[Updated] Breaking News: Decay of Soyuz r/b stage from André Kuipers' launch to ISS observed from the Netherlands!

UPDATE - the final TIP for Soyuz r/b 38037 / 2011-078B has been released by USSTRATCOM near 18h GMT and it indeed shows that this was the Soyuz r/b: reentry time is quoted as 16:25 +/- 1 minute GMT at 49 deg N, 7 deg E. This fits the observations well.

In the Dutch press, there meanwhile appears to be a lot of confusion. The Dutch National Police claims that they talked to "NASA" who apparently said it was a "meteor" (or "comet"). So THAT is widely claimed in the press now, to the point of calling the identification with the Soyuz 3rd stage "speculation". Which it is not: it is based on factual data and now clearly confirmed by the USSTRATCOM JSpOC TIP message. What more do you want?!

I have no idea to whom (or even where: NASA is big...) the Police spoke, but for all things it could have been the JPL janitor....

At any rate: appart from my analysis below (which is already clear), the USSTRATCOM TIP message mentioned above makes unambiguously clear that this was the Soyuz 3rd stage.

Note that to access the USSTRATCOM TIP message via the link above you need an approved account. USSTRATCOM is the US military Command responsible for tracking manmade objects in space, and perhaps better known under their former name NORAD.

- end of update

Multiple reports are coming in, among others by experienced Dutch meteor observers Carl Johannink (Gronau) and Arnold Tukkers (Denekamp), of a bright and very slow fragmenting object seen low in the west-southwest near Venus at 16:26 UTC, 24 December.

From the descriptions it clearly was a reentry of an artificial object (space junk), as the event was too long in duration and too slow to be a meteoric fireball.

And it was not "just" a random bit of space debris, it turns out:

The observations fit with 2011-078B (#38037), the last stage of the Soyuz rocket that brought Dutch astronaut Andre Kuipers up to the ISS earlier this week. It was already predicted to decay near this moment by USSTRATCOM.

Below is the  predicted trajectory of the Soyuz  3rd stage for the Gronau/Enschede area (and below that, the ground trajectory). It is based on an orbit with an epoch near noon of 24 December (epoch 11358.49032868. Source: USSTRATCOM), so a few hours old, which will introduce some minor discrepancies (a few seconds in time). But it fits the descriptions very well in terms of time and trajectory in the sky.

click images to enlarge

[UPDATE 7 October 2017]:

I recently modelled the re-entry of 2011-078B in GMAT, using the MSISE90 model atmosphere with actual Spaceweather of that time. Drag surface was set at 60% of the maximum drag surface for a Soyuz upper stage: this yields a decay position and decay time well in agreement with the JSpOC TIP position and is close to what the drag value for a tumbling, fragmenting object would be.

As seen from Gronau in Germany, it yields the following sky trajectory. Compare with Carl Johannink's description below: it matches his description well.

click map to enlarge

- end of update

- continuing original post:

Some quickly translated descriptions by two experienced Dutch meteor observers (compare to the sky trajectory map above for their area):

Arnold Tukkers, Denekamp (Netherlands):

At 17:26 CET (=16:26 UTC) I looked out of the window and saw a strange phenomena just above the rooftops behind us. It looked like a very, very slow meteor fragmented in several pieces. Like Peekskill but less bright.
Multiple fragments. Because it was so low in the sky, I walked upstairs and could still see the last part from the bedroom window. So it at least took 20 seconds. [...]
What a sight! Trajectory for me (did not see initial part) southwest-southeast. Altitude maximum 20 degrees. Colour brown-red.

Carl Johannink, Gronau (Germany):

Just was looking at Venus in evening twilight.
Left of it an object appeared from behind a cloud that I first thought to be an aircraft, but next I found something was not right. The thing sometimes brightened and became fuzzy, trailing a circa 8 degree long tail. Maximum brightness about -4.
The object roughly moved from SSW to SE at an elevation of about 15 degrees. The whole phenomena took over half a minute.

To see the second part of the trajectory I had to walk to a different room. Called in Elisabeth, together we saw the object fragment into pieces (each individual piece about mag. 0 to +1) and then fade out.

The whole event looked much alike to the New Years Eve satellite decay of 1978, albeit being somewhat less bright.

Update:
A number of video's from Germany have surfaced which likely show the event. Here are a few:
video 1
video 2
Video 3 (on the Bad Astronomer's blog)
Video 4
Video 5

FAQ

Read the answers to Frequently Asked Questions for this reentry case I published later here.