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  • richardmitnick 9:58 am on June 23, 2015 Permalink | Reply
    Tags: , , ESA Rosetta   

    From ESA: “Rosetta Mission Extended” 

    ESASpaceForEuropeBanner
    European Space Agency

    23 June 2015
    Markus Bauer







    ESA Science and Robotic Exploration Communication Officer








    Tel: +31 71 565 6799








    Mob: +31 61 594 3 954








    Email: markus.bauer@esa.int

    Patrick Martin
    ESA Rosetta Mission Manager
    Email: Patrick.martin@esa.int

    Matt Taylor






    ESA Rosetta project scientist






    Email: matthew.taylor@esa.int

    1
    Rosetta approaching comet

    The adventure continues: ESA today confirmed that its Rosetta mission will be extended until the end of September 2016, at which point the spacecraft will most likely be landed on the surface of Comet 67P/Churyumov-Gerasimenko.

    Rosetta was launched in 2004 and arrived at the comet in August 2014, where it has been studying the nucleus and its environment as the comet moves along its 6.5-year orbit closer to the Sun. After a detailed survey, Rosetta deployed the lander, Philae, to the surface on 12 November. Philae fell into hibernation after 57 hours of initial scientific operations, but recently awoke and made contact with Rosetta again.

    Rosetta’s nominal mission was originally funded until the end of December 2015, but at a meeting today, ESA’s Science Programme Committee has given formal approval to continue the mission for an additional nine months. At that point, as the comet moves far away from the Sun again, there will no longer be enough solar power to run Rosetta’s set of scientific instrumentation efficiently.

    “This is fantastic news for science,” says Matt Taylor, ESA’s Rosetta Project Scientist. “We’ll be able to monitor the decline in the comet’s activity as we move away from the Sun again, and we’ll have the opportunity to fly closer to the comet to continue collecting more unique data. By comparing detailed ‘before and after’ data, we’ll have a much better understanding of how comets evolve during their lifetimes.”

    Comet 67P/Churyumov-Gerasimenko will make its closest approach to the Sun on 13 August and Rosetta has been watching its activity increase over the last year. Continuing its study of the comet in the year following perihelion will give scientists a fuller picture of how a comet’s activity waxes and wanes along its orbit.

    The extra observations collected by Rosetta will also provide additional context for complementary Earth-based observations of the comet. At present, the comet is close to the line-of-sight to the Sun, making ground-based observations difficult.

    As the activity diminishes post-perihelion, it should be possible to move the orbiter much closer to the comet’s nucleus again, to make a detailed survey of changes in the comet’s properties during its brief ‘summer’.

    In addition, there may be an opportunity to make a definitive visual identification of Philae. Although candidates have been seen in images acquired from a distance of 20 km, images taken from 10 km or less after perihelion could provide the most compelling confirmation.

    During the extended mission, the team will use the experience gained in operating Rosetta in the challenging cometary environment to carry out some new and potentially slightly riskier investigations, including flights across the night-side of the comet to observe the plasma, dust, and gas interactions in this region, and to collect dust samples ejected close to the nucleus.

    As the comet recedes from the Sun, the solar-powered spacecraft will no longer receive enough sunlight to operate efficiently and safely, equivalent to the situation in June 2011 when the spacecraft was put into hibernation for 31 months for the most distant leg of its journey out towards the orbit of Jupiter.

    In addition, Rosetta and the comet will again be close to the Sun as seen from the Earth in October 2016, making operations difficult by then.

    However, with Rosetta’s propellant largely depleted by that time, it makes little sense to place the spacecraft in hibernation again.

    “This time, as we’re riding along next to the comet, the most logical way to end the mission is to set Rosetta down on the surface,” says Patrick Martin, Rosetta Mission Manager.

    “But there is still a lot to do to confirm that this end-of-mission scenario is possible. We’ll first have to see what the status of the spacecraft is after perihelion and how well it is performing close to the comet, and later we will have to try and determine where on the surface we can have a touchdown.”

    If this proposed scenario were played out, then the spacecraft would be commanded to spiral down to the comet over a period of about three months.

    It is expected that science operations would continue throughout this period and be feasible up to very close to the end of mission, allowing Rosetta’s instruments to gather unique data at unprecedentedly close distances.

    Once the orbiter lands on the surface, however, it is highly unlikely to be able to continue operations and relay data back to Earth, bringing to an end one of the most successful space exploration missions of all time.

    About Rosetta
    Rosetta is an ESA mission with contributions from its Member States and NASA. Rosetta’s Philae lander was provided by a consortium led by DLR, MPS, CNES and ASI. Rosetta is the first mission in history to rendezvous with a comet. It is escorting the comet as they orbit the Sun together. Philae landed on the comet on 12 November 2014. Comets are time capsules containing primitive material left over from the epoch when the Sun and its planets formed. By studying the gas, dust and structure of the nucleus and organic materials associated with the comet, via both remote and in situ observations, the Rosetta mission should become the key to unlocking the history and evolution of our Solar System.

    See the full article here.

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    The European Space Agency (ESA), established in 1975, is an intergovernmental organization dedicated to the exploration of space, currently with 19 member states. Headquartered in Paris, ESA has a staff of more than 2,000. ESA’s space flight program includes human spaceflight, mainly through the participation in the International Space Station program, the launch and operations of unmanned exploration missions to other planets and the Moon, Earth observation, science, telecommunication as well as maintaining a major spaceport, the Guiana Space Centre at Kourou, French Guiana, and designing launch vehicles. ESA science missions are based at ESTEC in Noordwijk, Netherlands, Earth Observation missions at ESRIN in Frascati, Italy, ESA Mission Control (ESOC) is in Darmstadt, Germany, the European Astronaut Centre (EAC) that trains astronauts for future missions is situated in Cologne, Germany, and the European Space Astronomy Centre is located in Villanueva de la Cañada, Spain.

