Testing a new lens for GEO and HEO (SamYang 2.0/135 mm)

The past week brought some clear skies. It also brougt me a new lens, a SamYang 2.0/135 mm ED UMC.

This lens had been on my wish-list for a while, as a potential replacement for the 1979-vintage Zeiss Jena Sonnar MC 2.8/180 mm I hitherto used for imaging faint Geosynchronous (GEO) and Highly Elliptical Orbit (HEO) objects, objects which are typically in the magnitude +10 to +14 range.

The 2.0/135 mm SamYang lens has gotten raving reviews on photography websites, several of these reviews noting that the optical quality of this lens is superior to that of a Canon 2.0/135L lens. And this while it retails at only half the price of an L-lens (it retails for about 460 to 500 Euro).

While I have the version with the Canon EF fitting, the SamYang lens is also available with fittings for various other camera brands.

Focussing is very smooth and easy with this lens. Unlike a Canon-L lens, the SamYang lens is fully manual (both focus and F-stop), but for astrophotography, manually focussing is mandatory anyway. The general build of the lens is solid. It is made of a combination of metal and plastic.

While not particularly lightweight, the lens is lighter in weight than my 1979-vintage Zeiss (which is all-metal and built like a tank, in true DDR fashion). The SamYang has a somewhat larger aperture (6.75 cm) than the Zeiss (6.42 cm), meaning it can image fainter objects. It also has a notably wider field of view (9 x 7 degrees, while the Zeiss has 7 x 5 degrees).

So for me, this seemed to be the ideal lens for GEO and HEO.

And after two test nights I can confirm: this SamYang lens indeed is spectacularly sharp. The first test images, made on January 15 and 16, have truely impressed me. Even at full F2.0 aperture, it is sharp from the center all the way to the edges and corners of the image.

Here is a comparison of the image center and the upper right corner of an image, at true pixel level. There is hardly any difference in sharpness:

click to enlarge

The images below, taken with the SamYang on a Canon EOS 80D, are crops of larger images, all but one at true pixel level.

The first image is a test image from January 15, a nice clear evening. It shows two objects in HEO: a Russian piece of space debris (a Breeze-M tank), and the classified American SIGINT satellite TRUMPET 1 (1994-026A). Note how sharp the trails are (this is a crop at true pixel level):

Click image to enlarge

The next night, January 16, I imaged several geostationary objects (which at my 51 degree north latitude are low in the sky, generally (well) below 30 degrees elevation). While the sky was reasonably clear, there were lingering aircraft contrails in the sky, locally producing some haze. Geostationary objects showed up well however, better than they generally did in the Zeiss images in the past.

The image below, which is a crop of a larger image, is not true pixel size, but slightly reduced in size to fit several objects in one image. It shows the Orion Nebula, several unclassified commercial GEO-sats, the Russian military comsat KOSMOS 2538 (BLAGOVEST 14L), and the classified Italian military communications satellite SICRAL 1B (2009-020A):

Click image to enlarge

The images below are all crops at true pixel level. The first one shows the US classified SIGINT satellite PAN/NEMESIS I (2009-047A), shadowing the commercial satellite telephony satellite YAHSAT 1B. It also shows a number of other unclassified commercial GEO-sats.

PAN/NEMESIS 1 is an NSA operated satellite that eavesdrops on commercial satellite telephony (see my 2016 article in The Space Review).

Note that this image - just like the next images- was taken at very low elevation, and from a light-polluted town center.

click image to enlarge

The image below shows another US classified SIGINT satellite, Mentor 4 (2009-001A), an ADVANCED ORION satellite. It shadows the commercial satellite telephony satellite THURAYA 2 (more backgrounds on this in my 2016 article in The Space Review). At magnitude +8, it is one of the brightest geosynchronous objects in the sky (note how it is much brighter than THURAYA 2):

click to enlarge

The last image below again is a classified US military SIGINT satellite, MERCURY 2 (1996-026A). While 24 years old it is, together with its even slightly older sibling MERCURY 1 (which I also imaged but is not in this image), probably still operational:

Click image to enlarge

After these two test nights, I am very enthusiastic about the SamYang lens. It is incredibly sharp, also in the corners, easy to focus, goes deep (in terms of faint objects), and overall performs excellent. I also like the wide field of view (compared to the 180 mm Zeiss which I previously used to target GEO). Together with the equally well performing SamYang 1.4/85 mm, it might be the ideal lens for imaging GEO and HEO.

