I went through the available Navcam and Osiris images, and the one that for my eye best explaines the possible location and situation of Philae is the Navcam mosaic "Comet_on_14_September_2014". After including the possible diamond shaped landing area after CONSERT triangulation (blue diamond) there are several possible places that are consistent with the information that Philae only gets 1.5 hours of sun per Chury-day (green markers). It is only a very rough analysis. As I see it, all possible places have in common, that the situation should really improve in the next months with the sun more to the south. North is roughly up in this image.
Philae was a full success up to now, congratulations to the Philae team, the Rosetta team and the teams with experiments on Philae!
But perhaps the Philae story is still not over now... and if it is really possible to wake up Philae again, perhaps his position will ensure an even longer life than predicted, with less sun heating up the surrounding area - perhaps even surviving the perihelion?
Click to view attachment
Image: ESA/Rosetta/NAVCAM, CC BY-SA IGO 3.0
Full Version: Philae landing on the nucleus of Comet 67P C-G
Pages: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29
Is there any way to know if the amount of sunlight increased with the move?
Wow...
old enough to remember Rangers and Surveyors, plowing through print sources for news on Veneras, Vikings,
Near and Hayabusa, Huygens, and now this,
Due to our current digital age, oddly felt the most participation with PHILAE. Twitter and all...
Tossed off my Jack Daniels to YA, ROSETTA/PHILEA team! You are a Magnificent group!!!!
PHILAE rise again!
Craig
old enough to remember Rangers and Surveyors, plowing through print sources for news on Veneras, Vikings,
Near and Hayabusa, Huygens, and now this,
Due to our current digital age, oddly felt the most participation with PHILAE. Twitter and all...
Tossed off my Jack Daniels to YA, ROSETTA/PHILEA team! You are a Magnificent group!!!!
PHILAE rise again!
Craig
Where can one find pictures of the lander descent?
Yes, this week was really special. Amazing how well it turned out, and I'm so glad that we were able to be there with Philae until the end.
I'm hopeful that this won't be the last we've heard from our hopper. And we still have an incredible spacecraft in orbit. Congratulations to everyone involved with the program.
Thank you Philae
Credits: ESA/Rosetta/Philae/CIVA
I'm hopeful that this won't be the last we've heard from our hopper. And we still have an incredible spacecraft in orbit. Congratulations to everyone involved with the program.
Thank you Philae
Credits: ESA/Rosetta/Philae/CIVA
I'd like to express my deep, deep admiration for the Rosetta/Philae team and their valiant efforts during this unbelievably busy time.
Seldom have we seen the inherent drama of space exploration so vividly before. The awe of discovery was underscored by the unfailing dedication of these people as they made the most of literally each precious minute, fighting for every bit of new knowledge.
To call this inspiring is an understatement. It was a moment of great pride for all humanity....and they're far from done.
Thank you, ladies and gentlemen.
Seldom have we seen the inherent drama of space exploration so vividly before. The awe of discovery was underscored by the unfailing dedication of these people as they made the most of literally each precious minute, fighting for every bit of new knowledge.
To call this inspiring is an understatement. It was a moment of great pride for all humanity....and they're far from done.
Thank you, ladies and gentlemen.
Here, here! I'll be glad to second that, my friend!
Three cheers!
-the other Doug (With my shield, not yet upon it)
Three cheers!
-the other Doug (With my shield, not yet upon it)
I don't post here often, but I'm happy to third the sentiment of #605 and #606.
Congratulations to the Rosetta and Philae teams on a magnificent achievement not only for ESA, but for human knowledge and daring as well.
Thank you ESA: you've made me extra proud to be European.
QUOTE (vikingmars @ Nov 11 2014, 10:03 PM) 
Thanks a lot Harder for your nice support, much appreciated...
Unforgettable moments !
Merci Olivier !
I couldn't have expressed it better nprev
This mission and the team behind are absolutely amazing !