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  • richardmitnick 7:41 am on June 20, 2015 Permalink | Reply
    Tags: , , ESA Rosetta,   

    From DLR: “Lander Control Center in contact with Philae once again” 

    DLR Bloc

    German Aerospace Center

    1
    Lander Control Center at DLR – Control Center for Philae

    The team at the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) received data from the Philae lander for the third time on 19 June 2015.

    ESA Rosetta Philae Lander
    Philae

    Between 15:20 and 15:39 CEST, Philae sent 185 data packets. “Among other things, we have received updated status information,” says Michael Maibaum, a systems engineer at the DLR Lander Control Center (LCC) in Cologne and Deputy Operations Manager. “At present, the lander is operating at a temperature of zero degrees Celsius, which means that the battery is now warm enough to store energy. This means that Philae will also be able to work during the comet’s night, regardless of solar illumination.” In the 19 minutes of transmission, the lander sent data recorded last week; from this, the engineers determined that the amount of sunlight has increased: “More solar panels were illuminated; at the end of contact, four of Philae’s panels were receiving energy”. There were a number of interruptions in the connection, but it was otherwise stable over a longer period for the first time. “The contact has confirmed that Philae is doing very well.”

    The lander had already reported from the comet twice after its seven-month hibernation; it sent data on 13 and 14 June 2015. The analysis by the DLR team at the LCC was clear – Philae has managed to survive the icy temperatures on Comet 67P/Churyumov-Gerasimenko – temperature and energy values show that the lander is now operational. In the first two contacts, it sent stored data from early May. “Philae was already awake at this time, but could not contact us,” explains DLR’s Philae Project Manager, Stephan Ulamec. Now, the trajectory of the Rosetta orbiter around the comet is being modified to optimise the possibility for renewed contact, to allow the orbiter to act as a relay between Philae and Earth.

    ESA Rosetta spacecraft
    ESA/Rosetta

    “However, we need a long and stable contact time to conduct research with Philae again as planned,” says Maibaum. If these conditions are met, the 10 instruments on board Philae could once again be operated from the LCC.

    See the full article here.

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    DLR Center

    DLR is the national aeronautics and space research centre of the Federal Republic of Germany. Its extensive research and development work in aeronautics, space, energy, transport and security is integrated into national and international cooperative ventures. In addition to its own research, as Germany’s space agency, DLR has been given responsibility by the federal government for the planning and implementation of the German space programme. DLR is also the umbrella organisation for the nation’s largest project management agency.

    DLR has approximately 8000 employees at 16 locations in Germany: Cologne (headquarters), Augsburg, Berlin, Bonn, Braunschweig, Bremen, Goettingen, Hamburg, Juelich, Lampoldshausen, Neustrelitz, Oberpfaffenhofen, Stade, Stuttgart, Trauen, and Weilheim. DLR also has offices in Brussels, Paris, Tokyo and Washington D.C.

     
  • richardmitnick 10:33 am on June 2, 2015 Permalink | Reply
    Tags: , , , ESA Rosetta   

    From ESA: “Ultraviolet study reveals surprises in comet coma” 

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    European Space Agency

    For more information, please contact:

    Markus Bauer







    ESA Science and Robotic Exploration Communication Officer








    Tel: +31 71 565 6799








    Mob: +31 61 594 3 954








    Email: markus.bauer@esa.int

    Paul Feldman
    Johns Hopkins University, Baltimore
    Email: pfeldman@jhu.edu

    Matt Taylor






    ESA Rosetta project scientist






    Email: matthew.taylor@esa.int

    Rosetta’s continued close study of Comet 67P/Churyumov–Gerasimenko has revealed an unexpected process at work, causing the rapid breakup of water and carbon dioxide molecules spewing from the comet’s surface.

    ESA Rosetta spacecraft
    Rosetta

    ESA’s Rosetta mission arrived at the comet in August last year. Since then, it has been orbiting or flying past the comet at distances from as far as several hundred kilometres down to as little as 8 km. While doing so, it has been collecting data on every aspect of the comet’s environment with its suite of 11 science instruments.

    One instrument, the Alice spectrograph provided by NASA, has been examining the chemical composition of the comet’s atmosphere, or coma, at far-ultraviolet wavelengths.

    At these wavelengths, Alice allows scientists to detect some of the most abundant elements in the Universe such as hydrogen, oxygen, carbon and nitrogen. The spectrograph splits the comet’s light into its various colours – its spectrum – from which scientists can identify the chemical composition of the coma gases.


    Rosetta’s imaging and spectroscopy instruments

    In a paper accepted for publication in the journal Astronomy and Astrophysics, scientists report the detections made by Alice from Rosetta’s first four months at the comet, when the spacecraft was between 10 km and 80 km from the centre of the comet nucleus.

    For this study, the team focused on the nature of ‘plumes’ of water and carbon dioxide gas erupting from the comet’s surface, triggered by the warmth of the Sun. To do so, they looked at the emission from hydrogen and oxygen atoms resulting from broken water molecules, and similarly carbon atoms from carbon dioxide molecules, close to the comet nucleus.

    They discovered that the molecules seem to be broken up in a two-step process.

    First, an ultraviolet photon from the Sun hits a water molecule in the comet’s coma and ionises it, knocking out an energetic electron. This electron then hits another water molecule in the coma, breaking it apart into two hydrogen atoms and one oxygen, and energising them in the process. These atoms then emit ultraviolet light that is detected at characteristic wavelengths by Alice.

    Similarly, it is the impact of an electron with a carbon dioxide molecule that results in its break-up into atoms and the observed carbon emissions.

    “Analysis of the relative intensities of observed atomic emissions allows us to determine that we are directly observing the ‘parent’ molecules that are being broken up by electrons in the immediate vicinity, about 1 km, of the comet’s nucleus where they are being produced,” says Paul Feldman, professor of physics and astronomy at the Johns Hopkins University in Baltimore, and lead author of the paper discussing the results.

    By comparison, from Earth or from Earth-orbiting space observatories such as the Hubble Space Telescope, the atomic constituents of comets can only be seen after their parent molecules, such as water and carbon dioxide, have been broken up by sunlight, hundreds to thousands of kilometres away from the nucleus of the comet.

    2
    Comet on 20 May 2015 – NavCam

    “The discovery we’re reporting is quite unexpected,” says Alice Principal Investigator Alan Stern, an associate vice president in the Space Science and Engineering Division of the Southwest Research Institute (SwRI).

    “It shows us the value of going to comets to observe them up close, since this discovery simply could not have been made from Earth or Earth orbit with any existing or planned observatory. And, it is fundamentally transforming our knowledge of comets.”

    “By looking at the emission from hydrogen and oxygen atoms broken from the water molecules, we also can actually trace the location and structure of water plumes from the surface of the comet,” adds co-author Joel Parker, an assistant director in SwRI’s Space Science and Engineering Division in Boulder, Colorado.

    The team likens the break-up of the molecules to the process that has been proposed for the plumes on Jupiter’s icy moon Europa, except that the electrons at the comet are produced by solar photons, while the electrons at Europa come from Jupiter’s magnetosphere.

    The results from Alice are supported by data obtained by other Rosetta instruments, in particular MIRO, ROSINA and VIRTIS, which are able to study the abundance of different coma constituents and their variation over time, and particle detecting instruments like RPC-IES.

    “These early results from Alice demonstrate how important it is to study a comet at different wavelengths and with different techniques, in order to probe various aspects of the comet environment,” says ESA’s Rosetta project scientist Matt Taylor.

    “We’re actively watching how the comet evolves as it moves closer to the Sun along its orbit towards perihelion in August, seeing how the plumes become more active due to solar heating, and studying the effects of the comet’s interaction with the solar wind.”

    More information

    Measurements of the near-nucleus coma of Comet 67P/Churyumov-Gerasimenko with the Alice far-ultraviolet spectrograph on Rosetta, by P Feldman et al is accepted for publication in Astronomy and Astrophysics.

    About Rosetta
    Rosetta is an ESA mission with contributions from its Member States and NASA. Rosetta’s Philae lander was provided by a consortium led by DLR, MPS, CNES and ASI.

    ESA Rosetta Philae Lander
    Rosetta’s Philae lander

    Rosetta is the first mission in history to rendezvous with a comet. It is escorting the comet as they orbit the Sun together. Philae landed on the comet on 12 November 2014. Comets are time capsules containing primitive material left over from the epoch when the Sun and its planets formed. By studying the gas, dust and structure of the nucleus and organic materials associated with the comet, via both remote and in situ observations, the Rosetta mission should become the key to unlocking the history and evolution of our Solar System.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    The European Space Agency (ESA), established in 1975, is an intergovernmental organization dedicated to the exploration of space, currently with 19 member states. Headquartered in Paris, ESA has a staff of more than 2,000. ESA’s space flight program includes human spaceflight, mainly through the participation in the International Space Station program, the launch and operations of unmanned exploration missions to other planets and the Moon, Earth observation, science, telecommunication as well as maintaining a major spaceport, the Guiana Space Centre at Kourou, French Guiana, and designing launch vehicles. ESA science missions are based at ESTEC in Noordwijk, Netherlands, Earth Observation missions at ESRIN in Frascati, Italy, ESA Mission Control (ESOC) is in Darmstadt, Germany, the European Astronaut Centre (EAC) that trains astronauts for future missions is situated in Cologne, Germany, and the European Space Astronomy Centre is located in Villanueva de la Cañada, Spain.

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  • richardmitnick 11:27 am on March 21, 2015 Permalink | Reply
    Tags: , , ESA Rosetta   

    From ESA: “Rosetta makes first detection of molecular nitrogen at a comet” 

    ESASpaceForEuropeBanner
    European Space Agency

    19 March 2015

    Markus Bauer





    ESA Science and Robotic Exploration Communication Officer






    Tel: +31 71 565 6799






    Mob: +31 61 594 3 954






    Email: markus.bauer@esa.int

    Martin Rubin
    University of Bern, Switzerland
    Email: martin.rubin@space.unibe.ch

    Kathrin Altwegg

    Principal investigator for ROSINA

    University of Bern, Switzerland

    Email: kathrin.altwegg@space.unibe.ch

    Matt Taylor




    ESA Rosetta project scientist




    Email: matthew.taylor@esa.int

    1
    First detection of molecular nitrogen at a comet

    ESA’s Rosetta spacecraft has made the first measurement of molecular nitrogen at a comet, providing clues about the temperature environment in which Comet 67P/Churyumov–Gerasimenko formed.

    ESA Rosetta spacecraft
    Rosetta

    Rosetta arrived last August, and has since been collecting extensive data on the comet and its environment with its suite of 11 science instruments.

    The in situ detection of molecular nitrogen has long been sought at a comet. Nitrogen had only previously been detected bound up in other compounds, including hydrogen cyanide and ammonia, for example.

    Its detection is particularly important since molecular nitrogen is thought to have been the most common type of nitrogen available when the Solar System was forming. In the colder outer regions, it likely provided the main source of nitrogen that was incorporated into the gas planets. It also dominates the dense atmosphere of Saturn’s moon, Titan, and is present in the atmospheres and surface ices on Pluto and Neptune’s moon Triton.

    It is in these cold outer reaches of our Solar System in which the family of comets that includes Rosetta’s comet is believed to have formed.

    2
    Comet on 14 March 2015 – NavCam

    The new results are based on 138 measurements collected by the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis instrument, ROSINA, during 17–23 October 2014, when Rosetta was about 10 km from the centre of the comet.

    “Identifying molecular nitrogen places important constraints on the conditions in which the comet formed, because it requires very low temperatures to become trapped in ice,” says Martin Rubin of the University of Bern, lead author of the paper presenting the results published today in the journal Science.

    The trapping of molecular nitrogen in ice in the protosolar nebula is thought to take place at temperatures similar to those required to trap carbon monoxide. So in order to put constraints on comet formation models, the scientists compared the ratio of molecular nitrogen to carbon monoxide measured at the comet to that of the protosolar nebula, as calculated from the measured nitrogen to carbon ratio in Jupiter and the solar wind.

    That ratio for Comet 67P/Churyumov–Gerasimenko turns out to be about 25 times less than that of the expected protosolar value. The scientists think that this depletion may be a consequence of the ice forming at very low temperatures in the protosolar nebula.

    One scenario involves temperatures of between roughly –250ºC and perhaps –220ºC, with relatively inefficient trapping of molecular nitrogen in either amorphous water ice or cage-like water ice known as a clathrate, in both cases yielding a low ratio directly.

    3
    Comet’s orbit

    Alternatively, the molecular nitrogen could have been trapped more efficiently at even lower temperatures of around –253ºC in the same region as Pluto and Triton, resulting in relatively nitrogen-rich ices as seen on them.

    Subsequent heating of the comet through the decay of radioactive nuclides, or as Rosetta’s comet moved into orbits closer to the Sun, could have been sufficient to trigger outgassing of the nitrogen and thus a reduction of the ratio over time.

    “This very low-temperature process is similar to how we think Pluto and Triton have developed their nitrogen-rich ice and is consistent with the comet originating from the Kuiper Belt,” says Martin.

    The only other body in the Solar System with a nitrogen-dominated atmosphere is Earth. The current best guess at its origin is via plate tectonics, with volcanoes releasing nitrogen locked in silicate rocks in the mantle.

    However, the question remains as to the role played by comets in delivering this important ingredient.

    “Just as we wanted to learn more about the role of comets in bringing water to Earth, we would also like to place constraints on the delivery of other ingredients, especially those that are needed for the building blocks of life, like nitrogen,” says Kathrin Altwegg, also at the University of Bern, and principal investigator for ROSINA.

    To assess the possible contribution of comets like Rosetta’s to the nitrogen in Earth’s atmosphere, the scientists assumed that the isotopic ratio of 14N to 15N in the comet is the same as that measured for Jupiter and solar wind, which reflects the composition of the protosolar nebula.

    However, this isotopic ratio is much higher than measured for other nitrogen-bearing species present in comets, such as hydrogen cyanide and ammonia.

    Earth’s 14N/15N ratio lies roughly between these two values, and thus if there was an equal mix of the molecular form on the one hand, and in hydrogen cyanide and ammonia on the other in comets, it would be at least conceivable that Earth’s nitrogen could have come from comets.

    “However, the amount of nitrogen found in 67P/Churyumov–Gerasimenko is not an equal mix between molecular nitrogen and the other nitrogen-bearing molecules. Rather, there is 15 times too little molecular nitrogen, and therefore Earth’s 14N/15N ratio cannot be reproduced through delivery of Jupiter family comets like Rosetta’s,” says Martin.

    “It’s another piece of the puzzle in terms of the role of Jupiter family comets in the evolution of the Solar System, but the puzzle is by no means finished yet,” says ESA’s Rosetta project scientist, Matt Taylor

    “Rosetta is about five months away from perihelion now, and we’ll be watching how the composition of the gases changes over this period, and trying to decipher what that tells us about the past life of this comet.”

    Molecular nitrogen in comet 67P/Churyumov-Gerasimenko indicates a low formation temperature, by M. Rubin et al is published in the 20 March issue of the journal Science. 10.1126/science.aaa6100

    ROSINA is the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis instrument and comprises two mass spectrometers: the Double Focusing Mass Spectrometer (DFMS) and the Reflectron Time of Flight mass spectrometer (RTOF) – and the COmetary Pressure Sensor (COPS). The measurements reported here were conducted with DFMS. The ROSINA team is led by Kathrin Altwegg of the University of Bern, Switzerland.

    An average ratio of N2/CO = (5.70 +/- 0.66) x 10–3 was determined for the period 17–23 October 2014. The minimum and maximum values measured were 1.7 x 10–3 and 1.6 x 10–2, respectively. Because the amount and composition of the gases change with comet rotation and position of the spacecraft with respect to the comet’s surface, an average value is used.

