Comet Dust

Dust particles from Comet 67P/Churyumov-Gerasimenko collected by ESA's Rosetta spacecraft. Copyright ESA/Rosetta/MPS for COSIMA Team MPS/CSNSM/UNIBW/TUORLA/IWF/IAS/ESA/ BUW/MPE/LPC2E/LCM/FMI/UTU/LISA/UOFC/vH&S

Dust particles from Comet 67P/Churyumov-Gerasimenko collected by ESA’s Rosetta spacecraft. Copyright ESA/Rosetta/MPS for COSIMA Team MPS/CSNSM/UNIBW/TUORLA/IWF/IAS/ESA/ BUW/MPE/LPC2E/LCM/FMI/UTU/LISA/UOFC/vH&S

One of the instruments on board ESA’s Rosetta called COSIMA, short for the COmetary Secondary Ion Mass Analyser one of three dust analysis experiments.

Essentially this instrument has a plate for catching dust grains from the comet at fairly low speeds. The dust grains shown above is two of the grains collected and they have yielded some interesting results.

I’ll let ESA explain:

Two examples of dust grains collected by Rosetta’s COmetary Secondary Ion Mass Analyser (COSIMA) instrument in the period 25–31 October 2014. Both grains were collected at a distance of 10–20 km from the comet nucleus. Image (a) shows a dust particle (named by the COSIMA team as Eloi) that crumbled into a rubble pile when collected; (b) shows a dust particle that shattered (named Arvid).

For both grains, the image is shown twice under two different grazing illumination conditions: the top image is illuminated from the right, the bottom image from the left. The brightness is adjusted to emphasise the shadows, in order to determine the height of the dust grain. Eloi therefore reaches about 0.1 mm above the target plate; Arvid about 0.06 mm. The two small grains at the far right of image (b) are not part of the shattered cluster.

The fact that the grains broke apart so easily means their individual parts are not well glued together. If they contained ice they would not shatter; instead, the icy component would evaporate off the grain shortly after touching the collecting plate, leaving voids in what remained. By comparison, if a pure water-ice grain had struck the detector, then only a dark patch would have been seen.

These ‘fluffy’ grains are thought to originate from the dusty layer built up on the comet’s surface since its last close approach to the Sun, and will soon be lost into the coma.

Be sure to check the Rosetta Blog. The have this and results from six other Rosetta’s science instruments since arriving at Comet 67P/Churyumov-Gerasimenko – great stuff!!

Cometary Wisps

Rosetta images the dust coming off Comet 67P/Churyumov-Gerasimenko  Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

Rosetta images the dust coming off Comet 67P/Churyumov-Gerasimenko Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

ESA’s Rosetta spacecraft took this image of Comet 67P/Churyumov-Gerasimenko last November with the OSIRIS camera. By overexposing the comet the wisps of cometary dust is highlighted.

Rosetta has an instrument called MIDAS and its job is to capture 67P/C-G particles. About the time this image was taken MIDAS captured a particle measuring 10 micrometres, which is way larger than was expected.

From the Rosetta blog (be sure to check it out)

“This is still the beginning of the activity compared to what we expect to see in summer this year,” says OSIRIS principal investigator Holger Sierks from the Max Planck Institute for Solar System Research (MPS) in Germany. “From the last perihelion passage we know that the comet will evolve by a factor of 100 in activity at that time compared to now.”

Rosetta Still Busy

One of the latest Rosetta images of Comet 67P/C-G.  Copyright ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0

One of the latest Rosetta images of Comet 67P/C-G. Copyright ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0

Rosetta continues to orbit around Comet 67P/Churyumov-Gerasimenko. This image is a mosaic taken on 03 January with Rosetta’s NAVCAM.

The view shows the newly named Imhotep region which is the smooth area and at least some of the rougher area above it. The name Imhotep is for the famous architect of Egyptian pyramids from the 27th century BC The name was released during the American Geophysical Union on 17 December 2014.

Check out the Rosetta Blog for the details and a larger version to really take advantage of the excellent detail.

Philae at Perihelion Cliff

Philae's look at its landing area. Image Credit: Copyright: ESA/Rosetta/Philae/CIVA

Philae’s look at its landing area. Image Credit: Copyright: ESA/Rosetta/Philae/CIVA

It be could be the location of ESA’s Philae lander on comet 67P/Churyumov-Gerasimenko has been narrowed down. The image above is from that location and we are looking at what has been named “Perihelion Cliff.”

The image was taken with the CIVA camera (Comet Infrared and Visible Analyser) on Philae.

To see a graphic showing the position of the Philae in the context of topographic modeling click here. (image credit as above via JPL)

Some of the first of the Rosetta results are being presented at the 2014 autumn meeting of the American Geophysical Union (AGU) going on right now in San Fransisco.

Rosetta will be doing a very close approach of the comet in February when it will come within 6.4 km / 4 miles of the surface.  I’m not sure where that will occur related to the location of Philae.

Knowing the location of Philae is would be a big relief.  I have not heard or seen specifically the location is known for certain, but we are closer to knowing than we were.

From JPL:

Rosetta is a European Space Agency mission with contributions from its member states and NASA. Rosetta’s Philae lander is provided by a consortium led by the German Aerospace Center, Cologne; Max Planck Institute for Solar System Research, Gottingen; French National Space Agency, Paris; and the Italian Space Agency, Rome. NASA’s Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena, manages the U.S. participation in the Rosetta mission for NASA’s Science Mission Directorate in Washington.

