International Space Station

The International Space Station is the largest human-made object ever assembled off-planet: a pressurised volume the size of a Boeing 747's interior, an acre of solar panels, orbiting at roughly 400 km and 27,600 km/h. A permanent crew of six or seven has lived aboard continuously since November 2000 — the longest unbroken human presence in space.

What you actually see is sunlight reflecting off those solar arrays and the aluminium modules. That reflection only works when the ISS is above your horizon and still catching the Sun while your sky is already dark — which is why passes cluster in the hour or two after sunset, and the hour before sunrise. When it flies into Earth's shadow mid-sky, it doesn't slow down or disappear — it just stops reflecting sunlight, and vanishes within seconds.

Reading the numbers on each card: max altitude is how high above the horizon the ISS climbs at its peak, in degrees. Anything above 40° is a spectacular pass; below 15° it will be brief and low. The appear and disappear compass directions tell you exactly which patch of horizon to face — the ISS almost always moves west-to-east, but the exact track depends on the orbit geometry for your latitude.