* We are working on flight control and science operations for Rosetta, now orbiting comet 67P, and Philae, which landed on the comet surface last week. Ask us Anything! AMA!
A 3D image shows what it would look like to fly over the surface of comet 67P/Churyumov-Gerasimenko. The image was generated from data collected by the Rosetta Lander Imaging System (ROLIS) aboard the European Space Agency's Philae spacecraft during the descent to the spacecraft's initial touchdown on the comet Nov. 12. The European Space Agency also released an audio track of the first of the lander's three touchdowns on the surface of the comet.
The stereographic image was generated using two images acquired by ROLIS when Philae was a little less than 2 miles (3 kilometers) from the surface. The images were taken two minutes apart - about one hour prior to the spacecraft's initial touchdown on 67P at 8:03 a.m. PST (11:03 a.m. EST). In the image, the landing site Agilkia can be seen immediately below. In the top right of the field of view, one of the landing gear feet can be seen. The resolution is about 10 feet (3 meters) per pixel. To appreciate the 3D effect, the image must be viewed with red-blue glasses.
At the time Philae made its first touchdown on the comet, a short but significant "thud" was heard by Philae's Cometary Acoustic Surface Sounding Experiment (CASSE) as the spacecraft made its first touchdown. The two-second recording from space is the very first of the contact between a man-made object with a comet upon landing. The CASSE sensors are located in the feet at the base of all three legs of the lander. ...
P41C-3942 Color Variegation on 67P/Churyumov-Gerasimenko
Thursday, December 18, 2014 08:00 AM - 12:20 PM
Moscone South
Poster Hall
The ESA Rosetta Mission entered active operations around comet 67P/Churyumov-Gerasimenko in early August 2014. The full nucleus will be mapped at multiple resolutions before the Philae landing in November. The mapping will include imaging using the full spectral range of the Narrow Angle Camera of the OSIRIS imaging system (245nm to 1000nm in 11 optical filters). The color mapping will be done under good illumination condition at ~1m/pixel as part of the pyramid arc approach phase. This will later be followed by higher resolution imaging (down to 20 cm/pixels) of parts of the nucleus. These higher resolution images are acquired under somewhat worse illumination conditions because of the high angle between the orbital plane and the Sun direction.
This contribution will discuss the color variegation observed on the comet surface and its relationship to surface morphology and cometary activity.
A link to this image was posted in the comments section of the ESA Rosetta blog
Re: ESA: Rosetta: 100 days to wake-up
Posted: Thu Nov 27, 2014 6:50 pm
by MargaritaMc
This was posted by the author, a regular commentator, on the most recent Rosetta Blog
Click to play embedded YouTube video.
Tribute to Rosetta mission : Philae "Major Tom" 2014
Sylvain Verlaine
Published on 19 Nov 2014
ENGLISH :
In this great 80's song, replace "Earth" by "comet 67P/Churyumov–Gerasimenko", "Major Tom" by "Philae lander", "his wife" by "Rosetta probe" and you get the (nearly) perfect description of the first smooth landing(s) of an human object on a comet.
Congratulations to all who made this possible, especially the European Space Agency teams.
Now, a few days after this historical event, we are waiting for "Philae - Major Tom" to call back us...
Credits :
(Most) pictures ; (c) ESA / Rosetta
Music : "Major Tom (coming home)" by Peter Schilling.
This blog post is contributed by Ian Wright and his colleagues from the Ptolemy team
For scientists engaged with large complex projects like Rosetta, there is always a delightful period early on when, unbound by practical realities, it is possible to dream. And so it was that at one time the scientists were thinking about having a lander with the capability to hop around a comet’s surface. In this way it would be possible to make measurements from different parts of the comet.
Interestingly, this unplanned opportunity presented itself on 12 November 2014, when Philae landed not once but three times on Comet 67P/Churyumov-Gerasimenko. ...
...Because of the relatively high power consumption of Ptolemy, it was a race against the clock. The battery had to hold out, both to perform the measurements and to relay the data back to Rosetta and then home. For those involved, it’s hard to describe the shared emotions on that day, helplessly watching a voltage heading towards the end-stop.
Nevertheless, the very good news is that Ptolemy definitely returned data from its various stops on the comet. However, the data are complex and will require careful analysis: this will take time. Also, because the instrument was operated in ways that hadn’t initially been planned for, it will be necessary to go back into the laboratory to run some simulated tests, to ensure that the on-comet data obtained in similar configurations can be understood. ...
The team is looking forward to making these analyses over the coming months and sharing the results with you.
Ptolemy Principal Investigator: Ian Wright, Open University, Milton Keynes, UK.
Margarita
A reaction to Philae landing...
Posted: Mon Dec 08, 2014 11:08 am
by MargaritaMc
I know this is belated, but it's so lovely to see an (English...) scientist being so passionate!
Her reaction is a priceless example of the importance of the mission to those who worked on it.
There is a BBC video interview with Prof Grady here along with Emily Lakdawalla of the Planetary Society.
M
PS. Dr Grady is the Professor (head of department) of Planetary Sciences at the Open University and is part of the team who built the Ptolemy instrument.
ESA: Rosetta fuels debate on origin of Earth's oceans
ESA’s Rosetta spacecraft has found the water vapour from its target comet to be significantly different to that found on Earth. The discovery fuels the debate on the origin of our planet’s oceans.
The measurements were made in the month following the spacecraft’s arrival at Comet 67P/Churyumov–Gerasimenko on 6 August. It is one of the most anticipated early results of the mission, because the origin of Earth’s water is still an open question. ...
... Interestingly, the D/H ratio measured by the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis, or ROSINA, is more than three times greater than for Earth’s oceans and for its Jupiter-family companion, Comet Hartley 2. Indeed, it is even higher than measured for any Oort cloud comet as well.
“This surprising finding could indicate a diverse origin for the Jupiter-family comets – perhaps they formed over a wider range of distances in the young Solar System than we previously thought,” says Kathrin Altwegg, principal investigator for ROSINA and lead author of the paper reporting the results in the journal Science this week. ...
Released 10/12/2014 8:00 pm
Copyright Spacecraft: ESA/ATG medialab; Comet: ESA/Rosetta/NavCam; Data: Altwegg et al. 2014 and references therein
Description
Rosetta’s measurement of the deuterium-to-hydrogen ratio (D/H) measured in the water vapour around Comet 67P/Churyumov–Gerasimenko. The measurements were made using ROSINA’s DFMS double focusing mass spectrometer between 8 August and 5 September 2014.
Deuterium is an isotope of hydrogen with an added neutron. The ratio of deuterium to hydrogen in water is a key diagnostic to determining where in the Solar System an object originated and in what proportion asteroids and/or comets contributed to Earth’s oceans.
The graph displays the different values of D/H in water observed in various bodies in the Solar System...
Like many small bodies in space such as most asteroids, Rosetta’s comet 67P appears grey. This can be seen in images obtained by Rosetta’s scientific imaging system OSIRIS after careful processing. To create an image revealing 67P’s “true” colours, the scientists superposed images taken with the camera’s red, green and blue filters.
“We like to refer to OSIRIS as the eyes of Rosetta”, says the instrument’s Principal Investigator Holger Sierks from the Max Planck Institute for Solar System Research (MPS). “However, these eyes are quite unlike our own.” The imaging system is equipped with several colour filters allowing only light within a limited range of wavelengths to pass through. As a result, the intensity variations seen in OSIRIS images are based only on a small part of the sunlight reflected by the comet. “For scientific questions, these images are superior to those containing all wavelengths”, explains Sierks. For example, the fingerprints that certain minerals or processes such as space weathering leave in the light reflected from the comet can be tracked down this way.
But what is 67P’s “true” colour? To create an image as it would be seen by the human eye, the OSIRIS team superposed three images taken with the red, green and blue filters, a principal also employed in computer and TV monitors. “In the case of OSIRIS, the three images have to be taken one after the other while Rosetta continues to speed through space and the comet’s nucleus rotates”, Sierks explains. The three images are therefore not only shifted with respect to each other, but also taken from slightly different observing geometries. Only a careful superposition can therefore reconstruct such a colour image of 67P.
“As it turns out, 67P looks dark grey, in reality almost as black as coal”, says Sierks. In order to make surface details visible, the intensity of these images is enhanced, thus creating lighter hues of grey. ...
Comet Landing Named Physics World Breakthrough of the Year
ESA Rosetta blog: ROSETTA SCIENCE TO BE PRESENTED AT AGU
Some of the first scientific results from the Rosetta mission after its arrival at Comet 67P/Churyumov-Gerasimenko on 6 August and since the landing of Philae on 12 November will be presented to the scientific community next week, during the 2014 autumn meeting of the American Geophysical Union (AGU). The meeting, the largest annual Earth and space science conference in the world, is being held in San Francisco from 15–19 December.
... some of the presentations in a number of sessions will be streamed live for you to follow. Visit AGU’s website and follow the links from “Virtual Options” to see when virtual sessions are available. Given the location of the conference, all times are given in Pacific Standard Time (PST).
In addition, at 08:00 PST on 17 December there will be a press conference highlighting the latest Rosetta and Philae science: this press conference will also be live streamed. Speakers will include Matt Taylor (ESA Rosetta Project Scientist), Claudia Alexander (NASA Rosetta Project Scientist), Kathrin Altwegg (ROSINA Principal Investigator), and Jean-Pierre Bibring (Philae lander Lead Scientist). Further details can be found here.
In the meantime, you can also preview abstracts on the topics that will be discussed, here
...
Rosetta to Swoop Down on Comet in February NASA | JPL-Caltech | Rosetta | 2014 Dec 19
Click to play embedded YouTube video.
The European Space Agency’s orbiting Rosetta spacecraft is expected to come within four miles (six kilometers) of the surface of comet 67P/Churyumov–Gerasimenko in February of next year. The flyby will be the closest the comet explorer will come during its prime mission.
“It is the earliest we could carry it out without impacting the vitally important bound orbits that are currently being flown,” said Matt Taylor, the Rosetta project scientist from the European Space Research and Technology Center, Noordwijk, the Netherlands. “As the comet becomes more and more active, it will not be possible to get so close to the comet. So this opportunity is very unique.”
The low flyby will be an opportunity for Rosetta to obtain imagery with a resolution of a few inches (tens of centimeters) per pixel. The imagery is expected to provide information on the comet’s porosity and albedo (its reflectance). The flyby will also allow the study of the processes by which cometary dust is accelerated by the cometary gas emission. ...
A short note from the blog team here at ESA: after an amazing but exhausting year, we're going to take a year-end break between Monday, 22 December 2014 and Monday, 5 January 2015...
The only exception might be if Philae is located in images taken by Rosetta in recent days and, in that case, we'd aim to bring you the news as soon as possible.
Nature news article covering some of AGU presentation
Posted: Tue Dec 23, 2014 4:43 pm
by MargaritaMc
News from the AGU meeting is covered in this Nature news article http://www.nature.com/news/comet-lander ... S-20141223.
It mostly covers the search for Philae but also mentions some of the OSIRIS photos that were shown, but not made available publicly.
Sneak peak
In the meantime, Rosetta has been sending back its first findings from orbit. At the AGU meeting, the OSIRIS images garnered the most attention for their high-resolution glimpses of the comet’s surface. The OSIRIS team has released only a small amount of its images publicly, holding the rest back for internal analysis — a policy that many external scientists have grumbled about. At a standing-room-only talk, Sierks flicked through a series of dramatic landscapes.
The comet is covered by small pits that seem to have vented gas, and 'boulders' that may be icy blocks in the process of disintegrating. In other areas, fine-grained dust blankets the surface, and large cracks run through the blocky-looking cliffs that dominate much of the comet. There are small terraces that look like stepping stones, one after the other, down the sides of a slope.
Perhaps most strikingly, the sides of some cliffs are peppered with round objects that Sierks dubbed “dinosaur eggs”. They may represent some kind of big pebble, where cometary material has clumped together.