Astrometric data on the targetted satellites from these test images are here and here. The astrometric solutions on the star backgrounds in the images had a standard deviation of about 2".

Added 20 Jan 2020:

This last image (reduced in resolution to fit) was taken this evening (20 January) and shows Trumpet 1 (1994-026A) passing the Pleiades:

Click image to enlarge

[Updated] A potential use for satellites in Zuma-like 50-degree inclined orbits

SpaceX's launch of the Zuma satellite on 8 January was interesting, and not just because of the ongoing saga of whether it failed or not (see a previous post).  

The odd 50-degree orbital inclination is another element that made this launch interesting (see discussion in my pre-launch post here: sightings of the Falcon 9 Upper Stage over Sudan after launch later confirmed this orbital inclination).

New ideas started to form post-launch after the Falcon 9 sightings from Sudan made me realize that while it indeed was launched into a 50-degree inclined orbit, the orbital altitude (900-1000 km apogee) was higher than I initially expected, making a proposed link to USA 276 unlikely.

And then @Cosmic_Penguin posted this small message thread on Twitter, referencing this interesting publication. That struck a chord and reinforced an emerging idea about a potential role for satellites in such 50-degree inclined, ~1000 km altitude orbits.

As @Cosmic_Penguin notes, the publication specifically discusses ~50-60 degree inclined, ~1000 km altitude orbits. And it is all about Space-based Radar.

The report pitted several radar sat constellation configurations against each other, but all of them assumes the satellites being in a 1000 km high, 53 degrees inclination orbit. That's very close to the current search estimation of ZUMA's orbit by @Marco_Langbroek. 🤔 (2/2)

— Cosmic Penguin (@Cosmic_Penguin) 10 januari 2018

I had just been looking into the coverage of the Zuma orbit, and it lines up with content in that report.

The map below is a ground coverage map of Zuma, would it have been alive and well. One of the uses of a ~50 degree inclined ~1000 km altitude Space Based Radar satellite mentioned in the report, is for shipping surveillance.

Indeed, a satellite in a Zuma-like orbit would basically cover all Ocean surfaces, except for the high Arctic and Antarctic, which are not that interesting for the purpose discussed below (moreover, the Arctic is extensively covered by groundbased and airborne radar).

click map to enlarge

A (Radar) satellite in this kind of orbit therefore would be very useful to keep track of illicit shipping movements on the High Seas.

Think stuff like embargo-runners, e.g. embargo-breaking shipments of coal and oil to for example North Korea, illegal weapons exports from North Korea, oil exports from Syria, illicit weapons transports to the Middle East, and human trafficking as well as drugs shipments.

Ships engaged in such illegal activities sometimes turn off their transponder, making it harder to track their whereabouts once out of sight of landbased shipping radar (see also the story about one particular embargo-breaking ship here). The classified US NOSS duo ELINT satellites and similar Chinese Yaogan triplets are meant to track ships from passive radiosignal crosslocation, but when a ship displays strict radio silence, these systems will not detect them either. But Space-Based Radar will.

Embargoes have become an important geopolitical tool when outright war is deemed not an alternative. We currently see embargoes enforced with regard to for example Syria and North Korea. Means to enforce embargoes including detecting and stopping potential embargo violations therefore have become important. Human trafficking and drugs trafficking are growing geopolitical problems as well.

So was Zuma meant to be an (experimental, i.e. a technology demonstrator) version of such a Space Based Radar for Ocean shipping surveillance? It is an option.

