Located in central New Hampshire’s mountains, Gemma is positioned at the end of a steep, half-mile gravel drive. Characterized by granite bedrock outcroppings and situated at the center of a three-mile radius “dark” landscape with very little light pollution, the exposed site is ideal for sky observation.
The observatory’s design eschews a traditional dome in favor of a synthesized architectural form providing more usable space: a faceted turret, expressed as an extension of the stark surroundings. An unconventional pattern of lock-seamed zinc cladding mediates between the irregular site topography and the building’s geometry, reflecting the building’s orientation to both geological and celestial landmarks. Its dimension, color, and patina engender a material relationship to the gray granite outcroppings that characterize the summit, while its heat transfer capability facilitates sky observation by minimizing temperature differential distortion.
Inside, the first floor is comprised of a research office, sleeping bunk, and warming room, and is super-insulated to prevent interior/exterior temperature differentials from creating heat eddies that would impede astronomical viewing. As a counterpoint to the exterior and its context, the interior is lined with fir plywood, creating a haven of refuge and warmth from the harsh surroundings. A helical, plywood-and-steel stair leads from the cantilevered entry canopy to a fissure in the cladding that opens to the exterior observation deck and telescope. Continuing, the stair arrives at Gemma’s primary viewing space in the turret, a 16’ diameter platform with a telescope and an array of cameras. A single person can rotate the turret by hand with an assembly typically used in high-precision manufacturing facilities, and a hand-cranked sliding hatch opens the telescope to the sky. A rift in the zinc cladding creates a corner window, framing Polaris when the turret is locked into the southern cardinal position.