PS. My usual source of information, Emily Lakdawalla, is unaccountably silent and hasn't written anything about the AGU - other than to post, on the 15 December, that she would be at the AGU and would be reporting from there.
Re: ESA: Rosetta: 100 days to wake-up
Posted: Tue Dec 23, 2014 11:42 pm
by geckzilla
She's on holiday vacation. Saw her post on Twitter pleading with her email inbox to stop filling up during it.
Re: ESA: Rosetta: 100 days to wake-up
Posted: Wed Dec 24, 2014 5:06 pm
by MargaritaMc
geckzilla wrote:She's on holiday vacation. Saw her post on Twitter pleading with her email inbox to stop filling up during it.
Thanks for the info. I was thinking of asking about her on unmannedspaceflight.
I will be in attendance tomorrow through Thursday to cover Curiosity and Rosetta news, and doing my best to blog about them as time allows.
...Stay tuned for the latest in planetary science news from AGU!
The contrast is so marked to her wonderful blogging during her stay in Darmstadt for the Philae landing.
M
Re: ESA: Rosetta: 100 days to wake-up
Posted: Wed Dec 24, 2014 6:32 pm
by MargaritaMc
There is a talk here by Dr Claudia Alexander to the Bay Area SETI Institute, seemingly whilst she was in San Francisco for the AGU conference. (She is NASA's rep on the Rosetta mission.)
Click to play embedded YouTube video.
Rosetta: Wild Bounce at comet Churyumov-Gerasimenko - Claudia Alexander
Published on 11 Dec 2014 Claudia Alexander, Jet Propulsion Laboratory
Rosetta is the third cornerstone mission of the European Space Agency's (ESA) Horizon 2000 Programme. It's goals are to examine some of the original material of the solar system with a comprehensive evaluation of the minearologic, isotopic, and organic constituents of a comet; understand how the body works as a machine to absorb and re-radiate energy from the sun; and understand more about the origins of the solar system.
In this talk, I'll explain the science background of some of the mysteries of comets including pros and cons about why we think comets might have brought Earth's water, concepts regarding missing nitrogen in the outer solar system, and material the comet is made of (CAIs & IDPs). The talk will include early images of the comet's activity. I'll set the stage for the landing and walk through the 60 hours of time spent on the comet's surface. Finally I'll present an overview of initial findings.
In the first OSIRIS image release of 2015, the team provides an unprecedented look at the finer details of 67P/C-G’s dust jets.
Comet 67P/Churyumov-Gerasimenko has shown activity in the form of jets for many months now, but the latest image reveals that the large-scale jets seen in previous images can now be resolved into many smaller jets emerging from the surface, which seem to merge together further away from the comet nucleus. Although much activity still emanates from the ‘neck’ region, jets are also appearing from both of the comet’s two lobes.
OSIRIS wide-angle camera image acquired on 22 November 2014 from a distance of 30 km from Comet 67P/C-G. The image resolution is 2.8 m/pixel. The vertical line in the bottom right of the image, which seems to separate two regions of the coma with slightly different brightness, is the shadow of the nucleus cast onto the coma.
Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
...It is part of a set of observations dedicated to the investigation of the comet’s general activity. As such, the nucleus is deliberately overexposed in order to reveal faint jets and the collimated nature of the streams of gas and dust rising from the surface.
“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.”...
Comet 67P/Churyumov-Gerasimenko has shown activity in the form of dust jets for a few months now. Recent OSIRIS images reveal that large scale jets as seen in previous images can now be resolved into many smaller jets emerging from the surface and then unite further away from the comet nucleus. The ‘neck’ region is still showing a very strong activity but jets are also emerging from the comet’s ‘head’ and ‘body’ with the increased activity of the comet....
Crack extension in Anuket
This OSIRIS narrow-angle camera image shows part of a large fracture running across Comet 67P/Churyumov–Gerasimenko’s neck, in particular where it has left Hapi and is extending into Anuket. In this orientation, the Seth region is at the uppermost left and Hapi in the lower left.
Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
ESA: Getting To Know Rosetta's Comet
Rosetta is revealing its host comet as having a remarkable array of surface features and with many processes contributing to its activity, painting a complex picture of its evolution.
In a special edition of the journal Science, initial results are presented from seven of Rosetta’s 11 science instruments based on measurements made during the approach to and soon after arriving at Comet 67P/Churyumov–Gerasimenko in August 2014...
These are among the very first scientific results from Rosetta and there is much more to come as the scientists work through the data and as the comet continues to evolve during its closest approach to the Sun. They are described in more detail in accompanying posts on the Rosetta blogand in the 23 January 2015 Science special edition:
“Dust Measurements in the Coma of Comet 67P/Churyumov- Gerasimenko Inbound to the Sun Between 3.7 and 3.4 AU” by A. Rotundi et al. (GIADA)
“Subsurface properties and early activity of comet 67P/Churyumov-Gerasimenko” by S. Gulkis et al. (MIRO)
“The Morphological Diversity of Comet 67P/Churyumov-Gerasimenko” by N. Thomas et al. (OSIRIS)
“On the nucleus structure and activity of comet 67P/Churyumov-Gerasimenko” by H. Sierks et al. (OSIRIS)
“Time variability and heterogeneity in the coma of 67P/Churyumov-Gerasimenko,” by M. Hässig et al. (ROSINA)
“Birth of a comet magnetosphere: a spring of water ions,” by H. Nilsson et al. (RPC-ICA)
“67P/Churyumov-Gerasimenko: The Organic-rich surface of a Kuiper Belt comet as seen by VIRTIS/Rosetta” by F. Capaccioni et al. (VIRTIS)
Based on the press release of the Swedish Institute of Space Physics summarising the results of the Rosetta Plasma Consortium’s (RPC) Ion Composition Analyser (ICA) that are presented in the journal Science today, and on follow-up discussion with Hans Nilsson, RPC-ICA principal investigator.
The RPC-ICA instrument onboard Rosetta has been watching the early stages of how a magnetosphere forms around Comet 67P Churyumov-Gerasimenko as it moves closer to the Sun along its orbit and begins to interact with the solar wind
Based on inputs from GIADA team members Alessandra Rotundi (instrument PI) and Marco Fulle, following the publication of “Dust Measurements in the Coma of Comet 67P/Churyumov-Gerasimenko Inbound to the Sun Between 3.7 and 3.4 AU” in the journal Science today. GIADA is Rosetta’s Grain Impact Analyzer and Dust Accumulator
This entry is based on the Southwest Research Institute’s press release and covers the results of the ROSINA instrument – the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis – that were published today in the journal Science.
Scientists working on the ROSINA instrument have discovered that Comet 67P/Churyumov-Gerasimenko’s atmosphere, or coma, is much less homogenous than expected and that comet outgassing varies significantly over time
* The issue of Science is not behind a paywall Edit: In my excitement, I forgot to put the full Sciencemag edition details.
It is Volume 347 Issue 6220 January 23, 2015
On Nov. 12, 2014, the European Space Agency’s Rosetta mission made history when its Philae lander touched down on the surface of comet 67P/Churyumov-Gerasimenko. While this exciting technical achievement gained lots of headlines, it was only the beginning for researchers back on Earth who are receiving and analyzing comet data. The latest chapter in the story provides the closest and most detailed look at a comet that scientists have ever seen. ...
In some of the first research findings to be published from the European Space Agency’s Rosetta Mission to the comet 67P/Churyumov-Gerasimenko, scientists including astronomer Peter Schloerb of the University of Massachusetts Amherst report early measurements of the comet’s subsurface temperature and production of gas from the surface of its nucleus. ...
As the Rosetta spacecraft orbits comet 67P/Churyumov-Gerasimenko, an international team of scientists have discovered that the comet’s atmosphere, or coma, is much less homogenous than expected and comet outgassing varies significantly over time, as reported in a paper published in the Jan. 23, 2015, issue of Science. ...
