Pajamäki Solar System Scale Model

The Pajamäki Solar System Scale Model stretches across Helsinki and Espoo, displaying a 1.4-meter Sun mounted on a 20-meter pole with planets positioned according to their actual distances from the Sun. Earth and its moon appear as holes punched through steel plates, a design change made after the original spherical structures suffered repeated damage.

Amateur astronomer Leo Sulamaa designed this astronomical education model in 1992 using a scale where one millimeter represents 1000 kilometers in space. The project was created to help the general public grasp the enormous distances that separate objects in our solar system.

The installation uses multilingual information panels in Finnish, Swedish, and English to help residents and visitors understand planetary sizes. As people walk through both cities following the model, they gain a sense of how these cosmic distances shape our place in space.

The model spreads across two cities, so exploring it by bicycle or during a long walk works best, though walking distances between planets are significant. Information panels at various locations help you navigate between sites and better understand the scale relationships.

At this scale, light would travel at just 0.3 meters per second, revealing how incredibly fast light actually moves across cosmic distances. One light year would stretch nearly 9,460 kilometers in real distance, putting the universe's speed and scale into perspective.