This mission and the team behind are absolutely amazing !
First of all I would like to congratulate the people at ESA for delivering the first lander to a a comet and provided us with a historical spectacle and looking forward to watching Rosetta in the next few months.
It is sad to hear that Philae had to go to safe mode due to power issues. Did the drilling part work as some media is reporting it did. Do we have confirmation of that and do we have results? Media is also reporting that the lander was rotated by 35 degrees. Did it take a different view of the comet from the surface? Can anyone confirm these reports?
It is sad to hear that Philae had to go to safe mode due to power issues. Did the drilling part work as some media is reporting it did. Do we have confirmation of that and do we have results? Media is also reporting that the lander was rotated by 35 degrees. Did it take a different view of the comet from the surface? Can anyone confirm these reports?
I merged the raw CIVA image and the heavily brightened image to make both Philae's foot and cliff visible:
And I jump in to add with a fifth or is that sixth sentiment, amazing work and hurray!
The news about the drilling came to me via teletext yesterday, so I knew they were attempting to do what they came for.
And now learning they did pull the science data out in the nick of time.
What a thriller!
They deserve that Champagne for the science campaign, I will toast to Philae myself but it will have to wait until tonight. =)
The news about the drilling came to me via teletext yesterday, so I knew they were attempting to do what they came for.
And now learning they did pull the science data out in the nick of time.
What a thriller!
They deserve that Champagne for the science campaign, I will toast to Philae myself but it will have to wait until tonight. =)
nprev,
thanks for yr well-chosen words. I sincerely hope that Rule 2.6 applies for your post!
2.6 When mentioning scientists, engineers, or other mission personnel, please write as though they are reading the Forum. In fact, many of them are. In particular, avoid criticizing missions on the basis of hindsight and/or incomplete information.
thanks for yr well-chosen words. I sincerely hope that Rule 2.6 applies for your post!
2.6 When mentioning scientists, engineers, or other mission personnel, please write as though they are reading the Forum. In fact, many of them are. In particular, avoid criticizing missions on the basis of hindsight and/or incomplete information.
QUOTE (Julius @ Nov 15 2014, 01:40 PM)
Did the drilling part work as some media is reporting it did. Do we have confirmation of that and do we have results? Media is also reporting that the lander was rotated by 35 degrees. Did it take a different view of the comet from the surface? Can anyone confirm these reports?
Yes,the drilling sequence was successful. But they didn't confirm yet if a sample had been actually collected and delivered to COSAC.
Yes, Philae had time to take and transmit a ROLIS image of the new position after having rotated.
Fantastic that all the science results were transferred just in time. Cannot wait to hear about them in future weeks and months. Congratulations to the team!
QUOTE (vikingmars @ Nov 11 2014, 10:03 PM)
We had also the President of the French Republic sitting at the front row in front of us. He told us that he had some fun looking at the "3D images" and "CIVA-P" presentations I made with "Malmer"...
Click to view attachment Click to view attachment
Click to view attachment Click to view attachment
Incroyable! - Félicitations!
For me we learn even from the difficulties Philae experienced in landing, and getting the science is wonderful. Congratulations!
As we get a better orientation of the horizon profile as seen from Philae it should of course be possible to see how the sun's apparent path through the sky will change relative to it's horizon. One piece of information I'd be curious about is the rotation axis of the comet itself. Is this posted anywhere? Where in the sky is the comet's North celestial Pole pointed? We can then get a feel for the upcoming changing "seasons" for Philae.
Starting to address this, an earlier estimate (of two possible axis locations) was published here:
http://www.aanda.org/articles/aa/abs/2014/...aa24590-14.html
This axis could possibly change during the mission due to outgassing forces.
Starting to address this, an earlier estimate (of two possible axis locations) was published here:
http://www.aanda.org/articles/aa/abs/2014/...aa24590-14.html
This axis could possibly change during the mission due to outgassing forces.
