Home›Maneuver Tracker›Close Approaches›COSMOS 2125 ⟷ DELTA 1 DEB
HighCross-border
Live forecastConfirmed by the latest screening, 10 Nov 00:12 UTC.
Closest approach10 Nov 202607:49 UTC
Relative speed14.28 km/sat the closest approach
Altitude1,471 kmlow Earth orbit
Separation now—live

RU COSMOS 2125 and US DELTA 1 DEB are predicted to reach a closest approach of 7.87 km at 2026-11-10 07:49 UTC, at a relative speed of 14.28 km/s. Confirmed by the latest screening, 10 Nov 00:12 UTC. 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 each pass is re-checked every 20 minutes as new element sets are published. See the Satellite Maneuver Tracker for the live picture and space situational awareness for context.

Why it mattersOne side of this pass cannot maneuver, so any avoidance decision rests with the other operator. Screening continues as new element sets arrive.

The Two Objects

Dossiers from the satellite directory
NORAD 21100
CountryCIS
Launched1991-02-12
COSPAR1991-009A
Maneuver capableUnknown
NORAD 12530
CountryUS
Launched1976-07-29
COSPAR1976-077DK
Maneuver capableNo
Uncontrolled debris fragment tracked by the public catalogue. About space debris →

Where This Happens

Altitude context
DEBRIS BELT 700–1000 KM2006001,0001,5002,000 kmTHIS PASS · 1471 KMISS 420Starlink 550

At 1471 km this pass sits in low Earth orbit. Objects here stay up for decades: there is too little atmospheric drag to clean the band naturally. Why crowded bands matter →

History Between This Pair

3 predicted passes under 10 km
Pair history · COSMOS 2125 ⟷ DELTA 1 DEB
2026-11-10 09:464.67 km Live forecast14.28 km/s1,473 kmView →
2026-11-10 07:497.87 km Live forecast14.28 km/s1,471 kmShown above
2026-11-04 20:587.63 km Final forecast14.19 km/s1,458 kmView →

Repeat encounters are common for objects in near-intersecting orbital planes. Each pass is re-screened as fresh element sets arrive; "Final forecast" means the screening still predicted it within 45 minutes of its time, "Not re-confirmed" means later screening stopped finding it.

Forecast Record

Every figure published for the pass shown above, newest first. Nothing is overwritten: a withdrawn forecast keeps its figure, with the newer check beside it, and the best estimate after the pass is a row of its own.
Computed · figure · predicted time · orbit data · by
9 Nov 21:51 UTC7.87 km Forecast10 Nov 07:49 UTC9 Nov 11:59 UTCRe-check
9 Nov 11:54 UTC7.84 km Forecast10 Nov 07:49 UTC8 Nov 23:13 UTCRe-check
9 Nov 11:35 UTC9.58 km Forecast10 Nov 07:49 UTC8 Nov 23:13 UTCScreen

These Objects Elsewhere

Other screened approaches · 7 days
3.48 km11-10 06:45 UTC
COSMOS 2125SL-8 DEB
4.11 km11-04 21:07 UTC
COSMOS 2531DELTA 1 DEB
4.22 km11-09 05:39 UTC
COSMOS 2008COSMOS 2125

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 →