Make a Panorama
Panorama is a great feature to show space. There are Blender and other free tools to achieve this.
First of all, use the Blender BGC Script to create a Cubic panorama. This wil render six images representing the faces of a cube where the camera is in the center.
Stitching images to panorama
I didn't found any open source solution for this step. So no software for Linux plateform. The solution would be to have a open source software to assemble these 6 images into an equirectangular image.
QTVR panorama can be easily played by Quicktime software but only on Mac and Windows plateforms.
Fortunately, there is a free Java panorama viewer. It's a Java applet called PTViewer. So you can show your panorama to Linux users too (and by the web if you need).
You must use a special version of PTViewer to play QTVR panorama. Here you can donwload a template with all files you need.