Software - Sky Planetarium

As an avid amateur astronomer who also has interests in software development I've worked for many years, on and off, developing this planetarium software. 

This program was designed to be a planetarium simulator with an emphasis on practical usefulness to the average amateur astronomer.  As such, its function ranges from getting aquainted with the constellations and star names to planning observing sessions and controlling your Meade or Celestron telescope through the ASCOM telescope interface.

The latest shareware version of Sky Planetarium handles the imaging requirements of many amateur astronomers too. With built in support for auto-guiding, plate-solving, and image acquisition. Cameras supported include ASCOM cameras, Webcams, and the Meade DSI series. Both Color and B&W cameras are supported with flexible debayering/demosaicing. The imaging console can save images in .bmp .jpg and several variations of the FITS file format. Cameras can even be shared between some tasks in Sky Planetarium (one camera doing both plate-solving and imaging for example.)

ASCOM feature support for telescopes, cameras, focusers, and filter-wheels is fairly extensive. Sky Planetarium also supports observatory operation features like shutter (or roof) control through the Dome interface and Safety Monitor integration. There's even support for emailing status reports for unattended observatory operation. For telescopes, parking support is enabled if available as is homing (among other features.) For cameras support is included for gain setting, readout modes, binning, color, etc.

Goto Assist helps goto telescope mount pointing operation by mathematically modeling the most common geometrical deficiencies of German Equatorial and Fork mounted telescopes. Once setup, a corrected location is calculated prior to issuing any goto commands to improve pointing accuracy. Specifically, the errors compensated for include: offset errors in RA/Dec on both sides of the meridian, polar alignment elevation, polar alignment azimuth, non-perpendicularity of RA/Dec axis/optics, tube flexture, Dec axis flexture, and (if applicable) fork flexture. Models can be saved and loaded. My OnStep telescope mount goto controller uses the same system internally and moving model coefficients between Goto Assist and OnStep is supported. This allows high performance models to be developed and then uploaded into OnStep where the improved pointing accuracy works with other applications (my Android App, Sky Safari, CdC, etc.)

The POI Sequencer allows lists of objects to be compiled for automated imaging runs. You choose the objects, exposure time, filters, etc. and the sequencer will move the 'scope to each object and take the image(s). If plate-solving is configured and enabled it will be used to refine the goto positions.

For my OnStep telescope drive controller additional features are available over what ASCOM allows. These features include help with aligning the mount, real-time display of PEC playback and recording, reading and writing PEC data, tracking rate control, working with object libraries, status information, etc.

Download Sky Planetarium version 4.093, scroll down to see revision history/notes.
Download Prior Sky Planetarium version 3.94 for Windows (Stable, released November 16th '16, as shareware.)

  Versions prior to 3.91 needed to be "Run as administrator" (for Windows Vista and later): THIS IS NO LONGER REQUIRED.
  Versions prior to 4.071 needed the microsoft help viewer (32bit version) installed for help to work: THIS IS NO LONGER REQUIRED.

During installation, Sky Planetarium will prompt you to install certain software before it is installed:
  The ASCOM Platform should be installed.
  Plate-solving requires that Python 2.6.6 be installed.
  If you have a Meade DSI camera you should install those drivers first (Envisage.)

The development notes should give you an idea of the range of features available (updated 5/31/13) in this release, and screen shots are below:

And some screen shots of the current release, available for download below:

Here are some of it's other features:
  • Maps from nearly any time.  From the distant past to the distant future.  See the precession of the Earth's axis and how it affects the stars' position.
  • The Location Tool allows you to quickly choose your geographic location from a map (or a list of cities.)
  • The Time Tool graphically shows sun rise/set and moon rise/set times along with Local time, UT, etc.   It's an analog clock and gives you a nice "feel" for the passage of time and it's effect on the night sky's appearance.
  • The Magnifier Tool shows you what's under the cursor when you point to objects on the main map.  This tool can mimic the view through various telescope/eyepiece combinations.  It can also keep track of points of interest, which are locations you set on the map and can cycle through quickly with the number keys or via a menu selection.
  • The built-in BASIC scripting language includes the ability to pull data from catalogs, control a telescope and take images.
  • Other features include: a calendar of celestial events (computed on-the-fly), simulated sky glow during sun rise/set, fairly accurate planetary positions/depictions... including Jupiter's moons and Saturn's rings.
  • Naturally, help is available throughout the program.

