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How to See the ISS & Satellites

The ISS passes overhead 4–6 times a day and is the third-brightest object in the night sky. No equipment needed — just your eyes and a clear horizon. Here's how to predict passes, photograph the station, and catch Starlink trains.

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🌃Why satellites are a great target
The most accessible "something to look at tonight" in astronomy

You don't need any equipment — just your eyes, a tracker app, and a clear horizon. From a city center with terrible skies for everything else, you can watch the ISS sail directly overhead. Beyond it, there are over 10,000 active satellites you might catch: Starlink trains after fresh launches, Tiangong (China's station), spent rocket bodies, weather and military satellites, and a growing population of CubeSats.

What you're actually seeing

Satellites are sunlit reflections of metal and solar panels — steady-moving "stars" that cross the sky in 1–10 minutes. The bright ones (ISS, Tiangong, Hubble) are easily naked-eye. Most are mag 3–6 (binocular targets). Geostationary satellites sit motionless above the equator at mag 9–12 — telescope targets that don't move.

🚀The International Space Station
The brightest, easiest, and most reliable satellite to catch
Altitude
About 400 km (250 miles). Decays slowly; periodically reboosted by visiting cargo craft.
Orbital period
About 92 minutes — 15.5 orbits per day.
Speed
About 28,000 km/h (17,500 mph). Crosses the whole visible sky in 5–6 minutes.
Brightness
Magnitude −2 to −5 at favorable passes. Only the Sun, Moon, and (rarely) Venus are brighter.
Size
About a football field (110 m × 75 m) — the largest human-built structure ever in space.
Visibility window
Visible only when sunlit — best 1–2 hours after sunset and before sunrise. In the deep middle of the night it's in Earth's shadow and invisible.
📋Reading a pass prediction
What the numbers in any tracker app actually mean
Time
When the pass starts. Make sure your app is set to your local timezone.
Start direction
Compass direction where the ISS first appears — usually WSW/SW for northbound passes, NW for southbound.
Maximum altitude
How high it climbs at peak. 60°+ = excellent (nearly overhead), 30–60° = good, under 30° = low and often blocked by trees or buildings.
End direction
Where it exits view — usually opposite the start, but a pass can end early in the eastern shadow.
Brightness
Predicted peak magnitude. −3 or brighter dominates the sky; −1 to −2 is normal; 0 or fainter is dim but still visible.
Duration
Usually 4–7 minutes. Shorter passes are lower altitude or eclipsed mid-pass.
The "disappearing ISS"

Sometimes the ISS suddenly fades and vanishes mid-pass while still high in the sky. That's it entering Earth's shadow — no longer lit by the Sun, so it simply blinks out. The reverse (a satellite appearing where there was nothing) is the same thing in reverse: emerging from shadow into sunlight.

📷Photographing the ISS
From a simple trail shot to a silhouette against the Moon
Trail across the sky
Easy · camera + tripod

Lens: wide-angle 14–35mm. Settings: ISO 400–800, f/4–5.6, 30 s to 4 min. If the pass is longer than your camera allows, shoot back-to-back frames and stack them with StarStaX (lighten mode).

Include a foreground — a tree, building, or mountain. Start the exposure just before the pass begins; the ISS records as a bright unbroken line that dramatically outshines the star trails.

Lunar / solar transit
Advanced · spectacular

Catch the ISS silhouetted against the Moon or Sun — the transit lasts about 1 second. Use transit-finder.com to find transits within driving distance (you may need to drive 10–50 km into the narrow track).

Gear: 300mm+ lens or a telescope. For the Sun, a proper solar filter is mandatory (see the Solar Observing Guide). Pre-focus, then fire a high-fps burst (10+ fps) to cover the ~1-second pass.

Detailed ISS imaging
Very advanced

Resolving the solar panels and modules requires an 8-inch+ telescope on a fast or specialized satellite-tracking mount, plus a camera at 100+ fps, stacking the best frames from the few seconds it's well-resolved. Not beginner work — but the detail achievable from amateur gear (Legault, Voltmer) is genuinely remarkable.

Beyond the ISS
Tiangong, Starlink, Hubble, and the rest
Tiangong (Chinese Space Station)

Completed 2022. Smaller than the ISS but increasingly visible — peak magnitude around −1, comparable to Sirius. Often passes within hours of the ISS at a similar orientation due to similar orbital parameters.

Starlink trains

For 2–7 days after a fresh SpaceX launch (60+ satellites at once), they appear as a dramatic line of evenly-spaced bright dots — the famous "string of pearls." Predict them at findstarlink.com. Photograph like an ISS trail. They're bright enough to streak astrophotos — an unavoidable part of modern skies.

Hubble Space Telescope

Mag 1–3 at favorable passes. Visible only from latitudes 28°N–28°S because of its low orbital inclination — north of that you may never see it. Tracking apps include it.

Iridium flares (mostly historical)

The original Iridium satellites famously flashed to mag −8 — brighter than Venus — as their flat antennas mirrored the Sun to a tiny ground spot. The constellation was retired by 2019; the replacements don't flare. RIP one of the great satellite experiences.

Reentries

Spent rocket stages and dead satellites occasionally reenter as dramatic fireballs. Predictable to within hours, but the track is uncertain by minutes (thousands of km). Track them at aerospace.org or satview.org.

Geostationary satellites

TV/comms satellites at 35,786 km hang motionless above the equator (their orbit matches Earth's rotation). Mag 9–12 — a telescope target. On a clock-driven mount, the geostationary "star" stays still while real stars drift past it.

🧰Tools & apps
Where to get the predictions
Heavens-Above
The encyclopedic tracker — every visible satellite for the next 10 days with star-chart pass maps. Free, no login. heavens-above.com
NASA Spot the Station
Official ISS predictions with email/SMS alerts. Simpler than Heavens-Above but ISS-only. spotthestation.nasa.gov
ISS Detector
Mobile app with push notifications for ISS, Tiangong, Starlink and more.
Sky Tonight / Star Walk 2
Point your phone at a moving object and the app identifies it.
findstarlink.com
Dedicated Starlink-train predictions, updated within hours of each launch.
Transit Finder
ISS lunar & solar transits within driving distance — essential for transit photography. transit-finder.com
CelesTrak
The source of the orbital elements (TLEs) all prediction software uses — for advanced users feeding data into custom tools. celestrak.org
Quick start: see the ISS tonight
Five minutes from "never tried" to waving at the crew
  1. Check tonight's ISS passes for your location (the What's Up Tonight dashboard predicts them on-device — or use spotthestation.nasa.gov).
  2. Note the time and direction of the next pass with a peak altitude over 30°.
  3. Be outside 5 minutes early. Look toward where the pass starts — usually the western sky.
  4. Watch for a bright moving "star" — fast, steady, no blinking. It crosses overhead in 4–6 minutes.
  5. Wave. There are humans up there.
📄 Download this guide as a printable PDF

When does the ISS pass over tonight?

The dashboard predicts the ISS passes visible from your exact location tonight — computed live on your device — alongside the moon, planets and a clear-sky score, so you know whether the sky will cooperate.