On 2026-10-17 02:17 UTC, CN SJ-17 and US WESTAR 3 reached a closest approach (TCA) of 7.97 km, with a relative velocity of 0.72 km/s. This is a cross-border encounter between objects of different nations, the kind of event closely watched for space-security implications. Miss distance and time of closest approach are computed by propagating the latest published orbital elements for both objects, and values update as new element sets are published. See the Satellite Maneuver Tracker for the live picture and space situational awareness for context.
The Two Objects
Where This Happens
This pass happens near the geostationary belt, where satellites hold fixed longitude slots and relative speeds are low. Close approaches here are usually slow drifts rather than crossing passes. About GEO →
History Between This Pair
Repeat encounters are common for objects in near-intersecting orbital planes; each pass is re-screened as fresh element sets arrive.
How These Numbers Are Computed
Miss distance and TCA come from propagating the latest published orbital elements for both objects and searching for the minimum separation over the screening window. Element sets carry kilometre-scale uncertainty, so figures here describe a close pass, not a collision prediction; a change in either object's published elements re-computes the pass automatically. What is a conjunction? → How conjunction assessment works →