Download Older Versions of "Sky Planetarium"
Sky Planetarium version 3.12 (released Mar 29th '08) (download here)
Sky Planetarium version 3.27 (released Nov 4th '13) (download here)

Version history:
4.0x Fixes/additions:
• 11-23-16: 4.0 Marks moving to latest Delphi Compiler (10.1) Tons of minor modifications, most involving string handling. I also made a few improvements to ASCOM camera handling.
• 11-27-16: 4.01 Many little bug fixes and added some "Points of Interest" features. Mainly this involves displaying telescope/eyepiece and now camera fov indications on the main map which is useful for planning imaging sessions.
• 11-29-16: 4.02 Bug fixes for catalog import tool. Also added "Mv Unknown" type for importing catalogs without object magnitude information.
• 12-3-16: 4.03 Added OnStep "Preferred Pier Side" feature support.
• 12-4-16: 4.04 Sky guide (upper left corner) now has nicer appearance. Fixes to plate solving. Fixed color image file import, looks like canon cr2 files open now. Other minor improvements here and there too.
• 12-13-16: 4.05 Fixed NOVAS Site init. bug for "Planet" position accuracy improvements (esp. for our Moon.)
• 12-15-16: 4.06 Overhauled star display code for more realistic plots.
• 12-16-16: 4.061 Minor adjustments to star display code.
• 12-19-16: 4.062 Bug fix to star Flamsteed no's. Cursor over star now shows more info. including Bayer or Flamsteed no.
• 12-20-16: 4.064 Re-enabled night vision mode (fixed numerous display issues with it.) Fixed telescope align problem with older OnStep versions.
• 12-23-16: 4.071 Reworked/updated help is now in html help format. Fixed date/time terms to agree with modern standards.
• 12-29-16: 4.072 More updates to the help file. Attempt to fix locale issue.
• 1-12-17: 4.073 Added "User Catalog" feature for easily adding objects. Changed installer to NOT overwrite the object database file so custom catalogs should be safe with upgrade installs now. Several minor bug fixes etc. too.
• 1-13-17: 4.074 Added "User Catalog" save/load CSV format.
• 1-13-17: 4.075 Added help to catalog import tool. Minor bug fixes/improvements and added AREA field type to import tool.
• 1-15-17: 4.076 Added AREA field type support to the plotter and Object Information dialog.
• 1-19-17: 4.077 Fixed Goto Assist bug I introduced about 6 months ago, had to do with OnStep LST synchronization. Added support for send/recv. of FF/TF/DF coefficients to OnStep so full pointing models are now supported in OnStep.
• 1-19-17: 4.078 Threw in some Goto Assist improvements and updated help: Goto assist models need info about pointing errors, goto calibration points, these can now be aquired automatically using the sequencer and plate solving.
• 1-21-17: 4.079 Goto Assist fixes. There were differences in the sign of coefficients found by the search routine in SP vs. what OnStep uses. Still need to test more, but searches seem to rapidly converge now. Modeling for EM10 run of six calibration stars (all acquired automatically see 4.078 notes) converged quickly to about 60 arc-seconds RMS.
• 1-22-17: 4.08 Fixes to plate-solve options "Sync and goto again" and "Guide to corrected location". Updated help for plate-solving too.
• 1-22-17: 4.081 More Goto Assist fixes. Found a critical bug, looks better but still need to test.
• 1-25-17: 4.082 Goto Assist improvements. Speed and several other refinements, including keeping user from searching too deep while building models and the ability to show "Goto Calibration points" on the map to help visualize what the model is doing.
• 1-25-17: 4.083 More Goto Assist fixes. This was tested with real stars and is working very well for me now (with the model running in Goto Assist and with the model uploaded to OnStep.).
• 1-26-17: 4.085 Goto Assist UI improvements. Renamed offsets, Dec sign inversion for West offset vs. East allows same correction. Added option for high res. (0.1x FOV) view of model. Updated help to match.
• 2-3-17: 4.086 Goto Assist UI improvements. Added option more resolution options for examining the pointing model performance.
• 2-3-17: 4.087 Fixed recently introduced bug in Plotter (crashes SP.)
• 3-7-17: 4.088 Goto Assist, added "Auto Solve" feature.
• 3-8-17: 4.089 Fixed plate-solve bug involving southern declinations.
• 4-20-17: 4.09/4.091 Added ability to "Quick connect" to several ASCOM devices at once.
• 5-11-17: 4.092 Catalog import tool bug fix.
• 5-12-17: 4.093 User catalog import bug fix. Added ability to add POI's from Find dialog.

