More on the 21 September 2012 fireball: why it definitely was a meteor

I should have done this analysis earlier but did not have the time available until now. What follows now is a quick and back-of-the-envelope kind of calculation, but in my (not so) humble opinion it is adequate to the question at hand.

It concerns, of course, the splendid slow fireball seen widely over NW Europe near 21:55 UT on 21 September 2012. I posted on it before, focussing on saying "no" to the suggestion that this could have concerned a satellite reentry. In the post that now follows, I further strengthen the conclusion that it was not a satellite reentry, but a genuine meteoric fireball.

The map above gives a quick (and not particularly accurate) back-of-the-envelope reconstruction of the fireball trajectory. It is based on trajectory descriptions from Bussloo in the Netherlands and Dublin in Ireland: by taking reported altitudes (with respect to stars) and general directions of reported start and endpoints, and an assumed altitude of 50 km, the trajectory above is what approximately results. (update 19:10 UT, 24 Sep: an updated version of the map is at the bottom of this post).

The resulting trajectory is some 1000-1200 km long. In what now follows, I have taken 1100 km as the distance travelled by this fireball.

Observers near the western and eastern ends of the trajectory would probably not see the complete trajectory. Observers approximately mid-way, in mid-Britain, would potentially see most if not all of the trajectory (from experience I know you can see bright fireballs from distances of 500 km).

Observers report durations between 20-60 seconds: most video's on the web suggest a 40+ seconds duration.

It would take a reentering satellite travelling at 8 km/s (the orbital speed at decay altitudes) about 138 seconds or roughly 2.25 minutes to travel this distance. While the reported fireball durations are long, none of the reports nor videos comes even remotely close to that value.

A meteoric fireball travelling at the lowest speed possible for such an object, 11.8 km/s, would take 93 seconds to travel that distance. This is still longer than almost all of the reports suggest, but clearly getting closer.

If we take an estimated duration of 60 seconds, the 1100 km trajectory length results in a speed of  approximately 18 km/s.

18 km/s is a very reasonable speed for a slow, asteroidal origin fireball.

(it is, let me repeat, also way too fast for a satellite reentry).

Meteorite dropping fireballs typically have speeds between 11.8 and 27 km/s. A speed near 18 km/s sits squarely in the middle of that speed interval.

(update: diagram added 14:45 UT, 24 Sep)

(click diagram to enlarge)

The 60 seconds probably represents the upper boundary value for the duration of the fireball. If we take a shorter duration of 40 seconds, the speed already increases to 27.5 km/s.

This quick back-of-the-envelope reconstruction therefore shows that this must have been a meteoric fireball, quite likely of asteroidal origin, and we definitely can exclude a satellite reentry.

The fragmentation described and filmed is not unusual for meteorite dropping fireballs (see the video's of the Peekskill meteorite fall in my previous post). The object probably entered the atmosphere under a very shallow angle, which together with the slow speed explains the unusually long duration of the event.

Meteors of this kind are rare, but they have been seen before. Think of the Peekskill meteorite fall, but also the famous 1972 daylight fireball over the Grand Tetons (that had a duration of over 100 seconds) and the Cyrilid Meteor Procession from 1913 (that lasted minutes).

Note: a previous post gives a number of other lines of evidence which likewise suggest this fireball was not man-made space debris.

UPDATE: a further update is given in a new post: a very cautious orbital solution suggests an Aten orbit.

Note 2: on how I made this quick and (emphasis) rough trajectory reconstruction. I took observations that contain clear sky locations: e.g. a sighting from Dublin stating it went "through the pan of the Big Dipper"; the description from Bussloo observatory in the Netherlands; and later adding a.o. a photo from Halifax, UK, showing it just above the tail of Ursa Major. These descriptions can be turned into directions and elevations. Next, I drew lines from these sighting points towards the indicated directions, marking distances roughly corresponding to 30, 50 and 80 km altitude as indicated by the observed elevation [ distance = altitude / tan(elevation) ]. Near the start of the trajectory I marked 50 and 80 km, for Britain and Ireland I marked 30 and 50 km. These points then provide you with a rough trajectory.
From Dublin the object passed through North towards west. From Bussloo the object started NE (azimuth 60 degrees): these are important points of information too as it shows that the object started at least as far east as the Dutch-German border (and more likely over Sleswig-Holstein in N-Germany) and had its endpoint at least as far west as the northern part of Ireland.