Condensed from @Philae_MUPUS:
QUOTE
First off: some reported MUPUS results as found in media are wrong. They never asked us.
MUPUS TM worked fine throughout the whole timeline and sees a very cold steep wall in front of us. TM sees clear diurnal temperature signal. Around local noon direct sunlight on that wall caused a steep temperature increase and also steep temperature drop shortly after. Data indicate low thermal diffusivity and fluffy substance.
The anchors still below Philae in shadow see the diurnal heat wave as well and at the same time as TM and the solar panels.
Penetrator was deployed to the commanded distance. Remember that device had not been switched on since 2002. Temperature inside PEN dropped significantly compared to status before deployment.Might have hit a pile of stuff on the way out. Another instrument saw better performance thereafter - we might have changed Philae's attitude.
Hammering started as intended in the lowest of 3 power settings (expecting a fluffy soft surface). The depth sensor shows some up and down but no progress. The control loop increased to power setting 2. Depth sensor still shows no progress. Control loop goes to power setting 3. Still no progress! This means that the stuff is really hard! A very interesting finding, not visible from orbit!
We have a secret power setting 4. Nicknamed "desperate mode". Beyond the design specs. We activated it. The truly genius designer of the hammer, Jerzy Grygorczuk, always said "be careful with power mode 4. And still no progress. The hammer gave up and failed after 7 minutes. Jerzy was right. We were desperate, activated, were punished. Surface must be >2 MPa hard! The comet remains surprising bizarre and uncooperative. To put this into perspective: MUPUS performed beautifully inside the specifications. The comet failed to cooperate. The loss of subsurface data is sad. The detection of this very hard crust is a great find the orbiter couldn't have done.
MUPUS TM worked fine throughout the whole timeline and sees a very cold steep wall in front of us. TM sees clear diurnal temperature signal. Around local noon direct sunlight on that wall caused a steep temperature increase and also steep temperature drop shortly after. Data indicate low thermal diffusivity and fluffy substance.
The anchors still below Philae in shadow see the diurnal heat wave as well and at the same time as TM and the solar panels.
Penetrator was deployed to the commanded distance. Remember that device had not been switched on since 2002. Temperature inside PEN dropped significantly compared to status before deployment.Might have hit a pile of stuff on the way out. Another instrument saw better performance thereafter - we might have changed Philae's attitude.
Hammering started as intended in the lowest of 3 power settings (expecting a fluffy soft surface). The depth sensor shows some up and down but no progress. The control loop increased to power setting 2. Depth sensor still shows no progress. Control loop goes to power setting 3. Still no progress! This means that the stuff is really hard! A very interesting finding, not visible from orbit!
We have a secret power setting 4. Nicknamed "desperate mode". Beyond the design specs. We activated it. The truly genius designer of the hammer, Jerzy Grygorczuk, always said "be careful with power mode 4. And still no progress. The hammer gave up and failed after 7 minutes. Jerzy was right. We were desperate, activated, were punished. Surface must be >2 MPa hard! The comet remains surprising bizarre and uncooperative. To put this into perspective: MUPUS performed beautifully inside the specifications. The comet failed to cooperate. The loss of subsurface data is sad. The detection of this very hard crust is a great find the orbiter couldn't have done.
From wikipedia http://en.wikipedia.org/wiki/67P/Churyumov...0%93Gerasimenko
North pole RA 69 deg, declination 64 deg
North pole RA 69 deg, declination 64 deg
QUOTE (ugordan @ Nov 15 2014, 11:43 AM)
Data indicate low thermal diffusivity and fluffy substance.
How did they test for fluffiness?
How is it different from low density?
If spacedust slowly solidifies in very low gravity, low density seems unsurprising-- lots of embedded 'vacuum'...?
QUOTE (Jorn Barger @ Nov 15 2014, 09:59 AM)
How did they test for fluffiness?
Go read the tweets. Rapid temperature change thru the diurnal cycle means a low thermal inertia which infers low density, 'fluffy' material.