3.9x Fixes/additions:
• 11-10-16: 3.9 Reorganization of the Telescope Control dialog and added ability to turn the automatic meridian flip feature on/off. Minor graphic improvements to the UI. Fixes to FITS file import (to support incorrectly formatted FITS files.) Added/updated celestial object images, including those of many Messier objects.
11-11-16: 3.91 Fixes issues which resulted in Sky Planetarium needing to be "run as Administrator". Fixed hover over solar system object accuracy issue. Better constellation name placement. Made some installer tweeks to keep from overwriting user settings.
11-14-16: 3.92 Fixes some annoying directory handling issues. Fixes to indication of preferred align locations for southern hemisphere users.
11-16-16: 3.93 Align status now resides in OnStep. This allows Sky Planetarium to follow/take over alignment from the Android App, etc.
11-16-16: 3.94 Added goto state query for OnStep.

3.8x Fixes/additions:
• 4-13-16: 3.8 Adds remote/unattended observatory control features: ASCOM Dome and Safety support (Dome support limited to open/closing the sutter/roof for now) and Email notifications. SP can close the shutter/roof automatically (on safety triggered events or from the imaging sequencer.) Roof closing can be tied to mount parking and will then wait for a successful park before closing the roof. Provision for sending safety status and imaging progress Emails is included. I also added support to CloudSensorEvoPlus weather monitoring (in addition to it's ASCOM Safety Monitor driver.) This weather information is picked up for the refraction calculations in SP and is also placed into FITS images (and saved) as they are acquired.
4-15-16: 3.81 Drops the built in web-browser in favor of using the default windows web-browser. This is used by the object information dialogs and overcomes javascript problems with SIMBAD.
4-22-16: 3.82: Adds flush() to startup logging to help with debugging.
10-17-16: 3.83: Adds ability choose install location. Adds more flexible multi-star align support for OnStep. Fixes default path to python for plate-solves.
10-18-16: 3.84: Multi-star align fixes for OnStep.
10-27-16: 3.85: Added exception handling to bmp/jpg image format handling, this stops some really annoying crashes. Overall these image types still don't work correctly, but "force-mono" option now allows some functionality. Not critical to OnStep function, all of this is for testing/learning features (Image File Camera).
11-2-16: 3.86: Added tracking rate display for OnStep.
11-9-16: 3.87: Display of object Hour Angle was added to info. dialogs. Minor image catalog handling improvements, including seperating user catalogs from built-in catalogs. This allows user image links (associated with objects) to remain untouched after an update install. I added/updated images for many objects.

3.71x Fixes/additions:
• 3-16-16: 3.71 Adds some OnStep alignment status support. 3.711 Fixes PEC disabled problem. 3.712 Added code to handle more ASCOM exceptions in telescope thread. Adds polar align tool. 3.713 Fixes city database issue.
3.70 Fixes/additions:
• 3-16-16: 3.70 Added support for OnStep error reporting. Fixed some Alt/Az mode issues (trying to get PEC data). Fixed occasional lines across main map.
3.69x Fixes/additions:
• 3-14-16: 3.69 Added support for OnStep's new tracking rate compensation features. 3.691: Fixes ALT/AZ mode OnStep connect problem. 3.692: Fixes to plate solve image scaling.
3.68x Fixes/additions:
• 2-22-16: Again, fixes to closing telescope connection. 3.681 adds middle mouse click un-zooms map, fixes city name Edmonton. 3.682 adds pec improvements. 3.683 Fixes park indication, slows down ASCOM comms a bit. 3.684/5 Fixes more threading issues. 3.686 Made the telescope thread cycle a bit faster. Double-buffered the PEC graph so it doesn't flicker anymore. 3.687 Adds refraction rate tracking control improvements.
3.64/3.65/3.66/3.67 Fixes/additions:
• 2-14-16: Performance/threading related fixes. 3.65 adds scroll wheel support. 3.66 fixes bug closing telescope connection. 3.67 tweeks ASCOM telescope timing.
3.63 Fixes/additions:
• 2-11-16: Added indication of OnStep align areas on the main map.
3.62 Fixes/additions:
• 2-8-16: Added separate thread for ASCOM telescope connection. Fixed recently introduced PEC import/export bug.
3.61 Fixes/additions:
• 2-7-16: Improved sidereal time routine.
3.60 Fixes/additions:
• 2-3-16: Fixed/slightly improved PEC graphic display.
3.58, 3.59 Fixes/additions:
• 1-21-16: Added/fixed error checking for OnStep connect (again for PEC.)
3.57 Fixes/additions:
• 1-17-16: Fixed OnStep UTCOffset upload. Added more error checking to OnStep connect (PEC.)
3.56 Fixes/additions:
• 12-31-15: Reworked telescope sync/align slightly. Added image catalog support for stars. Added object and star lookup online using SIMBAD.
3.55 Fixes/additions:
• 11-11-15: Fix to Bright Limb angle for Moon/Planets, this corrects a bug that crept in while adding NOVAS support a while back.
3.54 Fixes/additions:
• 10-14-15: Fixes to filter-wheel position exposure and focus control. Exposure setting now remains disabled until changed filter position arrives. POI Sequencer and Script BASIC automation features now adjust focus offset with filter-wheel position changes.
Also, refraction rate tracking enable/disable buttons now send the correct commands.
3.53 Fixes/additions:
• 10-8-15: Fixes to OnStep parking behaviour. Telescope dialog is generally more tolerant of communictions errors now too.
3.52 Fixes/additions:
• 8-25-15: Imaging console bug fix, minor improvements to camera error handling.
3.51 Fixes/additions:
• 8-18-15: Minor PEC Improvements, added OnStep PEC index indication.
3.50 Fixes/additions:
• 7-28-15: Added code to correct the aspect ratio of images from cameras' if required (imaging console/plate-solving/guiding/or saved in bmp or jpg formats.) Added x,y coordinate and ADU display to the IC.
Improved ASCOM focuser control, now supports older interface v1... Tested and working with my FLI PDF and OnFocus. Fixed bugs so ASCOM filter-wheel focus offsets work correctly. Also, added more focuser error reporting to the log.
Improvements to application message flow for better stability while imaging (my Quantix camera would periodically disconnect in the IC if OnStep was connected, this is fixed.)
3.41-3.42 Fixes/additions:
• 6-30-15: Bug fix, high precision planetary coordinates were being used only inside the solsys info. dialog. They are now used on the map/finder/calendar too.
• 7-2-15: Bug fix, Planetary moons/rings position.
3.40 Fixes/additions:
• Fixed recently introduced bug related to saving settings. Added Focuser presets and position reporting in mm when available.
3.39 Fixes/additions:
• Fixed bugs related to loading and saving basic language scripts. Added telescope tracking on/off control to scripts. Added telescope connection detection to scripts. Added ability to select imaging camera from scripts. Added optional [date] and [time] to file and directory naming for images.
3.381 Fixes/additions:
• Fixed minor coordinate display bug. Fixed star catalog path bug.
3.38 Fixes/additions:
• Fixed object catalog filtering bug. Added better support for searching star names... "36 Cyg", "Alp And", or "HD 1225" for example. More detailed description of OnStep alignment sequence in help. More detailed description of search features in help.
3.37 Fixes/additions:
• More Plate-Solve bug fixes/improvements, eliminates some "blocking" behaviour for smoother more stable operation. Added commands to Sky Planetarium's Script BASIC programming language to control telescopes and take images.
3.36 Fixes/additions:
• Added ability to directly set Goto Assist calibration point from Plate-Solve. Fixed Plate-Solve bug triggered by a minor protocol change.
3.35 Fixes/additions:
• Added support for OnStep Libraries. Integration of OnStep pointing model with Goto Assist.
3.34 Fixes/additions:
• Faster decoding of monochrome images. Faster histogram code.
3.33 Fixes/additions:
• Better and more flexible support for ASCOM color cameras.
3.32 Fixes/additions:
