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!!
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.
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.
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.
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.
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.