Again Terra SAR-X and TanDEM-X, and a rich batch of

Yesterday evening was a very dynamic evening, where conditions changed from clear to clouded to clear in matters of minutes.

Besides the unexpected recovery of a lost classified geostationary, I also observed a number of other geostationary satellites, and another fine flare of the close duo TerraSAR-X and TanDEM-X (for an earlier observation, see here). They flared to mag. -1 at about 17:18:20 UTC, yielding the image below:

click image to enlarge

Movement is from left to right, with TerraSAR-X leading. The distance between the two objects was 3' (arcminutes).

Among the geostationary satellites imaged, were the classified objects PAN (2009-097A) and the Mentor's USA 202 (Mentor 4, 2009-001A) and Mentor 2 (98-029A). In addition, the commercial geosats Express AM-1 (2004-043A), Hellas-sat 2 (2003-020A), Paksat-1 (96-006A, close to PAN) and Thuraya 2 (2003-026A, close to USA 202). This in addition to the recovery of DSCS 3-11 (2000-001A) and the closeby commercial geosats Turksat 2A (2001_002A) and Turksat 3A (2008-030B) .

Below two images show the couple Mentor 4 (USA 202) and Thuraya 2 imaged with the Carl Zeiss Jena Sonnar MC 2.8/180mm; and Mentor 2 imaged with the Canon EF 2.5/50 Macro.

click images to enlarge

Terra SAR X and Tandem X flying in formation (and flaring!)

Over the past months, the two German remote sensing research satellites Tandem X and Terra SAR X (2010-030A and 2007-026A) operated by the German agency DLR have been manoeuvred to form a very tight formation, cruising up together with a distance of no more than a few hundred meters.

This provides a very nice sight for observers, especially since both satellites also produce slow, naked eye flares when the sun-satellite-observer angle is favourable.

Yesterday evening near the end of twilight, I had a favourable pass, with the duo cruising through the zenith at an altitude of around 515 km. They flared while they did this, to mag. +1, at about 17:01:15 UTC (28 Nov), give or take a few seconds. My camera opened just a few seconds after the flare peak, and captured the pair while slowly fading in this 10 second image:

click image to enlarge

Movement is from bottom right to upper left. I measure a distance of 70 arcseconds (or just over 1 arcminute) between the two objects on this image, corresponding at face value to about 175 meter distance. But because there is a small altitude difference between the two objects as well, the true separation between the two is a bit more than this value. Terra SAR X (2007-026A) is the slightly leading and slightly brighter object in the formation.