa, yellow; Ganymede, red and Callisto, blue. Numerical information is normally printed in light blue.
On colour printers, Io is drawn in black, Europa in green , Ganyemde in red and Callisto in Blue.
If, when using the magnification option, some satellites move out of the side-view display window, they will not be drawn. The corresponding numerical information of any such satellite will then be printed in black.
When a satellite is transiting Jupiter, (passing in front of Jupiter's disk), then it's numerical information is printed in Yellow.
Finally, if a satellite is being occulted by Jupiter, (behind Jupiter's disk), it's corresponding numerical information is printed in Navy.
|V1.1||Bug Fix: The labels for System I and System II Central Meridians were reversed.
Bug Fix: When closing Tracks form, the time and date were reset to current time/date.
Bug Fix: Minutes > 59 no longer allowed. Seconds > 59 no longer allowed.
New: Calculation of Great Red Spot transit times for selected month/year.
New: Printout of GRS transit times for month/year available.
New: User update of GRS Longitude.
New: Tracks Window and GRS Window will update if the month changes when in animation mode or Now button pressed.
New: Tracks and GRS Windows can be toggled between UT and Local Time.
New: Timezone support added. Daylight Savings Time taken account of.
New: Default optical configuration is now Astro Scope.
New: Tracks window now reflects optical configuration chosen. Printout is the same.
New: Help file updated with new information and features.
|V1.11||Bug Fix: JupSat95 now works correctly on Windows which use the 'Large Fonts' setting.
New: The colour used to represent Callisto was changed from mid-blue to light blue (some users found mid-blue almost invisible on their monitors).
|V1.12||Bug Fix: Tracks diagram failed to update correctly when switching optical configurations (this bug only manifested itself in modes < 1024x768 although it did occur in all resolutions).
Bug Fix: Running an animation caused the clock to reset to UTC instead of maintaining local time (occurred on non-GMT timezones).
Bug Fix: When the Stop button was clicked after doing animation, and JupSat95 was in RealTime mode before doing the animation, the clock would reset to the PC's current time.
Bug Fix: If a date/time control was clicked after doing animation, the time and central meridian values would change somewhat unpredictably.
New: Coloured dots have been added alongside the satellite names to indicate each satellite's colour in the satellite display windows.
New: Added a North/South hemisphere switch to the main application window which flips compass directions in E/W.
|V1.13||Bug Fix: Tracks screen no longer prints same diagram for local time and Universal Time.
New: Date and time controls are now disabled when in realtime mode so time editing is not allowed.
|V1.14||Bug Fix: Satellite tracks diagram correctly reflects the orientation of the satellites in the southern hemisphere for chosen optical configuration. The same fix was applied to the satellite tracks printout.|
JupSat95 is a shareware application. However, it will not become crippled at some future date or after some indeterminate number of uses. The author leaves it to the good graces of those using the application to consider donating to him a small stipend of IR£5, STG£5 or US$5.
Corporate users must register the software after an evaluation period of 21 days. Payments must be as indicated above.
Cheques, Postal Orders, Money Orders should be made payable to (or notes sent to):
54a Landscape Park
The author welcomes comments or suggestions on JupSat95 (and reports of any bugs you might find) and can be contacted via his web page:
Dublin Night Sky Observer
or directly at: firstname.lastname@example.org
Download the latest version of JupSat95 (V1.14) here: