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.