What might argue against it is the extreme secrecy surrounding the launch. Very few details were made public about the Zuma payload, the Agency operating it was not disclosed, and the launch was announced very late.

For all of this, explanations can be sought, but that admittedly all is "special pleading". For example, maybe the secrecy is there because the mission involves cutting edge experimental Radar technology. Or the secrecy could simply be the result of the "secrecy cult" in some parts of the US Government going over the top. Or it could point to operation by an Agency that wants to keep this operation on the down low - e.g. the CIA. And I can think of a few more - much more outlandish, which is why I won't mention them here - potential reasons.

We have seen this kind of secrecy before with PAN (and its later sister ship CLIO), with Prowler, and more recently with USA 276. All of these were experimental satellites doing unusual things: PAN roved between, snug up to and eavesdropped on commercial geostationary satellite telephony satellites. Prowler was an experiment for covertly inspecting other geostationary satellites on-orbit. And USA 276 remains mysterious but a series of very close encounters to the International Space Station suggest it might be a technology demonstrator for observing rendez-vous manoeuvres in space.

Zuma (the more so now it might have failed) also strongly brings the infamous USA 193 satellite to mind, although there we do know that it was a satellite for the NRO, and likely an experimental radar satellite [edit: see added note 2 below].

Nevermind what Zuma really was meant to be, and who was to operate it: the message to take home is that High Seas shipping surveillance is a potential and viable role to keep in mind for any future satellite launched in a ~1000 km altitude, ~50 degree inclined orbit.


Added note 1: Cosmic Penguin pointed out to me that this was also earlier brought up in a forum post by Ed Kyle.

Added note 2, 12 January 2018:  This article suggests Zuma might be an electro-optical/SAR hybrid and a follow-on to the infamous USA 193:

"Second, the Northrop Grumman satellite may be a follow-on to another failed satellite US 193. [...] ...., a source with direct knowledge of the program told me it was a blend of radar and electro-optical and would not provide any more detail than that. A source with wide knowledge of classified space programs has told me that the Northrop Grumman-built Zuma may be the next iteration of this. Both were apparently experimental satellites, in that they were not part of a large constellation of similar satellites."

Such a spacecraft would be well suited for the purpose indicated in this blog post.

Also, Northrop-Grumman, the company that built Zuma, has actually worked on developing ideas for Space Based GMTI Radar, which again would suit well to the purpose I suggest in this blog post.


Acknowledgement: Hat Tip to @Cosmic_Penguin on Twitter for putting ideas into my brain.

SIGINT Galore!

USA 136 (Trumpet 3), a TRUMPET in HEO. 28 Nov 2016
click to enlarge

The evening of 28 November was very clear - no moon and an extremely transparent sky, with temperatures around zero.

I used it to target several objects in GEO and HEO. Due to the favourable sky I could use exposure times twice as long as usual.

All the classified objects imaged were Signals Intelligence (SIGINT) satellites, i.e. eavesdropping satellites. The image above shows you one of the TRUMPET satellites, USA 136 (1997-068A), crossing through Andromeda. This is an object in a 63 degree inclined HEO orbit. The satellite was coming down from apogee at that moment and at an altitude of ~31 500 km.

Below is another object in HEO, USA 184 (2006-027A). This too is a SIGINT satellite, part of the TRUMPET-Follow On program (aka Advanced TRUMPET. It also serves as a SBIRS platform.

USA 184, a TRUMPET-FO in HEO, 28 Nov 2016
click to enlarge

This object was near apogee at this moment, at an altitude of 39 000 km over the Faroër Islands, which is why it looks stellar in this 20-second exposure. The star field is in Cassiopeia.

Both these objects hadn't been observed by our network for a while, hence they were somewhat off their predictions (1.5 degrees in position in the case of USA 136; and 1 degree off position in the case of USA 184).

