Today’s CometWatch entry was taken three days after the perihelion of Comet 67P/Churyumov-Gerasimenko, on 16 August 2015. At the time, Rosetta was 331 km from the comet, which in turn was just over 186 million km from the Sun and almost 265 million km from Earth. This single frame NAVCAM image has a resolution of 28.2 m/pixel and it measures 28.9 km across.


NAVCAM image of Comet 67P/C-G taken on 16 August 2015, 331 km from the comet centre. Credits: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0

With the large comet lobe pointing to the top left of the image and the small lobe to the bottom right, this spectacular view shows the activity of 67P/C-G just a few days after its closest approach to the Sun. The image has been processed in Lightroom to bring out the jets of dust streaming away from the nucleus.

It is interesting to compare today’s image with previous CometWatch entries, in particular those from 24 June and 14 July, in which the comet appears in a similar orientation. With that in mind, you might want to compare the images for evidence of increased activity. But take care to use the unprocessed images shown at the bottom of each CometWatch entry, not the Lightroom processed ones.

In today’s view, the elongated depression of Aten stands out on the large lobe, partly in shade; to its right, parts of the Aker and Khepry regions are also visible. On the small lobe, Bastet is well in sight while Ma’at and Hatmehit are cast in shadow, as are also Hapi on the neck and parts of Babi, Seth and Ash on the large lobe.

To find your way around the regions of 67P/C-G, you can explore the recently released interactive comet viewer.

The original 1024 x 1024 image of today’s CometWatch is provided below: