Today’s CometWatch entry is an image of Comet 67P/Churyumov-Gerasimenko taken on 6 August 2015, exactly a year to the day of Rosetta’s historic rendezvous. The image was taken 261 km from the comet centre.


Comet 67P/C-G on 6 August (with contrasts enhanced) from a distance of 261 km. With a scale of 22.3 m/pixel, the image measures 22.8 km across. Credits: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0

Currently, the comet is around 186 million km from the Sun, and it will reach perihelion – the closest point to the Sun along its orbit – next Thursday. This image shows an intense comet activity, with prominent outflows and jets of material and the unlit patches of the nucleus standing out as a silhouette against the overall bright background.

Due to the increased concentration of gas and dust over the last few months, Rosetta is now studying the comet from safer distances, and is currently operating some 300 km out.

In the spirit of celebrating Rosetta’s first year at the comet, we tried to compare this image with one that was taken exactly one year ago, on rendezvous day, 6 August 2014. The result was posted as ESA’s Space Science Image of the Week.

The original 1024 x 1024 pixel image for today’s CometWatch entry is provided below: