The reentry of Starlink-1541 over the northern Netherlands on 24 July 2026

click map to enlarge

On 24 July 2026 near 20:26 UTC (22:26 CEST), a defunct Starlink satellite, Starlink-1541, reentered over the North Sea, northern Netherlands and Germany. 

I observed the reentry myself (along with many, many other people). I was on a sailing holliday onboard the historic sailing vessel 'De Onderneming' at that time. We had sailed from Medemblik to Oudeschild on the island of Texel that day, and were sitting on deck in the harbour of Oudeschild (53.03898 N, 4.85058 E) during twilight, when Ide, the deck-hand who was facing west, suddenly said "What is that?!".

As I turned my head in the direction she was pointing into, I saw a bright fast moving object rising from the west in the twilight sky, leaving a trail in its wake. It initially was "blinking" in a semi-regular fashion, which put me on the wrong foot for a few seconds, thinking: "aircraft?". But then, as it rose higher in the sky and passed through the zenith, fragmentation became obvious, and I realised it was a space debris reentry. It continued fragmenting while moving to the eastern horizon. It left a vapour trail that lingered for more than 10 minutes.

I did not have my phone directly at hand, as it was charging in the cabin inside our ship. So I do not have imagery of the reentry itself, but did shoot this image of the lingering vapour trail:

lingering vapour trail. Click image to enlarge

This lingering vapour trail consists of amongst others fine aluminium and carbon particles

A nice collection of photographs and video of the event was gathered by the IMO here, and in this NOS news item (which quotes me). The video below of the event is from the meteor camera of Erwin Harkink (NL000C) in Elst, the Netherlands, where it was lower in the sky:

Of course, my next question was: "what object was this?". As I was on holliday, I did not have my laptop with software with me, only my phone. Logging into Space-Track, a TIP message (22:51 UTC ± 2 hr) with a difference of (at that time) about two hours for Starlink-1541 (2020-055AB) seemed to indicate that satellite as a potential candidate, but with only my phone at hand I had no means to check whether the time of the event matched a pass over the Netherlands. Luckily, Joseph Remis on twitter quickly made the connection and established Starlink-1541 as the identity of this reentering object. 

Several hours later, the final post-reentry TIP issued by CSpOC appeared and was a clear match: 24 July 2026 20:26 ± 1m UTC near 52.7 N, 9.6 E (as mentioned before on this blog, Jonathan McDowell and I believe that these very accurate post-reentry issued ±1m TIP's are based on US DoD satellite observations of the reentry fireball). As Dutch News reports at that time where still identifying the event as a 'meteor', I had a post-midnight whatsapp interview with a journalist of the National Broadcaster NOS about the real character of the fireball in order to set the record straight.

After returning home a week later, I used the latest orbital data available from CSpOC to run a reentry model on Starlink-1541 using our Delft University of Technology's Astrodynamics Toolkit (Tudat), in order to try to reconstruct the likely reentry trajectory. I varied the drag area in the model untill it resulted in typical reentry altitudes (< 90 km) over the northern Netherlands around 20:26 UTC. This is the resulting approximate trajectory (meaning: there is some leeway in exact altitudes and times, but in general this trajectory should be close to reality); the first map gives approximate times, the second approximate atmospheric altitudes:

trajectory and approximate positions (click map to enlarge)

trajectory and approximate atmospheric altitudes (click map to enlarge)

As can be seen, at the harbour of Oudeschild on Texel (one of Dutch Wadden islands) we were almost directly underneath the path of the reentry. Indeed, we saw it pass almost through the zenith, in agreement with this sky-track for Oudeschild harbour resulting from the Tudat reentry reconstruction (note that it was in twilight so only the brightest stars were visible in reality):

reconstructed sky trajectory for Oudeschild (click map to enlarge)

Starlink-1541 (2020-055AB) was launched from Cape Canaveral on 7 August 2020 on a Falcon 9, with 60 other Starlinks and two additional satellites. On 8 February 2026, after 5 years of service, it lowered its orbit in preparation for deorbit. On 24 July 2026, it met its end over the Dutch Wadden Sea.

Starlink-1541 orbital history (click diagram to enlarge)

This was my first ever reentry observation (I tried several times when pre-reentry forecasts suggested an object might reenter over the Netherlands, but in vain): something that was high on my wishlist and can now be struck off. 

I was lucky to see it. Initially, I was to go on holliday on the Scottish west coast, but the sailing vessel in question got a damaged motor, so that holliday was cancelled. I then went on a shorter alternative sailing holliday on the Dutch Wadden Sea with 'De Onderneming'. This brought me right under the reentry path! We were also lucky to be outside on deck when it happened. If only I would have had my phone in my pocket rather than charging inside the ship....

Imaging the oldest pieces of Space Debris still on orbit using the TU Delft MISO telescope

 

The Vanguard 1 upper stage (1958-002A). Click image to enlarge

The Space Age started almost 69 years ago, with the launch of Sputnik 1. Very little hardware representing that dawn of Space exploration is still on orbit. The oldest two pieces of Space Debris  that are still orbiting Earth are Vanguard 1 (1958-002B) and the upper rocket stage (1958-002A) from this launch.

Vanguard 1 was launched on 17 March 1958, half a year after Sputnik. It was the second successful American satellite launch, and chronologically the fourth satellite to orbit our planet, after Sputnik 1 and 2 and Explorer 1. This satellite therefore truely represents the dawn of the Space Age and our very first steps into space.

 

Vanguard 1 on top of the upper stage, before launch in 1958. Image US Naval Research Laboratory

On the night of 25-26 April 2026, using the TU Delft 40.2-cm MISO telescope on the rooftop of the Delft University of Technology Aerospace faculty, I imaged both Vanguard 1 and its upper stage, while they were near Apogee. 

The upper stage was bright enough to see in the imagery when tracking at sidereal rate (i.e. on the stars), as can be seen in the image in top of this post, where the small streak is the moving upper stage.

Below is another image of the Vanguard upper stage, but this time with the telescope tracking the motion of the upper stage (hence why it is now a dot and the stars are now trailed). It is a 1-second exposure:

The Vanguard 1 upper staged imaged while tracking the object motion. Click image to enlarge

Below is a similar image, but this time showing Vanguard 1, again in a 1-second exposure tracking the satellite motion. Unlike the upper stage, Vanguard 1 was too faint to see in images tracked at sidereal rate. The image actually shows a moment where the small satellite was briefly brighter due to a glint on some reflective surface on the satellite. In imagery taken before and after this, it was fainter (but visible). Imaging a 15-cm diameter, grapefruit-sized object (see below) at a 4525 km range is quite a thing!

Vanguard 1 imaged while ttracking on the satellite motion. Click image to enlarge

Vanguard 1 is small: it is an aluminium sphere of only 15 cm in diameter, with some thin 0.9 meter antennae protruding, and a mass of 1.46 kg. It was placed in an elliptic 650 x 3970 km, 34.25 degree inclined orbit in 1958. Today, 68 years later, it is in a 653 x 3818 km orbit with perigee over the southern hemisphere. Vanguard 1 functioned for six years.

 

In that sense, the Vanguard RB (1958-002A), the upper stage from its launch, is the oldest still orbiting piece of space debris, as Vanguard 1 itself only became space debris when it ceased functioning in 1964.

The images above were taken when both objects were near their apogee. Vanguard 1 was at an altitude of 3760 km, and a range of 4525 km from the Delft telescope, and geographically over Northwest Africa, during the imaging. 

The Vanguard upper stage, with dimensions of 1.5 x 0.8 meter, was at an altitude of 3620 km and a range of 5130 km from the Delft telescope, and geographically over Northeast Africa, during the imaging.

[MULTIPLE UPDATES] Possible Space Debris found near Newman, Australia on Oct 18, might be Jielong 3 upper stage remains

click map to enlarge

On 18 October 2025 near 14:00 local time (= 18 October ~6:00 UTC), a strange object was found on or near a dirtroad in the outback of  the Pilbara region in Western Australia. The object, suspected to be space debris, was found some 30 km east of the small mining town of Newman, as reported by ABC.

The object (photo's in the ABC report) resembles a COPV (Composite-Overwrapped Pressure Vessel), a type of space debris that often survives reentry. It reportedly was burning when found (this seems to be visible in the first photograph in the ABC report), which is unusual and against expectations for space debris. Nevertheless, the character of the object and a good match of the find location to a reentry on 18 October does persuade me to conclude that this is space debris indeed.

A possible candidate for the origin of this apparent space debris is a Chinese Jielong 3 upper stage, catnr. 61237, COSPAR 2024-173L. This object reentered on October 18, although (again! See this recent reentry) no TIP was issued by CSpOC.

