diff --git a/modules/skybrowser/include/pair.h b/modules/skybrowser/include/pair.h
index 450a97d214..cd619e6632 100644
--- a/modules/skybrowser/include/pair.h
+++ b/modules/skybrowser/include/pair.h
@@ -45,55 +45,66 @@ public:
     // user-defined copy assignment (copy-and-swap idiom)
     Pair& operator=(Pair other);
 
-
-    void lock();
-    void unlock();
-    void setImageOrder(int i, int order);
-    void removeHighlight(glm::ivec3 color);
+    // Target & Browser
+    void initialize();
+    // Highlighting
+    void removeHighlight(glm::ivec3 color); 
     void highlight(glm::ivec3 color);
-    void setEnabled(bool enable);
-    void disable();
-    
+    // Animation
     void startAnimation(glm::dvec3 coordsEnd, float fovEnd, bool shouldLockAfter = true);
-    void centerTargetOnScreen();
     void incrementallyAnimateToCoordinate(double deltaTime);
     void incrementallyFade(float goalState, float fadeTime, float deltaTime);
-    bool hasFinishedFading(float goalState);
-    bool isCoordOnPair(glm::vec2 mousePosition);    
-    bool isEnabled();
-    bool isLocked();
 
-    void initialize();
-    glm::ivec3 borderColor();
-    glm::dvec3 targetDirectionEquatorial();
-    glm::dvec3 targetDirectionGalactic();
-    std::string browserGuiName();
-    const std::string& browserId() const;
-    const std::string& targetId() const;
-    float verticalFov();
-    const std::deque<int>& getSelectedImages();
-    void selectImage(const ImageData& image, const int i);
-    void removeSelectedImage(const int i);
-    void loadImageCollection(std::string collection);
-    void setImageOpacity(const int i, float opacity);
+    // Browser
     void sendIdToBrowser();
     void updateBrowserSize();
+
+    // Target
+    void centerTargetOnScreen();
+    void lock();
+    void unlock();
+
+    // Boolean functions
+    bool hasFinishedFading(float goalState) const;
+    bool isCoordOnPair(glm::vec2 mousePosition) const;
+    bool isEnabled() const;
+    bool isLocked() const;
+
+    // Setters
+    void setEnabled(bool enable);
     void setIsSyncedWithWwt(bool isSynced);
 
+    // Getters by value 
+    float verticalFov() const;
+    glm::ivec3 borderColor() const;
+    glm::dvec3 targetDirectionEquatorial() const;
+    glm::dvec3 targetDirectionGalactic() const;
+    std::string browserGuiName() const;
+    std::string browserId() const;
+    std::string targetId() const;
 
+    // Getters by reference
     ScreenSpaceSkyTarget* getTarget();
     ScreenSpaceSkyBrowser* getBrowser();
+    const std::deque<int>& getSelectedImages() const;
     
+    // WorldWide Telescope image handling
+    void setImageOrder(int i, int order);
+    void selectImage(const ImageData& image, int i);
+    void removeSelectedImage(int i);
+    void loadImageCollection(const std::string& collection);
+    void setImageOpacity(int i, float opacity);
+
+    // Comparision operators
     friend bool operator==(const Pair& lhs, 
                            const Pair& rhs);
     friend bool operator!=(const Pair& lhs, 
                            const Pair& rhs);
 
 private:
-
     static std::string _selected;
-    bool isTargetFadeFinished(float goalState);
-    bool isBrowserFadeFinished(float goalState);
+    bool isTargetFadeFinished(float goalState) const;
+    bool isBrowserFadeFinished(float goalState) const;
 
     ScreenSpaceSkyTarget* _target{ nullptr };
     ScreenSpaceSkyBrowser* _browser{ nullptr };
diff --git a/modules/skybrowser/src/pair.cpp b/modules/skybrowser/src/pair.cpp
index b3ab88a070..7494d5349a 100644
--- a/modules/skybrowser/src/pair.cpp
+++ b/modules/skybrowser/src/pair.cpp
@@ -130,7 +130,7 @@ namespace openspace {
         _target->highlight(color);
     }
 
-    bool Pair::isTargetFadeFinished(float goalState)
+    bool Pair::isTargetFadeFinished(float goalState) const
     {
         // Is fading finished?
         float targetDiff = abs(_target->opacity() - goalState);
@@ -138,13 +138,13 @@ namespace openspace {
         return targetDiff < FadeThreshold;
     }
 
-    bool Pair::isBrowserFadeFinished(float goalState)
+    bool Pair::isBrowserFadeFinished(float goalState) const
     {
         float browserDiff = abs(_browser->opacity() - goalState);
         return browserDiff < FadeThreshold;
     }
 
-    bool Pair::isCoordOnPair(glm::vec2 mousePosition)
+    bool Pair::isCoordOnPair(glm::vec2 mousePosition) const
     {
         const bool onBrowser = _browser->coordIsInsideCornersScreenSpace(mousePosition);
         const bool onTarget = _target->coordIsInsideCornersScreenSpace(mousePosition);
@@ -164,12 +164,12 @@ namespace openspace {
         _target->setEnabled(enable);
     }
 
-    bool Pair::isEnabled()
+    bool Pair::isEnabled() const
     {
         return _target->isEnabled() && _browser->isEnabled();
     }
 
-    bool Pair::isLocked()
+    bool Pair::isLocked() const
     {
         return _target->isLocked();
     }
@@ -182,42 +182,42 @@ namespace openspace {
         _browser->updateBorderColor();
     }
 
-    glm::ivec3 Pair::borderColor()
+    glm::ivec3 Pair::borderColor() const
     {
         return _browser->borderColor();
     }
 
-    glm::dvec3 Pair::targetDirectionEquatorial()
+    glm::dvec3 Pair::targetDirectionEquatorial() const
     {
         return _target->equatorialAim();
     }
 
-    glm::dvec3 Pair::targetDirectionGalactic()
+    glm::dvec3 Pair::targetDirectionGalactic() const
     {
         return _target->directionGalactic();
     }
 
-    std::string Pair::browserGuiName()
+    std::string Pair::browserGuiName() const
     {
         return _browser->guiName();
     }
 
-    const std::string& Pair::browserId() const
+    std::string Pair::browserId() const
     {
         return _browser->identifier();
     }
 
-    const std::string& Pair::targetId() const
+    std::string Pair::targetId() const
     {
         return _target->identifier();
     }
 
-    float Pair::verticalFov()
+    float Pair::verticalFov() const
     {
         return _browser->verticalFov();
     }
 
-    const std::deque<int>& Pair::getSelectedImages()
+    const std::deque<int>& Pair::getSelectedImages() const
     {
         return _browser->getSelectedImages();
     }
@@ -236,17 +236,17 @@ namespace openspace {
         }
     }
 
-    void Pair::removeSelectedImage(const int i)
+    void Pair::removeSelectedImage(int i)
     {
         _browser->removeSelectedImage(i);
     }
 
-    void Pair::loadImageCollection(std::string collection)
+    void Pair::loadImageCollection(const std::string& collection)
     {
         _browser->loadImageCollection(collection);
     }
 
-    void Pair::setImageOpacity(const int i, float opacity)
+    void Pair::setImageOpacity(int i, float opacity)
     {
         _browser->setImageOpacity(i, opacity);
     }
@@ -293,7 +293,7 @@ namespace openspace {
         startAnimation(viewDirection, currentFov, false);
     }
 
-    bool Pair::hasFinishedFading(float goalState)
+    bool Pair::hasFinishedFading(float goalState) const
     {
         return isTargetFadeFinished(goalState) && isBrowserFadeFinished(goalState);
     }