Close approach · predicted from public data

CSS (TIANHE) and GLOBAL-12: 19.6 km apart

CSS (TIANHE) (satellite) and GLOBAL-12 (satellite) are predicted to pass 19.6 km apart at 2026-10-12 15:03 UTC, about 382 km up, closing at 10.3 km/s.

After this encounter passes we check fresh tracking data for a week and report here what happened.

At this moment in the animation

Time (UTC): —
To closest approach: —
Distance between them: —
CSS (TIANHE) altitude: —
GLOBAL-12 altitude: —

Distance between the two objects, 45 minutes before to 15 minutes after the closest approach (log scale).

Closest approach

Latest data (ours): 19.6 km
Screening (SOCRATES): 2.75 km
Relative speed: 10.34 km/s
Crossing angle: 84.6°
Over: 23.3°N, 111.0°E
Worst-case probability: 1 in 2,207,506

The two predictions differ by 16.8 km. The screening used orbit data 5.4 days old at the time of approach; small errors grow fast, and satellites like Starlink manoeuvre routinely. The newer data is usually the better guide.

The two objects

Object	NORAD	Type	Latest orbit data	Data age at approach
CSS (TIANHE)	48274	working satellite	2026-10-08 06:26 UTC	4.4 d screening: 5.3 d
GLOBAL-12	49772	working satellite	2026-10-08 01:16 UTC	4.6 d screening: 5.4 d

What this is, and is not

This is a prediction built from public orbit data, which is accurate to roughly a kilometre and comes without uncertainty estimates. Operators get better data and formal warnings, and may already have moved. A prediction of a few hundred metres is common and rarely ends in a collision; it is the sheer number of them that makes orbit dangerous.

Orbits are calculated in your browser with SGP4, the same model used to produce the data, from CelesTrak GP data (CCSDS OMM). Screening by CelesTrak SOCRATES Plus. Earth imagery: NASA Blue Marble.