    The 14N/15N ratio for the N2 in Comet 67P/Churyumov–Gerasimenko is assumed to be 441, the value for the protosolar nebula as measured from Jupiter and the solar wind, while the corresponding value for nitrogen in hydrogen cyanide and ammonia is 130, as measured at other comets. The value for the Earth’s nitrogen is 272.

    Rosetta is an ESA mission with contributions from its Member States and NASA. Rosetta’s Philae lander was provided by a consortium led by DLR, MPS, CNES and ASI.

    ESA Rosetta Philae Lander
    Philae lander

    Rosetta is the first mission in history to rendezvous with a comet. It is escorting the comet as they orbit the Sun together. Philae landed on the comet on 12 November 2014. Comets are time capsules containing primitive material left over from the epoch when the Sun and its planets formed. By studying the gas, dust and structure of the nucleus and organic materials associated with the comet, via both remote and in situ observations, the Rosetta mission should become the key to unlocking the history and evolution of our Solar System.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    The European Space Agency (ESA), established in 1975, is an intergovernmental organization dedicated to the exploration of space, currently with 19 member states. Headquartered in Paris, ESA has a staff of more than 2,000. ESA’s space flight program includes human spaceflight, mainly through the participation in the International Space Station program, the launch and operations of unmanned exploration missions to other planets and the Moon, Earth observation, science, telecommunication as well as maintaining a major spaceport, the Guiana Space Centre at Kourou, French Guiana, and designing launch vehicles. ESA science missions are based at ESTEC in Noordwijk, Netherlands, Earth Observation missions at ESRIN in Frascati, Italy, ESA Mission Control (ESOC) is in Darmstadt, Germany, the European Astronaut Centre (EAC) that trains astronauts for future missions is situated in Cologne, Germany, and the European Space Astronomy Centre is located in Villanueva de la Cañada, Spain.

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  • richardmitnick 5:21 pm on January 22, 2015 Permalink | Reply
    Tags: , , , ESA Rosetta,   

    From Nature: “Science pours in from Rosetta comet mission” 

    Nature Mag
    Nature

    22 January 2015
    Elizabeth Gibney

    The first major haul of research from the European Space Agency’s Rosetta mission, published in seven papers in Science on 22 January, reveals a rich and diverse landscape on 67P/Churyumov–Gerasimenko, the most studied comet in history. The best images from the haul are pictured below.

    1
    Charting gravity
    Using data from the Optical, Spectroscopic, and Infrared Remote Imaging System (OSIRIS) and the Radio Science Investigation instrument, the Rosetta mission team calculated the comet’s gravitational field1. The gravitational potential (pictured) also takes into account a pull caused by the comet’s rotation. The resulting force is greatest on top of the lobes, but it is about six times weaker in the neck region, where dust can lift off more easily. The team also used the data to calculate the comet’s density, finding that the body is relatively fluffy and porous — with a density of around half that of water, giving clues as to its structure and strength.

    2
    Different terrains
    Images taken by the OSIRIS camera reveal vastly different kinds of terrain, including dunes, ripples and fractures2. Rosetta scientists have split the comet into regions defined by surface structure (see false-colour image), with each named after an Egyptian god. Hatmehit, for example, is a smooth depression on the ‘head’ of the duck-shaped comet that could be a dust-filled impact crater. Other areas, such as Seth and Hathor, are rough with steep cliff-like structures. However, the porosity of the comet means that rock-like structures are in fact compacted dust. Many structures look as though they are formed by gas moving dust around the surface, say the authors, in the same way that wind shapes sand in a desert

    3
    Clues to the origins
    Detailed pictures, at their best with a resolution of 15 centimetres per pixel, show structures that could hint at the comet’s history1. Three-metre-wide features nicknamed “goosebumps”, pictured here running down the inside of a pit in the Seth region, are found all over the comet. Holger Sierks of the Max Planck Institute for Solar System Research in Göttingen, Germany, who is principal investigator on the OSIRIS camera instrument, says that the pebble-like shapes could hint at the scale on which grains of dust and ice first clumped together in the early Solar System. “The hypothesis is these might be the building blocks of comets,” he says.

    4
    The neck riddle
    Data from several instruments show that the comet’s neck is the source of most of its streaming gas and dust. To understand why the region is so active, the Rosetta team looked at how much thermal energy hits the surface per 12.4-hour rotation (left) and per 6.5-year solar orbit (right). The neck receives less energy from the Sun than the rest of the comet because it is shaded, but they found that a suntrap effect from radiation bouncing between opposite cliff walls goes some way towards compensating for that. Other possible reasons for the region’s high activity include its low gravitational pull, which means that little force is needed to blow dust away, and that the region might have a different composition than other regions, or have more ready access to water beneath the surface1. The team has still to answer whether the neck denotes a join between two comets or has been carved out of a single comet by erosion. Evidence of differences between the two lobes would indicate the former, but so far the two lobes seem to have very similar structures, says Sierks.

    6
    Coming from afar
    This visible and infrared portrait of 67P’s surface, obtained by the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS), shows an abundance of opaque, organic compounds, but very little water ice. This would be consistent with an origin for the comet in the distant Kuiper belt — beyond the orbit of Neptune — rather than closer to Jupiter, as its current orbit would suggest.

