Wednesday, 5 June 2013

Tracking ESA's ATV-4 "Albert Einstein" the coming nights

If all goes well, ESA's cargoship ATV-4 "Albert Einstein" will be launched from Kourou on top of an Ariane rocket tonight at 23:52 CEST (21:52 UTC). It will dock to the International Space Station ISS on 15 June. A live webcast of the launch will be featured here.

During the 10 days it takes to get to the ISS, it will make several visible passes over Europe, starting the coming night (June 5/6). On the night of June 14/15, it will be possible to see ATV-4 and the ISS pass around the same time, closing in on each other just hours before docking.

For those of you who want to try to photograph an ATV pass themselves, I have written a tutorial, that is featured on ESA's ATV weblog.

Visible passes for NW Europe the coming night (June 5/6) occur at approximately:

* 01:47 CEST (23:47 UTC)
This is a pass that is very favourable for the UK, Netherlands and mid-Germany. In the Netherlands we will see the ATV pass right through the zenit! Here is a trajectory card (valid for Leiden, the Netherlands: elsewhere in Europe the trajectory will be different! For elsewhere in the Netherlands, the trajectory might slightly shift) and a map of the relevant groundtrack:





* 03:20 CEST (01:20 UTC)
A pass in twilight over a.o. the southern UK and France (but also visible from the Netherlands and Germany):



Please note that the spacecraft is actively manoeuvering, and this means that the listed pass times are approximate: there might be differences up to a few minutes with the real pass times.

If you want to get an accurate sky trajectory map for your own location, then Heavens-Above should have predictions available from the moment of launch. A live ground tracking application is available here (it will tell you over which part of the globe the ATV is, but not where in your sky however).

If your are able to run your own predictions (e.g. with Heavensat), then ESA has kindly made TLE's available here.

The relevant TLE for tonight (5/6 June) is:

ATV-4
1 00000U 13156A   13156.95908050  .00000000  00000-0  11891-3 0  0008
2 00000 051.6512 167.2588 0016658 269.7524 354.7951 16.02929810 00002

Depending on the illumination conditions, the ATV can reach mag. +1 and hence be easily visible by the naked eye during a favourable pass.


Monday, 6 May 2013

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.

Friday, 3 May 2013

No, fragments of the Tunguska object have not been found - or at least there is no real positive proof of that


The twittersphere, science news sites and mailinglists are abuzz with the story that fragments of the object that caused the famous 30 June 1908 Tunguska explosion have been found.

Most of them link to this post on the MIT Technology Review blog, which bases itself on this manuscript posted to Arxiv.org by  a Russian named Andrei Zlobin.

To cut it short: it is highly unlikely the objects in question, which were reportedly retrieved from shoal sediments of the Khusmo river, are fragments of the Tunguska object. The "evidence" provided is wholly unsatisfactory. I am convinced the manuscript will not pass peer review (note that papers posted on Arxiv.org are manuscripts: the paper in question hasn't been accepted for publication by any scientific journal yet. And it shouldn't be, in my opinion).

In my opinion the pictured objects look like normal terrestrial iron hydroxide concretions, such as you can find in sandy soils with fluctuating water table and in bogs (and in river sediments that sample such environments). Morphologically they are quite typical for such concretions, especially specimens #3 and #1.

The shell-like character (e.g. #3) is characteristic, as such concretions often form as layers around a core of other material. So I see no reason at all to think these must instead be meteoritic.

In addition, the arxiv paper doesn't give any chemical analysis at all in support of the suggestion these are meteoritic particles. This while such an analysis is the least what you would expect for a claim like this.

The arxiv paper doesn't give any clear chronostratigraphical links between these particles and 1908 (and with this the Tunguska explosion) either. Why should this be particles from the 1908 explosion? What points to that particular origin for these particles? Do they come from sediments that are unambiguously dated to 1908? Zlobin gives no arguments at all.

In other words: this is highly dubious and for now a totally unbelievable story. It is a pitty that many science news websites, starting with the MIT Technology Review but also including Space.com are so uncritically disseminating this Arxiv.org manuscript.

Sunday, 28 April 2013

PANSTARRS and Polar Light - Finland, March 2013

From 17 to 24 March I was in Finland, having fun in the snow at the Arctic circle. We stayed at Basecamp Oulanka at Juumajärvi, 66.26 N, from where we did snowshoe hikes, a husky sled tour, some cross-country skiing, and a trip to a world-famous bird shelter in order to see the Golden Eagle.



Of course, when going to the Arctic circle you hope for Aurora Borealis - the Northern Lights. I had seen Northern Lights before, from the Netherlands (where it is rare but on occasion can be seen), and it was stunning. So my hopes were high for an even better Arctic display. In addition, comet PANSTARRS was slowly moving out of the solar glare around that time. My secret mission: to get an image of the comet with Northern lights.

Mission accomplished, on the very first evening:

click image to enlarge

The photograph is a stitch of two images made with the EOS 60D and a Tamron 17-50mm at 17mm. It was made in late evening twilight of March 17th, the start of an evening with incredible Northern Lights. An M1-class solar flare on the 15th resulted in an earth-directed CME which arrived at the 17th - our first evening in Finland. The result: astonishing Aurora all over the sky, with two especially intense periods between 20-21h local time and around local midnight. The first peak was very colorfull, with a.o. deep purples in addition to green. During the second peak near midnight, it was mostly green Aurora It was very lively, significantly changing on sub-second scales. Rays, dancing curtains, multiple corona's, it was all visible. Seeing Northern Lights in Orion was quite special too.

This all with friendly temperatures of -25 C... As I repeatedly worked the camera with my gloves off, my fingers got numbed, resulting in some images later that night where the camera had moved during exposure, because I hadn't thightened the clampscrews of the tripod head enough. I also used one of my woolen gloves to put the Aputure timer in, as the batteries suffered from the cold. The camera itself help up remarkably well though.

During the first peak I took pictures from the nearby lake Juuma: during the second peak I photographed from the basecamp itself, using the wooden chalets to create some scenic foregrounds. Lenses used were a SamYang 3.5/8mm semi fish-eye, and the 17-50mm Tamron. Here are some pictures (exposures range from 2 to 10 seconds:

click images to enlarge










I took a number of series for a time lapse, resulting in this movie (put it on HD and full-screen: it is 1200x800 pixels):


As it turned out, that night was the only night with aurora that week - but what a splendid show it was! The local Fin people claimed it was the best show of the season.

The next evening, I targetted comet 2011 L4 PANSTARRS in evening twilight, using the Zeiss 2.8/180mm. The following image is a stack of 9 images of 1s each, taken from an unguided stationary tripod:

click image to enlarge

Just before leaving for Finalnd, I already had some views of the comet from (near) my home town Leiden in the Netherlands as well. This image was shot on March 12th from the Cronesteyn polder just east of Leiden:

click image to enlarge




After I returned from Finland, I took a last picture of the comet in the evening of April 2nd, when it was close to M31, the Andromeda Galaxy. This image is a stack of 21 images of 1s each taken with a SamYang 1.4/85mm at F2.8. I had to do quite some image processing, as the images were suffering from light pollution:

click image to enlarge

Tuesday, 23 April 2013

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).

Friday, 12 April 2013

The discovery of asteroid 2013 GM21

I am way behind with my reporting on this blog, for which I apologize. I still have satellite observations from early March to report, as well as (somewhat off-topic) observations of comet 2011 L4 PANSTARRS and spectacular Aurora borealis (Northern Lights) from Finland mid March. For various reasons, I did not come to that yet. Maybe coming weekend...

Meanwhile, a short report on my latest asteroid discovery: 2013 GM21, which was published in the DOU MPEC K13-G54 today (Apr 12, 2013: look for object K13G21M).

On  April 6th, I was on my own initiative (and successfully) trying to get follow-up observations on three objects (2013 EZ102, 2013 EB103 and 2013 EC103) which Krisztian Sarneczky and I discovered in the Konkoly survey from MPC 461 (the 60-cm Schmidt of Konkoly, HU) mid-March. I was "remotely" using the 81-cm Schulman telescope of the Mt. Lemon Sky Center (MPC G84) for that, one of the telescopes in the SSO Network.

In the images that should (and did) contain 2013 EZ102, I found two other moving objects. Both were unidentified - i.e., they were not in the MPCOrb asteroid database of the IAU Minor Planet Center and could be new discoveries! So they were submitted to the MPC with the temporary designations LaMa515 and LaMa516.

One of these (LaMa515) turned out to have been observed by another observatory just days before, so that one was not a new discovery: the other observatory alas beat me to it.


 photo 2013_GM21_LaMa516_6APR_G84_anim_zps6ec97a6c.gif
click image to enlarge


The second object however, a mag +19.5 to +20 object I temporarily designated LaMa516 moving quite close to 2013 EZ102 in the images, turned out to be truely new: my observations of April 6th were the first! It can be seen in the blink above, which shows you a small part of the April 6th discovery images. 2013 EZ102 is in the images too.

I next obtained new images, based on a very rough search orbit fit, on April 7th, 8th and on April 11th, again using the 81-cm telescope of MPC G84. As a result, it was formally MPEC-ed today by the MPC as 2013 GM21: my second asteroid discovery using a "remote" telescope! And my 69th asteroid discovery in total (and 5th in 2013, the other four being in the Konkoly survey. For a full list of my discoveries see here).

The asteroid is a borderline Maria family main belt asteroid. With H=16.8, it is an estimated 1.5 km large. It has the following orbital elements (source: MPC):

2013 GM21

Epoch 2013 Mar. 29.0 TT = JDT 2456380.5   MPC
M 351.06235              (2000.0) 
n   0.24233744     Peri.   39.90632             
a   2.5479390      Node   164.25356             
e   0.0734092      Incl.   17.12483
q   2.3608968      T       2456417.38101 JDT 
P   4.07           H   16.8 
From 13 observations 2013 Apr. 6-11.
 
 


click images to enlarge

As can be seen in the orbital plots, the orbit is well inclined to the ecliptic. I discovered it when it was in opposition and close to perihelion of its orbit, these two factors combining in a maximum brightness for the object. This is basically the same situation as with my earlier discovery 2012 SM58.

Sunday, 17 February 2013

Movie: Why the Russian Super Meteor was not related to asteroid 2012 DA14 - explained with the help of an orange

Dutch note: een Nederlandstalige versie van deze video is eerder hier gepost.



Added Note: the reality is slightly more complex than I present it in the video, as objects that graze just past the earth limb are slightly deflected by earth gravitation and can end up on (low) northern latitudes. Latitude 55 N is out of the question though, and as this added detail might make the story too complex I decided to leave it out.

Filmpje: waarom de supermeteoor boven Rusland niets te maken heeft met planetoide 2012 DA14 - uitgelegd met behulp van een sinaasappel

Note to English readers: an English version of the Dutch language video below is posted in a separate post here.




Toegevoegde noot: Het is in werkelijkheid iéts complexer dan ik hier doe voorkomen, omdat een langs de rand van de aarde scherend object door de aardse zwaartekracht iets wordt afgebogen en er zo dus wel fragmenten op (lage) noordelijke breedtegraden terecht kunnen komen. Maar 55 Noord is echt buiten de mogelijkheid, en ik heb dit er daarom maar uit gelaten omdat het anders misschien te complex werd.

Saturday, 16 February 2013

On national television about 2012 DA14 and the Russian super meteor

Yesterday was a crazy day, that started as soon as I woke up, opened my e-mail and saw the messages about the Russian super meteor event. Next, my telephone was red-hot from phone calls, and my e-mail and twitter flowed over from private messages by persons and news media seeking information.

I got two TV crews visiting me, plus a radio reporter, and I turned down a couple of other media requests.

At 22:00 (10 pm) Dutch time I was Live in the broadcast of 'Nieuwsuur', a prominent news program on Dutch national television channel Nederland 2. Through a satellite connection, I was interviewed by the news anchors in the studio, while I was standing next to my telescope in my courtyard. The topics were both the Russian event and the 2012 DA14 asteroid fly-by.

 TV van in the street



screenshots from the live Nieuwsuur broadcast

The video (in Dutch) can be seen here. It starts directly with my item.

I was also interviewed by a regional TV and radio station, TV West. The video of that TV appearance (again in Dutch of course) can be viewed here [link fixed: it initially erroneously linked to the Nieuwsuur item]: my item starts at 3:40 in the video.



TV West filming my explanation


Screenshots from the TV West broadcast

Radio reporter interviewing me

Friday, 15 February 2013

[updated] HUGE fireball over Russia this morning! Not 2012 DA14 related.

A HUGE fireball has appeared over Chelyabinsk, Russia, this morning. And with HUGE I mean: HUGE. Apparent brightness rivalling the sun, and very strong sonic booms leading to glass damage and people being wounded by flying glass. This must have been a seizable object entering the atmosphere.

Phil Plait, the "Bad Astronomer" has very good coverage including some amazing videos here, so I will refer to him for imagery and the general story (apart from two I include below: one showing the meteor, the other one the arrival of the shock wave).





Below, I will briefly explain why this fireball cannot have been a fragment of 2012 DA14, the ~50 meter wide asteroid that will pass very close to earth coming evening (Feb 15, 2013).

First of all (and Phil Plait points this out as well), the fireball in Russia came from the wrong direction. Several of the videos show it appearing in the east near the rising sun, coming from a N-NE direction. That is the wrong direction: fragments of 2012 DA14 are on a south-north trajectory.

What is even more important: fragments of 2012 DA14 could never enter the atmosphere as far north as latitude 55 N (Chelyabinsk). Fragments in orbits similar to that of the asteroid, have a theoretical geocentric radiant at declination -81 degrees, i.e. almost at the southern celestial pole. They hence approach earth from due south. This means that the northern hemisphere is out of reach of these fragments: the northern hemisphere represents (as seen from these approaching fragments) the "far side" of the earth.

[video added 18/02/2013]


[added 18/02/2013] In the above video I explain this more visually, with the help of an orange. In reality, it is slightly more complicated than I present it in the video, as objects grazing the earth's limb are actually slightly attracted by earths gravity and can end up a little bit over the line between "front" and "far" side of the earth. Ending up at latitude 55 N is nevertheless out of the question.

The funny thing is that the latitude of Chelyabinsk and the approach direction of 2012 DA14 (and fragments in a swarm around it) are well established facts, even if the trajectory of the Russian fireball is less so at the moment. So it is quite nice that from the encounter geometry with the 2012 DA14 orbit and the latitude of the Russian meteor alone, we can actualy already exclude a connection between the two with a quite strong certainty.

Fragments in 2012 DA14-like orbits and the Russian fireball itself are also too fast to be temporarily captured in earth-orbit, so that is no explanation either.

This fireball was not man-made space junk either. Besides coming from an unlikely direction, it is too fast and much too bright for that.

These are amazing times: the reentry of a Russian rocket stage seen from NW Europe on the evening of the 13th, then this hughe meteoric fireball over Russia this morning, and a close pass of asteroid 2012 DA14 tonight. Wow!

