More than 2 billion gallons of water circulate everyday beneath New York City. COSMO is a movable artifact, made out of customized irrigation components, to make visible and enjoyable the so-‐far hidden urbanism of pipes we live by. An assemblage of ecosystems, based on advanced environmental design, engineered to filter and purify 3.000 gallons of water; eliminating suspended particles and nitrates, balancing the PH, and increasing the level of dissolved oxygen. The United Nations estimates that by 2025 two thirds of the global population will live in countries that lack sufficient water. COSMO is designed as both an offline and an online prototype. Its purpose it to trigger awareness, and to be easily reproduced all around the world, giving people access to drinking water, and to a dialogue about it. But above all, COSMO is a party-‐artifact that moves to go there wherever the party happens. It is a device meant to gather people together, as pleasant and climatically comfortable as a garden and at the same time as visually rich as a mirrored disco ball. As a result of a complex biochemical design, its stretched-‐out plastic mesh glows automatically whenever its water has been purified. With COSMO, the party is literally lit up every time the environment is being protected.