I also briefly imaged a part of the geosynchronous belt, much lower in the sky. The targetted GEO objects were SIGINT satellites too: both Mercury 1 and Mercury 2 (1994-054A and 1996-026A), The Advanced ORION satellites Mentor 4 and Mentor 6 (2009-001A and 2012-034A) and the NEMESIS satellite PAN (2009-047A).

PAN and Mentor 4 (both shown below) have a story attached to them and were the subject of my recent article in The Space Review, which you can read here.

PAN (USA 207), a NEMESIS in GEO, 28 Nov 2016
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Mentor 4 (USA 202), an Advanced ORION in GEO, 28 Nov 2016
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A NEMESIS in the sky: PAN, Mentor 4 and close encounters of the SIGINT kind

I have published an article with the above title in The Space Review. Click here to read it.

Geostationary bonanza

click to enlarge

The images above and below are two small parts of one single image shot on May 2nd 2016, using a SamYang 1.4/85mm lens on a Canon EOS 60D with 30 seconds exposure (ISO 1000) under a very dark sky. These two image excerpts overlap in the corner: the upper right corner of the image excerpt above overlaps with the lower left corner of the image excerpt below.

Although both sub-images are only a few degrees wide, they show a bonanza of objects, including 3 classified objects.

In the image above, 11 objects including the classified SIGINT satellite PAN (2009-047A) are visible. PAN is parked next to the commercial communications satellite Yahsat 1B.

In the image below, 10 objects including two classified objects are visible: the two classified objects are the SIGINT satellite Mercury 1 (1994-054A), and the SIGINT satellite Mentor 4 (2009-001A), the latter parked next to the commercial communications satellite Thuraya 2.

The full 10 x 14 degree image, of which the images featured here are small excerpt parts, shows over 30 objects.

click to enlarge

Imaging a "UFO" (Ultra High Frequency Follow-On)

UFO F2 on 3 March 2016
(click image to enlarge)

The image above is my first image of a UFO...

(* cue X-Files tune *)

No need to call in Mulder, however. The object in the image is a geosynchronous satellite, UFO F2 (1993-056A).

The truth is out there

The acronym 'UFO' in this case does not stand for the classic Unidentified Flying Object. It stands for Ultra High Frequency (UHF) Follow-On, the name of a class of US Navy communication satellites.

The UFO satellite constellation consists of 11 satellites (not all of them operational) in geosynchronous orbit, launched between 1993 and 2003. It serves fleet-wide communication needs for the US Navy (including its submarines, but also Marine units on land). The system is currently being replaced by the newer MUOS constellation (see a previous post) and will gradually be phased out.

UFO satellite constellation on 9 March 2016
(click image to enlarge)

The first launch in the series, the launch of UFO F1 on 25 March 1993 with an Atlas 1 from Cape Canaveral, resulted in a partial failure to reach the intended geosynchronous orbit due to the failure of one of the rocket engines. The second UFO launch, UFO F2, the one imaged above, was the first truely successful launch of this satellite class.

USA 236 on 28 February 2016
(click image to enlarge)

I imaged more geosynchronous objects the past week, taking advantage of clear moonless evenings. The image above shows a star field in Orion in the evening of 28 February 2016, with USA 236 (SDS 3 F7, 2012-033A), an SDS data communications satellite in geosynchronous orbit. These satellites relay data from other US military satellites, optical and radar reconnaissance satellites in Low Earth Orbits such as the KH-11 'Keyhole'/CRYSTAL, Lacrosse (ONYX) and FIA (TOPAZ), to the US.

PAN on 28 February 2016
(click image to enlarge)

I also did my periodic revisit of the enigmatic SIGINT satellite PAN (2009-047A) as well (see image above). PAN is still stable at 47.7 E (see my long-term analysis here), near Yahsat 1B. The image above shows it near that satellite and a number of other commercial communications satellites in an image taken on 28 February 2016.

Mercury 1 r on 3 March 2016
(click image to enlarge)

On Feb 28 and March 3, I recovered Mercury 1 r (1994-054B), the upper stage from the launch of the Mercury 1 SIGINT satellite. We had lost this object for a while, it had not been seen for 153 days when I recovered it. The image above shows it in Hydra on 3 March 2016.

USA 186 on 5 March 2016
(click image to enlarge)

As spring is approaching, the visibility of satellites in Low Earth Orbit is gradually coming back for northern hemisphere observers.  This means we can take over from our lone southern hemisphere observer, Greg. The image above shows the KH-11 'Keyhole'/CRYSTAL optical reconnaissance satellite USA 186 (2005-042A) imaged on 5 March 2016.

Imaging Geostationary satellites, and PAN's past relocations

Last week saw some clear evenings, and I used one of them to image some geostationary satellites. It concerned "the usual suspects": MENTOR's, MERCURY's and the enigmatic, probably SIGINT satellite PAN (2009-047A). The latter satellite has not been moved for quite a while now: since the end of 2013 it is at longitude 47.7 E, parked close to a number of commercial comsats. In the past it was frequently relocated, taking positions next to various commercial COMSATS. In four years time between 2009-2013, it moved at least 9 times (which is a lot) to various longitudes between 33 E and 52.5 E.

PAN amidst several commercial COMSATS on 9 December 2015 (click to enlarge)

The diagram below charts these frequent movements of PAN. Relocations typically took place about once every 6 months. Late 2013, they stopped. PAN however must still be operational, as active station-keeping is necessary for it to stay at 47.7 E.

relocations of PAN over time, 2009-2015 (click to enlarge)

Four other SIGINT satellites and a military comsat were imaged as well: Mentor 4 (2009-001A) and Mentor 6 (2012-034A), Mercury 1 (1994-054A) and Mercury 2 (1996-026A), and the military comsat Milstar 5 (2002-001A).

Mentor 4, next to commercial comsat Thuraya 2 on 9 Dec 2015 (click to enlarge)

Mentor 6 and a number of commercial satellites, close to the Orion nebula, on 9 Dec 2015

Using the remote telescope at Warrumbungle (MPC Q65) in Australia, I recently (4 December 2015) also checked-up on the recently launched US Navy COMSAT MUOS 4 (2015-044A). It is still at its check-out location over the Pacific at longitude 172 W, but some recent press statements suggest check-out has been successfully completed, and it will be moved to its operational position at longitude 75 E near India in the spring of 2016.

CLIO

On 16 September 2014, the US military launched an enigmatic satellite (2014-055A) from Cape Canaveral into a geostationary orbit. It was not disclosed for which agency the object was launched (this is information that usually is disclosed). Nor what its function would be (this is information sometimes but not always disclosed). All we know is the rather uninformative name, CLIO, that it was built by Lockheed Martin and based on their commercial A-2100 bus.

CLIO imaged on May 13, 2015 (click image to enlarge)

CLIO is currently located at longitude 108.0 E, over Indonesia, where I imaged it yesterday using the 0.51-m telescope of Warrumbungle (MPC Q65) in Australia. The image can be seen above: CLIO is positioned just north of Telkom 1 (1999 042A), an Indonesian satellite for satellite telephony. (since Telkom 1 is also built on a Lockheed A2100 bus, the brightness difference in the image above is interesting, and probably due to different attitudes (orientations) of the satellites, although it potentially could also indicate custom components on CLIO, e.g. something like a large dish antenna).

click to enlarge

In many ways CLIO appears similar to another enigmatic satellite,  PAN (USA 207, 2009-047A), launched in September 2009 and infamous among our amateur tracking network for its frequent repositioning.

PAN was also built by Lockheed Martin and like CLIO based on the A-2100 bus. As with CLIO, the government agency behind it was not disclosed, and no indications of its role provided. What was known, is that PAN was developed and built rapidly (in less than 3 years time) using off-the-shelf commercial parts, apparently in response to an urgent need of some undisclosed government agency (which I suspect is either the CIA or NSA). Much speculation has occurred about the role of the spacecraft. The frequent relocations (which stopped at the end of 2013) make clear it is not a simple communications or early warning platform. PAN is currently located at longitude 47.9 E over east Africa.

Because of the similarities, several analysts believe that CLIO, five years after PAN, is a follow-on to the PAN program. The two satellites are currently 60 degrees separated in longitude.

An unknown object in (near) Geostationary orbit: Express AM-5?

The evening of December 29 2013 started clear, so I did a small survey of a part of the geostationary belt. Main focus of the session was PAN, as well as Mentor 4 and 6.

Inspecting the images I found an unidentified object in near-Geostationary orbit some 4 degrees east of PAN, between Mentor 6 and NSS 5, on several images (positions here). The image below shows it near M42, the Orion nebula, near 19:17 UT:

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In addition to the UNID you can also see a classified satellite at left, Mentor 6 (2012-034A), a SIGINT satellite also known under the code name Advanced Orion. At right are two commercial geostationary satellites, NSS 5 (1997-053A) and Galaxy 26 (1999-005A).

Cees Bassa in the Netherlands and Greg Roberts in South Africa also observed what is likely the same UNID object later that night. While it is not easy to fit a reliable orbit to such a relatively short span of observations, the suggestion is an object with an inclination near 0 and a Mean Motion of about 0.92 revolutions per day, i.e. an object near Geostationary altitudes.

The Mean Motion could suggest an old object being moved to a Graveyard Orbit. If this is the case, we haven't been able to identify which 'old' object it is yet.

Another option is that this is a new object. The only likely candidate in that case is the Russian satellite Express AM-5 which was launched on December 26th. This object seems to have been temporarily "lost" by JSpOC: as I write this (Jan 2),  Space-Track does not list orbital elements later than December 26th (when it was still in  a temporary transfer orbit).

For the moment, Mike McCants has given it the name UNK 131229 (with the acronym UNK meaning "Unknown").

This observing session also served to check on PAN (2009-047A). PAN is a highly mobile satellite and often moves position in May and December (I have written on the mystery of this satellite before). Not this time, it seems: it is still at the position it has been in for several months, forming a trio with the commercial satellites Yahsat 1B and Intelsat 10:

click image to enlarge

Other classified objects imaged this night were the old SIGINT Mercury 1 (USA 105, "Advanced Vortex", 1994-054A), and the SIGINT Mentor 4 (USA 202, 2009-001A). Mercury 1 was placed at 48 E and recovered by me about a year ago.

click images to enlarge

During this observing session, I captured a bright irregular orange light moving across the sky: a 'Thai Lantern' ( a miniature hot-air balloon). They are the cause of many false fireball and re-entry reports. Here it is, moving through Orion while carried by the wind:

Two days earlier, on December 27, I also did my periodic check on Prowler (90-097E), using the 61-cm Cassegrain of Sierra Stars Observatory in Markleeville, California (MPC G68).

I concluded the evening of the 29th by making some shots of M31, the Andromeda Galaxy. Unfortunately, some thin haze came in after a while. The image below is a stack of 16 haze-free images of 30 seconds exposure each, with a CLS filter (against light pollution - the images were taken from Leiden town center)) and Zeiss 2.8/180mm lens piggyback on the mount of my C6:

click image to enlarge

PAN has moved again [UPDATED]

On April 23 I wrote the following about PAN (2009-047A) and its frequent relocations in my post here:

"No doubt it will move again in the future, perhaps in May as December and May are frequently the months the satellite is moved"

I was very right with the "perhaps in May": PAN is on the move again!

Greg Roberts observing from South-Africa noted it missing at its old position on April 29. He recovered it on May 4th near the commercial geostationary Comsat Yamal 404. It is not (yet) clear whether that is its final position, or whether it is still drifting. Greg next initially thought he recovered it near the commercial comsat Yamal 404 on imagery from May 4th, but that turned out to be a mistake: as Mike McCants pointed out, the object in question was in reality the commercial geosat GSAT 8.

