KStars keeps track of thousands of comets and asteroids. It uses orbital data published by NASA's Jet Propulsion Laboratory (JPL); these data are known as "orbital elements". Because these small bodies are easily perturbed as they wander about the solar system, their orbital elements must be updated regularly. Updating the elements will also add any recently-discovered bodies. How to update the orbital elements of comets and asteroids: -=( 1 )=- The Easy Way. Start KStars, then open the "Get New Stuff" Tool by selecting "Download Data..." from the File menu, or by pressing Ctrl+D. If a new "ephemerides" package is available, select it and press the Install button. Voila! If the "ephemerides" package available from the "Get New Stuff" Tool is too old, you can use the menu items under "Settings" > "Updates" to download the last ephemerides from NASA's Jet Propulsion Laboratory website. -=( 2 )=- Doing it Manually. It is possible that the ephemerides package is not completely up-to-date. Fortunately, it's relatively simple to update the files manually whenever you want. ::NOTE:: If you find that the ephemerides package is woefully outdated, and you follow this manual-install procedure, PLEASE send your final comets.dat and asteroids.dat files to kstars-devel@kde.org! Now is your chance to be a KStars Hero! Step 1: The Comets You can use the following command to download comets.dat file from JPL website : wget -O comets.dat --post-data="obj_group=all&obj_kind=com&obj_numbered=all&OBJ_field=0&OBJ_op=0&OBJ_value=&ORB_field=0&ORB_op=0&ORB_value=&combine_mode=AND&c1_group=OBJ&c1_item=Af&c1_op=!%3D&c1_value=D&c2_group=OBJ&c2_item=Ae&c2_op=!%3D&c2_value=SOHO&c_fields=AcBdBiBgBjBlBkBqBbAiAjAgAkAlApAqArAsBsBtCh&table_format=CSV&max_rows=10&format_option=full&query=Generate%20Table&.cgifields=format_option&.cgifields=field_list&.cgifields=obj_kind&.cgifields=obj_group&.cgifields=obj_numbered&.cgifields=combine_mode&.cgifields=ast_orbit_class&.cgifields=table_format&.cgifields=ORB_field_set&.cgifields=OBJ_field_set&.cgifields=preset_field_set&.cgifields=com_orbit_class" http://ssd.jpl.nasa.gov/sbdb_query.cgi Delete or comment (with a '#') the first line. Finally, copy your modified "comets.dat" to ~/.kde/share/apps/kstars/ (for a single-user install) or $KDEDIR/share/apps/kstars/ (for a system-wide install). Step 2: The Asteroids You can use the following command to download asteroids.dat file from JPL website : wget -O asteroids.dat --post-data="obj_group=all&obj_kind=ast&obj_numbered=num&OBJ_field=0&ORB_field=0&c1_group=OBJ&c1_item=Ai&c1_op=%3C&c1_value=12&c_fields=AcBdBiBhBgBjBlBkBmBqBbAiAjAgAkAlApAqArAsBsBtCh&table_format=CSV&max_rows=10&format_option=full&query=Generate%20Table&.cgifields=format_option&.cgifields=field_list&.cgifields=obj_kind&.cgifields=obj_group&.cgifields=obj_numbered&.cgifields=combine_mode&.cgifields=ast_orbit_class&.cgifields=table_format&.cgifields=ORB_field_set&.cgifields=OBJ_field_set&.cgifields=preset_field_set&.cgifields=com_orbit_class" http://ssd.jpl.nasa.gov/sbdb_query.cgi Delete or comment (with a '#') the first line. Finally, copy your modified "asteroids.dat" to ~/.kde/share/apps/kstars/ (for a single-user install) or $KDEDIR/share/apps/kstars/ (for a system-wide install). -=( 3 )=- Another way. The last method is to point your browser to the following URL: http://ssd.jpl.nasa.gov/sbdb_query.cgi and generate the file using the form You must select the following columns to make the file compatible with kstars : - for comets 1 full name 2 modified julian day of orbital elements 3 perihelion distance 4 eccentricity of orbit 5 inclination angle of orbit in degrees 6 argument of perihelion in degrees 7 longitude of the ascending node 8 time of perihelion passage 9 orbit solution ID 10 absolute magnitude 11 slope parameter 12 Near-Earth Object (NEO) flag 13 comet total magnitude parameter 14 comet nuclear magnitude parameter 15 object diameter 16 object bi/tri-axial ellipsoid dimensions 17 geometric albedo 18 rotation period 19 orbital period 20 earth minimum orbit intersection distance 21 orbit classification -for asteroids 1 full name 2 Modified Julian Day of orbital elements 3 perihelion distance 4 semi-major axis 5 eccentricity of orbit 6 inclination angle of orbit in degrees 7 argument of perihelion in degrees 8 longitude of the ascending node in degrees 9 mean anomaly 10 time of perihelion passage 11 orbit solution ID 12 absolute magnitude 13 slope parameter 14 Near-Earth Object (NEO) flag 15 comet total magnitude parameter 16 comet nuclear magnitude parameter 17 object diameter 18 object bi/tri-axial ellipsoid dimensions 19 geometric albedo 20 rotation period 21 orbital period 22 earth minimum orbit intersection distance 23 orbit classification The advantage of this method is that you can play with several filters and get a file containing exactly what you want. Don't forget to delete or comment (with a '#') the first line. Finally, copy your files to ~/.kde/share/apps/kstars/ (for a single-user install) or $KDEDIR/share/apps/kstars/ (for a system-wide install).