759 NAVCAM images from around perihelion, covering the period 1 July to 25 August 2015, are now available in the Archive Image Browser.
Examples of the images in the latest archive release. All NAVCAM images credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0.
Browse them in the folders labelled “Comet Escort 3 MTP018” and “Comet Escort 3 MTP019”
Discussion: 25 comments
Please tell me the density of Chury. There is a veritable censureship when density comes up; my last two books on astronomy, beautiful format & pictures, but the essential numbers, 10 in all (, diameter, axis, etc.), but no density.
For Saturn, a small mention of a feeble density. Wow!
So for me, density is all. Thank you. Oh, Ceres too; and also Pluto & Charon.
.)
Hi Philippe. Around 0.5 kg/dm3. It’s a very heterogeneously distributed Object at the macro scale.
[Suspicion is void dominates] ;|
In a few images like this one
ROS_CAM1_20150707T214703_P.png of the dust field away from the comet one sees large circular ‘objects’ of varying size.
Generally objects are either an unresolved, single pixel point or pixel wide short line from motion, *or* a large blob.
Nothing intermediate, & the blobs have rather sharp circular edges.
My first thought was severely out-of-focus nearby dust, but that doesnt make sense really; why sharp edged, why nothing intermediate scale? Another possibility might be some sort of ‘lens flare’ effect from out of field comet or solar illumination?
Anyone got a good explanation for them?
Agree with your first thought, Harvey: “…severely out-of-focus nearby dust”.
A two seconds trail impression, electrostatically bonded. This library is ‘from the stand-by at the distance’. ROSETTA could have the time to accumulate its own ‘particle-o-sphere’.
Coinciding in this being a very particular sampling 🙂
https://imagearchives.esac.esa.int/picture.php?/38267/search/403
Another scenario is that ROSSETA is being impacted, generating much lower speed debris.
Another -closer- one:
https://imagearchives.esac.esa.int/picture.php?/38247/category/167
ROS_CAM1_20150707T202203
The far photos I expected the less are the ones explaining most 🙂
ROSETTA doing an extraordinary job up there. Future ROSETTA better served by resilient ‘falcons’ doing the near data sampling.
Quite a blast!
Lenses gave a reflective inverse!
ROS_CAM1_20150409T014502
https://imagearchives.esac.esa.int/picture.php?/28718/category/119
Another blast!
ROS_CAM1_20150414T062503
https://imagearchives.esac.esa.int/picture.php?/28845/category/119
A comprehensive set emily, dozens or perhaps hundreds of images. I have two questions for you.
First what is the vertical parallel feature the width of the nucleus that appears spasmodically in many of the images ? An optical artifact ?
and second, much activity displayed but not the intense activity you recorded and posted images of on here a few days before perihelion, which exceeded in intensity by several orders of magnitude anything before or since and which we were informed would be the subject of detailed further investigation. How does it not appear in this otherwise comprehensive set of images.
I’m not sure what feature exactly you’re referring to but it does indeed sound like it could be an artifact; if you can post a link to one such example then I can follow up if you would like more details.
On the activity question then don’t forget that we make a version of the image with enhanced contrast for our CometWatch entries to better see features like activity, but, perhaps more likely, you might be thinking of the outburst recorded by OSIRIS prior to perihelion (https://blogs.esa.int/rosetta/2015/08/11/comets-firework-display-ahead-of-perihelion/), in which case note that NAVCAM and OSIRIS don’t necessarily take images at the same time, so it is highly likely for a transient event like this that one camera might have seen it while another may not.
Hope that helps!
Ok thanks emily. It certainly looks like an artifact and other replies have indicated the type.
As for the highly active pre perihelion flare it must have been around the same time as the one you linked but that was not the one I was referring to.
It was a bigger collimated jet with an equally bright fan shaped emission next to it. I remember it being said at the time that it was so bright that no enhancement was necessary. It could of course also have been an OSIRIS image as you suggest.
I wish I could get back to it but I see no way on the your site now of getting back into the archive of posts other than the blank search facility, which I have never had much success with.
I think those vertical streaks are almost certainly an artifact related to the scanning of the image sensor. They tend to occur when there is a very bright region, probanly very heavily overexposed, because they have chosen exposure conditions to show the dust etc, overexposing the.nucleus.
This is known to cause problems.
However they don’t quite match my understanding of that effect, (and one or two I looked at don’t entirely fit the ‘overexposed region’ bit) but it looks closely related.
I think their appearance guarantees they are artefacts.
Hi OriginalJohn. On agreeing with Emily, think you are referring to the very fast 0.01s shots. At this epoch using also 1s ant 2.5s. Those are so dark that, when remapped, sensor background parasitic noise appears. Knowing that slow shots are for aura and particulate, wander why this extra quick ones 🙂
OK thanks logan.
It’s this type of thing:
https://www.ptgrey.com/KB/10317
And
https://www.andor.com/learning-academy/ccd-blooming-and-anti-blooming-the-principle-of-blooming
Remember this is an old sensor now! The technology has moved on pretty fast.
Yep. I guess that is it Harvey, although much more extreme here. Thanks.
Some quick shots are capturing outbursts. If taken at normal speed, sensor would be overexposed.
ROS_CAM1_20150419T125602
https://imagearchives.esac.esa.int/picture.php?/28915/category/119
Could bet there is a small bending upwards on the jetting as soon as it lives Ducky’s base.
On doing that, the flow also deviates from the lattice…
How could that be explained by pure molecular flow models?
ROS_CAM1_20150731T094814
https://imagearchives.esac.esa.int/picture.php?/38531/category/168
On being the body’s sunset horizon linear. and the foreground jetting origin also, tell Us that its form is planar. A fan shaped jet…
ROS_CAM1_20150807T020617
https://imagearchives.esac.esa.int/picture.php?/38627/category/168
This neck luminance is directly under the umbrella of body.
Only nine pixels are directly sun lighted.
Level of luminance is 43/255 average. Sun lighted jet crown 90/255…
ROS_CAM1_20150807T223200
https://imagearchives.esac.esa.int/picture.php?/38641/category/168
The 15ago22 outburst was over the ‘Great Slab’…
ROS_CAM1_20150822T060217
https://imagearchives.esac.esa.int/picture.php?/38868/category/168
ROS_CAM1_20150822T064704
https://imagearchives.esac.esa.int/picture.php?/38869/category/168
Ignore Time format, but 10º falling of ROSETTA over terminator line.
So homogeneous crown seems to suggest a kind of ‘cork off’..
These are ‘eclipses’ and are important to establish matching clues on a planetary scale..
ROS_CAM1_20150704T090002
https://imagearchives.esac.esa.int/picture.php?/38206/category/167