Above: Updated map version, 24 Sep 19:10 GMT , also showing the principle of how it was reconstructed for three sighting locations. With thanks to Ramon van der Hilst for providing more detailed information on sky trajectory as seen from Bussloo (NL) on request.

30 (mostly) geostationary objects in one image

Click image to enlarge

The image above was made by me just after midnight of June 18-19, 2012. It is a single image taken with my new Canon EOS 60D and a SamYang 1.4/85mm lens (800 ISO, 10s exposure). It was shot from the center of Leiden town.

The image shows a 11 x 14 degrees wide field low in the south-southeastern sky, between 20 and 30 degrees elevation above the horizon. Diagonally over the image runs a part of the geostationary belt, at declination -7.4 deg for my location.

In this single image, as much as 30 mostly geostationary satellites are visible: 23 commercial geostationary satellites, 1 classified military geostationary satellite (Milstar 5, 2002-001A), and 6 rocket boosters.

I did a poor job with the focus of this image, resulting in a slight unsharpness (especially near the edges of the image). Yet, the number of  objects nevertheless visible in this small piece of low southern sky is amazing!

This is just one of several images I took that night. Apart from Milstar 5, a number of other classified (military) geostationary satellites were imaged and astrometry on them obtained.



PAN in it's new position at 37.9 E

One of these objects is PAN (2009-047A), an enigmatic satellite I have written about before. Here is an image from June 18-19:

click image to enlarge

One of the curious aspects of this strange classified geostationary satellite operated by an undisclosed agency (see Dwayne Day's article in The Space Review), is that it is very frequently repositioned. It recently did so again (see my imagery of May 16, when it was still on the move). It has now stopped drifting and taken up position at 37.9 deg E (a position it has occupied before) not far from Paksat 1R, as can be seen in the image above. A stray Atlas Centaur rocket booster passed the area as well when the image was taken.


Vortex 4 and Mercury 2

Other classified objects imaged include  the older geostationary satellites Vortex 4 (1984-009A) and Mercury 2 (96-026A), the latter of which currently also is on the move (it is probably being sent to a disposal orbit after reaching the end of its operational mission):

click image to enlarge

Vortex 4  (launched on 31 January 1984) and Mercury 2 (USA 118, launched on 24 April 1996) both are SIGINT (eaves-dropping) satellites, with the Mercury being a further advanced version of the Vortex.

In addition, a newer SIGINT satellite was imaged as well,  Mentor 4 (2009-001A, one that frequently features in this observational blog, as it is bright and easy to observe), and the object designated by our amateur network as  UNK 060616 (probably an old r/b).


Prowler, AEHF 1 and DSP F15 imaged from Winer observatory, USA

While the above imaging was all done from my home in the Netherlands, I also imaged a few objects 'remotely' using the UoI Rigel (MPC 857) 37-cm Cassegrain telescope at Winer Observatory, Sonoita, Arizona, USA.

The enigmatic Prowler (1990-097E), a clandestine launch from Space Shuttle mission STS-38 which has featured on this blog more often (read the intriguing story of Prowler here; plenty of suspense!) was imaged on June 19 and 22. On June 19 I also imaged the military communications satellite AEHF 1 (2010-039A), and on June 22 the old DSP Infra-red early-warning satellite DSP F15 (1990-095A). Images of these objects below:

click images to enlarge

Comet 185P/Petriew

In addition to all these satellites, two  Solar System Minor Bodies were imaged: 2012 LZ1 and 185P/Petriew.

I posted imagery of the June 15 fly-by of Near Earth Asteroid (NEA) 2012 LZ1 here before in my previous post, and obtained more astrometry on this object on subsequent nights. In addition, I obtained some imagery on the faint periodic comet 185P/ Petriew on June 22. Below is a stack of 5 images of 45s exposure each:

click image to enlarge

Not a pretty picture, but the comet was near magnitude +17 to +18! My astrometry has been included in MPEC 2012-M33 (22 June).


New camera: a Canon EOS 60D

I had completely forgotten to mention this: during the second half of May, my EOS 450D camera broke down. During a macro-session on Dragonflies, the shutter broke. Much to my regret.

I had the choice between having the shutter repaired (expensive), or buying a new camera. I choose the latter option, as the new generation of EOS cameras performs notably better than the 450D, especially in performance at high ISO (less noise). So I decided to upgrade.

The choice I made was for the Canon EOS 60D, an 18 MP DSLR with Digic IV processor. So far (and having mostly used it for "normal" photography for now) I very much like it!

Before I can use it on satellites in Low Earth Orbit, I'll first have to complete a calibration program with the camera. This calibration entails the delay between the moment you press the shutter button and the exposure is actually taken; and the real duration of exposures (a "10 second" exposure is not exactly 10.00 seconds). I have some preliminary calibration results by now, but it will take some time before I have final results and can start to use the camera regularly on satellites. For geostationary satellites (where the timing accuracy isn't that much of a factor; rather the astrometry is) the preliminary results I have mean I can already use it (as has been done, see this post).

PAN is on the move, and detection of an unknown object in near-GEO

Last Wednesday evening (16 May) saw very clear skies. Combined with the absence of moonlight, an ideal situation to target geostationary objects, which are low in the sky for me at 52 N. As they are low  and I am in an urban environment, I need a very transparent sky.

Normally I use the 2.8/180mm Zeiss Sonnar, but this time I went for the SamYang 1.4/85mm. The limiting magnitude of this fine lens is only slightly less than that of the 180mm, but the FOV is twice as large (10 x 14 degrees). It is a geostationary magnet: in one single image I counted 20 geostationary or near-geostationary objects! In total, the session (a sweep of some 25 degrees of equatorial sky in the S-SE, at elevations of 15 to 25 degrees) recorded 38 objects: 7 classifieds, 30 unclassifieds and one unknown.


An UNKNOWN object on May 16

As part of the session, an object in near-Geostationary space was serendipitously observed that cannot be matched to any known object (for recorded positions, see here). It was slowly moving near the commercial geosats Eutelsat 36A and Eutelsat 36B (00-028A and 09-065A) and was captured on several images, small parts of four of which are shown below (note the movement relative to the stable Eutelsats):

click image to enlarge

As Heavensat with the latest orbital catalogues loaded showed nothing in this position I initially logged it as a 'UNID'. Then a check with Ted's IDSat software resulted in a very superficial match with the DSP F20 cover (00-024E), but a clearly non-linear delta T suggested this could be a spurious match (see the questionmark and note under my data report here).  Next Mike McCants contacted me, it was indeed a spurious match in his opinion as his analysis of my data suggested an approximate orbit that does not match the DSP F20 cover at all. So for now, the object is designated as UNKNOWN 120516.

Objects like this do not spontaneously materialize, and there is no recent launch that can account for this object. It is therefore likely an old object being relocated. According to Mike, one possible (but by far not certain) option is that it is the classified object Mercury 1 (94-054A, or USA 105), which has not been observed for some time, being retired and relocated to a graveyard orbit.

Unfortunately, both Greg Roberts in South Africa and me here in the Netherlands were clouded out last night and today, so follow-up using Mike's approximate search orbits is troublesome for the moment.


PAN being relocated again

Another classified geostationary object on the move again is the enigmatic PAN (09-047A). This object has an unusual history of frequent relocations, moving to and fro in longitude each few months. It was at 44.9 E in the spring of 2011, then relocated to 39.1 E in the summer of 2011 and next moved to 52.5 E somewhere between late October 2011 (I still observed it at 39.1E on 23 October 2011) and January 2012, when Greg Roberts noted it missing after which Ian Roberts recovered it at 52.5 E early February.

And now its is moving again: Greg Roberts was the first to note this on May 10 and recovered it on May 14 and May 16 while it was and is moving towards 39.1 E (a position it has previously occupied). I imaged it near 39.1 E too on Wednesday evening May 16. Below is a part of one of the images, showing PAN and several commercial geostationary objects, as well as two old rocket boosters in GTO:

click image to enlarge

 Other classified (near-)  geostationary objects observed this evening were the SIGINT Vortex 6 (89-035A, also in the process of being relocated), the SIGINT Mentor 4 (09-001A), it's rocket (09-001B), the Milstar 5 communication satellite (02-001A), the DSCS 3-13 R2 rocket (03-008C) and the DSP early-warning satellite DSP F23 (07-054A).

Apart from these geostationary objects, I observed the LEO object USA 186 (05-042A, a KH-12 Keyhole) as well that evening, in its new orbit after it manoeuvered earlier this year.

FIA Radar 1 through the Pleiades, and Geostationary satellites in Orion

 click image to enlarge

The picture above (10s exposure taken with a Canon 450D and SamYang 1.4/85 mm lens) shows the classified military Radar reconnaissance satellite FIA Radar 1 (10-046A) sailing smack through the Pleiades last Friday.

Friday evening started clear, and I took the opportunity do so some observing. Using the SamYang 1.4/85 mm and the Carl Zeiss Jena Sonnar MC 2.8/180mm, I not only obtained the picture of FIA Radar 1 above, but I also targetted some geostationary satellites, imaging several of them in Orion.

Among the targets were the classified military communication satellite Milstar 5 (02-001A), the SDS data relay satellite USA 227 (11-011A) and the SIGINT satellite Mentor 2 (98-029A). Two other classified objects were captured as by-catch of these objects: the SIGINT satellite Vortex 6 (89-035A) and the object "Unknown 110623" (11-674A), an amateur-discovered object in GTO that is probably a spent rocket booster of a military launch. Note how it created a tiny trail in the image below as it was moving northwards through Orion.

The images below show these objects. Milstar 5, Vortex 6, UNK 110623 plus the two non-classified commercial communication satellites Eutelsat W2 (98-056A) and Intelsat New Dawn (11-016A) are all in the same 10-degree wide 85mm image. The stars of Orion's belt are visible in the top of the image, and Milstar 5 is close to the Orion Nebula. Orion's belt stars are visible at left in the Mentor 2 image as well.

click images to enlarge

 

In one of the other images taken last Friday evening, another commercial geostationary communication satellite, Intelsat 4 (95-040A) was captured while it briefly flared brightly at about 18:58:30 UTC (27 Jan).

The FIA radar and a number of geostationary objects (Mentor 2, Mentor 4) and the NOSS 3-3 r/b were imaged by me two weeks earlier as well, observations on January 14 and 15 which I had not reported here earlier. I also tried to relocate PAN, which recently has been relocated again but so far has not been recovered, although both Greg in South Africa and I in the Netherlands have tried.

Observing Geostationary Satellites from Leiden and Arizona

While the focus was on LEO and HEO satellites earlier in October, I primarily targetted Geostationary satellites last week. Both from my own locality with my own equipment, as well as by means of a "remote" telescope in Arizona.

The two images below were taken from Leiden (the Netherlands) in the early evening of October 23, using my own equipment (Canon EOS 450D + Carl Zeiss Jena Sonnar MC 2.8/180mm).

They show the enigmatic, frequently re-locating PAN satellite (09-047A: see Dwayne Day's article here) and the SIGINT (eavesdropping) Mentor 4 (USA 202) satellite (09-001A), as well as a few commercial geostationary telecom objects: Hellas-sat 2 (03-020A), Thuraya 2 (03-026A) and Paksat 1R (11-042A).

click images to enlarge

As can be seen, PAN and Hellas-sat 2 are a very close pair now, so close that I am not actually 100% sure which one is which (the westernmost one or rightmost one is likely PAN). As can be seen in comparison to this post from May, it has relocated again, from 45.0 to 38.9 E - it did so in July, when I was on hollidays.

Somewhat earlier the same week, when the sky in Leiden was overcast, I took refuge by hiring a "remote" telescope again. This time not the 61-cm of SSON, but the 37-cm Cassegrain of Winer Observatory (MPC 857) in Sonoita, Arizona, USA. While a smaller instrument, this telescope has a larger FOV which is good if the satellite is a bit off from predictions, and allows te satellite to be captured on more than one image when a 3-image run is done. Also, it is cheaper to rent.

Targets were two "usual suspects": the enigmatic Prowler (90-097E: see story and links in my previous post here) on October 17 and 21 and the SBIRS-GEO 1 (11-019A) on October 21:

click images to enlarge

Note: because the telescope follows the stars, the satellites become trailed, unlike the images shot from Leiden which are from a stationary tripod (hence the stars trail, but the satellites not).

A few non-geostationary satellites were tracked the past two weeks as well. They include the STSS Demo 1 & 2 (09-052 A & B) and the USA 89 r/b (92-086C) on October 22, and the HEO ELINT & SBIRS platform USA 184 (06-027A) on October 15.

Prowler

Among the family of classified satellites, three stand out as more mystifying than the rest: Misty 1 & 2, PAN, and Prowler.

The latter has long existed in the realm of rumours only. It was launched by Space Shuttle Atlantis on mission STS-38, which was a classified DoD mission launched on 15 November 1990. Officialy only one satellite, USA 67, was launched from the Atlantis payload bay. This is believed to be a geostationary SDS communications satellite, SDS 2-2.

