Geodesium is the name of a music project by composer and recording artist Mark C. Petersen. The word is formed by combining the terms "geodesic dome" and "planetarium" and refers to the space music Petersen creates specifically for use as scores for planetarium shows.

Peteresen has produced soundtracks for over 50 planetarium shows performed in installations in 28 countries around the world. He has performed several live music shows in planetariums in the USA and the UK as well, but he considers his work to be a studio creation and not particularly well-suited to live performances, as his music features multiple electronic musical instruments, difficult to operate in real time. Read more on Last.fm. User-contributed text is available under the Creative Commons By-SA License; additional terms may apply.