QUOTE
If spacedust slowly solidifies in very low gravity, low density seems unsurprising-- lots of embedded 'vacuum'...?
No - not surprising. But awesome to confirm it via an in-situ measurement.
QUOTE (djellison @ Nov 15 2014, 12:14 PM)
Rapid temperature change thru the diurnal cycle means a low thermal inertia which implies low density, 'fluffy' material.
Isn't styrofoam fluffy by that definition?
"MUPUS consists of a roughly 40-centimeter-long glass fiber rod that contains 16 individual heaters and sensors. Each of them can be turned on and off separately, in order to measure the variation of thermal conductivity over the length of the probe. At the top, there is a hammering device used for fixing the probe and measuring the mechanical properties of the surface."
Does it report differences in resistance as it's hammering?
Is there anything in these or other expected tests that can differentiate water from other substances?
someone of the MUPUS team is tweeting a lots of details of the ops of the penetrator. interesting stuff!
https://twitter.com/Philae_MUPUS
https://twitter.com/Philae_MUPUS
QUOTE (Jorn Barger @ Nov 15 2014, 10:33 AM)
Isn't styrofoam fluffy by that definition?
Yes. It has a low thermal inertia.
However comets are not expected to be made of Styrofoam.
Some parts of comets are thought to be almost solid ice or rock, and some no more solid than a pile of cigarette ash.
QUOTE
Does it report differences in resistance as it's hammering?
Is there anything in these or other expected tests that can differentiate water from other substances?
Is there anything in these or other expected tests that can differentiate water from other substances?
Yes and yes - but results have not been released yet.
A very quick google for "Rosetta MUPUS pdf" will unveil a swath of PDF papers that discuss, in detail, the capabilities of the instrument.
You should also check, regularly, the MUPUS twitter feed ( as Paolo mentioned )
https://twitter.com/Philae_MUPUS
They are basically live-tweeting rudimentary analysis of their data.
QUOTE (djellison @ Nov 15 2014, 12:45 PM)
However comets are not expected to be made of Styrofoam.
Talc? Lithium?
The surface looked light and brittle to me in that first 'panorama'.
I've updated this post with the subsequent updates posted on the MUPUS twitter feed.
The tl;dr is that the surface appears to be remarkably hard, at least the point they attempted to penetrate.
The tl;dr is that the surface appears to be remarkably hard, at least the point they attempted to penetrate.
QUOTE (ugordan @ Nov 15 2014, 11:43 AM)
Surface must be >2 MPa hard!
According to the table here: http://www.oocities.org/unforbidden_geolog..._properties.htm
2 MPa is nothing.
"The tensile strength of ice varies from 0.7–3.1 MPa" http://link.springer.com/article/10.1023%2FA%3A1021134128038
QUOTE (Jorn Barger @ Nov 15 2014, 11:14 AM)
According to the table here: http://www.oocities.org/unforbidden_geolog..._properties.htm
2 MPa is nothing.
"The tensile strength of ice varies from 0.7–3.1 MPa" http://link.springer.com/article/10.1023%2FA%3A1021134128038
2 MPa is nothing.
"The tensile strength of ice varies from 0.7–3.1 MPa" http://link.springer.com/article/10.1023%2FA%3A1021134128038
How do you come to the conclusion that 2MPa is 'nothing'
The ranges of Ice you cite can exceed that.
It's also worth noting from the same paper you cite.....
"and the compressive strength varies from 5–25 MPa over the temperature range −10°C to −20°C"
Again - as I mentioned a few posts ago - please look at some MUPUS papers on line - you will learn a lot.
Pondering the riddle of a spinning body outgassing water despite no visible ice on the surface, all I came up with was a model where the ice effectively repels the space dust, bonding more strongly to itself (like surface tension), and the dust might even rise to the surface despite being heavier than the water, maybe even by centrifugal force... So finding 2MPa ice under a layer of cigar ash works great for me.
