• Added fonts for Russian, Chinese, and Japanese
• Updated translations
• Fixed date formatting for non-UTF8 locales
• Fixed crash for dates prior to JD -1.5 when local format is used
• Fixed star rendering for Macs with ATI graphics hardware (worked around
  a driver bug in point sprite support.)
• Fixed star glare clipping bug
• Fixed bug that caused some stars to be drawn untextured
• Fixed faster/slower options in the Windows time menu to adjust time by
  10x instead of 2x
• Fixed translation of time acronyms DST and STD
• Use localized versions of start script, guide, demo, license, and controls
  file from locale directory
• Fixed Windows 98/ME input problem; most keyboard commands weren't working on
  the OSes.
• Made Lua os functions available from celx scripts when access policy is "ask"

Improved rendering:
- Support for specular textures an normal maps for meshes
- Display of eclipse shadows cast onto meshes
- Per-pixel specular lighting for higher-quality specular highlights, i.e. fewer tessellation artifacts. This is especially noticeable with low polygon models with specular materials.
- Normal maps and specular materials can now be applied at the same time, for 'bumpy-shiny' effects
- Simulated scattering, for much more realistic rendering of planetary atmospheres.
- Lunar-Lambert photometric model for more realistic rendering of dust covered bodies such as the moon.
- Support for compressed normal maps; eliminates the need to use huge amounts of texture memory for high quality normal maps.

• Flexible reference frames
  - Celestia now supports flexible reference frames for specifying object trajectories and orientations. This makes it easier to import new objects into Celestia that have orbits defined in some reference frame other than the default ones enforced in 1.4.1.
  - New reference frames:
  - J2000Ecliptic: defined by the ecliptic and equinox of J2000.0. This
  is the default for objects orbiting stars. It may now be specified for
  other objects as well.
  - J2000Equator: defined by the Earth equator and ecliptic of J2000.0.
  - MeanEquator: reference frame defined by the equator of some arbitrary
  object. This was previously the default and only reference frame available
  for solar system bodies that didn't directly orbit stars.
  - BodyFixed: a reference frame that rotates with smoe specified object
  - TwoVector: a flexible system for defining reference frames based on two
  vectors, either a constant vector, object-to-object direction, or
  velocity vector. Useful for local attitude frames (among other things.)
  - Separate reference frames may be defined for the position and orientation
  of an object. As an example, it may be useful to specify the trajectory of
  an Earth-orbiting satellite in an Earth equatorial frame while its attitude
  is specified in an LVLH frame.
  - A new solar system object called a ReferencePoint is available. This is
  useful for defining the origin of a reference frame that doesn't happen
  to lie at the center of a planet, moon, or spacecraft.

• New trajectory types:
  - FixedPosition: For placing an object at a fixed point within its reference
  frame.
  - ScriptedOrbit: Allows the position of an object to be controlled by a Lua
  script.
  - SampledTrajectory: A more flexible version of SampledOrbit, with the option
  to specify single or double precision and cubic or linear interpolation.

• New rotation models:
  - In previous versions of Celestia, all objects rotated uniformly about a
  single axis (with optional precession about the z-axis.) Celestia 1.5.0
  introduces the concept of a generic rotation model, which is some function
  that specifies the orientation of an object over time.
  - Rotation models available in Celestia 1.5.0:
  - FixedRotation: For an object with an orientation that remains fixed
  within its reference frame. This was a notable omission in older version
  of Celestia.
  - UniformRotation: Describes a rotation of a constant rate about a fixed
  axis.
  - PrecessingRotation: UniformRotation plus a precession rate.
  - SampledOrientation: Analagous to SampledOrbit for position.
  SampledOrientation specifies a file of time tagged quaternions which
  are interpolated to give the orientation of an object.
  - ScriptedRotation: Allows the orientation of an object to be controlled
  by a Lua script.

• Galaxies:
  - Catalog improvements:
  - Included the complete local group of galaxies.
  - Updated catalog so that nearly 100% of galaxies now have distances.
  - Added support for custom galaxy templates; created a custom Milky Way
  template with all known galactic arms.
  - Improved appearance of Milky Way as seen from Earth.
  - Accelerated loading of large catalog files by using an improve name index
  (measured over 100x performance increase for 100k+ object catalogs)
  - Implemented distance-based fading of labels.

• Data file updates:
  - Extrasolar planets: added about 50 recently discovered extrasolar planets,
  and revised orbits of known ones based on new data.
  data.
  - Solar System: Added newly discovered outer planet satellites and names
  - Locations: Added new IAU names for features on planets, moons, and asteroids.
  - Near stars: Updated near star catalog with latest data from RECONS
  - Binary stars: Updated the binary orbit data in visual and spectroscopic binary
  catalogs, and included scripts that document the extraction of information
  in scientific data sets for use in Celestia star catalogs.
  - A new set of higher resolution textures was added for the Moon and several
  satellites of Saturn.

• CELX Scripting improvements:
  - OpenGL drawing commands allow scripts to display custom graphics on screen.
  - ScriptedOrbits and ScriptedRotations provide hooks for objects to be
  positioned and oriented with scripts.
  - The Lua hook mechanism gives CELX scripts the ability to handle mouse,
  keyboard, and tick events.
  - Many other CELX functions to enable scripts to accomplish much of what
  used to be possible only by modifying the Celestia source code.
  - Scripts may now be loaded quickly from the new Scripts menu.
  - Updated CELX interpreter from Lua 5.0 to Lua 5.1

• Accuracy
  - Established Barycentric Dynamical Time (TDB) as the time scale used
  internally by Celestia.
  - Established the origin of Celestia's coordinate system as the Solar System
  Barycenter and the reference frame as J2000 ecliptical.
  - Fixed support for JPL ephemerides. It is now posible to use the JPL
  DE405 and DE406 ephemerides whenever extremely accurate positions for
  the Moon and planets are required.
  - Added an orbit for the Sun around the solar system barycenter

• SPICE support:
  Celestia can now use extremely accurate planet orbits and spacecraft
  trajectories available in SPICE SPK files from JPL.

• Orbit rendering
  - Orbits are now properly depth sorted with respect to other solar system
  objects. They are no longer improperly drawn in front of objects that they
  are behind, and vice versa.
  - The jittering of orbit paths viewed at close distances has been reduced
  - Cubic splines are used to reduce the appearance of sharp angles in between
  orbit segments. This also has the effect of placing the rendered orbit path
  much closer to the the actual orbit path.
  - Star orbit paths are now shown, and may be toggled on and off indepently
  of the orbits for other objects.

• Translation:
  - Windows version finally supports multiple languages
  - New translations: Ukrainian, Russian, Arabic, Dutch, Chinese, Korean,
  Bulgarian.
  - All other languages updated
  - Added translations for constellations names.

• Miscellaneous
  - Added dynamic star labeling
  - Added support for labeled markers and new marker symbols
  - Enhanced InfoURLs so that they can refer to local files.
  - Added the capability to show reference vectors for objects, including
  frame axes, body axes, velocity vector, and sun direction.
  - Made label and line colors customizable via script.
  - Bound Shift+K and Shift+L to reduce or increase the time rate by a
  factor of 2.

• Annoying bugs fixed:
  - Fixed the video recording rate on Windows
  - Bad calculation of specular exponent when loading 3DS models. This caused
  models with specular materials to look very different in Celestia than they
  did in 3D modeling software.
  - Fixed precision problems that caused location labels to disappear and
  jitter at close range.
  - Implemented more robust handling of script errors so that they don't
  cause Celestia to crash.
  - Allow scripts to run before the first frame is rendered so that they can
  set the starting observer position.
  - Switched to double precision for rotation and precession periods; among
  other things, this keeps synchronous rotators from drifting out of sync.
  - Implemented adaptive tesselation for comet tails based on their size on
  screen. This makes comet tails appear smooth when seen up close.
  - Clamped the simulation time to prevent going too far into the past or future.
  - Fixed the cmod loader to work properly on 64-bit systems. A nasty bug was
  preventing 64-bit Linux versions of Celestia from displaying spacecraft.
  - Fixed problems with the displayed time rate getting out of sync with the
  actual time rate.