STS-38 mission patch

USSTRATCOM released catalogue numbers (but no public orbit) for three objects connected to this launch: the SDS satellite USA 67 itself (90-097B, 20963) plus two rocket bodies (90-097 C & D, 20964 and 20965).

The latter was puzzling, as it is one too many (see the discussion by Ted Molcan here), This was the start of the idea that a second, unacknowledged object was launched by STS-38 as well.

In 2004 an NBC journalist referred to such a secret payload by the name of Prowler, in a news-item discussing a Senate debate about a classified spy satellite program drawing criticism for massive cost overruns. The same journalist, citing anonymous sources, did so again in 2007.

According to these stories, Prowler was an experimental satellite used for close inspection of other (non-US) satellites in geostationary orbit (see discussion here), reportedly coming to within decimeters of some satellites. There are suggestions that it was a test of technology which, in wartime, could be used to sabotage enemies' space assets. It was also said to employ stealth technologies to evade easy detection.

Meanwhile, US amateur observers Ed Cannon and Mike McCants had discovered an unidentified near-geostationary object in July 1998. As time progressed and more and more ISON and amateur-discovered objects could be identified with specific launches, this one was one of few left unidentified. This in turn led to suggestions that the object in question was the rumoured unacknowledged STS-38 launch, Prowler. It was likely discovered only after its active lifetime ended, and it was put in a disposal orbit (see below).

Since then, a long term analysis by Ted Molczan has strengthened this identification. The object has al the right characteristics in terms of brightness behaviour and orbital behaviour. It currently is in an unusual librating disposal orbit that seems devised to keep it out of reach of Soviet tracking facilities (see discussion in depth by Ted here). In a second analysis, Ted showed that STS-38 indeed had the opportunity to launch this object and some tell-tale clues to that are present in the manoeuvering history of STS-38 Atlantis. The whole history of the object, from launch onwards but also including the final disposal orbit when the stealth character of the object was lost, was designed with low detectability by Soviet tracking facilities in mind (see Ted's discussion here).

The object now resides in a currently 13-degrees inclined orbit librating between 73 W and 136 W, putting it over the eastern Pacific, with visibility from the western United States. Over the past two weeks , I imaged it a number of times, using the 0.61-meter "remote" telescope of Sierra Stars observatory in California. Below is one of the better images, shot on the morning of July 6th:

click image to enlarge

PAN, and the NOSS 3-5 duo

Monday evening was a nice clear evening with a very transparent sky.

I observed the NOSS 3-5 duo (11-014 A & B), which was captured in a very fine image with a stray nearby, the rocket from the Kosmos 1697 launch (85-097B). De double parallel trail above is the NOSS duo, the single trail under an angle is the Russian rocket (bright star near trails is Deneb):

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I also took opportunity of the transparent sky to target some geostationary objects low in the southeast. Targets were PAN (09-047A) and Mentor 4 (09-001A):

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PAN at its new slot at 45.0 E

Below is an image I shot in the evening of May 9, under not too good conditions (moonlight, and some twilight left).

It shows PAN (09-047A) in its new position at 45.0 E, following the relocation from 49.0 E early May.

Image was shot using the Carl Zeiss Jena Sonnar MC 2.8/180 mm.

click image to enlarge

UNID-I 3 May 2011 = PAN [UPDATED]

On May 3rd, I found two unidentified geostationary objects close to Galaxy 27 and Intelsat 12 (see report and pictures here).

One, UNID-I, was stable in brightness. The other, UNID-II, was flashing. I imaged UNID-I the next night (May 4th) as well, showing it drifting westwards. I might have imaged UNID-II again too, though misidentifying it at that time as Intelsat 12 (except for the occasionally very bright UNID-II, the objects were, due to worse observing conditions, at the edge of detectability).

At that time (see the link above) there already was some suspicion that UNID-I could be the enigmatic classified geostationary satellite PAN (09-047A), caught in the act of yet another relocation.

That suspicion is now confirmed, following additional imaging by Peter Wakelin from the UK on May 8th. Still drifting when I picked it up on May 3rd, PAN now appears to have settled in a new position at 44.9 E, just west of Galaxy 27 and Intelsat 12. It has moved 2 degrees higher in my local sky, to an altitude of 19 degrees.