Wednesday, 13 February 2013

Fireball over NW Europe of the evening of 13 February 2013: Re-entry of a Soyuz r/b

Reports are pouring in of a very long duration, bright fireball near 22:15 CET (21:15 GMT) seen from Belgium, the Netherlands and Germany. Reports indicate 30-40 seconds visibility, and an "explosion" halfway, and some reports indicate sonic booms.

This fireball was with a high degree of certainty the re-entry of a Russian Soyuz 3rd stage, #39083 (2013-007B), the 3rd stage from the Soyuz that launched the Progress cargoship Progress-M 18M towards the ISS on February 11th.

USSTRATCOM issued a TIP message indicating decay at 21:15 +/- 1 m UTC near 49N, 13 E.

Below is a quick map (made using Orbitron) of the trajectory and approximate position of the re-entry.
click map to enlarge

Time, general description and reentry data all fit quite well.

Monday, 4 February 2013

OT - a new telescope and imaging the moon

Since 18 November I have done little in terms of satellite observing, for reasons outlined below. Therefore, a post that is slightly OT - but still astronomical in topic.

Generally bad weather over the past two months - lots of clouds, and even snow mid January - is one primary reason for my inactivity on the satellite observing front. Another is that mid-winter isn't the best period of the year at 52 N due to the "winter blackout" of many objects in LEO. Third, I am occupied these months by a few other things, including the "Super Secret Project" which I obviously can't talk about yet (but is very exciting).

The generally bad weather over December and January meant that I could not yet fully use my new toy. Near the start of December, I obtained myself a new telescope, partly with the proceeds of the Van der Bilt Prize. The telescope is a Celestron C6 Schmidt-Cassegrain (15 cm f=1500) on an SGT Advanced Goto equatorial mount. Here is me showing it off:


For quite a while I wanted a slightly bigger and optically better telescope than the simple Meade ETX-70 and small and very old 4.5" Newton I already had, yet found it just too expensive. The extra money from the Van der Bilt Prize meant it became just feasible for me to finally buy something better.

Since I have no option for a permanent setup and live small, it could not be a very large and heavy setup, so I choose this 6" Schmidt-Cassegrain (the mount is heavier than I expected though). Even though I have not been able to use it extensively yet, I so far like it very much!

Twice in January I could test it out on the moon. Here are some images shot on January 22nd. First, an old-fashioned single shot photograph of the moon disc (C6 prime focus with F6.3 flattener/reducer, and Canon EOS 60D, 1/160s at ISO 200). Seeing was quite mediocre, the air was not quite steady (the image was "wavy" as if reflected on the surface of water):

click image to enlarge

I also used the HD movie capabilities of my Canon EOS 60D to shoot a few short movies, and then stack frames from these movies using Registax. This results in a dramatic increase in detail. The images below are each the result of stacking 200 movie frames, selected out of movie sequences of ~550 frames each, and are my first ever experiments with Registax (which is quite complex to use for a novice):

click images to enlarge

Southern highlands: Clavius and Tycho

Northern part of Mare Imbrium with Sinus Iridium,
Plato and Vallis Alpes

Mare Humorum, Mare Nubium, with Gassendi
and Bullialdus

One of the intended primary goals for this telescope will be to observe asteroid occultations, with the WATEC 902H video camera plus GPS time inserter attached to it.Satellites are not the primary goal of this new instrument.

Wednesday, 9 January 2013

Mapping a year of space debris re-entries

The year 2012 saw as many as 72 uncontrolled re-entries of larger pieces of space debris.

Just for fun, I mapped the data for those 52 re-entries where the time of the re-entry is known to 15 minutes or better. The latter means that the general area over which the re-entry occurred can be established with some confidence.

click maps to enlarge



As can be seen from the kernel density map, Africa got the brunt of the re-entries last year. Common wisdom has it that most re-entries occur over the Pacific. That is true for controlled re-entries, but for uncontrolled re-entries that is not born out by the map above. There is a "but" in this all however: the aparent emptiness of the Pacific is, likely, an artifact of a lack of tracking sensors there. Re-entries over this part of the world will have larger uncertainties in their time of decay estimates, and hence they do not show up on this map.

