User Interface

Data download manager

As of version 2.1.0 Gaia Sky provides an integrated download manager to help visualize and obtain the available data packs and catalogs. Chances are that the download manager is the first thing you see when you launch Gaia Sky for the first time.

The download manager in action

The download manager pops up automatically when Gaia Sky is started if no base data or no catalog files are detected. It can also be launched manually from the preferences window, data tab.

Using the download manager, the user can select whatever datasets she wants, then click download and wait for the download and extract processes to finish. Once done, the data will be available to Gaia Sky the next time it starts.

GUI window

The Gaia Sky GUI is divided into seven panes, Time, Camera, Type visibility, Visual settings, Datasets, Objects, and Music.

User interface with all panes collapsed

Controls window with all panes, except the Time pane, collapsed.

User interface with camera pane expanded

Controls window with the Time pane and the Camera pane expanded.

The seven panes, except for the Time pane, are collapsed at startup. To expand them and reveal its controls just click on the little plus icon plus-icon at the right of the pane title. Use the minus icon minus-icon to collapse it again. Panes can also be detached to their own window. To do so, use the detach icon detach-icon.


You can play and pause the simulation using the play-icon/pause-icon Play/Pause buttons in the Controls window to the left. You can also use Space to play and pause the time. You can also change time warp, which is expressed as a factor. Use , and . to divide by 2 and double the value of the time warp.


In the camera options pane on the left you can select the type of camera. This can also be done by using the Numpad 0-4 keys.

There are five camera modes:

  • Free mode – the camera is not linked to any object and its velocity is exponential with respect to the distance to the origin (Sun).

  • Focus mode – the camera is linked to a focus object and it rotates and rolls with respect to it.

  • Game mode – a game mode which maps the controls wasd + mouse look.

  • Gaia scene – outside view of the Gaia satellite. The camera can not be rotated or translated in this mode.

  • Spacecraft– take control of a spacecraft and navigate around at will.

  • Gaia FOV – the camera simulates either of the fields of view of Gaia, or both.

For more information on the camera modes, see the Camera modes section.

Additionally, there are a number of sliders for you to control different parameters of the camera:

  • Field of view – control the field of view angle of the camera. The bigger it is, the larger the portion of the scene represented.

  • Camera speed – control the longitudinal speed of the camera.

  • Rotation speed – control the transversal speed of the camera, how fast it rotates around an object.

  • Turn speed – control the turning speed of the camera.

You can lock the camera to the focus when in focus mode. Doing so links the reference system of the camera to that of the object and thus it moves with it.


Lock the camera so that it stays at the same relative position to the focus object.

Finally, we can also lock the orientation of the camera to that of the focus so that the same transformation matrix is applied to both.


Lock the orientation so that the camera also rotates with the focus.

Additionally, we can also enable the crosshair, which will mark the currently focused object.

Type visibility

Most graphical elements can be turned off and on using these toggles. For example you can remove the stars from the display by clicking on the stars toggle. The object types available are the following:

  • Stars

  • Planets

  • Moons

  • Satellites, the spacecrafts

  • Asteroids

  • Labels, all the text labels

  • Equatorial grid

  • Ecliptic grid

  • Galactic grid

  • Orbits, the orbit lines

  • Atmospheres, the atmospheres of planets

  • Constellations, the constellation lines

  • Boundaries, the constellation boundaries

  • Milky way

  • Others

By checking the proper motion vectors checkbox we can enable the representation of star proper motions if the currently loaded catalog provides them. Once proper motions are activated, we can control the number of displayed proper motions and their length by using the two sliders that appear.

Visual settings

Here are a few options to control the lighting of the scene:

  • Star brightness – control the brightness of stars.

  • Star size – control the size of point-like stars.

  • Min. star opacity – set a minimum opacity for the faintest stars.

  • Ambient light – control the amount of ambient light. This only affects the models such as the planets or satellites.

  • Label size – control the size of the labels.

  • Elevation multiplier – scale the height representation.


There is a list of focus objects that can be selected from the interface. When an object is selected the camera automatically centers it in the view and you can rotate around it or zoom in and out. Objects can also be selected by double-clicking on them directly in the view or by using the search box provided above the list. You can also invoke a search dialogue by pressing Ctrl + f, / or simply f.


This tab contains all the datasets currently loaded. For each dataset, a highlight color can be defined. The dataset properties window can be used to define arbitrary filters on any of the properties of the elements of the dataset. Datasets can be highlighted by clicking on the little crosshair next to the name, below the color picker.


Since version 0.800b, Gaia Sky also offers a music player in its interface. By default it ships with only a few spacey melody, but you can add your own by dropping them in the folder $GS_DATA/music (see folders).


Drop your mp3, ogg or wav files in the folder $GS_DATA/music and these will be available during your Gaia Sky sessions to play.

In order to start playing, click on the audio-play Play button. To pause the track, click on the audio-pause Pause icon. To skip to the next track, click on the audio-fwd Forward icon. To go to the previous track, click on the audio-bwd Backward icon. The volume can be controlled by scrolling up and down, using the mouse wheel, over the volume indicator. The default volume value is 5%.

Bottom buttons

The buttons at the bottom of the control panel are described here.


With this button minimap you can toggle the minimap window on an off. You can also use Tab.

Load dataset

Use this button dsload to load a new VOTable file (.vot) into Gaia Sky. Refer to the STIL data provider section for more information on the metadata needed for Gaia Sky to parse the dataset correctly.

Preferences window

You can launch the preferences window any time during the execution of the program. To do so, click on the prefsicon Preferences button at the bottom of the GUI window. For a detailed description of the configuration options refer to the Configuration Instructions.


The log button logicon brings up the log window, which displays the Gaia Sky log for the current session. The log can be exported to a file by clicking on the Export to file button. The location of the exported log files is $GS_DATA (see folders).


The help button helpicon brings up the help dialog, where information on the current system, OpenGL settings, Java memory, updates and contact can be found.


Click on the cross icon to exit Gaia Sky. You can also use Esc.

Spacecraft UI controls

The spacecraft mode UI is described in the Spacecraft mode section.