I identified the object (note: so independently did Ravi Jagtiani) by assuming the report it was burning, although odd, is true, indicating a very recent impact. Using the latest orbital catalogue I first checked which objects were in orbits below 250 km on October 17-18, i.e. close to reentry, and next I ran a SatEvo analysis on this set to further cull it down to objects that should have been near reentry around that time. Starlink satellites could be excluded given the character of the debris. This left only a handfull of candidates. Of these, only one was in an orbit that would match passing close to Newman in the early hours of October 18: the mentioned Chinese Jielong 3 stage in a 97.6 degree inclined polar orbit. Using a standard SGP4 propagation as a first check, the ground-track would pass some 20-30 km east of Newman around 4:40 UTC on October 18. The rocket stage approached from the north-northeast moving towards the south-southwest.

The last available orbit for 2024-173L is for epoch 25291.03873492 (18 Oct 00:55 UTC), a few hours before the Newman object was found. Using that orbit as a starting point and deploying the reentry model we recently created in the open source Delft University of Technology Astrodynamics Toolkit (Tudat), I tried whether I could get a reentry trajectory to end ~30 km east of Newman. 

Not much information is known about the Jielong 3 components in terms of size and mass: therefore, estimates for size and mass of the upper stage had to be used. I assumed a size of about 1.5 x 1.5 meter (cf Jonathan McDowell's catalogue) and then by trail-and-error varied the mass to get an impact point as close to 30 km due east of Newman as possible.

An impact point situated directly ~30 km east of Newman results when I use a mass of ~301 kg, which seems a reasonable value for a small solid fuel upper stage build from composite. The two maps below show the Tudat modelled reentry trajectory that results from a 2.5 m² drag surface and 301 kg mass, with impact just after 4:40 UTC on 18 October (see also update II at the bottom of this post):

 

click map to enlarge

 

click map to enlarge

The modelled impact time is 1 to1.5 hours before the object was reportedly found. 

So it looks like the Jielong 3 upper stage 2024-173L is a good candidate for the origin of the possible space debris object found near Newman on October 18. Rather than a COPV from the stage, it could actually be (a significant part of) the upper stage itself, given the large size that the photo's suggest (and also given that the Jielong 3 upper stage is reportedly a solid fuel stage).

As we have seen with a number of recent reentries, CSpOC alas did not provide a TIP for this object (TIP = "Time of Impact Prediction", the reentry prediction by the CSpOC reentry model). They did however release an administrative "decay message" for 2024-173L for October 18 just after the reentry, indicating that it did reenter that day.

 

UPDATE I, 21 Oct 2025 00:20 UTC:

An EU-SST reentry analysis for the Jielong 3 upper stage 2024-173L is in good agreement with my Tudat analysis.

 

UPDATE II, 21 Oct 2025 15:45 UTC:

Using Tudat, I tried to fit the orbital evolution (based on US tracking data) for 2024-173L from July 1, 2025 to October 15, 2025 to the Tudat model, playing with mass and drag area, to get at empirical values for mass and drag area. One of the solutions that fits well is a mass of 300 kg and drag area of 2.2 m² , which is close to the values I used to get it to reenter near Newman as described earlier in this blogpost. 

click diagram to enlarge

With a 300 kg mass and 2.2 m² drag area, the Tudat reentry model has it nominally surviving untill ~5:17 UTC ± 65 min, nominally reentering half an orbital revolution after passing Newman: but passing Newman actually is well within the uncertainty window of this reeentry prediction (the blue line on the map shows the trajectory over the uncertainty window):

 

click map to enlarge

In other words: this too suggests that the object found near Newman could be (a part of) the Jielong 3 upper stage 2024-173L.

 

UPDATE III, 31 Oct 2025: 

A lone TIP has suddenly been issued for 2024-173L by CSpOC today: 18 Oct 2025 4:38 ± 1m UTC near nominally 18.1 S 121.2 E.  

This conforms well to the space debris being found in Newman, as the time and location likely are based (given the ± 1 minute uncertainty) on a satellite observation of the fireball, i.e. on the location at an altitude of 80-100 km. I have plotted the position in the map below, that also depicts our Tudat reentry trajectory with associated times.