Tuesday, 1 January 2013

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.

Monday, 24 December 2012

The flashing behaviour of North Korea's tumbling Kwangmyongsong 3-2 satellite

North Korea's first satellite Kwangmyongsong 3-2 (KMS 3-2) cannot be seen from the northern hemisphere at the moment (and hence cannot be observed by me currently). On the southern hemisphere, Greg Roberts (CoSatTrak) in South Africa is however successfully tracking the satellite.

He had a particular good pass on December 20th and obtained a very nice video record, tracking on the satellite with a motorized mount (note: movie has a period of black screen between opening title and start of the video record):

Greg Robert's video from S-Africa
(posted with permission)



The satellite is the object near the center of the screen, flashing about each 8.5 seconds with periods of invisibility inbetween. The moving streaks are stars (the mount is tracking the satellite as it moved along the sky): the other stationary dots in the image are hot pixels on the sensor of the video camera.

The video allows for an analysis of the flashing behaviour of the satellite. I used LiMovie to measure the satellites' brightness on the frames, resulting in the following lightcurve:

click diagram to enlarge

Visible is a clear ~8.45s periodicity with flashes of a specular character (suggesting a flat reflective surface). I have marked this with red triangles 8.45 seconds apart. In between the main flashes, a pattern of smaller secondary flashes can be discerned in a semi 8.45 second peridicity too (green triangles). They are not exactly positioned halfway between major flashes.

Assuming that each major flash is a flash caused by one of the sides of the KMS 3-2 cube-shaped body, then it completes a tumble once every ~33.8 seconds. Assuming that the less clear secondary flashes are due to a side of the cube as well, the tumbling periodicity would be half of that, i.e. 16.9 seconds.

Greg recorded the UNHA-3 r/b from the launch too. That one too is tumbling:

Greg Robert's video from S-Africa
(posted with permission)


Again, I used LiMovie to extract brightness information from each video frame. That was less successful with this video, because Greg's mount had difficulty keeping up with the fast-moving r/b for much of the record. A considerable part of the video could not be used for analysis, and I had to chop up the analysis in little non-continuous chunks:

click diagram to enlarge


What can be seen, is a flashing behaviour that starts slow and gentle and is increasing in rapidity near the end of the analysis, this being an effect of changing viewing angle.

Contrary to what some alarmist (sometimes almost hysterical) media reports have suggested, the tumbling of KMS 3-2 is by no means dangerous. David Wright over at All Things Nuclear has a very good debunking story about this all, pointing out the many misconceptions rampant in the reporting.

Monday, 17 December 2012

[UPDATED] A post-analysis of the N-Korean launch window, and N-Korean Spooks on my weblog?

On December 12, North Korea surprised the Western world by successfully bringing its first independently confirmed satellite into orbit: Kwangmyongsong 3-2, a reportedly 100 kg cubesat. For images of the satellite and an analysis of its likely components, see here. The satellite was launched with an UNHA 3 rocket from Sohae Launch Centre in Cholsan.

The successful launch came as a surprise for two reasons. First, all previous North Korean satellite launch attempts abysmally failed (even if N-Korea claimed they were a success).

Second, North Korea had indicated days before the launch that the launch was to be postponed to late December, for technical reasons. This appears to have been a deliberate disinformation ploy by N-Korea. According to South Korean press sources, it appears they also tried to play a ruse on the Americans, by pretending to dismantle the rocket when US imaging satellites were overhead, and continuing launch preparations when they were not.




Analysing the time of launch and US satellite coverage of the launch site

Well then: did the North Koreans indeed try to evade US (and Japanese) satellite surveillance?

First, they would not have been able to evade detection of the launch itself by US infra-red early warning satellites such as the DSP satellites and SBIRS in geostationary and HEO orbit. Coverage by these satellites is continuous.