Rosetta Update

Four image NAVCAM mosaic from images taken on 2 December 2014. Credits: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0

Four image NAVCAM mosaic from images taken on 2 December 2014. Credits: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0

I’ve not posted a Rosetta update in a little while. The spacecraft is still at 67P/Churyumov-Gerasimenko

This image is part of a four-frame mosaic and shows both lobes of the comet. Of particular interest is the 1 km wide depression on the left. It is thought this is the area where the little Philae lander ended up. High resolution imaging is being used to search for the lander – see “Homing in on Philae’s final landing site“.

See the frame with the depression described above.

From Rosetta blog:

This orientation also provides a good view onto the plateau that was previously considered as candidate landing site A – close to the ‘join’ between the two right-hand side images frames. The dark circular region is a large pit. The cliff walls that drop down onto this plateau seem to show slightly brighter sections, perhaps reflecting compositional differences, or fresher material that has yet to be degraded by exposure to the space environment.

Philae Inbound Photos

 ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

The Philae lander might be hibernating and as far as I know the whereabouts of the lander isn’t known for sure, we do know about the journey.

The mosaic above is a series of images taken by the OSIRIS narrow angle camera aboard Rosetta over about a half hour. At the time Rosetta was only 15.5 km / 28 miles from the surface of the comet.

The mosaic captures Philae starting at the lower left and follows it upward as labeled on the image.

Like I said in the beginning, mission managers don’t know where Philae is but they will find it. It is known the lander was moving east with a rate of travel about a half a meter per second, that’s really slow for a spacecraft. Think about a leisurely walk, now go slower by better than half, on average, you would still probably beat Philae in a race.

Will Philae be found? I would say yes most likely it will. Data returned from the mission including the CONSERT ranging data, OSIRIS and navcam images on Rosetta along with Philae’s ROLIS and CIVA cameras should reveal the resting spot. When the lander is found mission managers will have a much better idea about the future of the mission.

Fingers crossed.

Rosetta Blog

Sleep Well Little Philae

Decline in battery power aboard Philae. Credit: ESA via Twitter

Decline in battery power aboard Philae. Credit: ESA via Twitter

The Philae lander is now in an “idle mode” in which most of the systems on board are shut down, including communications.

Before going to sleep, Philae was able to send all of the science data collected so far and completed its main mission in the 57 hours on the comet surface.

Stephan Ulamec, Lander Manager said “This machine performed magnificently under tough conditions, and we can be fully proud of the incredible scientific success Philae has delivered.”

Contact with Philae was lost at 00:36 UT (20:36 EST for the US), according to Rosetta Blog this was about the time of a scheduled loss of signal anyway as Rosetta which was acting as a repeater orbited out of sight of Philae.

Rosetta mission control did try to rotate the lander as was reported and with that effort there was a possibility of communications at 10:00 UTC (05:00 EST) this morning (15 Nov) so Rosetta was listening but no signal came.

As Comet 67P/Churyumov-Gerasimenko gets closer to the Sun there is a possibility enough sunlight will eventually revive the batteries enough to get Philae back on-line. Still I have to wonder if the deep discharge state of the batteries will preclude that given the time and cold environment – time will tell.

A Stunning Look at Philae

Philae is right at home. Credits: ESA/Rosetta/Philae/CIVA

Philae is right at home. Credits: ESA/Rosetta/Philae/CIVA

WOW! This is just simply amazing.

This is a two image mosaic of Philae on the surface of the Comet 67P/Churyumov-Gerasimenko. Click the image and just marvel at the view of both Philae and the surface features.

You can get an even larger version at Rosetta blog’s Welcome to a Comet!

Philae is pretty close to a cliff that will shadow the solar panels for much of a day and this will limit how much Philae will be able to do at least in the short term. I’m pretty sure ESA is studying how to squeeze the most out of what they have you can be sure of that.
ESA is live streaming the media briefings, you can find out when by going to Rosetta Blog or you can check the Live Stream page.

Don’t forget about Twitter, I am on the run a lot the past couple days and it has been great for keeping up you can get all the images and briefings there too.

What a Day!

 ROLIS descent image of Comet 67P/C-G. Credits: ESA/Rosetta/Philae/ROLIS/DLR


ROLIS descent image of Comet 67P/C-G. Credits: ESA/Rosetta/Philae/ROLIS/DLR

As the Philae lander approached comet 67P/G-C it used the ROLIS instrument to take this image at 14:38:41 UT from just 3 km / 1.9 miles above the surface.

The ROLIS instrument looks downward during descent and gets close up views after landing so texture and microsturcture of surface materials.

Yes, that is part of the lander you see in the upper right.

ROLIS (ROsetta Lander Imaging System) is a descent and close-up camera on the Philae Lander. It has been developed by the DLR Institute of Planetary Research, Berlin.

I had to include the image below, I think it’s just excellent. We are looking at the Philae lander shortly after being released from the mother ship (Rosetta) after a 10 year trip together on this totally amazing mission.

Good luck Philae. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

Good luck Philae. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

No word yet on what is going on with the harpoons (anchors), but ESA did mention “Maybe today we didn’t just land once…we even landed twice!”

There will be plenty more images here, but check out the Rosetta Blog.

ESA Rosetta Mission on Twitter

Congratulations ESA !

I bet the smiles are abundant and they should be. :mrgreen: