COBS News archive

“Crescent comet” – CometWatch 15 and 16 April
April 24, 2015
Just when we think we have seen Comet 67P/C-G from all possible angles under the current illumination conditions, a striking view like this presents itself.

CometWatch 15 April – 4 hours later
April 24, 2015
Today's CometWatch entry is another single frame NAVCAM image taken on 15 April, almost four hours after the one that was published last Friday. The new picture was obtained at about 165 km from the centre of Comet 67P/Churyumov-Gerasimenko, where the resolution of NAVCAM is 14 m/pixel. The image has been cropped and measures 10.4 km (the original frame, provided at the end of the post, measures 14.4 km across).

OSIRIS catches activity in the act
April 24, 2015
Rosetta’s scientific imaging system OSIRIS has witnessed a new jet of dust emerging from the surface of Comet 67P/Churyumov-Gerasimenko. The image was presented during the European Geosciences Union General Assembly, EGU, in Vienna last week.

New Comet: C/2015 F4 (JACQUES)
March 31, 2015
CBET nr. 4085, issued on 2015, March 31, announces the discovery of a comet (magnitude ~16) by C. Jacques on CCD images taken on 2015, March 27.2 by C. Jacques, E. Pimentel and J. Barros with a 0.28-m f/2.2 astrograph at the SONEAR Observatory (Oliveira, Brazil). The new comet has been designated C/2015 F4 (JACQUES).

CometWatch 22 March
March 31, 2015
This single frame Rosetta Navigation Camera image was taken on 22 March 2015 at a distance of 77.8 km from the centre of Comet 67P/C-G. The image scale is 6.6 m/pixel and the 1024 x 1024 pixel image measures 6.8 km across.

CometWatch: Around Anubis and Atum
March 30, 2015
Today’s CometWatch entry presents a recent image of Comet 67P/Churyumov-Gerasimenko – taken on 21 March 2015 – along with three previously unpublished close-up images taken during last October’s 10 km bound orbit.

Imhotep up – CometWatch 20 March
March 27, 2015
This single frame NAVCAM image was taken on 20 March 2015 at a distance of 81.7 km from the centre of Comet 67P/Churyumov-Gerasimenko. The image scale of the original 1024 x 1024 pixel image is 7 m/pixel and the image measures 7.1 km across; a cropped, processed version is shown above.

New Comet: C/2015 F2 (POLONIA)
March 27, 2015
CBET nr. 4083, issued on 2015, March 26, announces the discovery of a comet (magnitude ~17) by R. Reszelewski, M. Kusiak, M. Gedek and M. Zolnowski on CCD images taken on 2015, March 23 with a remote-controlled 0.1-m f/5 astrograph of the Polonia Observatory at San Pedro de Atacama, Chile, in the course of their comet-search program. The new comet has been designated C/2015 F2 (POLONIA).

CometWatch 18 March
March 24, 2015
This single frame NAVCAM image was taken on 18 March at a distance of 81.4 km from the centre of Comet 67P/Churyumov-Gerasimenko.

CometWatch 14 March – 6 hours later
March 23, 2015
This single frame NAVCAM image was taken on 14 March at a distance of 81.4 km from the centre of Comet 67P/Churyumov-Gerasimenko. At this distance, the resolution of NAVCAM is 7.3 m/pixel. The image is cropped and measures 6.4 × 5.9 km (the original picture, uncropped, is provided at the end of the post and measures 7.1 km across).

Waiting patiently for Philae
March 23, 2015
For the past eight days, Rosetta has been sending signals to Philae and listening for a response, but the lander has not yet reported back. This report is provided by the German Aerospace Center, DLR.

Rosetta makes first detection of molecular nitrogen at a comet
March 23, 2015
ESA’s Rosetta spacecraft has made the first measurement of molecular nitrogen at a comet, providing clues about the temperature environment in which Comet 67P/Churyumov–Gerasimenko formed.

CometWatch 14 March
March 23, 2015
Today’s CometWatch entry was taken by Rosetta's Navigation Camera (NAVCAM) on 14 March at a distance of 85.7 km from the centre of Comet 67P/Churyumov-Gerasimenko.

CometWatch: Focus on Hapi’s boulders
March 17, 2015
With today’s CometWatch entry, we take a dip into the past, presenting a single frame NAVCAM image obtained on 17 October 2014, when Rosetta was in a bound orbit around Comet 67P/Churyumov-Gerasimenko. The image was taken from a distance of 10.0 km from the centre of the comet, and at that distance, the resolution of NAVCAM is 85 cm/pixel and the full field of view spans 870 metres.

Out of the shadow – CometWatch 9 March
March 16, 2015
Today’s CometWatch entry was captured on 9 March at a distance of 71.9 km from the centre of Comet 67P/Churyumov-Gerasimenko.

OSIRIS detects hints of ice in comet’s neck
March 16, 2015
If it could be seen with the naked human eye, the nucleus of Comet 67P/Churyumov-Gerasimenko would be a dark grey all over. With its array of specialised filters, however, Rosetta’s scientific imaging system OSIRIS can discern tiny differences in reflectivity at different wavelengths across the comet’s surface. In turn, these differences can reveal clues as to the local composition of the comet.

Waiting for a signal from Philae
March 11, 2015
This week, Rosetta will begin listening for signs that Philae is still “alive”. This report is provided by the German Aerospace Center, DLR.

CometWatch 6 March
March 10, 2015
Today’s CometWatch entry is a single frame NAVCAM image obtained on 6 March from a distance of 82.9 km from the centre of Comet 67P/Churyumov-Gerasimenko. The image has a resolution of 7.1 m/pixel and measures 7.2 km across.

CometWatch 28 February
March 09, 2015
Today’s CometWatch entry is a single frame NAVCAM image obtained on 28 February from a distance of 102.6 km from the centre of Comet 67P/Churyumov-Gerasimenko. The image has a resolution of 8.7 m/pixel and measures 9.0 km across.

Rapid changes observed in a comet’s plasma tail
March 06, 2015
Images from a December 2013 observation of the comet C/2013 R1 (Lovejoy) reveal clear details about rapidly changing activity in that comet's plasma tail. To get this image, astronomers used Subaru Telescope's wide-field prime-focus Suprime-Cam to zero in on within 0.8 million kilometers of the comet's plasma tail, resulted in gaining precious knowledge regarding the extreme activity in that tail as the comet neared the Sun. Their results are reported this week in a paper in the March 2015 edition of the Astronomical Journal.