Ian Roberts, another South African observer, then located what likely indeed is PAN near Intelsat 12 on May 6th. Greg Roberts then managed to find it in his earlier images of May 4th as well, confirming Ian's observations.

Just goes to show that even the most secret of all satellites cannot escape the inquisitive eyes of a dedicated amateur.

PAN and Mentor 4 in March

Finally, an update on my observing activities in March. With apologies that it took so long.

In this post, early March observations of the classified geostationary satellites PAN and Mentor 4 will feature. In a second post following this one, I will report on some non-satellite observations: comet PANSTARRS and a fabulous display of Aurora borealis which I observed from Finland.


PAN and Mentor 4

As I noted on the blog before, weather has been extremely bad here since mid November 2012. Many nights were clouded, we had unusual amounts of snow, and spring set in very late (in fact, only last week).

click image to enlarge

The few clear nights we had, usually coincided with a bright moon in the sky. As wintertime is a bad time for LEO objects at latitude 52N  (the visibility window is very short, restricted to twilight) the focus is on objects in GEO during this season: but that necessitates clear moonless nights....

On the evening of March 4 I did an attempt, which was cut short when clouds and haze moved in. The pictures came out bad, but I did manage to image PAN (2009-047A) and Mentor 4 (2009-001A), as can be seen in the picture above. Mentor 4 is a SIGINT: PAN probably is too.

PAN was moved again in December-January, this time taking up position at 42.5 E close to the commercial telecom sat Nigcomsat 1R.

Since its launch in 2009, this enigmatic satellite has frequently moved, and this is unusual. PAN was stationed at 33.0 E from late 2009 to May 2010 and then was moved to 38.0 E. It was moved again to 49.0 E in December 2010, followed by a move to 44.9 E in the spring of 2011. Then it was relocated to 39.1 E in the summer of 2011 and next moved to 52.5 E somewhere between late October 2011 and January 2012. In May 2012 it was moved back to 38.0 E. In December 2012, it moved to 42.5 E. No doubt it will move again in the future, perhaps in May as December and May are frequently the months the satellite is moved.

Note: the listed positions for PAN are based on privately archived TLE's for the satellite. The TLE source is Mike McCants and the TLE's are based on amateur observations of the satellite, notably by Greg Roberts (S-Africa), Peter Wakelin (UK), Ian Roberts (s-Africa) and me (Netherlands).

2012 in summary

It is time for a summary of the observations conducted in 2012.

I have been less active in 2012 than in previous years, logging about half the number of observational nights and obtained positions. The number of classified objects tracked however was somewhat higher.

Number of observing nights: 44
Number of obtained positions:  555
Number of classified objects tracked: 50

These data compared to previous years:

 (click diagram to enlarge)

As in previous years, springtime saw most observational activity:

(click diagrams to enlarge)

The following tables give a summary of the objects observed (with the "obs" column refering to the number of positions obtained on the object):

(click tables to enlarge)

Just for fun, I plotted all obtained positions on an RA/DEC map:

 (click diagram to enlarge)

So, what went on and what was special in 2012?

I continued my coverage of PAN and other geostationary satellites (well visible near declination -7.4 in the diagram above). On May 16, an unknown object in GTO (Unknown 120516) was briefly detected. In November, I found an unidentified geosynchronous object at 48 E that turned out to be the relocated object Mercury 1.

In February, a week after the lauch of the Iranian satellite Navid, I managed to photograph it in orbit.

In the last days of March, I filmed and photographed ESA's cargoship ATV-3 several times. This included vudeo and photographs less than 20 minutes after launch, when it made a deep twilight pass over Leiden. I photographed it again in September, after the ATV decoupled from the ISS again. Both times, my video and photography was featured on ESA's website.

2012 was the year of Dutch astronaut André Kuipers' 6-month stay at the ISS. I attended a live in-flight video contact at ESA/ESTEC Noordwijk on May 29. Earlier, on March 16, I listened in live to a radio contact between Kuipers (onboard ISS) and a Dutch school class with my radio receiver.

Live radio receptions were also obtained during the flight of Soyuz TMA-04M on May 16.

Mid-2012, the Japanese spy satellite IGS 1B performed an uncontrolled reentry, and over the spring and early summer I closely followed its demise, which finally took place on July 26, when I was on hollidays in Italy.

Among the new launches tracked was NROL-36, the new NOSS 3-6 duo (see here and here) launched in September. NROL-15 (a new Mentor, Mentor 5) was also tracked

October was very sad, as it saw the death of our cat, Pippi, on October 30. As related in the link, Pippi was a frequent companion during my observing sessions.

November 2012 was special, as I received the 2012 Dr J. van der Bilt Prize of the Royal Dutch Astronomical Association (KNVWS) on November 10 (see photographs here and video here).

December saw some unusual visitors to this weblog, connected to North Korea's first successful satellite launch.

I also did a number of interviews this year.

2012 was also a good asteroid year too. I discovered 3 new asteroids: 2012 SM58 in September using the 0.61-m telescope of Sierra Stars Observatory and a number of objects with Krisztián Sárneczky in the Piszkéstető (Konkoly) survey.

PAN, other Geostationary satellites, and another UNID (this time Greg's)

As reported earlier I had a prolific observing session on Geostationary satellites in the evening of November 18th, discovering amongst others an unidentified geostationary object now temporarily designated Unknown 121118 (see here and follow-up here with imagery by Greg from S-Africa: an more on it near the end of the current post).

Below is some more imagery showing various classified and unclassified objects. All images were made using a Canon EOS 60D with a SamYang 1.4/85mm lens at ISO 1000.


Unknown 20121117 (Greg's UNID)

The November 18th imagery includes imagery of a second unidentified object, Unknown 121117 discovered by Greg Roberts (CoSaTrak) from South Africa a day earlier on the 17th (a third initially reported  'unid 'by Greg turned out to be identifiable as a known object, a Chinese CZ-3C r/b). So Greg recovered my Nov 18th UNID on the 19th, and I recovered Greg's Nov 17 UNID on the 18th: nice teamwork!

The image below shows it together with a number of nearby commercial geosats (the veil-like lighter streaks in the image are cirrus clouds, who had begone to invade an initially clear sky):

click image to enlarge

Below is one of Greg's images of the object from 17 November taken from S-Africa: in my image above taken a day later the object has drifted quite a distance more to the West.

(image courtesy Greg Roberts, CoSatTrak S-Africa)

Unknown 121117 is a truely uncatalogued object. There is nevertheless some idea about the identity of this satellite, but I am currently not allowed to provide more information.



PAN

PAN (09-047A) and the nearby commercial geosat Paksat 1R visible in Greg's Nov 17th image are visible on my Nov 18th imagery as well. The image below basically fits to the upper image above (see the Eutelsat pair visible in both images), giving you a sense how Greg's Unknown 2012117 has moved in a day time:

click image to enlarge

I have written about PAN on this blog several times before: it is an enigmatic classified satellite that frequently relocates.


Mentor 4, Thuraya 2 and the Mentor 1r

Among the other objects imaged were the SIGINT Mentor 4 (and the nearby commercial satellite Thuraya 2), and a r/b from the Mentor 1 launch, Mentor 1r.

Mentors (the biggest geostationary satellites in existence and the biggest man-made objects in space with exception of the ISS) are relatively bright objects (typically mag. +8):

click image to enlarge

I already posted imagery of another Mentor, Mentor 5, as well as the SIGINT Vortex 6 in an earlier post.


More on my UNID, Unknown 121118

This object in an 8.5 degree inclined geosynchronous orbit (see here and here for earlier coverage) remains 'unidentified' (i.e., is not present in public orbital catalogues such as USSTRATCOM's): we are however starting to believe it could be a classified object that has recently been moved to this location from somewhere else. It is currently positioned over 48.3 E and appears stable in longitude:

click map to enlarge

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.