• Fixed: Imaging console would take an extra exposure before stopping when processing large images.
• Fixed: Object catalog import, precession was broken. Added: support for more user defined object catalogs.
• Fixed: Bias frames are now forced to 0 seconds exposure, if a shutter is available it's kept closed.
3.31 Fixes/additions:
• Fixed: ASCOM telescope guide rate control, now works with simulator. Telescope Pad now groups pulse-guide rates separately from guide rates as a reminder that these can be maintaned separately in OnStep.
• Added: Tool-tip in PEC control to explain features.
3.30 Fixes/additions:
• Added: Support for full OnStep telescope mount control through ASCOM POTH connection.
• Added: Support for OnStep tracking rate settings. Preliminary OnStep PEC controls update to support latest features, ie. PEC Index.
• Added: Sequencer switched to non-modal window for easier control/use.
• Fixed: Sequencer controls imaging-console exposure number correctly now.
• Fixed: Sequencer warning (incorrect imaging parameter) no longer causes hang.
3.291 Fixes/additions:
• Fixes monthly report, slow displaying but it's back to showing the moon phases and progress bar works.
3.29 Fixes/additions:
• Added logging/made fixes in various areas (esp. ASCOM cameras'.)
• Added separate window for telescope guide and focuser control.
• Fixed bug, guide actions sometimes don't stop.
• Fixed bugs in POI sequencer.
3.28 Fixes/additions:
• Fixed bug, POI sequencer etc. too many timers and things happening at once, message handling was stalling causing odd behaviour. Also, reordered sequencer logic to keep messages flowing.
• Fixed bug, settings file loading caused crashes - overflow.
• Fixed bug, internal .bmp file loading for better compatibility with images.
• Help system refresh, all the latest features are now documented and explained. I'm still using the ancient Microsoft Help format. The help viewer is still available to download for even the very latest Windows (8.1) and it does the job.
• Added code to allow the Points of interest Sequencer to actually Park the telescope if the option is set.
• Added features to Camera settings. Already included support for defining telescope optics has been combined with the Camera settings to allow calculation and display of CCD X/Y pixel and field sizes in arc units. This information will eventually be used in many places throughout Sky. For now, the Autoguiding dialog reports the guide star FWHM size/standard-deviation (of recent movements) in arc-seconds (") and the Imaging Console reports the CCD field width and height in arc-minutes (').
• Added telescope current position bullseye and plate-solve markers to the magnifier.
• Plate-Solving, fixed problem with solve starting unintentionally when solve after goto is enabled. Fixed solves repeating.
• Autoguide, improved visualization of guide star. Added option to disable Dec guiding. Adjustable delay between exposures, historical centroid averaging (w/display.) Configure calibration movement amount (seconds of guiding). Various Declination guiding options (Off/Auto/North only/South only/Full).
• ASCOM Telescope, fixed OnStep PEC data handling errors (including better compatibility exporting to EQMOD's PecPrep). Also fixed PEC int overflow error (StepsPerWormRotation.) Clear PEC data now erases the local buffer immediately. PEC data display updates immediately now for data clear and scale changes. PEC maximum buffer length extended to 3384 seconds.
• ASCOM Filterwheel, fixed error trying to query driver info. that's unavailable in ASCOM standard.
• FITS file I/O, fixed a problem with int16 format saves.
3.27 Fixes/additions:
• Fixed open file dialog, now remembers last path.
• Fixed minor accuracy issue involving telescope mount coordinate coversions.
• Fixed object information for the Moon not working (trying to use NOVAS for the Moon, not currently supported).
• POI (Point of Interest) graphics changed for better presentation.
• POI's accuracy improved, now using J2000 coordinates for about ±10 arc-second accuracy with Stars and Deep-Sky objects (use the "Add POI" button in the object information dialogs).
• First release with POI Sequencer, allows object lists to be built for automated gotos/imaging.
• Rewrite of Plate-Solving code "objectized" for better Sequencer integration and eventual integration with the imaging console.
• Object database moved from simple file-based system to SQLite. Support for importing arbitary celestial object catalogs.
3.26 Fixes/additions:
• Corrected a bug that prevents certain ASCOM telescope mounts from using Goto Assist.
• Started a fix for an Auto Guiding problem caused by ASCOM PulseGuide blocking behaviour.
• Internationalization fixes.
3.25 Fixes/additions:
• Logs that were in the various dialogs dealing with telescope control and imaging are now consolidated into one unified log.
• Additional logging of the ascom filter-wheel, focuser, and camera actions was also added.
• Fixed a bug; disconnection from some ascom devices wasn't taking place when closing program.
3.24 Fixes/additions:
• Plate-solving fixes for More robust interaction with Python scripts and more flexible decoding of returned results ( is a moving target!).
• Also, fixes a bug with different versions of Windows not decoding Python command parameters consistantly.
3.23 Fixes/additions:
• Fixed several minor bugs in the Plate Solve system.
• Fixed minor bug with telescope goto/sync accuracy.
• Added Goto Assist, when active applies to all telescope gotos/syncs.
3.22 Fixes/additions:
• Positions of the Major planets are now calculated via the USNO's NOVAS through ASCOM (when available). This improves the positional accuracy for those objects to the sub arc-sec level. Where ASCOM NOVAS is not available or not used (as in Sun, Moon, Comets, and Asteroids) the in-built routines have been updated for modest accuracy improvements. Star and deep sky object astrometry now includes annual aberration and nutation, these object positions should be accurate to something around the ±10 arc-sec level. ASCOM Telescope goto's now include better support for refraction and the ability to send coordinates in LocalTopocentric form, or precessed to B1950, J2000.0, or J2050.0 as requested by the ASCOM driver.
3.21 Fixes/additions:
• Added support for Serial-Port Dtr/Rts control of Philips LX modified web-cams (SC1/SC2). Improved LX capture with "bright frame" detection.
3.20 Fixes/additions:
• Installer is now done, includes the ability to pull together the DSI drivers and register the .NET components to communicate with the DSI family imagers.
• Fixed calendar/date pickers. Calendar was built with Delphi TCalendar component which is no longer available in my version of Delphi. Adapted TStringGrid to do the same thing.
• Added support for Imaging. Camera support includes: ASCOM b/w and color cameras (including CCD temperature control if present). DSI-I and DSI-II mono are tested, color and DSI-III support is experimental. VFW cameras (webcams, including SC modded LX type).
• Added support for ASCOM filter wheels.
• Added support for ASCOM focusers.
• Added Imaging Console for aquiring sequences of images, supports saving in FITS format (several integer and floating point types) and jpeg or bmp. Moves filter-wheel, adjusts focus, adjusts exposure length, and names files as you specify in sequence. Pre-processing can convert to B/W, invert/mirror the image, and handle various Debayer/Demosaic variations. When previewing the image in the console, you can shrink or stretch the image and overlay several different cross-hairs. Double-clicking gives a highly zoomed area for focusing help.
• Added Plate-Solving (through Figures out where you're at in the sky, easy to setup and use.
• Added Auto-Guiding. Adapts to your camera/optical orientation and issues guiding commands to your ASCOM compativle mount.
• Added Telescope control features. Some are OnStep specific, for example PEC read/write and visualization. While others should work with any mount with an ASCOM driver that supports them. For example, the Home and Park/Un-Park commands. Another general purpose feature is the Goto Assist. This allows you to apply geometric corrections to an equatorially mounted telescope/mount and provides an "improved guess" at where your telescope is actually pointing in the form of an second bullseye marker on the map.
3.12 Fixes/additions:
• Fixed main window sizing issues it now works properly when the Windows Start Menu is positioned anywhere, not just at the bottom of the screen.
The main window now responds properly to being maximized (by loosing it's scroll-bars) on XP and Vista.
• Fixed tool window visual corruption when Windows Start Menu is of large size.
• Updated help system to cover all current features.
• More updates to global location dialog, it now shows a thumbnail of the current horizon image. It's also smarter about saving defaults, it asks to save if you changed something about the location.
3.11 Fixes/additions:
• Added code to preserve image/note associations on re-install or upgrade.
• Fixed bug that caused the loss of image and note associations for celestial object catalog.
• Fixed bug that caused comets and asteroids to sometimes not be displayed in the magnifier.
• Fixed bug in "Celestial Object Information" dialog that caused descriptive text to be hidden when selecting the same object more than once.
• ky now disables access to all location and time setting mechanisms when a telescope is connected.
• Corrected problem with online downloading of elements from the MPC.
• More updates to globe menu/location dialog, misc. small improvements.
3.10 Fixes/additions:
• Added support for the ASCOM telescope interface.
• Corrected Daylight Savings Time routines to current US standard.
• Corrected bug that caused "Early Tonight" time setting to be one day early.
• Corrected bug that crashed program on loading "Points of Interest".
• Added support for online download and display of objects from POSS, etc.
• Misc. improvements for saving/loading Comet and Asteroid elements including online downloading of elements from the MPC.
3.00 First release of the third re-write (from the ground up, Circa 1999) of Sky.

2.0 Second version of Sky (Circa 1993). I think this was written in Borland Pascal 2.0

1.0 First version of Sky (Circa 1992). This was written with Turbo Pascal Windows 1.0 I believe.

Pre-1.0 version of Sky (Circa 1986). This was written in Modula-2 on an (4 MHz) Heathkit H89A running CP/M. I had a fancy graphics card that could plot star maps. It was a slow process. And yes, some bits of code in Sky are still relatives to this version.