But that was probably not N-Korea's goal anyway. Their goal reportedly was to try to convince analysts of imagery from US imaging satellites (optical and radar) that the rocket was not yet complete at the launch site, and not yet ready to launch for a while. The aim was apparently to throw off US predictions about the "when" of the launch until the very moment of launch itself.

Their concern hence was with US and Japanese optical and radar imaging satellites such as the KH-12 Keyholes, Lacrosses, FIA and IGS. These imaging satellites move in LEO, and coverage is not continuous- not yet at least.

Indeed, the timing of the North Korean launch (00:49 UTC on December 12) is interesting. It coincides with the end of a one hour long interval with no coverage of the launch site by US or Japanese Low Earth Orbit imaging satellites.

By contrast, in the hours prior to and after this one-hour gap in coverage, such periods of non-coverage were much shorter (typically 10-15 minutes at best), as can be seen in the coverage analysis images below and the movie near the top of this post (movie, images and analysis made using JSatTrak).

click image to enlarge


As can be seen from the coverage analysis, this hour long interval between 23:45-00:45 UT really stands out compared to the hours before and after. The N-Koreans launched right at the end of this interval at 00:49 UT, just when the launch site was coming into reach of the FIA Radar 2.

I feel the launch right at the end of this interval is no coincidence: they picked a moment where prior to launch they would have a substantial gap in US satellite surveillance available to complete their launch preparations. The one-hour long interval seems to have provided the North Koreans enough time to remount whatever they dismounted or camouflaged as a ruse, and launch.

(some remarks on the analysis and movie above: for a few of the satellites shown, positions are not 100% certain. For example, the Keyhole USA 186 hasn't been observed for a while because of the midwinter blackout. Satellites included in the analysis are the Japanese IGS, the US Keyholes, Lacrosses and FIA [edit: plus SPOT, Worldview and Quickbird commercial imaging satellites]).

Update 17/12 12:45 UT: 
I initially forgot to include the GeoEye Worldview and Quickbird commercial imaging satellites in the analysis. These commercial sats are frequently hired by the US government for selected imaging and used by independent analysts as well.

I have now added these satellites to the analysis, and the one-hour gap coverage between 11 Dec 23:45 and 12 Dec 00:45 UT keeps standing:




click image to enlarge

Update 17/12 16:00 UT:
Also added the French SPOT satellites to the analysis. Again, the 1-hour coverage gap between 11 Dec 23:45 and 12 dec 00:45 UT keeps standing.



Korean Spooks on my weblog?

There is a bizarre twist to this all that involves this weblog. In the late morning of December 8th, four days before the launch, an IP solving to North Korea visited this weblog. It entered through web-searches that included the keywords 'tle', 'KH-12' and 'Lacrosse 5'. A screenshot of the web statistics is below:

click image to enlarge

North Koreans with access to international websites are about as rare as, well, North Korean unicorns. Only a very select handful of North Koreans -mostly direct family members of Kim Jong Un- are allowed access to the internet.

Disclaimer: I was (and am) slightly suspicious. IP's can be spoofed, and two things caught my eye. One is the OS listed, Windows Xp. N-Korea is supposed to have its own OS, 'Red Star'. But then, maybe they only use this for their own, completely internal version of the internet. Or maybe western webstatistics providers cannot properly recognize it and list it as Xp (plus it could be a knock-off of Xp, even).

Second initially suspicious detail: the 10:05 and 10:07 visits have the word "satelliet", not "satellite" in the search string. That raised some suspicion as "satelliet" is the Dutch word for "satellite". However: that could also be a simple typo (switching the last two characters - a very common kind of typo) instead of a Dutchman typing.

Assuming that this was a real N-Korean visit, then the visit is highly interesting with reference to the apparent ruse played on US satellite surveillance of N-Korea as analysed above.

For here we apparently have a North Korean, a country where the average Kim is not allowed access to the internet, looking for orbital information on US surveillance satellites on my weblog!

