Fortnight 200 m Conjunction Report - Apr 3rd to April 16th 2025
There were 123 and 141 conjunctions under 200 m for the last two weeks.
Summary
There are 123 conjunctions under 200 m for the week 2025-04-03 to 2025-04-09 and 141 conjunctions under 200 m for the week 2025-04-10 to 2025-04-16
The majority of conjunctions occur at altitudes less than 600 km
The closest conjunctions each week were:
24 m between Starlink-4793 (ID: 53867) and Object AB (ID: 57191) at a geodetic altitude of 540 km on 2025-04-06
17 m between Iridium 82 (ID: 25467) and Starlink-3868 (ID: 52649) at a geodetic altitude of 550 km on 2025-04-15
At any point you can get this data yourself by going to https://overhead.docksat.space and signing up for a free account using the Log In button ( then Create Account ). If you want to download the complete history and other data you can also sign up for a subscription
For context, all of these objects recorded by the Overhead app are moving at velocities of 5 km/s upwards so a conjunction of 50 m represents a timeframe of 10 ms. Relative velocities can be over 10 km/s. There would not be time to make a significant manoeuvre, if at all.
Total Counts
The total conjunction counts produced by the Overhead web app relating to Payload-To-Other conjunctions excluding payloads to payloads in their own family (ONEWEB to ONEWEB for example) is shown below.
The relative conjunction distances and altitudes where they occur (note distance axis is reversed) are shown below:
Data for the graphs can be found at:
Overhead Weekly Report - 2025-04-09
Overhead Weekly Report - 2025-04-16
Closest Conjunctions
The closest conjunction this week were:
24 m between Starlink-4793 (ID: 53867) and Object AB (ID: 57191) on 2025-04-06 at 18:29:53.03 UTC at a geodetic altitude of 540 km, position 21.8° N, 36.6° E
17 m between Iridium 82 (ID: 25467) and Starlink-3868 (ID: 52649) on 2025-04-15 at 23:30:07.45 UTC at a geodetic altitude of 550 km, position 32.1° S, 58.9° W
Object AB has been recently reported for a close conjunction on this substack. It is a Russian-launched satellite that is only tracked but detailed information is not known.
Iridium 82 was launched in 1998 and was part of a commercial communications network designed by Lockheed Martin. The orbit has been changing over recent years and slowing decaying as can be seen in the altitude chart.
Satellite data is shown below (Note each dot is a different interaction with a different satellite).
Altitude:
Overhead:
Payload family percentages (i.e. what payload family makes up the most conjunctions):
Both Object AB and Iridium 82 appear to interact with Starlink the most.
Summary (again)
There are 123 conjunctions under 200 m for the week 2025-04-03 to 2025-04-09 and 141 conjunctions under 200 m for the week 2025-04-10 to 2025-04-16
The majority of conjunctions occur at altitudes less than 600 km
The closest conjunctions each week were:
24 m between Starlink-4793 (ID: 53867) and Object AB (ID: 57191) at a geodetic altitude of 540 km on 2025-04-06
17 m between Iridium 82 (ID: 25467) and Starlink-3868 (ID: 52649) at a geodetic altitude of 550 km on 2025-04-15
As described in What is Overhead? these conjunctions are calculated from projected positions for a 24 hour period using satellite TLE data from Space Track.org where data is updated each day. Conjunctions are filtered to leave Payload-to-Other types, excluding payload families to each other. Data starts from Jan 1st 2021 until now. Take from that what you will and use at your discretion.
