TRACKER LAUNCH DATE ASTRONOMY SPACEX CONTROVERSY FAQ REFLECT ORBITAL
41.9°NLATITUDE
55°MAX ELEVATION
CST/CDTTIMEZONE
~−4PEAK MAGNITUDE
◈ PRE-LAUNCH — NO MIRROR IN ORBIT YET
EARENDIL-1 is targeting a mid-2026 launch. There is currently no space mirror in orbit. Pass predictions for Chicago will go live on OrbitalNodes.ai from launch day — exact times, directions, and beam target information updated in real time.
EARENDIL-1 PASS ARC AND BEAM FOOTPRINT — CHICAGO
30° 60° 90° 5km beam footprint Peak 55° — high in the sky NW NE CHICAGO · 41.9°N · EARENDIL-1 PASS GEOMETRY 3–5 passes/week (season) mag ~−4 at peak
EARENDIL-1 VIEWING CONDITIONS — CHICAGO BY MONTH VIEWING QUALITY BY MONTH J F M A BEST M BEST J BEST J BEST A BEST S BEST O GOOD N D STATS 70° MAX ELEV 3–5/week PASSES/WK B7 BORTLE 41.9°N NW → NE ★ BEST: APR–OCT Southern winter — long nights, low humidity ✗ AVOID: DEC–FEB Summer haze, short nights UNIQUE Southern hemisphere — revers
PASS GEOMETRY

What to Expect in Chicago

LATITUDE AND PASS GEOMETRY
From 41.9°N on the US Midwest plains, EARENDIL-1 passes rise in the SW and transit toward the NE — the standard northern-hemisphere direction for sun-synchronous satellites. Maximum elevation reaches ~55°. Chicago's remarkably flat terrain (the city is built on a former glacial lakebed) gives unobstructed horizons in every direction except over Lake Michigan to the east, which is itself an unblocked sky. EARENDIL-1 orbits at a similar inclination to the ISS, meaning it will pass over Chicago multiple times per week when operational. The mirror is steerable, so it will only be at full brightness during targeted commercial passes.
VIEWING WINDOW
April through October (southern hemisphere autumn/winter) offer the best conditions. Southern hemisphere seasons are reversed. June and July — southern winter — give the longest dark evenings and best satellite viewing. Summer (December–January) brings long twilight. Like all satellites, EARENDIL-1 is only visible during twilight — when your sky is dark but the mirror is still in direct sunlight. Outside this window it is either invisible in daylight or in Earth's shadow.
LIGHT POLLUTION BORTLE 7
Central Chicago sits at Bortle 8 — among the most light-polluted major cities in North America. EARENDIL-1 at magnitude ~−4 is nonetheless easily visible from the lakefront, Navy Pier, or Grant Park. The beam footprint illumination on the ground is significantly more dramatic. Starved Rock State Park (~95 miles SW, Bortle 4) is the closest accessible dark sky, and Cherry Springs State Park in Pennsylvania (~10 hours east) or the Headlands Dark Sky Park in Michigan (~5 hours NE) are the region's premier dark-sky destinations.
5KM BEAM FOOTPRINT
A 5km beam footprint could span from Navy Pier to Willis Tower and onto Greektown in a single pass — covering virtually the entire core of downtown Chicago. Alternatively, a beam targeting the lakefront could illuminate Millennium Park, Grant Park, and Museum Campus simultaneously, with Lake Michigan providing a dramatic reflective backdrop. The footprint moves at orbital velocity (7.6 km/s) but lingers over the target for several minutes during pass peak. Observers inside the beam experience concentrated sunlight equivalent to a bright full Moon illuminating the scene.
SEASONAL NOTES
Autumn (September–October) offers Chicago's most reliable viewing — clear skies following frontal passages, mild temperatures, and minimal humidity. Winter can produce exceptional clarity after Arctic air masses, though cold. Summer is humid and prone to thunderstorms. Spring is variable. Starved Rock and the Indiana Dunes offer dark-sky destinations within a 2-hour drive.
OBSERVER GUIDE

What EARENDIL-1 Will Look Like from Chicago

From Chicago, 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 Loop. It will be one of the brightest objects in the Chicago sky during a pass, particularly striking against the Lake Michigan horizon to the east.

The mirror is steerable — between targeted commercial passes, Reflect Orbital tilts it away from Earth, making it much dimmer or invisible. During an active commercial pass you'll see a sudden brightening as the beam angle locks onto the target region. The pass ends abruptly when the mirror tilts away again.