 

click map to enlarge

Possible Space Debris impact in Kenia: a piece of the Ariane SYLDA 2008-034C? [updated]

the metal ring found near Mukuku in Kenia. Image: Kenia Space Agency

the metal ring found near Mukuku in Kenia. Image: Kenia Space Agency

the metal ring found near Mukuku in Kenia. Image: Kenia Space Agency

 

On 30 December 2024, reportedly near 12:00 UTC, an odd object is believed to have fallen from the sky near the village of Mukuku in Kenia (approximately 1.58 S, 37.61 E, some 100 km from the Kenian capital Nairobi). It is metal ring of about 2.5 meter in size and reportedly 500 kg mass, although that mass could be an estimate only.

The Kenya Space Agency is investigating, believing it to be Space Debris. Apart from the metal ring in the pictures, other fragments looking consistent with space debris, for example what looks like carbon wrap and isolation foil, were found several kilometers away from it (see video below):

 

It is still not entirely clear if the object is space debris (although it looks likely), and if so, which object from what launch. There are two reentry candidates for this date, only one of which looks viable as a candidate (see also Jonathan McDowell's summary here).

That viable candidate is object 33155 (2008-034C), an Ariane SYLDA adapter from flight V184, the launch of ProtoStar 1 and BADR 6 to geosynchonous orbit on 7 July 2008. This SYLDA adapter was left in a 1.6 degree inclined GTO following the launch and had its reentry on or near December 30. 

As I will investigate below, using a reentry simulation, both the location where the ring was found and the reported fall time are realistic for it to be this object.

CSpOC, the US military tracking network, last recorded 2008-034C in a 1923 x 146 km orbit on December 23, i.e. a week before the Kenia impact. As this is a very low inclination orbit (1.56 degrees), it belongs to a class of objects that is ill-tracked due to a lack of tracking stations close to the equator. This explains the 1-week gap between the last available orbit and the reentry.

As a note: what is a SYLDA? A SYLDA ("SYstème de Lancement Double Ariane") is a kind of hollow shell put over the first payload, in order that a second payload can be mounted above it.The conical upper part of the SYLDA has a smallest diameter near 2.6 meter, i.e. similar to the size of the ring found in Kenia, which then could be an upper Payload Adapter Fitting (PAF).

A SYLDA (black) as part of a stage, satellite and fairing stack (image: ESA)

An Ariane SYLDA (image: ESA)

CSpOC issued a reentry TIP for this SYLDA for 30 December 2024, 21:38 UTC +- 59 minutes. That is the date of the Kenia event, but not the correct time, as the Kenia event reportedly happened near 12:00 UTC, nine hours earlier. However, the quoted uncertainty of 59 minutes from this TIP is not realistic, if based on the last available orbit (a week old at the time!). A more realistic uncertainty estimate would be +- 1.5 days. 

Ignoring the CSpOC TIP time, I did an independent impact prediction, using the development version of the open source TU Delft Astrodynamics Toolbox (TUDAT).

I used the last available orbit (epoch 24358.42010446) and the nrlmsise00 model atmosphere to run a reentry prediction, using a trial-and-error approach to see whether I could tinker with the drag area such that it would reenter near 1.58 S, 37.61 E near 12:00 UTC on December 30. 

From @DutchSpace on twitter, who is very knowledgeable on Ariane hardware, I got a mass of 505 kg for the SYLDA in question. The dimensions for the SYLDA on flight V184 should have been about 4.5 x 6.4 meter (there are different versions of SYLDA with different mass and sizes).

After some trial-and-error, I can make the object reenter at 1.57 S, 37.61 E  on 30 December 2024 at 11:49 UTC, close to the reported location and time, if I use an average drag area of ~18.24 m². That is a value which is about 63% of the maximum drag area of this SYLDA (roughly 28.8 m²). This is a reasonable value: during earlier reentry analysis for elongated objects like rocket stages (or in this case, a hollow elongated adapter), I found that a drag area of about 60% - 62% of the maximum area is usually a good approximation to account for the variability in drag due to tumbling .

Below is what the approach trajectory from this simulation would be:

click map to enlarge

While my TUDAT simulation does not prove that the object is debris from 2008-034C (SYLDA), it does show that it is feasible for the reported time and location.