Disclaimer: wild hypotheses abound
Disclaimer: wild hypotheses abound
QUOTE (Paolo @ Nov 15 2014, 05:58 PM)
From wikipedia http://en.wikipedia.org/wiki/67P/Churyumov...0%93Gerasimenko
North pole RA 69 deg, declination 64 deg
North pole RA 69 deg, declination 64 deg
Thanks Paolo. I'm retooling my comet ephemeris program to help with this question. My preliminary numbers are that the current solar declination referred to the comet's rotational equator is about +37 degrees. The sun slowly moves south to reach the equator (equinox) on May 11, 2015. By September 5, 2015 it reaches the southernmost extent (southern hemisphere summer solstice) at -52 degrees. I will be checking these numbers, though at least I have the program running now to calculate this. Appears to be quite a swing in store over time.
This might be interesting if we were able to draw the cometary celestial equator on the Philae mosaics. This equator is located 90 degrees away from the North pole axis mentioned here.
By the way the sun's magnitude seen from the comet now is -24.4. At perihelion in August this will brighten to -26.3, or a factor of 6.
Here's what I get for the solar declination and distance from Comet 67P for the next year or so:
Click to view attachment
Looks like the declination doesn't change much for a couple months. That's per SPICE. Declination right now is +37.2 as you say.
Click to view attachment
Looks like the declination doesn't change much for a couple months. That's per SPICE. Declination right now is +37.2 as you say.
My admiration to the whole Rosetta/Philae team also I was so pleased to be able to follow this historic mission through social media including USF, thanks so much to all.
Click to view attachment
Click to view attachment
QUOTE (jmknapp @ Nov 15 2014, 08:05 PM)
Here's what I get for the solar declination and distance from Comet 67P for the next year or so:
Naïve question: Since declination is measured relative to the plane of the equator, is this declination relative to the Earth's equator or comet 67P C-G's?
QUOTE (SteveM @ Nov 15 2014, 09:09 PM)
Naïve question: Since declination is measured relative to the plane of the equator, is this declination relative to the Earth's equator or comet 67P C-G's?
In this case, relative to 67P's equator. In SPICE:
CODE
#define COMET "CHURYUMOV-GERASIMENKO"
#define COMETFRAME "67P/C-G_CK"
subpnt_c("Intercept: ellipsoid",COMET,et,COMETFRAME,CORR,"SUN",spoint,&trgepc,srfvec); // spoint is intercept point (in the comet frame) of line from the sun to the comet
reclat_c(spoint,&rad,&ra,&dec); // convert rectangular coords to latitudinal
dec *= dpr_c(); // convert radians to degrees
#define COMETFRAME "67P/C-G_CK"
subpnt_c("Intercept: ellipsoid",COMET,et,COMETFRAME,CORR,"SUN",spoint,&trgepc,srfvec); // spoint is intercept point (in the comet frame) of line from the sun to the comet
reclat_c(spoint,&rad,&ra,&dec); // convert rectangular coords to latitudinal
dec *= dpr_c(); // convert radians to degrees
The comet is modeled as a tri-axial ellipsoid which is clearly a crude approximation, so who knows, maybe the actual geometry changes this picture appreciably.
So it's fluffy, but as hard as solid ice? Is it vacuum cemented together or something, or a thin layer of 'fluffy' on top of 'solid', I wonder?
The first landing site is certainly 'fluffy' (judging by the bounce mark), but the actual area Philae ended up looks much more like a solid. Vertical surfaces don't get much dust on Earth, so there shouldn't be much accumulation there either.
QUOTE (Vultur @ Nov 16 2014, 08:52 AM)
So it's fluffy, but as hard as solid ice? Is it vacuum cemented together or something, or a thin layer of 'fluffy' on top of 'solid', I wonder?
Not as hard as solid ice, but harder than loose snow.
A scientist here used a definite term to describe the properties.
