It’s time to have a nap. I tilt the window over its middle axis to let the butterfly out. A breeze ruffles the drapes. Now, it sits on the glass and throws an enormous shadow on the yellow cloth. 

When the Sun, the Earth and one of the outer planets of the Solar System perfectly align, with the Earth positioned in the middle, the outer planet is said to be ‘in opposition’. It’s a moment of planetary approach and of optimal viewing conditions: the Earth and the outer planet are at their closest and brightest. 

September 2020, three days before Neptune is in opposition, I meet Frédéric on top of a hill in Luxembourg. 

Earlier that day he had sent me the coordinates of an airfield for remote controlled aeroplanes. He told me to meet him there at 20h. The airfield is situated on the top of a hill, granting a clear view of the horizon. Removed from highways and city centres, only the southern horizon lights up, where the Grand Duchy’s capital is located, some 15 kilometres farther. The weather is promising: ‘We might get a chance to see and photograph Neptune!’ he wrote. 

I get there early. Frédéric is already setting up his tripod. Two elderly men are training for the perfect landing.

The planet Uranus should have followed a course as predicted by Newton’s laws. It didn’t. There were ‘residuals’, the 19th-century observers said: irregular data, which had to be interpreted as Uranus deviating from the projected trajectory. They could think of three possibilities. A) The planet Uranus was too far away from the Sun, which might render the Law of Gravitation invalid. B) The observations were incorrect. C) There was another planet, still further and yet unknown, with its own gravitational field and pull, causing Uranus to deviate from its course.

Following hypothesis C, astronomers predicted the position of a planet with a gravitational field, influencing Uranus, by means of mathematical calculations. Telescopes were directed to that calculated spot. There was a luminous point, with a touch of bright azure blue.

As the light of celestial objects travels through the Earth’s atmosphere, the various wavelengths that make up this light are refracted differently. This effect is called ‘dispersion’ and results in colour fringing on the edges of planetary discs: images with a sliver of blue at the top and a red one at the bottom appear.

When celestial objects are positioned close to the horizon (like Neptune when observed from Luxembourg) the images are severely affected: the path of the light through the atmosphere is longer, leading to greater dispersion. 

For the same reason sunsets are red, Neptune turns from a monochromatic blue disc into a misaligned, multicoloured oval. 

While calibrating their telescopes, or dealing with unforeseen, cloudy weather, amateur astronomers tend to trade the far for the not-so-far, and point their telescopes at their immediate surroundings.

As an architectural structure, the pier is fundamental in observational astronomy: it can be found in the backyards of amateur observatories, as well as in professional ones. This column is a quintessential part of the physical interventions that are necessary to distinguish noise from valuable data. The pier disjoints the telescope from the observer, from the observatory and from the surroundings. Tremors of passing cars, the astronomer’s footsteps and coughs, the neighbour’s soundsystem: they could result in an agitated telescope. A falling mug would cause the instrument to shift lightyears away from its target.

A seminar on spectroscopy: how, by splitting light into different, separate rays, it becomes possible to deduct the chemical composition of stars and planets far beyond our reach, as those elements have an effect on the light that reaches the spectroscope. Beautiful graphs presenting colour in schemes of black and white. From the moment the course gets into the physics of light, my mind wanders off. What approaches the observer turns blue, what elongates itself becomes red. The teacher’s leather shoes squeak as he goes back and forth between his self-made spectroscope and the desk. Redshift. Blueshift.

We meet him a couple of weeks later on the rooftop of a university building. He opens one of the half-domes. The sound of the mechanics is as obtuse as the shape it alters. A command on the computer based on coordinates: above our heads, the telescope slews slowly, only to halt at an apparently indistinct black region. From within the dome, we send ourselves an email with the photographs that we took of Neptune. 

University classes will start in a couple of weeks. The city air is crisp. The roundabout below is strangely calm. On the horizon, the canopy of a southern forest delineates the sodium-lit sky. 

It is said that ‘if a space traveller were unfortunate enough to enter the atmosphere of one of the giant planets [such as Neptune], he or she would not find a single solid surface. Instead, as he or she descended into the planet, our traveller would find that the temperature, pressure, and density would all continue to increase smoothly, with no sharp transitions. Assuming that he or she was adequately protected from the temperature, pressure, and radiation, our traveller would eventually “float” at that level in the atmosphere where the surrounding density and his or her own density were equal.’¹ 

It is said that it storms on Neptune.
Violently.
1200 mph. 

They observed a great dark spot and called it: The Great Dark Spot.

It rains diamonds on Neptune.

A scene in German author and director Alexander Kluge’s Die Patriotin: a half-dome opens; the protagonist, Gabi Teichert, stares into the telescope. A montage follows: the waxing crescent moon coming into focus; a night vision of a cityscape with industrial elements; archival footage of a cityscape with skyscrapers during daytime; a giant fire; a woman giving birth aided by a midwife; raindrops falling into a puddle of water; a time-lapse video of a city at sundown; a ship floating by with, in the background, on the shore, windmills; images of tanks rolling by; close-ups of a purple-lit face of someone looking into the camera; archival footage of an air raid.^{1, 2}

In a conversation with Ben Lerner, Kluge sees himself as someone ‘creating constellations’: ‘We deal with moving bodies. “Moving reality.” […] And this is something that you cannot present in a linear way, but in the form of constellations. “Constellation” refers to cosmic matter and gravitation. There are suns, moons, planets. There are also the dust particles, tiny particles that orbit around the sun for centuries according to physical laws. And there’s no hinge, no screw that connects them. Invisible connections.’³

Theory becomes the apparatus. A metonymic relation. A trope of nearness. Miniscule gravitational disturbances become known as a kilometres-long, L-shaped facility. Particle physics: a circular tunnel beneath the Geneva hinterland. 

Somewhere in the early 1970s, our grandfather, a carpenter by trade, buys a telescope^1,2, installs it on the lawn, and points it over the hedge. ‘I remember seeing the craters on the moon. The rings of Saturn,’ he told us. 

In the shabby plywood box I made to transport the telescope lies a metal ring I ground flat to be able to attach my camera and focus it on infinity.

The hedge, now three metres in height, shields the lower part of the sky from sight and needs pruning.

The car is parked on a gravel path, a few metres down from the small road crossing the village. It would be hopelessly stuck the next morning. While trying to capture Neptune through the rental telescope, I run back and forth between the tripod on the small lawn and the trunk several times to get other eyepieces and adapters.

I align the telescope, using three stars: Vega, Arcturus and Deneb. 

I hear an animal. I look up and notice the interior light of the car has switched on. 

A motorcycle around 3:14. The driver is shifting gears rapidly. I don’t see any headlights in the valley.

Fog sets in. Saturn practically disappears from sight. Jupiter appears as a blob. 

I’m 380m above sea level. The highest hill in the area is barely 500m of height. Still, the fog and the settling dew, along with the nightly cold give it something strangely alpine. 

The fog lifts.

I can still clearly see the ridge in the east. It should be darker.

The orthopaedic surgeon left early that morning for his shift at the hospital some twenty kilometres away. It must have been around the time Neptune was at its highest, invisible in the morning sky. 

When he got back later that day, we attached a tow cable to the front of my car and the back of his.

A first try at using the instrument for making a recording: excitement as we succeed in pointing the telescope at the brownish dot afar we just noticed on the other side of the valley. As it continues scavenging, we wait for night to set in. 

Summer 2019, between the swingset and the mesh greenhouse, astrophotographer Angelo Van Daele closes the observatory. The wheels roll smoothly across the rails embedded within a concrete slab. His former observatory is now a chicken coop. His neighbour’s trees need pruning. The camera mounted on the exterior of the shed allows him to see the instrument from inside the house.