How about that 'other' candidate? That was an Atlas Centaur booster, 2004-034B, for which CSpOC gives a TIP of 30 December 2024 21:30 +- 1 m UTC. However, the orbital plane of this candidate did not pass over Kenia at the reported time (12:00 UTC), and moreover, this object was still detected on-orbit several hours after the reported time of the Kenia event (see also Jonathan McDowell's analysis here): the last reported orbit is for epoch 30 December 2024 15:50 UTC (but it is always possible that a part came off earlier). For these reasons, it is not that likely that the Kenia event was due to a part of this object.

@DutchSpace on twitter, who as mentioned is very knowledgeable on Ariane hardware, so far has trouble positively identifying the ring as a SYLDA part (and that worries me). If the reported mass of 500 kg is correct, that is too heavy for it to be part of this SYLDA too. I have some suspicion however that the reported mass is an overestimate.

For now the verdict is: possibly the reentry of parts of the Ariane SYLDA 2008-034C, but not proven beyond doubt yet.

Here is the final output [revised after running both a TUDAT and TUDAT script update] of my TUDAT reentry model (I had it stop at 50 km altitude, as at that altitude the object should have completely fragmented and decelerated, with fragments falling down basically vertically):

mass: 505 kg
drag area: 18.236375 m^2
altitude limit: 50000.0 meter

propagation start: 2024-12-23 10:04:57.030000 UTC
propagation end:   2024-12-30 11:49:25.029545 UTC
final altitude:    49.879

reentry after 7.072 days

REENTRY AT:
2024-12-30 11:49:25.029545 UTC
lat: -1.57
lon: 37.61

Values in the last three lines are nominal only, the error margins over a 7-day integration period are large. Also ignore the superfluous digits. As a reminder: I tinkered with the drag area untill I got a value that made it reenter as close to 1.58 S, 37.61 E and 12:00 UTC as possible, and the above output gives the relevent drag area and the resulting modelled reentry time and location.

The TUDAT script used can be downloaded here (note: you have to use this script with the 'development version' of TUDAT, as the current non-development release of TUDAT has a bug where the epoch of a TLE is incorrectly read). The development version of TUDAT and installation instructions can be found here.

UPDATE 9 Jan 2025:

In a statement to Gaël Lombart of Le Parisien, Arianespace engineers have cast doubt on the identification of the crashed object as a SYLDA part, indicating that the size of the ring does not fit and stating that "this part does not belong to an element of a European launcher operated by Arianespace". So the mystery remains as to what this object's origin is.

The ISS EP9 battery pack observed on its last revolution before reentry

ISS EP9 battery imaged on 8 March 2024 18:17 UTC (click image to enlarge)

On 11 January 2021, a 2.6-tons car-sized container with old NiH batteries was detached from the International Space Station using the Canadarm2 robotic arm, and released into space. The object, called "ISS DEB (EP BATERRY)" by CSpOC, catalogue number47853, COSPAR 1998-067RZ, had since been slowly coming down for an uncontrolled reentry.

This reentry happened on 8 March 2024, at 19:29 +- 1 m UTC according to CSpOC, near 22 N, 85.5 W, over Yucatan and the western Caribean (the +-1 minute time uncertainty indicates that this is likely based on a SBIRS satellite detection of the reentry fireball).

Earlier similar packs of discarded NiH batteries were taken onboard visiting HTV supply spacecraft, to return and burn up in a controlled reentry with the HTV. For this last pallet, no HTV was available anymore, hence why it was unceremoniously tossed into space for a natural, uncontrolled reentry.

 

Canadarm2 releasing the container with NiH batteries into space (image: NASA)

In Germany, for some odd reason the news of the imminent reentry lead to a minor scare, with the German government issuing an alert through their cellphone civilian alert system, as the object would briefly pass over Germany within the (at that time almost a day wide!) reentry uncertainty window.

This alert was unnecessary in my opinion: yes, this was not a small object, and more solid than a rocket stage, but still, objects this size and mass and even bigger reenter several times a month - this was not an unusually large piece of space debris reentering. The very weekend following on this reentry for example, a 5-tons Chinese rocket stage, i.e. twice as heavy, would have an uncontrolled reentry as well. 

Chances of the pallet with discarded batteries coming down over Germany were less than 1%, and even if it would have done so, it would break up into much smaller pieces during reentry, and most of these would burn up in the atmosphere. Some pieces might survive and reach Earth surface, as with any reentry of a somewhat larger object, but the hazard is relatively small and is not of catastrophic proportions. Using the civilian alert system for catastrophies to issue alerts was panic-football, in my opinion, and it unnecessarily spread fear. 

Maybe it was meant to avoid panic in case of a reentry - with a spectacular light show in the sky and possible sonic booms - over Germany: but this alert reached the opposite I feel, creating unrest rather than avoiding it.

On its last orbit, slightly over an hour before reentry, I imaged the object passing over Leiden, the Netherlands around 18:17 UTC (March 8: 19:17 local time), as can be seen in the image above. This was in early twilight.

The object was moving very fast, zipping across the blue twilight sky, and bright: at magntiude -1 to -2 brighter than the brightest stars in the sky. I had no trouble seeing it naked eye. The image in top of this post is a 1/25th second exposure showing it passing through the constellation Auriga, almost right overhead (the bright twilight sky combined with a fast wide angle lensnecessitated a short exposure time).

A day earlier, on March 7th when all the anxiety in Germany erupted, I filmed it under terrible observing conditions (clouds came in just as the object was about to pass), where it was bright enough to shine through the clouds:

The reentry of a Soyuz rocket stage over southern Australia on August 7

click map to enlarge

 

On 7 August 2023 at 13:20 UTC, Russia launched the first of it's improved GLONASS-K2 navigation satellites from Plesetsk Cosmodrome. The launch employed a Soyuz 2.1b rocket with a Fregat upper stage. The payload and the Fregat upper stage were subsequently catalogued in 19156 x 19135 km resp 19182 x 19005 km, 64.8 degree inclined Medium Earth Orbits (MEO), as catalogue numbers 57517 and 57518.

Some 40 minutes after the launch, people from southern Australia and Tasmania were treated to a spectacular sight of a bright slow-moving, fragmenting fireball that crossed the sky. Many eyewitness video's were posted on social media and poicked up by the News media: for a few fine examples see here, here, here and  here. Immediate suspicions were raised that this was space debris.

Indeed, the fireball was the Soyuz 3rd stage reentering the atmosphere. A Navigational Warning for space debris connected to this launch had been published earlier (HYDROPAC 2502/23), for an area south of Australia and Tasmania:

021113Z AUG 23
HYDROPAC 2502/23(75,76).
TASMAN SEA.
WESTERN SOUTH PACIFIC.
TASMANIA.
DNC 05, DNC 06.
1. HAZARDOUS OPERATIONS, SPACE DEBRIS
   071300Z TO 071600Z AUG, ALTERNATE
   1300Z TO 1600Z DAILY 08 AND 09 AUG
   IN AREA WITHIN 35 MILES OF TRACKLINE JOINING
   43-10.00S 148-55.00E, 53-30.00S 163-20.00E.
2. CANCEL THIS MSG 091700Z AUG 23.

The time window matches well with the Australian reentry sighting. The area defined by the Navigational Warning matches a launch into a ~63 degree inclined parking orbit from Plesetsk:

click map to enlarge

 

The Soyuz 2.1b rocket consists of four side boosters ('stage 1'), a core stage ('stage 2') and a third stage. On top of that is (for this launch) the Fregat upper stage. The Soyuz rocket brings the Fregat upper stage and GLONASS payload in a low parking orbit. From there, a series of firings of the Fregat stage bring the payload to 19150 km Medium Earth Orbit (MEO). The Fregat upper stage is left on orbit, but the Soyuz stages deorbit downrange from the launch site: the last of these stages, is the stage that reentered over southern Australia about half a revolution after the launch.

GLONASS is the Russian equivalent of GPS.

Some first analytical results on the debris from the Russian ASAT test of 15 November 2021

 

click image to enlarge

 

In my previous post I discussed the November 15 Anti-Satellite (ASAT) test on the defunct Kosmos 1408 satellite by Russia. On December 1, CSpOC released the first sets of orbital elements for debris fragments created by the test. As of yesterday 2 December, when I made the preliminary analysis presented below, orbits for 207 fragments were published (many more will probably be added in the coming days and weeks). 

They allowed to construct the Gabbard-diagram below, which for each debris fragment plots the apogee altitude (blue) and the perigee altitude (red) against orbital period. They also allowed a preliminary analysis on the delta V's (ejection velocities) imparted on the debris fragments by the intercept.

 

click diagram to enlarge

 

Let's first discuss the Gabbard diagram. Gabbard diagrams show you at a glance what the altitude distribution of the created debris fragments is. As can be seen, most of the debris has a perigee (lowest point in the elliptical orbit) near the original orbital altitude of the Kosmos 1408 satellite (490 x 465 km: the intercept happened at an altitude of ~480 km): but a part of the generated debris evidently has been expelled into orbits with perigees (well) below that altitude too. The apogee altitudes (highest point in the elliptical orbit) are mostly scattered to (much) higher altitudes. In all, debris moves in orbits that can bring some debris as low as 185 km and as high as 1290 km. As can be seen, the debris stream extends downwards into the orbital altitudes of the ISS and the Chinese Space Station. About 35% (one third) of the currently catalogued debris has a perigee altitude at or below the orbit of the ISS: about 18% at or below the orbit of the Chinese Space Station. Upwards, the distribution extends well into the altitudes were many satellites in the lower part of Low Earth Orbit are operating, with the bulk of the debris reaching apogee altitudes of 500 to 700 km.

The plots below show the altitude distributions for apogee and perigee of fragments as a bar diagram:

Distribution of perigee altitudes. Click diagram to enlarge

Distribution of apogee altitudes. Click diagram to enlarge

From the change in apogee and perigee altitudes and change in orbital inclination of the debris fragments in comparison to the original orbit of Kosmos 1408, we can calculate the ejection velocities (delta V) involved. It is interesting to do this and compare it to similar data from two other ASAT tests: the Indian ASAT test of 27 March 2019 and the destruction by an SM-3 missile of the malfunctioned US spy satellite USA 193 on 20 February 2008.

In the plot below, I have plotted the density of debris against ejection velocity (in meter/second) for the Nov 15 Russian ASAT test as a bar diagram (with bins of 5 m/s: the blue line is the kernel density):

click diagram to enlarge

In the diagram below, where I have removed the bars and only plotted the kernel density curves, a comparison is made between ejection velocities from the Russian ASAT test and the Indian and US ASAT tests of 2019 and 2008:

 

click diagram to enlarge

The two diagrams below do the same, in combined bar-graph form, for both the earlier ASAT tests. The first diagram compares the delta V distribution from the Russian ASAT test (blue) to that of the 2008 USA 193 destruction (red); the second diagram does the same but compared to the 2019 Indian ASAT test:

delta V of Russian ASAT fragments vs USA 193. Click diagram to enlarge

delta V of Russian ASAT fragments vs Indian ASAT. Click diagram to enlarge

The diagrams clearly show two things: the distribution of ejection velocities from the Russian ASAT test peaks at lower delta V's than that of the debris from the USA and Indian ASAT tests. In addition, the distribution is more restricted, lacking the tail of higher ejection velocities above 200 meter/s present in the distribution from the other two ASAT tests (we should note here however that this is all still based on early data, and addition of new data over the coming weeks might alter this picture somewhat).

This tallies with what we know about the Russian ASAT test: rather than a head-on encounter with the interceptor moving opposite to the movement of the target, such as in the 2008 American and 2019 Indian ASAT tests, the Russian ASAT intercept was performed by launching the interceptor in the same direction of movement as the target (as shown by NOTAM's related to the launch of the interceptor, see map below), letting the target "rear-end" the interceptor. This results in lower kinetic energies involved, explaining the more compact fragment ejection velocity distribution emphasizing lower ejection velocities. In addition, the possible use of an explosive warhead on the interceptor rather than a kinetic kill vehicle might have some influence.

click map to enlarge

So the Russian test seems to have been designed to limit the extend of ejection velocities and from that limit the extend of the orbital altitude range of the resulting fragments. That is in itself commendable, but it doesn't make this test less reckless or irresponsible. 

The Gabbard diagram near the top of this post, and the bar graphs below it, show that debris was nevertheless ejected into a wide range of orbital altitudes, from as low as 200 km to as high as 1200 km, with a peak concentration between 400 and 700 km altitude. The orbital altitude range of the debris includes the orbital altitudes of crewed space stations (ISS and the Chinese Space Station), thereby potentially endangering the crews of these Space Stations, as well as the busiest operational part of Low Earth Orbit. The diagram below gives the perigee altitude distribution of objects (including "space debris") in Low Earth Orbit, for comparison (note, as an aside, the prominent peak caused by the Starlink constellation at 550 km).

click diagram to enlarge