Unlike a steady satellite, EARENDIL-1 may show subtle brightness variations as the mirror adjusts its aim. Watch for a brief period of maximum brightness near the peak of the pass when the geometry is optimal — this is when the 5km ground footprint is directly beneath the mirror at closest approach.

Track EARENDIL-1 from Chicago at Launch

OrbitalNodes.ai will provide real-time pass predictions for Chicago from the moment EARENDIL-1's orbital data is published. No app download required — runs entirely in your browser with GPS-accurate directions.

◈ OPEN ORBITALNODES.AI
FAQ

Space Mirror Questions — Chicago

How bright will EARENDIL-1 appear from Chicago?

At peak overhead passes, EARENDIL-1 is designed to reach magnitude ~−4 — comparable to Venus at maximum brightness. This is easily visible from the lakefront, Navy Pier, the Willis Tower Skydeck, or anywhere in the Loop despite Chicago's significant urban light pollution (Bortle 8). Between commercial illumination passes, Reflect Orbital tilts the mirror away from Earth, reducing brightness significantly.

How high will EARENDIL-1 appear from Chicago?

From 41.9°N in the US Midwest, EARENDIL-1 can reach ~55° elevation on the best passes. Passes rise in the SW and transit toward the NE — the standard direction for northern-hemisphere observers of sun-synchronous satellites. Higher elevation passes give a longer viewing window and brighter appearance. Chicago's latitude is similar to Madrid, Rome, and Beijing.

When is the best time to see it from Chicago?

September through October offers Chicago's most reliable viewing — clear skies following frontal passages, mild temperatures, and minimal humidity. Winter (December–February) can produce exceptional clarity after Arctic air masses, though temperatures often drop below −20°C. Summer is humid with frequent afternoon thunderstorms that often clear by evening. Spring is variable with rapidly changing weather fronts.

Will the beam footprint hit Chicago?

A 5km beam footprint could span from Navy Pier to the Willis Tower and onto Greektown in a single pass — covering virtually the entire downtown core. Alternatively, a beam targeting the lakefront could illuminate Millennium Park, Grant Park, and the Museum Campus simultaneously. A pass aimed at the Lincoln Park neighborhood could cover from Diversey Harbor to North Avenue Beach. Whether any specific location falls in the footprint depends on Reflect Orbital's commercial contracts and targeting decisions. The beam is steerable and can be directed to specific cities or regions for commercial lighting purposes.

Is EARENDIL-1 visible yet?

No — EARENDIL-1 has not launched yet. Reflect Orbital is targeting a mid-2026 launch. There is currently no space mirror in Earth orbit. OrbitalSolar.ai will update with live pass data from the moment orbital elements are published after launch. Check the mission tracker for current launch status.

Why does the mirror move differently from Chicago than from other cities?

From the Northern Hemisphere at 41.9°N, EARENDIL-1 rises in the SW and transits NE — the standard direction for northern observers of sun-synchronous satellites. Southern Hemisphere observers in Sydney, Melbourne, or Cape Town see the mirror image of this pass, with the satellite rising in the NW and transiting NE. This is because sun-synchronous satellites track the boundary between Earth's day and night sides.

How does Chicago's flat terrain and Lake Michigan shoreline interact with the 5km beam?

Chicago is built on a former glacial lakebed — the terrain is among the flattest of any major city, giving unobstructed views to every horizon. Lake Michigan stretches east for hundreds of kilometers, providing a completely dark seaward horizon free of any land-based light pollution. A 5km beam footprint could cover the entire downtown core from Navy Pier to Greektown, or alternatively illuminate the lakefront from Millennium Park to Museum Campus with the lake as a dramatic reflective backdrop. Chicago's geography makes it visually distinctive for orbital mirror demonstrations — the combination of dense vertical skyline and vast flat water creates unique beam-illumination imagery.

What dark-sky locations near Chicago are best for watching the mirror pass?

The Blue Mountains (90 minutes west, Bortle 3–4) give the clearest sky with minimal light dome interference. Ku-ring-gai Chase National Park (45 minutes north) is excellent for clear northern passes. Royal National Park (45 minutes south) has a clear southern horizon. For serious observation, Observatory Hill in the CBD works for the bright mirror itself — at magnitude −4 it needs no dark sky — but the Blue Mountains are far better for seeing the beam footprint effect against a dark sky backdrop.

// ALSO TRACK SATELLITES OVER CHICAGO

OrbitalNodes.ai tracks the ISS, Tiangong, Hubble, and all satellites over Chicago in real time — including exact pass times, directions, and brightness predictions.

→ SATELLITES OVER CHICAGO — ORBITALNODES.AI