Noticed the following on Cruise Mapper's website:
Viking Saturn is one of the world's cruisers (following Cunard's RMS Queen Mary 2) with an onboard planetarium. Named "Explorers' Dome", this theatre-like venue is circular, with capacity 26 seats and located forward on Deck 8, facing Explorers Lounge. It uses the latest video projecting technology to show constellations and other space-related 3D videos on its domed roof.
Hope it's true as it would be an interesting opportunity.