International Space Station — Live Tracking
Real-time position, next visible pass over your city, magnitude, duration, elevation. Everything you need to never miss an ISS pass over your home again. With a 400 km orbit, 28,000 km/h speed and 16 Earth orbits per day, the station offers 1 to 3 visible opportunities per day from any major city — provided you know when and where to look.
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What is the ISS?
The International Space Station (ISS) is the largest artificial object ever placed in orbit around Earth. Built by five space agencies (NASA, Roscosmos, ESA, JAXA, CSA) between 1998 and 2011, it constitutes a scientific cooperation without equivalent — and arguably, on a historical scale, one of the last great functional international projects before the geopolitical fragmentation of the 2020s.
Its mass approaches 420 tons today, its overall dimensions reach 109 m × 73 m (the wingspan of an American football field), and its habitable volume is equivalent to that of a Boeing 747. Six to seven astronauts have lived there permanently since November 2000 — over 25 consecutive years of uninterrupted human presence in space, a record nothing threatened before the arrival of the Chinese Tiangong station in 2021.
400 km orbit, 28,000 km/h, 16 orbits per day
The ISS evolves in a low circular orbit at roughly 400 km altitude (with a slight oscillation between 380 and 420 km, due to residual atmospheric friction requiring periodic reboost manoeuvres). At this altitude, its orbital speed is 27,600 km/h (7.66 km/s), allowing it to complete a full orbit in exactly 92.68 minutes. As a direct consequence, the crew observes 16 sunrises and 16 sunsets per 24 Earth hours, a cycle that completely transforms their biological perception of time.
The orbital inclination of 51.6° from the equator was chosen to allow the Baikonur cosmodrome (Kazakhstan, latitude 46° N) to launch Soyuz vehicles directly to the station. This inclination means the ISS ground track oscillates between 51.6° N and 51.6° S — encompassing most populated areas of the globe. This is why the ISS is observable from over 95% of cities worldwide at least a few times per month.
The station entered orbit on November 20, 1998 with the Zarya module, and the first permanent crew (Expedition 1) arrived on November 2, 2000. End of life is officially scheduled for late 2030 or early 2031, with controlled deorbit planned in the southern Pacific (Point Nemo, the spacecraft cemetery). This 2025-2030 window is therefore the last opportunity to observe this historic object — hence the renewed public interest in recent years.
How to see the ISS from your home?
Seeing the ISS with the naked eye is surprisingly simple, provided you respect three rules: the station must be above your horizon, it must be lit by the Sun, and you yourself must be in the dark. This triple constraint drastically limits the usable windows.
The two-window trick: before dawn and after dusk
Visible passes from any temperate location concentrate in two precise windows: 1 to 2 hours before sunrise and 1 to 2 hours after sunset. During these intervals, the Sun is sufficiently low (between -6° and -18° below the horizon — civil to astronomical twilight) for you to be in semi-darkness, while the ISS, at 400 km altitude, remains fully illuminated. In the middle of the night, however, Earth's shadow extends several hundred kilometers beyond the station's altitude: the ISS enters this shadow periodically and becomes invisible.
In practice, from a temperate-latitude location, you see on average 1 to 3 visible passes per day, with more favourable periods around the summer solstices, when the lighting geometry allows the station to remain illuminated longer during each pass (sometimes two consecutive passes 90 minutes apart remain both visible).
Recognising the ISS with the naked eye
The ISS appears as a very bright, white-yellow point, without flashing, crossing the sky in a straight line at constant speed. Its apparent magnitude during an optimal zenith pass reaches -5.9, making it the brightest artificial object in the sky — about three times brighter than Venus, with only the Sun and Moon outshining it. The complete sky traversal typically lasts 2 to 6 minutes, depending on whether the pass is grazing (short, low elevation) or zenithal (long, up to 87° elevation).
If you observe with 7×50 or 10×50 binoculars, you may sometimes perceive a slight brightness variation due to the rotation of the station and its solar panels — the effect is subtle but visible when the ISS passes high on the horizon, particularly toward the end of the pass when it begins to enter Earth's shadow, gradually turning to a copper red before disappearing abruptly.
Calculating a pass: magnitude, duration, elevation
Every ISS pass is characterised by five parameters that together determine the observation quality. Understanding their meaning lets you instantly prioritise the passes announced by prediction tools.
Start time and total duration
The start time is when the ISS crosses your horizon (typically at 10° elevation). The total duration of the pass varies from 1 to 6 minutes. A long pass means the trajectory is broadly zenithal, hence visible longer before the station disappears at the opposite horizon.
