diff --git a/package.json b/package.json
old mode 100755
new mode 100644
index 310dc7b..56c0f76
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "satsim",
-  "version": "0.3.0",
+  "version": "0.4.0",
   "description": "SatSim for JavaScript.",
   "homepage": "https://github.com/ssc-ai/satsimjs/",
   "license": "MIT",
@@ -45,7 +45,7 @@
     "webpack-dev-server": "^4.3.1"
   },
   "dependencies": {
-    "cesium": "^1.111.0",
+    "cesium": "^1.113.0",
     "mathjs": "^11.11.1",
     "satellite.js": "^5.0.0"
   }
diff --git a/src/index.js b/src/index.js
old mode 100755
new mode 100644
index cb12b6e..5a70a68
--- a/src/index.js
+++ b/src/index.js
@@ -1,4 +1,4 @@
-globalThis.SATSIM_VERSION = "0.3.0-alpha"
+globalThis.SATSIM_VERSION = "0.4.0-alpha"
 
 export { default as Universe } from './engine/Universe.js'
 
@@ -30,4 +30,5 @@ export { default as Toolbar } from './widgets/Toolbar.js'
 export { createViewer, mixinViewer } from './widgets/Viewer.js'
 
 export { fetchTle } from './io/tle.js'
-export { southEastZenithToAzEl, spaceBasedToAzEl } from './engine/dynamics/gimbal.js'
\ No newline at end of file
+export { southEastZenithToAzEl, spaceBasedToAzEl } from './engine/dynamics/gimbal.js'
+export { getVisibility } from './engine/geometry/visibility.js'
\ No newline at end of file