The identity of the second, flashing UNID, UNID-II which is still drifting westwards on May 8th, is still uncertain. While it is possibly the Indian communication satellite GSat-2 (03-018A) in the act of relocating, Space-Track still lists that object stable in its usual orbit slot placing it at 48 E. So we have something of a remaining mystery to solve there (although in the end, it will probably turn out to be Gsat-2, with Space-Track for some reason failing yet to recognize it is being moved).

UPDATE 09/05/2011: about an hour after I posted this, Space-Track updated the orbit for Gsat-2, showing that UNID-II is indeed Gsat-2, probably on it's way to the graveyard orbit. So, it appears I beat Space-Track to it by several days!

PAN (09-047A) has a history of frequent relocations, making this already enigmatic satellite the more enigmatic. Previous to this early May 2011 relocation, it relocated in early December 2010, an event that I was the first person to detect as well. So far, it has been located at 33.0 E from late 2009 to May 2010 and then was moved to 38.0 E; then to 49.0 E in December 2010; and now to 44.9 E in May 2011.

[UPDATED] Two Unidentified Geostationary Objects on May 3 and 4

May 3 was an unusually clear evening, and I decided to target a few classified geostationary satellites, using the Carl Zeiss Jena Sonnar MC 2.8/180mm.

While imaging the region of PAN (09-047A) and Mentor 4 (09-001A), I found two unidentified objects. Yes: two.

The first object, UNID-I, was discovered close to the commercial geosats Galaxy 27 (99-052A) and Intelsat 12 (00-068A). It was present on multiple images, and the astrometry shows it is stable in declination. It was about as bright as the two commercial geosats, and stable in brightness.

The plot thickened, when a second unidentified object, UNID-II, was discovered just east of the first, just north of the commercial geostationary Syracuse 3A (05-041B). This object was irregular in brightness, alternating between faint and very bright (comparable to Mentor 4 at peak brightness, i.e. about mag. +8).

Below image shows UNID-I near Galaxy 27 and Intelsat 12:

click image to enlarge

The two images below show UNID-II near Syracuse 3A, and the clear flaring behaviour of the UNID.

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On May 4th, the sky quality was poorer. Nevertheless I tried to recover the two objects, with partial success: UNID-II was captured again on several images.

It had drifted westwards, closer to Galaxy 27 and Intelsat 12 towards the position of UNID-I. The latter was not visible on the images, most likely due to the poor sky quality (Galaxy 27 and Intelsat 12 were barely visible either).

The object showed a clear variable brightness behaviour, being invisible in one image and very bright in the next one taken 30s later. Together with the slowly changing declination, this shows that the object is likely UNID-II, not UNID-I.

Below images were taken 30 seconds apart: the object is bright in one, and invisible in the other:

click image to enlarge

In the series of images, it is present in the following images:

from - to (UTC, May 4th)
---------------------------------------
21:03:02.30 - 21:03:12.35
21:04:02.30 - 21:04:12.35 - very bright
21:05:02.30 - 21:05:12.35
21:07:32.30 - 21:07:42.35
21:08:02.30 - 21:08:12.35
21:08:32.30 - 21:08:42.35 - very bright
21:11:02.30 - 21:11:12.35
21:12:02.30 - 21:12:12.35
21:13:02.30 - 21:13:12.35 - very bright
21:14:02.30 - 21:14:12.35 - very bright
---------------------------------------

As can be seen, there is a clear semi-1 minute periodicity in this.

I have no idea as to the true identity of these two objects. As I could find no trace of PAN (09-047A) near Yamal 202 on my May 3rd images, it is possible that UNID-I is PAN once again relocating.

The presence of a second, tumbling/spinning object, UNID-II, close to it however suggests that more is going on. Finding two UNID's close together is definitely weird and might suggest a connection between the two objects.

UNID-II has a small but clear inclination to it's orbit and appears to be drifting westwards. UNID-I is stable in declination, indicating an inclination close to zero. It might be drifting as well (only more observations will tell, given that I failed to find it on May 4th).

UPDATE 5-5-2011:
Ted Molczan feels UNID-II (the flashing one) could be the Indian commercial geosat Gsat 2 (03-018A) in the act of relocating. UNID-I could indeed well be, as I suggested in my report on Satobs, the classified geosat PAN (09-047A) relocating, according to Mike McCants. I captured the same satellite relocating in December last year: this enigmatic satellite is frequently on the move.

Flaring Keyholes in a moonlit sky, and a BWGS meeting

The "Supermoon" of yesterday was not my only observational target. The sky was very transparent, and hence even with this full "supermoon" low in the southeast, conditions were fine for satellite observations.

I imaged two Lacrosses and two KH-12 Keyholes: Lacrosse 3 (97-064A), Lacrosse 5 (05-016A), USA 129 (96-072A) and USA 186 (05-042A). In one of the images, Rubin 4/SL-8 (03-042B) was captured as a faint stray.

Both of the Keyholes and one of the Lacrosses (Lacrosse 3) flared: KH-12 USA 129 did so while the camera was open, yielding the picture below (note the Hyades at the bottom):

click image to enlarge

Flare times:

USA 129: 20:29:08 UTC
USA 186: 20:14:40 UTC
Lacrosse 3: 19:52:40 UTC

Below images show Lacrosse 3 ascending and brightnening over the chimney (with Canis minor in the upper right corner: this was just before it flared), and Lacrosse 5 descending through the tail of the Big Dipper (the fuzzy arc is a reflection from a nearby lightsource):

click images to enlarge

These observations were all done just after returning from a trip to Belgium, where we had a meeting of the BWGS (Belgian Working Group Satellites). It was a small but nice gathering (six attendants, including this author). Below some pictures showing me (left) and Leo Barhorst (right): and BWGS president Bram Dorreman (all pictures taken by Koen Geukens):

click images to enlarge

On the agenda were amongst others the future of flash observations; the observations of flaring geostationary satellites earlier this month; while I did a very short photo-presentation on the recent PAN relocation story (see also here). Our host that day was Koen Geukens.

Satellites near the Pleiades

Yesterday evening (Saturday 29 January) some satellites seemed to be in love with the Pleiades. In a somewhat hazy sky, I observed Lacrosse 3 (97-064A) cruising near the Pleiades and Hyades in twilight, and half an hour later watched the NOSS 3-4 duo (07-027 A & C) cruise right through the Pleiades.

Below are the resulting images. The top image of the NOSS duo cruising through the Pleiades (movement is from top to bottom, with 07-027A leading) was made using the Canon EF 100/2.8 Macro USM lens: the images of Lacrosse 3 were made using the EF 50/2.5 Macro lens.

click images to enlarge

The FIA Radar 1 (10-046A) was imaged as well. Unlike a few nights ago, it did not flare.

The previous night had a better quality sky, so I targetted a few geostationary satellites low above the horizon. Classified geostationary targets imaged were PAN (09-047A), Mentor 2 (98-029A), Mentor 4/USA 202 (09-001A) and the Milstar 5 r/b (02-001B). A number of commercial geostationary satellites were captured as well.

Below image, taken with the Carl Zeiss Jena Sonnar MC 2.8/180mm, shows PAN with the nearby commercial geostationary Yamal 202 (03-053A).

click image to enlarge

The image below, taken with the EF 2.5/50mm Macro, shows Mentor 2, with the stars of Orion's belt and Orion's nebula M42 at left:

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I also accidentally captured a mag. +2.5 sporadic meteor in one of the images taken with the Carl Zeiss 180 mm (FOV only 5 x 7 degrees!):

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The FIA Radar, USA 179 (SDS 3-3) and more

On the 5th, 9th, 10th and on the 16th of January, the skies shortly cleared in the evening and I observed the FIA 1 Radar (10-046A) making some nice passes through the winter sky. On the 16th it was a particularly close race with clouds coming in (the last image in the series has clouds in the image frame).

Below are two images: one from the 10th showing the FIA 1 Radar passing close to the Pleiades; the other showing it passing through the alpha Persei association on Jan 16th.

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I also observed the Molniya orbit satellite USA 179 (SDS 3-3) on the 16th, which was close to the alpha Persei association too. As it was too faint for the 50mm lens, I used the Carl Zeiss Jena 180mm lens for it (brightest star in image is alpha Persei):

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Other objects observed include PAN (09-047A) on the 9th of January. It is still in the fixed position at 49.0 E where it is since December 24 (see earlier post here). That same evening, Mentor 4 (USA 202), Mentor 2 and the Milstar 5 r/b were observed as well. A flashing H2A rocket, 06-059A, was captured as a stray. On the 5th of January, the IGS R2 r/b was captured in twilight, being very fast and very bright.