Each night a plethora of amateur-astronomers gazes into the sky. Their instruments and locations are often inferior to the means available to professionals. Yet, what they lack in terms of technology and location, darkness and mirror surface, they make up for in the collectivity of their observations. They are patient observers, spread around the globe, not bound to the strict schedules and limited availability of the large telescopes in the Atacama Desert. 

When amateur astronomy became fashionable, it led to a surge of information stemming from a large group of distinct observers: seafarers, physicians, typists, masons. Theirs were valuable data, but if they were to be put to scientific use, they needed to be standardised. How to overcome the subjective element inherent in every empirical observation? The amateurs had to be instructed to recognize patterns, by means of visual examples. They had to be trained to use the right terms to describe their observations. They had to turn chaos into order. Recognize what they were looking at. A nebula. A red giant. Neptune’s faint blue-greenish colour resembling the flame of the gas stove.

In Six Stories from the End of Representation, James Elkins writes: ‘Astrophysicists are well practised in “cleaning up” photographic plates by adjusting colour and contrast, removing images of dust, correcting aberrations, restoring lost pixels, and balancing uneven background illumination. When it comes to blur, the usual strategy is to specify what counts as “smooth” and what counts as “pointlike,” and then refine the image until it exhibits the required pointlike properties’¹. Still, some astronomic images keep a certain amount of blur (although it would be technically possible to delineate them). Elkins continues: ‘blur does not need to be a matter of distance from some hypothetical optimal clarity: it can be a functional scale, independent of the viewer’s notions of clarity and even of the image itself’².

On the night of 22 November 2021, I join John Sussenbach in his backyard while he captures Neptune.

He invites me to join him and his wife for dinner. A prayer. Soup and bread. The images he makes, he explains, are complex from a temporal point of view. The light coming from Neptune has travelled for four hours before it reaches us. Moreover, these images are not photographs of a singular moment, but stacked frames of a video-recording. In doing so, he can, to some extent, eliminate the effects of a bad ‘seeing’: the negative effect atmospheric turbulence has on the light that reaches the telescope.

A bright dot is jumping around on his laptop’s screen. ‘That’s Neptune’, he says. With his index finger he follows the dot. ‘That’s the bad seeing. That’s the unrest.’

The next day I send him the photograph I took of him standing on his ladder, dangerously placed on the edge of the tarp covering his pool. ‘Nice to see the open star cluster Pleiades in your photograph’, he replies. He attaches the image he made that night: ‘If there would have been a clear storm on Neptune, it would have shown’.

‘My backyard is oriented perfectly, I can see the entire southern sky without obstructions. 
In two years, they will start building an apartment block, though, two floors high with a roof on top. The height is not a problem, but of course it does mean heat and potential turbulence. I just hope they will be well insulated.

This is what I like doing. I have never been interested in remote observations.¹ In my backyard. I hear the geese flying overhead at night. An owl. The silence. I want to be near.’

An observer draws on experience, and instantly sees a female partridge. Cumulus clouds. The Southern pole star. It’s the ‘all-at-once-ness of virtuoso perception’, Lorraine Daston writes: ‘Sure, swift, and silent, “without pause for mental analysis,” observation is grounded in long familiarity with the phenomena in question, be they curlews or streptococcus bacteria’ (101).

Sundown at the public observatory in Beisbroek. A choir of birds mixes with the continuous hiss of the freeway nearby. The camera captures the receding colours. The blinds are open; the half dome is closed. 

A documentary approach: moving along a tension between proximity and distance. If the pendulum swings to either side, it becomes difficult to speak of the documentary. Proximity without distance, and distance without proximity, undermine it, precisely because any approach is then out of the question.

As we point the telescope to the sky – cloudy, and filled with chaotic bursts of rain – the dispersion of the city lights accentuates the swirling, frantic raindrops. The roof we are standing on is uneven. A puddle forms underneath the apparatus, around the right leg of the tripod and our feet. The sound of a car on a wet street, below. A kitchen light is flicked on. Temperature is low for a mid-September night, and getting lower by the minute. It seems impossible to tell the depth of field we are documenting, and at what distance from our position these fleeting constellations occur.