“146 years after Edison’s first filament, our night is caged in a blinding bubble. Hibernating inside this glowing shield, we’ve lost touch with deeper nights and stranger worlds. For instead of looking up, we have looked down, in high-rise ecstasy, surrendering to the god’s-eye view that shrinks the social to an ant-like miniature. Yet amid this era of extreme light pollution, Centrala gently urges us to look up again – not
with an architecture of power but of attunement; a Celestial Architecture meant to be looked through, not at.”
Søren Nørkjær Bang
A dispersed observatory of atmospheric phenomena, assists in interpreting the sky’s appearance and the natural changes it reveals. It teaches orientation in time and space without digital aids, fostering mindful presence in the world and reinforcing a sense of planetary belonging. Comprising ten architectural, topographical, and garden installations embedded within Warsaw, Celestial Architecture provides spaces to experience the diversity and subtlety of celestial phenomena, the Earth’s natural cycles, and the dynamism of the elements. Each of these structures is intentional, not just in what it observes, but also in where it is. They build on the legacy of sky watchers, connecting the city with the sky.
The Silver Garden
The Silver Garden — a crater-like landscape filled with silvery plants, designed to enhance your experience of Earthshine—the faint glow visible on the Moon’s unlit portion, caused by sunlight reflected off Earth’s atmosphere. Observing variations of this glow helps monitor Earth’s albedo, a key indicator of global warming. This achromatic night-time garden also invites contemplation and celebration of the lunar calendar: the monthly cycle of bright and dark nights tied to the Moon’s phases. 52°15’59.2″N 20°53’06.3″E
Collage created with the support of Natalia Budnik and Karolina Borucka.
5-day-old waxing crescent moon, with earthshine on the dark side by 2014 Alan Dyer
Quadrant for observing the Earth’s shadow – the planet’s shadow projected onto the atmosphere during dawn and dusk, opposite the sunrise and sunset.
Quadrant for observing the Earth’s shadow – the planet’s shadow projected onto the atmosphere during dawn and dusk, opposite the sunrise and sunset. It manifests above the horizon as a dark band surmounted by the pink “rim” of the anti-twilight arch. The Earth’s shadow visually demonstrates our globe’s rotation. While observing this phenomenon, some experience the “overview effect” — a profound sense of planetary unity. 52°09’12.3″N 21°03’12.2″E
20.12.2023, 7:08 Photo: Simone De Iacobis
The Drifting Rainbow Observatory
The Drifting Rainbow Observatory is a floating platform, designed to be anchored and rotated in response to atmospheric conditions and the Sun’s position. Fog, mist, spray, dew-laden air, and rain veils increase the likelihood of encountering a spray bow. Hovering above the water, the platform also enables observation of other types of rainbow: vibrant arcs after rainfall, deep red rainbows at twilight, fogbows (also known as white rainbows), lunar rainbows under moonlight, and dew bows at sunrise. The platform operates along the Warsaw section of the Vistula, between the 502nd and 528th kilometer of the river.
Meridian, a movable parabolic roof designed for observing zodiacal light (counterglow)
Meridian is a movable parabolic roof designed for observing zodiacal light (also known as counterglow)—a faint luminance visible in the night sky along the ecliptic (the zodiac). The structure is dedicated to the Warsaw Meridian, at longitude 21°00’00″E. When light pollution hampers visibility at this location, the Meridian is relocated to darker observation sites. When oriented along the west–east axis, the roof blocks extraneous light, and observations are conducted through a sliding shutter that reveals a narrow strip of sky along the meridian, with Polaris visible to the north. The design is inspired by Jean Prouvé’s Salle méridienne at the Paris Observatory, built in 1951.
Étienne Léopold Trouvelot, The Trouvelot Astronomical Drawings, 1881–1882, Crystal Bridges Museum of American Art, Bentonville, Arkansas.
A dolmen for observing distortions of the solar disk, revealing the unseen layers of the atmosphere, its structure, and how the air warps our view of the Sun.
A dolmen for observing distortions of the solar disk, revealing the unseen layers of the atmosphere—its structure and how the air warps our view of the Sun during sunrise and sunset. The design references megalithic structures once used to observe recurring natural phenomena. A circular arrangement of stone seating, shaped like distorted solar outlines, allows for the comparison of sequential changes in the Sun’s appearance. When the terrain creates a layer of less dense air, a lower distortion—an illusory reflection of a sunspot just above the horizon—becomes visible. 52°13’30.7″N 21°07’14.7″E
Photo: Simone De Iacobis, 25.07. 2024, 5:15
The observation platform dedicated to clouds
An observation platform dedicated to clouds, including varieties previously unseen in Warsaw, such as Asperitas (rough) and Mammatus (cellular pouches). Cloud colors can reveal atmospheric conditions—such as frostiness in the upper layers (noctilucent clouds) or dryness above the city (alpenglow). New cloud types were officially added to the International Cloud Atlas by the World Meteorological Organization in March 2017. Elevated to the height of the hornbeam treetops, the platform offers a wide, unobstructed view of the sky. While observing these fleeting formations, the structure provides a sense of solidity, akin to standing on a large rock. Jørn Utzon’s platform descriptions from 1962 serve as direct inspiration for this observatory. 52°18’50.9″N, 20°55’47.8″E
The sky colour observation grotto
The sky colour observation grotto is set below ground level, allowing for observations from beneath the horizon. The dome’s oculus, positioned above the main hall, facilitates zenith observation, where the daytime blue appears most saturated. In the medium-sized hall, one can appreciate the sky’s gradual lightening towards the horizon. The changing tones of the sky’s colouration illustrate atmospheric density: the blue deepens as the atmosphere thins. The smallest hall’s observation window frames the almucantar 7° above the horizon, where the blue transitions into a whitish band, particularly noticeable during dry periods. These observations offer a journey through varying shades of blue. Architectural vaults evoke the structure of the “celestial vault” in terms of atmospheric density, tension, its spatial continuity, and the “medium’s graininess” (the molecular structure of matter) as described by Marian Smoluchowski in 1911. At night, under a starry sky, the blue airglow, the atmosphere’s inherent luminescence, can be observed as skyglow. It appears most intense before midnight, approximately 10° above the horizon. Occasionally, a “bright night” is due to the natural luminosity of airglow, rather than urban light pollution. The grotto is nestled within a meadow in Bródno Park, 52°17’28″N 21°02’07″E. Its form is reminiscent of the underground astronomical observatory Stjerneborg (Star Castle), built by Tycho Brahe on the island of Ven in 1584.
Horace-Bénédict de Saussure, second diagram of the cyanometer, 1788 Collection Musée d’histoire des sciences, Geneva
The Mirror of atmospheric reflectance
The Mirror of atmospheric reflectance. Photometeors occur in Warsaw on two scales: the celestial sphere and the immediate human surroundings. In the distant view, one can perceive: a luminous rim (glory), rings around the sun and moon discs (halo), or their colourful glow (corona). In the close view, one may discern directional, specular reflections: reflexes, airborne glimmers, scintillating lights, scintillations caused by water reflection, and streaks of light on waves. Their mobility and ephemeral nature require calibrated attention, stillness, and contemplation of the subtle modulation of space by light. A pond contributes to generating these phenomena – a section of its canopy’s underside shimmers depending on the Sun’s position. A bench along the reservoir’s inner circumference enables slow movement, following the luminosity. A “celestial mirror” at the centre is a concavity that allows one to track the gliding shadow. Location: at the foot of the escarpment in Powiśle, at the site of a former pond, 52°14’20.0″N 21°01’22.7″E. The greatest number of observation days, meaning cloudless days, occur in Warsaw in May and September. It’s not just about the vastness of the sky, but also about these small, fleeting moments of beauty.
Fata Morgana of the ocean waves and the sun glitter. Author: Brocken Inaglory
Tower for the observation of the sky’s edge
Tower for the observation of the sky’s edge, and phenomena related to atmospheric turbidity and air’s components. Situated on the continuation of the Stanislaus Axis in Warsaw, at 52°13’07.5″N 21°05’18.5″E, its location allows for unobstructed, long-range observations, enabling the assessment of aerial perspective and the law of contrasts – the perception of differences in luminance and colour. It shows how the air itself modifies visual perception. Depending on whether observations are made with or against the sun, the structure functions as a colour-type or silhouette-type observation point (in the latter everything appears as a mere silhouette). From this vantage, one can evaluate visibility, meaning the range at which objects are discernible, as well as obscured visibility or atypical visibility ranges, such as those following strong winds, indicating exceptional atmospheric transparency. The atmosphere acts as an instrument, and we merely observe its interaction with light and distance. The gradual increase in transparency and diffused clarity from August to January is attributed to the annual cycle of decreasing water vapour in the atmosphere. Following volcanic eruptions in distant locations on the planet, the Bishop’s Ring may occur – very rarely also in Warsaw – which is a whitish halo around the Sun with a faint bluish tint on its inner edge. This indicates the arrival of dust particles approximately 1µm (1/1000 mm) in size, illustrating the interconnectedness of remote Earth systems. The tower’s form references the Ulugh Beg Observatory in Samarkand, dating from 1420.
Mountains of Wadi Shawka at sunrise, Al Hajar mountain range, UAE. Author: Florian Kriechbaumer
The frost hollow
The frost hollow, a terrain depression designed for observing frost phenomena, is situated within the municipal forest of Białołęka Dworska, aligned north-south along the Warsaw meridian at 52°21’13.0″N 21°00’00″E. This location has served as a site for urban ecology and climatology studies. The terrain feature is a wedge-shaped, dry ditch, paved with stone setts. Its north-south orientation encourages the flow of the coldest, heaviest air from the north, which settles within the depression, forming a cold air pool. A sanctuary for frost, this area allows for the observation of its beauty amidst a warming climate. In Warsaw, severe frost is becoming increasingly infrequent, leading to the decline of: white frost – frozen dew, rime ice – supercooled water droplets freezing onto surfaces; hoarfrost – a deposit of fine ice crystals from water vapour, glaze – a glassy coating formed when cold air freezes moisture, and ice fog – freezing fog. This observational “cold hollow” is intended to enhance the conditions necessary for these phenomena to occur. The contrasting colour of the stone also facilitates the observation of diamond dust – the precipitation of minute, unbranched, needle-like ice crystals. These sparkling points descend so slowly that they appear suspended in the air. As low temperatures become less common, it is vital to observe optical phenomena during transient frosts, such as those occurring in mid-May during the period known as the Ice Saints’.
