COBS News archive

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.

All-round activity – CometWatch 25-26-27 February
March 06, 2015
Today’s CometWatch features not one, but four single-frame NAVCAM images taken between 25 and 27 February at distances around 80 to 100 km from the centre of Comet 67P/Churyumov-Gerasimenko. More details on the distance, size, and resolution for the individual images are provided in the captions below.

Comet flyby: OSIRIS catches glimpse of Rosetta’s shadow
March 04, 2015
Images from the OSIRIS scientific imaging camera taken during the close flyby on 14 February have now been downlinked to Earth, revealing the surface of Comet 67P/C-G in unprecedented detail, and including the shadow of the spacecraft encircled in a wreath of light.

Sideways – CometWatch 26 February
March 03, 2015
This four-image mosaic comprises images taken from a distance of 94.3 km from the centre of Comet 67P/Churyumov-Gerasimenko on 26 February. The image resolution is 8.0 m/pixel and the individual 1024 x 1024 frames measure 8.2 km across. The mosaic measures 14.6 × 14.7 km.

SOHO sees something new near the sun: Comet survives close encounter
March 02, 2015
An unusual comet skimmed past the sun on Feb 18-21, 2015, as captured by the European Space Agency (ESA) and NASA's Solar and Heliospheric Observatory, or SOHO.

CometWatch: The challenges of a close flyby
March 02, 2015
In today’s CometWatch post, we not only present a previously unseen NAVCAM image from the close flyby on 14 February, but we also reflect on some of the challenges encountered in operating in this new environment.

CometWatch 20 February
March 02, 2015
Today’s CometWatch entry is a single frame NAVCAM image obtained on 20 February from a distance of 118.5 km from the centre of Comet 67P/Churyumov-Gerasimenko. The image has a resolution of 10.1 m/pixel and measures 10.3 km across.

CometWatch 14 February – flyby special
February 19, 2015
On Saturday, Rosetta passed within just 6 km of the surface of Comet 67P/Churyumov-Gerasimenko in the first dedicated close flyby of the mission. The closest approach took place at 12:41 UT over the Imhotep region on the comet’s large lobe.

And away again – CometWatch 15 February
February 19, 2015
After Rosetta's close flyby just 6 km from the surface of Comet 67P/Churyumov-Gerasimenko on 14 February, the spacecraft has once more moved away from the comet as part of its new phase of operations, reaching a distance of 255 km from the centre of 67P/C-G on 17 February.

Last stop before close flyby – CometWatch 9 February
February 16, 2015
Today’s CometWatch entry is a single frame NAVCAM image taken on 9 February from a distance of 105 km from the comet centre. The image resolution is 8.9 m/pixel; the processed image below has been slightly cropped to eliminate vignetting in the upper corners, and measures 8.5 x 8.5 km (the original, provided at the end of the post, measures 9.1 x 9.1 km).

New perspectives – CometWatch 6 February
February 12, 2015
Today’s CometWatch entry presents the NAVCAM’s first single frame image capturing the entire comet nucleus since leaving bound orbits last week. The image was taken on 6 February from a distance of 124 km to the centre of Comet 67P/Churyumov-Gerasimenko. The 1024 x 1024 pixel image frame therefore has a resolution of 10.6 m/pixel and measures 10.8 km across.

Seasonal forecasts for 67P/C-G
February 10, 2015
Based on the press release of the Max Planck Institute for Solar System Research, Germany. Scientists from Rosetta’s OSIRIS team have been analysing the images of Comet 67P/Churyumov-Gerasimenko and comparing them to a thermal model to estimate how much material the various parts of the comet will lose through Sun-driven sublimation during one orbit. That is, as the Sun heats the comet, ices sublimate and the resulting gases drag dust into the comet’s coma.

Last waltz at 28 km – CometWatch 3 February
February 10, 2015
This four-image mosaic comprises images taken from a distance of 28.7 km from the centre of Comet 67P/Churyumov-Gerasimenko on 3 February. The image resolution is 2.4 m/pixel and the individual 1024 x 1024 frames measure 2.5 km across. The mosaic has been slightly cropped, and it measures 4.2 x 4.6 km.

Anuket vs. Anubis – CometWatch 31 January
February 10, 2015
This four-image mosaic comprises images taken from a distance of 28.0 km from the centre of Comet 67P/Churyumov-Gerasimenko on 31 January. The image resolution is 2.4 m/pixel and the individual 1024 x 1024 frames measure 2.4 km across. The mosaic has been slightly cropped, and it measures 4.6 x 4.3 km.