Rosetta is revealing its host comet as having a remarkable array of surface features and with many processes contributing to its activity, painting a complex picture of its evolution. In a special edition of the journal Science, initial results are presented from seven of Rosetta’s 11 science instruments based on measurements made during the approach to and soon after arriving at Comet 67P/Churyumov–Gerasimenko in August 2014. ...
This animation comprises 24 montages based on images acquired by the navigation camera on the European Space Agency's Rosetta spacecraft orbiting Comet 67P/Churyumov-Gerasimenko between Nov. 19 and Dec. 3, 2014. Image credit: ESA/Rosetta/NAVCAM
There has been a significant increase in the amount of water "pouring" out of comet 67P/Churyumov-Gerasimenko, the comet on which the Rosetta mission's Philae lander touched down in November 2014.
The 2.5-mile-wide (4-kilometer) comet was releasing the earthly equivalent of 40 ounces (1.2 liters) of water into space every second at the end of August 2014. The observations were made by NASA's Microwave Instrument for Rosetta Orbiter (MIRO), aboard the European Space Agency's Rosetta spacecraft. Science results from the MIRO team were released today as part of a special Rosetta-related issue of the journal Science.
...In another 67P paper released today, it was revealed that the comet's atmosphere, or coma, is much less homogenous than expected and that comet outgassing varies significantly over time.
"If we would have just seen a steady increase of gases as we closed in on the comet, there would be no question about the heterogeneity of the nucleus," said Myrtha Hässig, a NASA-sponsored scientist from the Southwest Research Institute in San Antonio. "Instead we saw spikes in water readings, and a few hours later, a spike in carbon dioxide readings. This variation could be a temperature effect or a seasonal effect, or it could point to the possibility of comet migrations in the early solar system."
... "Taken together, the MIRO outgassing results and results about heterogeneous fountains from ROSINA suggest fascinating new details to be learned about how comets work,"said Claudia Alexander, NASA project scientist for the U.S. Rosetta team, from JPL. "These results are helping us move the field forward on how comets operate on a fundamental level."
Based on the NASA-JPL press release* reporting the results of Rosetta’s MIRO instrument, NASA’s Microwave Instrument on the Rosetta Orbiter and with additional inputs from the MIRO team
The blue arrow indicates Comet 67P/Churyumov–Gerasimenko’s rotation axis, and the red and green arrows display its equatorial x- and y-axes, respectively.
Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
Based on the press release of the National Institute for Astrophysics in Italy covering the results of the VIRTIS instrument – the Visible and Infrared Thermal Imaging Spectrometer on Rosetta – that were published last night in the journal Science. The results are based on data collected by VIRTIS between August and December 2014.
On the left, an image of the nucleus of Comet 67P/C-G obtained with the Navigation Camera (NAVCAM) on Rosetta. On the right, in a similar orientation, a map of the spectral slope of the surface of the nucleus. The spectral slope is used to extract information about the composition of the material present on the surface. Small values of the spectral slope (in blue) are clearly seen in the 'neck' region, which is the one that, to the day, has shown the largest degree of cometary activity in terms of gas and dust emission. Credit: ESA/Rosetta/NAVCAM(left); ESA/Rosetta/VIRTIS/INAF-IAPS/OBS DE PARIS-LESIA/DLR (right)
The first surprising result emerging from VIRTIS’s study of Comet 67P/Churyumov-Gerasimenko is the measurement of its albedo, or how much sunlight is reflected by the surface of the nucleus. With an albedo of only 6%, about half as much as the Moon's, 67P/C-G is one of the darkest objects in the Solar System.
Such a low reflecting power indicates that the surface of the comet contains minerals such as, for example, iron sulfides, but also carbon-based compounds. The low albedo also indicates that there is little or no water ice on the outermost layers of the surface of the nucleus.
“This clearly doesn't mean that the comet is not rich in water, but only that there is no water ice in the outermost shell, just over one millimetre thick,” explains Fabrizio Capaccioni, VIRTIS Principal Investigator from INAF-IAPS in Rome, Italy. “The reason for this is rooted in the recent history of the comet's evolution, since repeated passes in the vicinity of the Sun cause surface ice to sublimate.”