This moreover was someone with at least some knowledge of satellites - again, not your average North Korean Kim, but suggestive of someone from the NK space program or intelligence program. The specific keywords 'tle' (two-line elements, i.e. a set of satellite orbital elements) and 'Lacrosse 5' (a US radar imaging satellite) and 'KH-12' (US Keyhole-12/Advanced Crystal optical imaging satellites, i.e. the satellites USA 129, USA 161, USA 186 and USA 224) bear this out.

Yet this person wasn't perhaps entirely informed. He or she searched for orbital information on those US optical and radar imaging satellites that form the backbone of US space-based surveillance, but notably missing from the search queries is the most recent addition to the US radar surveillance constellation, the two FIA Radar satellites. Also missing are Japan's IGS satellites. But, maybe, after checking for the KH-12 and Lacrosse 5 they realized they should not be on my blog for this information - they should be at Mike's website for that.

Thursday, 29 November 2012

Video of my lecture (in Dutch) on Hunting for Asteroids and the Van der Bilt Prize ceremony, 10 November 2012

As related earlier on this blog, I was much honoured to receive the Dr J. Van der Bilt Prize of the Royal Dutch Astronomy and Meteorology Association (KNVWS) on November 10, 2012.

The post linked above already provides a narrative of that day and a couple of photographs. This current post is to point the interested reader to video of the ceremony (in Dutch), shot by my GF:



As is customary, I did a 1-hour lecture on (part of) the activities which earned me this prestigious prize. In my case, the lecture focussed on my asteroid search activities.

Video of that is below, in three parts of approximately 20 minutes each. The lecture is in Dutch. Ignore the camera repositioning near the start of part I, it becomes stable after a few minutes (when also my lecture gathers more steam):

Part I (20 minutes):

Part II (20 minutes):

Part III (15 minutes):

Friday, 23 November 2012

UNID geosat Unknown 121118 is probably the classified SIGINT Mercury 1 (94-054A)

As I reported on this blog earlier, I discovered an unidentified object in an 8.4 degree inclined geosynchronous orbit in the evening of November 18 (see images below). It was given the designation "Unknown 121118" and also observed by Greg Roberts from South Africa the next evening, showing it to be truely geosynchronous at longitude 48 E.

click images to enlarge



I initially thought it would probably be a commercial satellite that had been recently relocated. However, as USSTRATCOM has still not identified the object, we are beginning to suspect it is a classified object, and we have some idea of its identity.

Ted Molczan pointed out that the 8.44 degree inclination is similar to that of Mercury 1 (94-054A). The brightness of the object is similar too. Mercury 1 was last located over the western Atlantic near 43 W, and had not been observed for over two months. Peter Wakelin imaged its former position on November 21 and could not find it. So there is a good chance it has been moved, and is my Unknown 121118, now located at 48 E.


click map to enlarge

The Mercury (also known as 'Advanced Vortex' ) geostationary satellites are classified US military SIGINT ('eavesdropping') satellites. Two were launched during the 1990-ies: the launch of a third one failed when the rocket booster malfunctioned, destroying the satellite. Mercury 1 (94-054A) launched on 27 August 1994 was the first. Given that it now appears to have been repositioned and is station-keeping at 48 E, is appears to be still operational, 18 years after it was launched.

Why it has been repositioned over 48 E, somewhere within the last two months (and probably near the more recent part of that timespan) is a matter of speculation. Maybe it is monitoring communications on the Syria-Turkey border; maybe it is listening in on Iran; or maybe it is monitoring communications of Somalian pirates near the Horn of Africa.

In June this year I imaged Mercury 1's sister ship Mercury 2 (see here), which was of a similar brightness as 'Unknown 121118'. That object at that time seemed headed for a graveyard orbit and hasn't been observed for a while. It has a slightly larger orbital inclination than Mercury 1 / Unknown 121118.