Maximum elevation
The maximum elevation (in degrees above the horizon) is the number-one quality criterion. A pass at 10-30° remains grazing and easy to miss behind a roof or trees; a pass at 30-60° is comfortable; a pass at 60-87° (zenithal or near-zenithal) is spectacular, with the ISS passing practically vertically. Passes above 70° elevation are absolutely worth prioritising.
Apparent magnitude
Magnitude is the inverse logarithmic unit measuring brightness of celestial objects. The lower it is (and negative), the brighter the object. Reference scale: Sirius, the brightest star in the sky = -1.46; Venus at maximum = -4.7; full Moon = -12.7. The ISS during an optimal zenith pass reaches -5.9, making it the brightest artificial object in the sky. During a grazing pass at 15° elevation, its magnitude drops to -1 or -2 but it remains widely visible to the naked eye.
Appearance and disappearance azimuth
Azimuth is the direction (in degrees from North, or as cardinal points) where the station appears and disappears. A typical trajectory for mid-latitudes is SW → NE or W → E, with variations depending on the orbit. Note these two cardinal points in advance: they tell you where to look at the start, and let you anticipate the full trajectory.
For a first visible pass, remember: max elevation ≥ 30°, duration ≥ 3 min, magnitude ≤ -2. Any pass that ticks these three boxes is guaranteed spectacular and easily spotted, even from a moderately polluted urban area.
The 5 best cities for ISS observation
Any city can observe the ISS, but some benefit from particularly favourable conditions: relatively preserved sky on suburban edges, clear horizon, suitable public sites. Here is our top 5 calibrated for 2026.
- London Despite intense light pollution (Bortle 8-9 in central London), the ISS remains widely visible thanks to its negative magnitude. Recommended spots: Greenwich Park (also for the historical observatory), Hampstead Heath, Richmond Park. For zenithal passes, no matter the city: step out on your balcony, look up. Best photo framings combine the ISS with illuminated landmarks (St Paul's, the Shard, Tower Bridge).
- New York City Lower latitude than European capitals: passes sometimes more grazing toward the north. Brooklyn Bridge Park offers an exceptional clear horizon over the East River. Central Park (intramural) remains usable. For optimal conditions, drive to Bear Mountain (1 h): Bortle 4, panoramic horizon. Spectacular framings with the Manhattan skyline as foreground.
- Sydney Maritime advantage: absolutely clear southern horizon over the Pacific. Passes descending toward the southeast are visible down to very low on the horizon. Spots: Bondi Beach for late passes, Mrs Macquarie's Chair to frame ISS + Sydney Harbour Bridge + Opera House, North Head for clean horizon. Southern hemisphere = inverted geometries vs Europe.
- Paris Historical capital of European astronomy. Spots: Trocadéro esplanade with view on the Eiffel Tower, Buttes-Chaumont park, Bois de Vincennes. The Cité de l'Espace in Toulouse and CNES regularly organise public observation sessions during zenith passes. Bortle 8-9 in central Paris but ISS magnitude largely overcomes light pollution.
- Tokyo Largest metropolis in the world, with intense light pollution but cultural fascination for space (JAXA, Kibo module on the ISS). Spots: Tokyo Skytree observation deck, Odaiba waterfront for clear horizon over the bay, Mount Takao (1 h) for Bortle 4 sky. Photo framings combining ISS + Mount Fuji are the holy grail for Japanese astrophotographers.
Note for other cities: observation is equally possible from Berlin, Madrid, Rome, Los Angeles, Chicago, Toronto, Mexico City, Buenos Aires, Cape Town, Mumbai, Singapore. The Vigi-Sky and NASA Spot the Station tools allow instant pass calculations from any geographical point.
Photographing the ISS during a pass
Photographing the ISS is one of the most accessible night astrophotography exercises. Two approaches are possible: the continuous light trail (the ISS appears as a long white line crossing the sky) or the transit in front of a remarkable object (Moon, Sun, landmark).
Mode 1 — The continuous light trail
This is the simplest approach, accessible from entry-level DSLR bodies and even some modern smartphones in extended night mode.
- Body: DSLR or mirrorless with manual mode (M). Recent smartphones (iPhone 14+, Pixel 7+, Samsung S22+) in "Night Mode" or "Pro" 30 seconds.
- Lens: wide-angle 14-24 mm, aperture f/2.8 or wider.
- ISO: 800 to 1,600.
- Aperture: as wide as possible (f/2.8, f/1.8).
- Exposure: 30 seconds in single shot, or — pro method — stacking multiple 15-30 second shots via star-trail (apps: StarStaX, Sequator) to capture the complete trail.
- Focus: manual, at infinity, verified via live-view on a bright star.
- Tripod: essential. Any motion blur ruins the image.
- Trigger: intervalometer or 2 s self-timer to avoid finger micro-shake on the shutter.
Mode 2 — Transit in front of the Moon or Sun
The silhouette of the ISS crossing the Moon or Sun is one of the holy grails of astrophotography. These transits last between 0.5 and 1.5 seconds (the ISS appears tiny, around 50 arcseconds, vs 30 arcminutes for the Moon or Sun), and their prediction is ultra-localised: a transit visible from your street will not be from 200 m away. The reference tool is transit-finder.com by Xavier Jubier, which calculates to the second and metre. For these images, plan a telescope or 500-1000 mm telephoto, 1/1000 s shutter speed, fast burst mode. Solar observation requires imperatively a certified solar filter — any negligence causes irreversible eye damage.
ISS vs Starlink vs airplane comparison
Confusion between ISS, Starlink satellites, airliners and other celestial objects is the origin of more than half of the UFO reports processed by Vigi-Sky. The following table allows identifying the observed object in seconds.
| Criterion | ISS | Starlink (train) | Airliner | Isolated satellite |
|---|---|---|---|---|
| Magnitude | -4 to -6 | +3 to +5 | +0 to +2 | +3 to +6 |
| Colour | White-yellow | Faint white | Multi (red/white/green) | Faint white |
| Flashing | None | None | Yes (1-2 Hz) | None |
| Shape | Single point | Train of 10-30 aligned points | Multi-light | Single point |
| Apparent speed | Fast (5-10°/min) | Fast (5-10°/min) | Slow (1-2°/min) | Variable |
| Sound | None | None | Audible if close | None |
| Pass duration | 2-6 min | 3-8 min | 5-15 min | 2-8 min |
| Trajectory | Rectilinear | Rectilinear (file) | Quasi-rectilinear | Rectilinear |
The classic trap is the fresh Starlink train (launch less than 24 h ago): the satellites still grouped, at low altitude, can reach magnitude 1-2 and constitute one of the most reported UFO observations since 2019. The distinctive signature — a straight, silent file of luminous points moving at constant speed — is unique and easily recognisable once the visual pattern is memorised.
History of the ISS (1998-2030)
The ISS is one of the most ambitious technological projects ever undertaken, direct heir to the Skylab (1973-1979, US), Salyut (1971-1991, USSR) and Mir (1986-2001, Russia) programs.
With its end of life scheduled for 2030-2031, the ISS enters its last half-decade of existence. For observers, this means around 50 occasions per year and per location remain to observe this historic object before its definitive disappearance — hence the growing value of every pass captured in photo or video. The Chinese station Tiangong, in service since 2021, will progressively take over as the main orbital habitat, but will be less visible from northern latitudes (inclination 41.5°, lower latitude limit).
ISS observation FAQ
How many visible passes per month from a typical city?
On average 12 to 18 visible passes per month from any temperate-latitude city, of which 3 to 5 are considered excellent (elevation > 60°). Density varies with orbital mechanics: some weeks present up to 3 visible passes per day, others none. This is normal — it is linked to orbital inclination and lighting phase.
Why does the ISS sometimes disappear mid-pass?
When the station enters Earth's projected shadow, it stops being illuminated by the Sun and becomes invisible in less than 30 seconds. You then see the bright point turn to copper red (atmospheric refraction effect, similar to a miniature lunar eclipse) before disappearing. It is one of the most impressive observation moments. Conversely, the ISS can "appear" abruptly mid-sky when it exits the shadow.
Can I talk to the ISS or see an astronaut?
Not with the naked eye. Astronauts are visible only through the many live video broadcasts (NASA TV, ISS Live YouTube channel). Equipped radio amateurs can however capture the ISS VHF/UHF transmissions on frequencies 145.800 MHz (downlink) and 437.800 MHz (digipeater). The ARISS program regularly organises radio contacts between astronauts and schools worldwide, including dozens in Europe and the US each year.
What if I miss an important pass?
No worries: there is always another pass in the next 24-48 hours. Configure the Vigi-Sky widget alerts or the NASA Spot the Station app to be notified in advance. To miss no exceptional pass (elevation > 70°, duration > 5 min), Vigi-Sky maintains a monthly calendar by major city in its Celestial Calendar.
Is the ISS dangerous for airplanes or satellites?
No. The ISS evolves at 400 km altitude, ten times higher than airliners (10 km). It regularly performs avoidance manoeuvres (3 to 7 per year on average) to avoid orbital debris, a sign that low orbit is becoming crowded. Debris from voluntary destructions (Russian Cosmos-1408 anti-satellite test in November 2021, Indian Mission Shakti test in 2019) are the main contributors to these alerts.
At night, look up: for 25 years, humans have been living up there without interruption. No generation before ours could say that.
Track the ISS live
Our real-time tracker integrates ISS position, visible passes from your city, and Starlink constellation trajectory. Everything you need to plan your next observation session from home.