PAN (no longer drifting) on January 2nd 2011

As I discovered on December 8th 2010 (see here), PAN had started to drift away from it's old position at 38.0 E on 2010 December 1st (see here).

Greg Roberts in South Africa and me in the Netherlands followed it drifting eastwards at a rate of about 0.5 degrees/day over mid-December 2010. I dropped out of the chase after December 14th, when a long period of wintery weather with snow started in the Netherlands.

On December 27th, Greg failed to recover it at the position projected by the drift rate and surmissed it had stopped drifting. He confirmed this on December 29th, when he found it in position 49.0 E. It has stayed in that stable position since.

Below diagram shows that it reached that position at 2010 December 24.2:

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Yesterday evening (2 January 2011) I managed to image PAN in it's new 49.0 E position during a short period of clearings:

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I am happy the drift has stopped, as PAN otherwise would have slowly drifted out of my reach. In it's new position, it is lower and more to the northeast in the sky for me: actually it is now quite low at an altitude of only 17.9 degrees (just above tree-top and roof-top level for my locality), 5 degrees lower in altitude and 11.3 degrees more eastward in azimuth than it was in November 2010.

Below diagram shows the change in azimuth and altitude between late November 2010 (right) and now (left).

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A second NROL-41 (FIA Radar 1) patch

Grey overcast skies and snow do not allow observations currently. South-African observations by Ian Roberts show that PAN was still drifting as off 21 December. Will be interesting to see where the drifting stops (if it continues this way, it will soon drift out of my reach).

In a week or so from now, I will be preparing my overview of 2010 observations. For now, I want to fill the weather-induced lul in observations by showing a recent addition to the patch collection.

A patch for NROL-41, the FIA Radar 1 launch (2010-046A), was shown earlier on this blog here. Recently I however acquired a second patch, which is of much better design:

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Patch designs of the black space program have become a bit generic and bland lately, perhaps as the result of this NRO Director's memo, but the NROL-41 patch above is beautiful. And, with hindsight, offering some clues (to what we now already know from our own observations).

The clue is in the heroine archer. She is aiming for the setting sun (i.e., westwards). I feel this could very well be an allusion to the unusual retrograde (westward) orbit of the FIA 1 Radar.

The purple 'vermicelli' pattern in the nighttime earth actually includes a few character combinations, i.e. acronyms, of units and organizations connected to the launch. Recognizable are amongst others 'NRO', and what appears to be '4 SLS' and 'LRS' or 'LRSW'.

It would be interesting to know what the three white stars in the patch rim signify.

When did PAN start to drift?

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Answer: on December 1st. Which tallies with it still being at her old position at 38.0 deg E on November 28.

Mystery satellite "UNKNOWN 101208" is PAN!

Those of you following this observing blog and the Satobs list, will be aware of the observations of the past week of what appeared to be an unknown geostationary satellite.

It was first observed on December 8th by me, and next by Greg Roberts as well (see here for the discovery, as well as here, and here for the follow-up).

It was first thought to be perhaps DSCS 3-11, but that turned out to be incorrect. So it was a bit of a mystery, as no recent launch was a candidate either. And geosats just don't "materialize" in the sky. Obviously, this was an older geosat being relocated: but which one?!

The mystery has now been solved, by Greg Roberts. The satellite is PAN (2009-047A), relocating to a position more to the east.

Greg imaged the old position of PAN (close to Paksat 1) on the 12th, but couldn't detect it. So he made the obvious conclusion: PAN was gone and identical to the eastwards drifting satellite we called "Unknown 101208" since December 8th.

I can actually confirm Greg's result of the 12th: I imaged the "old" position as well that same evening and like Greg find no trace of PAN, only Paksat 1 is present.

So how about my "observation" of PAN near the "old" position on December 8th, the same evening that I first spotted "Unknown 101208"?!?

It is very embarasing, but I turn out te have been fooled by an image artefact! With hindsight, I should have been suspicious: the little dot I thought was PAN was quite faint, and visible on only one out of 2 images. This unlike my November 28th observations, when the true PAN clearly showed up in its "old" position on multiple images.

Below image shows the image artefact that fooled me on the 8th (the insets show details of this image, and a second image taken 20 seconds later on the same evening which only shows Paksat 1 - which with hindsight should have warned me).

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Here is another image, showing PAN and Paksat 1 on November 28, and Paksat 1 with PAN no longer present on December 12th.

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With the current drift rate of just under 0.5 deg/day, PAN probably started to relocate on or around December 1st.