Predicted pass geometry, viewing conditions, and beam footprint data for Tokyo when EARENDIL-1 — the first commercial orbital mirror — launches later in 2026.
High pass — well placed above the rooftops for most of its transit.
90°Overhead Pass
SW→SERises · Sets
3–5Passes / Week
mag −4Peak Brightness
Predicted geometry for the planned 88° near-polar orbit at 625 km. Eärendil-1 has not launched, so these are modelled figures, not observations — and because the orbit is not sun-synchronous, pass times drift through the year rather than recurring at a fixed hour.
TOKYO35.7°NViewing conditions by month
J
F
M
A
M
J
J
A
S
O
N
D
Best monthsLess favourable
Best: OCT–MAR. Northern winter — long dark nights and the most reliable clear spells.
90°Overhead Pass
3–5/wkPasses
B9Bortle
Seasonal guidance only — based on this location’s latitude and climate, not on Eärendil-1 observations. The mirror has not launched, and because its orbit is not sun-synchronous the pass times themselves drift through the year independently of the weather.
PASS GEOMETRY
What to Expect in Tokyo
LATITUDE AND PASS GEOMETRY
At 35.7°N in the Northern Hemisphere, EARENDIL-1 passes are rising in the SW and crossing toward the SE. The mirror can pass directly overhead — an 88° orbit crosses this latitude. EARENDIL-1 orbits in an 88° near-polar orbit at 600–650km altitude, meaning it will pass over Tokyo multiple times per week when operational. The mirror is steerable — it will only be at full brightness during targeted commercial passes.
VIEWING WINDOW
OCT–APR offers the best conditions. Autumn (October–November) is Tokyo's best season: monsoon has cleared, humidity drops, and views to the west from higher ground are dramatic. June–September cloud cover is near-continuous. Like all satellites, EARENDIL-1 is only visible during twilight — when your sky is dark but the mirror is still in direct sunlight.
LIGHT POLLUTION BORTLE 9
Inner city — severe light pollution. EARENDIL-1 at magnitude −4 is bright enough to be clearly visible from central Tokyo regardless of light pollution — comparable to Venus at maximum brightness. For darker skies, Mount Takao (50km west) or Okutama (70km) for dark skies offers better conditions.
LOCAL CONTEXT
Tokyo at Bortle 9 is one of the most light-polluted major cities on Earth — but EARENDIL-1 at magnitude −4 is bright enough to be clearly visible even here. Like Venus in daylight, it punches through city glow. Japan's culture of astronomical interest means passes will likely be widely followed.
5KM BEAM FOOTPRINT
The 5km beam is comparable to the distance from Shinjuku to Shibuya. A targeted pass during evening peak demand could illuminate the urban canyon of central Tokyo — a commercially interesting proposition for Reflect Orbital.
OBSERVER GUIDE
What EARENDIL-1 Will Look Like from Tokyo
From Tokyo, EARENDIL-1 passes will appear as a fast-moving point of light crossing the sky in approximately 3–4 minutes. At peak brightness it will reach magnitude −4 — comparable to Venus at maximum and clearly visible even from the city centre. It will be one of the brightest objects in the sky during a pass.
The mirror is steerable — between targeted commercial passes, Reflect Orbital tilts it away from Earth, making it much dimmer. During an active pass you'll see a sudden brightening as the beam angle locks onto the target region, then abrupt dimming when the mirror tilts away again.
Track EARENDIL-1 from Tokyo at Launch
OrbitalNodes.ai will provide real-time pass predictions for Tokyo from the moment EARENDIL-1's orbital data is published. No app download required.
OrbitalSolar.ai. “EARENDIL-1 Over Tokyo”. https://orbitalsolar.ai/tokyo/
Figures on this page are modelled from Eärendil-1’s planned 88° orbit at 625 km — the spacecraft has not launched, so nothing here is an observation. Released under CC BY 4.0: quote, republish or build on it with credit to OrbitalSolar.ai.
JAPAN