It has no counterpart in english but loosely translated it comes out as 'crusted snow'.
I'm losing faith that better panoramas are still forthcoming.
The BBC is saying more photos were indeed taken :
"Among other returns, Philae took another picture of the surface with its downward-looking Rolis camera. "
Rosetta BBC News
I doubt if they will release anything until Monday.
"Among other returns, Philae took another picture of the surface with its downward-looking Rolis camera. "
Rosetta BBC News
I doubt if they will release anything until Monday.
QUOTE (kenny @ Nov 16 2014, 02:31 PM)
The BBC is saying more photos were indeed taken :
yep, SD2 tweeted this a few hours ago:
QUOTE
ROLIS is the instrument that may identify the area where SD2 drilled. We're collaborating to detect SD2 footprint on their wonderful images
QUOTE (jmknapp @ Nov 16 2014, 03:16 AM)
In this case, relative to 67P's equator. In SPICE:
The comet is modeled as a tri-axial ellipsoid which is clearly a crude approximation, so who knows, maybe the actual geometry changes this picture appreciably.
The comet is modeled as a tri-axial ellipsoid which is clearly a crude approximation, so who knows, maybe the actual geometry changes this picture appreciably.
I would suggest the comet shape isn't really a factor in these measurements of declination. As long as we know the rotation axis orientation we know where CG's celestial pole and equator are.
It is another matter as to the local orientation of the surface where Philae is, along with the associated planetographic "cometographic" coordinates that would relate to surface orientation in a shape model. And in more detail we can hopefully learn the actual orientation of Philae and the small-scale undulations of the terrain in its immediate vicinity.
Nonetheless it would be of interest to see where Philae lies on a map of the comet and to see what the latitude and longitude are in the coordinate system being used now in making the maps. Depending on conventions being used, these coordinates can be expressed either as planetographic or planetocentric.
Is there a cylindrical projection available?
As for the exact geometry, I was thinking that it's possible that just a few degrees change in declination might make a big difference in lighting at a specific site, more than if it was a smooth ellipsoid, because of nonlinear shadow effects.
As for the exact geometry, I was thinking that it's possible that just a few degrees change in declination might make a big difference in lighting at a specific site, more than if it was a smooth ellipsoid, because of nonlinear shadow effects.
There has been Phil's map (post #44) and some rotating shape models posted in this thread: http://www.unmannedspaceflight.com/index.php?showtopic=7883. The original landing site was somewhat north of the equator.
And indeed - one can hope we are seeing a nearby cliff or something that is barely blocking out the sun over some period of time (in the best scenario). Judging from Phil's map and the bounce ellipse posted recently (Jorn Barger #511 in this thread), the crater/cliff faces may be looking off to the southwest. That would bode fairly well for improvement with the sun's shift, even though it looks to have bounced to a slightly more northerly latitude.
This appears consistent with Malmer's shape model here: http://www.unmannedspaceflight.com/index.p...st&p=214013. This shape model I suppose could be visualized for various solar declinations.
And indeed - one can hope we are seeing a nearby cliff or something that is barely blocking out the sun over some period of time (in the best scenario). Judging from Phil's map and the bounce ellipse posted recently (Jorn Barger #511 in this thread), the crater/cliff faces may be looking off to the southwest. That would bode fairly well for improvement with the sun's shift, even though it looks to have bounced to a slightly more northerly latitude.
This appears consistent with Malmer's shape model here: http://www.unmannedspaceflight.com/index.p...st&p=214013. This shape model I suppose could be visualized for various solar declinations.
Oh those couple of images are just so COOl!
Hats off to the Rosetta team for all that they have accomplished.
Hats off to the Rosetta team for all that they have accomplished.
QUOTE (Rakhir @ Nov 16 2014, 11:39 AM)
Philae spotted...
As previewed by Gerald and Emily in posts 534 and 537 of this thread.Big, big thanks to the Rosetta team for providing these images! Great job, getting that shot!
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