    References
    1.Sierks, H. et al. Science http://dx.doi.org/10.1126/science.aaa1044 (2015)
    2.Thomas, N. et al. Science http://dx.doi.org/10.1126/science.aaa0440 (2015)
    3.Hässig, M. et al. Science http://dx.doi.org/10.1126/science.aaa0276 (2015)
    4.Capaccioni, F. et al. Science http://dx.doi.org/10.1126/science.aaa0628 (2015)
    6.Gulkis, S. et al. Science http://dx.doi.org/10.1126/science.aaa0709 (2015)

    Additional reporting by Davide Castelvecchi

    See the full article here.

    Please help promote STEM in your local schools.

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    Nature is a weekly international journal publishing the finest peer-reviewed research in all fields of science and technology on the basis of its originality, importance, interdisciplinary interest, timeliness, accessibility, elegance and surprising conclusions. Nature also provides rapid, authoritative, insightful and arresting news and interpretation of topical and coming trends affecting science, scientists and the wider public.

     
  • richardmitnick 4:29 pm on December 10, 2014 Permalink | Reply
    Tags: , , , , ESA Rosetta   

    From ESA: “Rosetta Fuels Debate on Origin of Earth’s Oceans” 

    ESASpaceForEuropeBanner
    European Space Agency

    10 December 2014

    Kathrin Altwegg
    Principal investigator for ROSINA
    University of Bern, Switzerland
    Email: kathrin.altwegg@space.unibe.ch

    Markus Bauer




    ESA Science and Robotic Exploration Communication Officer





    Tel: +31 71 565 6799





    Mob: +31 61 594 3 954





    Email: markus.bauer@esa.int

    Matt Taylor



    ESA Rosetta project scientist



    Email: matthew.taylor@esa.int

    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.

    ESA Rosetta spacecraft
    ESA/Rosetta

    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.

    c
    Comet on 20 November – NavCam

    One of the leading hypotheses on Earth’s formation is that it was so hot when it formed 4.6 billion years ago that any original water content should have boiled off. But, today, two thirds of the surface is covered in water, so where did it come from?

    In this scenario, it should have been delivered after our planet had cooled down, most likely from collisions with comets and asteroids. The relative contribution of each class of object to our planet’s water supply is, however, still debated.

    The key to determining where the water originated is in its ‘flavour’, in this case the proportion of deuterium – a form of hydrogen with an additional neutron – to normal hydrogen.

    This proportion is an important indicator of the formation and early evolution of the Solar System, with theoretical simulations showing that it should change with distance from the Sun and with time in the first few million years.

    One key goal is to compare the value for different kinds of object with that measured for Earth’s oceans, in order to determine how much each type of object may have contributed to Earth’s water.

    Comets in particular are unique tools for probing the early Solar System: they harbour material left over from the protoplanetary disc out of which the planets formed, and therefore should reflect the primordial composition of their places of origin.

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    Kuiper Belt and Oort Cloud in context

    But thanks to the dynamics of the early Solar System, this is not a straightforward process. Long-period comets that hail from the distant Oort cloud originally formed in Uranus–Neptune region, far enough from the Sun that water ice could survive.

    They were later scattered to the Solar System’s far outer reaches as a result of gravitational interactions with the gas giant planets [Jupiter and Saturn] as they settled in their orbits.

    Conversely, Jupiter-family comets like Rosetta’s comet were thought to have formed further out, in the Kuiper Belt beyond Neptune. Occasionally these bodies are disrupted from this location and sent towards the inner Solar System, where their orbits become controlled by the gravitational influence of Jupiter.

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    Kuiper Belt

    Indeed, Rosetta’s comet now travels around the Sun between the orbits of Earth and Mars at its closest and just beyond Jupiter at its furthest, with a period of about 6.5 years.
    Deuterium-to-hydrogen in the Solar System

    Previous measurements of the deuterium/hydrogen (D/H) ratio in other comets have shown a wide range of values. Of the 11 comets for which measurements have been made, it is only the Jupiter-family Comet 103P/Hartley 2 that was found to match the composition of Earth’s water, in observations made by ESA’s Herschel mission in 2011.

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    Photograph from close approach by EPOXI mission

    NASA EPOXI
    NASA/EPOXI

    ESA Herschel
    ESA Herschel schematic
    ESA Herschel

    By contrast, meteorites originally hailing from asteroids in the Asteroid Belt also match the composition of Earth’s water. Thus, despite the fact that asteroids have a much lower overall water content, impacts by a large number of them could still have resulted in Earth’s oceans.

    It is against this backdrop that Rosetta’s investigations are important. 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.

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    ESA Rosetta Rosina
    Rosina Instrument

    “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.

    “Our finding also rules out the idea that Jupiter-family comets contain solely Earth ocean-like water, and adds weight to models that place more emphasis on asteroids as the main delivery mechanism for Earth’s oceans.”

    “We knew that Rosetta’s in situ analysis of this comet was always going to throw up surprises for the bigger picture of Solar System science, and this outstanding observation certainly adds fuel to the debate about the origin of Earth’s water,” says Matt Taylor, ESA’s Rosetta project scientist.

    “As Rosetta continues to follow the comet on its orbit around the Sun throughout next year, we’ll be keeping a close watch on how it evolves and behaves, which will give us unique insight into the mysterious world of comets and their contribution to our understanding of the evolution of the Solar System.”

    See the full article here.

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    The European Space Agency (ESA), established in 1975, is an intergovernmental organization dedicated to the exploration of space, currently with 19 member states. Headquartered in Paris, ESA has a staff of more than 2,000. ESA’s space flight program includes human spaceflight, mainly through the participation in the International Space Station program, the launch and operations of unmanned exploration missions to other planets and the Moon, Earth observation, science, telecommunication as well as maintaining a major spaceport, the Guiana Space Centre at Kourou, French Guiana, and designing launch vehicles. ESA science missions are based at ESTEC in Noordwijk, Netherlands, Earth Observation missions at ESRIN in Frascati, Italy, ESA Mission Control (ESOC) is in Darmstadt, Germany, the European Astronaut Centre (EAC) that trains astronauts for future missions is situated in Cologne, Germany, and the European Space Astronomy Centre is located in Villanueva de la Cañada, Spain.

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  • richardmitnick 5:48 pm on December 3, 2014 Permalink | Reply
    Tags: , , , , , , , ESA Rosetta   

    From ESA: “The quest for organic molecules on the surface of 67P/C-G” 

    ESASpaceForEuropeBanner
    European Space Agency

    From The Rosetta Blog

    ESA Rosetta spacecraft
    Rosetta

    02/12/2014
    This blog post is contributed by Ian Wright and his colleagues from the Ptolemy team.

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    Ptolemy on Philae Lander

    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.

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    Comet 67P/Churyumov-Gerasimenko

    The Ptolemy instrument on Philae is a compact mass spectrometer designed to measure the composition of the materials making up 67P/C-G, with a particular focus on organic molecules and mineral components. Earlier in 2014, Ptolemy had collected data at distances of 15,000, 13,000, 30, 20, and 10 km from the comet, while Philae was still attached to Rosetta.

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    But from 12 to 14 November, along with some other instruments on the lander, Ptolemy had the chance to operate at more than one location on the comet’s surface.
    Rosetta’s OSIRIS narrow-angle camera images of Philae’s first touchdown on the comet. Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

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    OSIRIS

    Ptolemy performed its first ‘sniffing’ measurements on the comet just after the initial touchdown of Philae. At almost exactly the same moment, the OSIRIS camera on Rosetta was imaging Philae flying back above the surface after the first bounce.

    Later, once Philae had stopped at its final landing site, Ptolemy then made six subsequent sets of measurements, sniffing the comet’s atmosphere at the surface between 13 and 14 November. Finally, a slightly different experiment was also conducted on 14 November, which was completed only 45 minutes before Philae went into hibernation as its primary battery was exhausted.

    For this “last gasp” experiment, the team used a specialised oven, the so-called “CASE” oven, to determine the composition of volatiles (and perhaps any particulates) that had accumulated in it. The Ptolemy team also used the same opportunity to reconfigure their analytical procedures, to see if they could make some isotopic measurements. Unfortunately, there was no chance to use Ptolemy in conjunction with SD2, as this was confined to the sister instrument, COSAC, given the limited power and time available.

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    The experiments conducted by Ptolemy on the surface of Comet 67P/C-G. Table courtesy of the Ptolemy team.

    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.

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    Scientists from the Ptolemy team at the Lander Control Centre at DLR in Cologne, Germany, during the night between 14 and 15 November 2014, just before Philae went into hibernation. Photo courtesy of Ian Wright.

    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.

    In the first instance, however, the team will be concentrating on the data acquired immediately after the first touchdown. It will be fascinating to compare the rich spectrum of organic compounds detected by Ptolemy with the measurements made by COSAC about 14 minutes later.

    The Ptolemy team has lots of questions. Exactly what organic compounds are present and in what ratios? How did things change between the various sets of measurements? What does these data tell us about the composition of the 10–20 cm depth of surface dust that got kicked up during the first bounce? And what can these materials tell us about the fundamental make-up of comets?

    The team is looking forward to making these analyses over the coming months and sharing the results with you.

    See the full article here.

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    The European Space Agency (ESA), established in 1975, is an intergovernmental organization dedicated to the exploration of space, currently with 19 member states. Headquartered in Paris, ESA has a staff of more than 2,000. ESA’s space flight program includes human spaceflight, mainly through the participation in the International Space Station program, the launch and operations of unmanned exploration missions to other planets and the Moon, Earth observation, science, telecommunication as well as maintaining a major spaceport, the Guiana Space Centre at Kourou, French Guiana, and designing launch vehicles. ESA science missions are based at ESTEC in Noordwijk, Netherlands, Earth Observation missions at ESRIN in Frascati, Italy, ESA Mission Control (ESOC) is in Darmstadt, Germany, the European Astronaut Centre (EAC) that trains astronauts for future missions is situated in Cologne, Germany, and the European Space Astronomy Centre is located in Villanueva de la Cañada, Spain.

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  • richardmitnick 3:09 pm on November 20, 2014 Permalink | Reply
    Tags: , , , , ESA Rosetta, , Philae obelisk   

    From livescience: “Philae Lander, Like Philae Obelisk, Is a Window to the Past” 

    Livescience

    November 19, 2014
    Ben Altshuler, Oxford University

    Benjamin Altshuler is on the classics faculty at the University of Oxford and is the current Classics Conclave fellow at the Centre for the Study of Ancient Documents. Altshuler is a specialist in reflectance transformation imaging (RTI), a computational photographic method that illuminates surface features undetectable by direct observation.

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    This image shows the power of reflectance transformation imaging (RTI) in an image of the Philae obelisk.
    Credit: Ben Altshuler, Oxford University

    The real voyage of discovery consists not in seeking new landscapes but in having new eyes. — Marcel Proust

    Separated by two millennia, the Philae lander and the Philae obelisk illuminate two separate and shared paths of discovery. The Philae lander, recently launched from the European Space Agency (ESA) mothership Rosetta, is the robotic space vehicle that landed on comet 67P/Churyumov-Gerasimenko last week in hopes of unlocking some of the secrets of ancient comets. The Philae obelisk, like the much better known Rosetta stone, helped unlock the ancient secrets of Egyptian hieroglyphs 200 years ago. Both are now connected by technology, as the same types of sensors aboard the Philae lander are now helping archaeologists unlock the obelisk’s messages to reveal secrets about ancient Egypt.

    ESA Rosetta Philae Lander
    ESA/Rosetta Philae Lander

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    Philae obelisk

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    67P/Churyumov-Gerasimenko

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    Rosetta stone

    A message in granite

    The story begins 2,100 years ago, when a group of priests in Egypt successfully petitioned their king Ptolemy VIII for a tax cut. The priests created a permanent document of their success in the form of a 7-meter-tall (23 feet) granite obelisk. Never intending their success to be a hidden secret, the priests had their accomplishment inscribed onto the obelisk in Greek, with prayers written in Egyptian hieroglyphs, for all to see and understand forever.

    However, by the fall of their eventual Roman conquerors 600 years later, the knowledge of hieroglyphs perished, and the obelisk’s Egyptian inscription remained unreadable for centuries.

    Then, in the 19th century, Egyptologist Jean-Francois Champollion used the recently discovered tri-lingual inscription on the Rosetta stone and the bilingual inscription on the Philae obelisk to decode hieroglyphs. While the importance of the Rosetta stone cannot be underplayed, the obelisk’s role in cementing hieroglyphs as a phonetic language was invaluable.

    Digital eyes to see the past

    Now, new computer-based imaging technologies called polynomial texture mapping (PTM) and multispectral imaging (MSI) are allowing researchers to revisit the Philae obelisk and reveal parts of the inscriptions that have eroded with time.

    While archaeology has often benefited from expanded excavations and deeper trenches, the field is now entering an age in which the most spectacular finds are not coming out of the ground but out of existing museum collections. Digital archaeology is allowing experts to uncover secrets in plain sight; indeed, to go beyond the boundaries of human sight and document sketch lines under layers of paint, transcribe badly eroded inscriptions and recover the faintest manuscripts.

    With the power of these technologies growing exponentially, the next ground-breaking find could just as easily be discovered in the basement of a museum as under the streets of Cairo.

    PTM is a powerful computational photographic technology that is literally shedding new light on ancient objects. Its ability to analyze the smallest features of surface topology has led to breakthroughs in the fields of epigraphy, archaeology and papyrology. The discoveries have been so frequent and significant that museums and archaeologists around the world are seeking to make PTM the standard international protocol for artifact documentation. Indeed, the age of digital archaeology has begun a quiet revolution in classical studies. Scholars no longer feel limited by what they can see with their own eyes.

    More than anything else, it is the sheer volume of data gathered by PTM that sets it apart from what is currently the most common documentation methods used in museums: simple photography. While a conventional photograph can adequately capture color information, it can only convey a very crude sense of shape and surface texture through a fixed number of highlights and shadows.

    By contrast, PTM, in addition to capturing superb color data, can record detailed shape and texture measurements at the level of individual pixels. This massive quantity of incremental data not only provides a far more comprehensive method for object documentation than simple photography can, but it also opens up a range of opportunities for computer-driven rendering techniques — potentially including the use of 3D printers — for creating highly detailed depictions of objects for study and analysis. PTM combines digital photography, specialized lighting techniques and sophisticated computer software to combine dozens of images into an interactive image that enables researchers to read worn inscriptions or recover artistic details.

    Current PTM work has already allowed researchers to confirm early transcriptions of the hieroglyphic and Greek text on the Philae obelisk and to begin studying the tool marks. In the coming weeks, epigraphists will also employ MSI and focus on the Greek text at the base of the obelisk where significant portions of the text are almost completely eroded, leaving huge swaths of text unaccounted for.

    It is hoped that ultraviolet and infrared light will pick up some of the original paint that adorned the obelisk and help researchers read more of the text to get a better understanding of the exact correspondence between Ptolemy VIII and the priests of Philae. Moreover, in a language where a single word, or even a single letter, can change the entire meaning of a sentence, every single minim picked up by PTM could contribute to, or even change, our current understanding.

    Digital eyes in space

    Meanwhile, 300 million miles away at comet 67P, the Philae lander is equipped with ROLIS (Rosetta-Lander Imaging System) and CIVA (Comet Nuclear Infrared and Visible Analyzer), both of which use digital imaging technologies and multispectral analyzers to “see” the comet and send images back to Earth.

    ESA Rosetta Philae Rolis
    ROLIS

    Over the next several months, scientists will use the same spectral properties that researchers are using to pick up traces of paint on the obelisk, albeit of different elements, to analyze and isolate the exact makeup of the comet. By understanding this, more can be learned about the origins of comet 67P, other comets in our solar system and the nature of the entire solar system.

    Although the Philae lander has now run out of power due to a malfunction in the landing apparatus, the data gathered in its short time on the comet is currently being analyzed by scientists and looks to shed light on many of the questions posed at the beginning of the mission. As the comet gets closer and closer to the sun, Rosetta will have to take over the mission continue to use mapping technologies similar to PTM to assess the changes in the topography of the comet. By monitoring 67P’s vital signs constantly, scientists look forward to seeing a process that has only ever been observed from millions of miles away.

    It is powerful to recognize that so many technologies being used in space to lead scientists to the origins of the solar system have equally valuable uses on Earth, helping archaeologists uncover lost secrets of the past.

    See the full article here.

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  • richardmitnick 2:51 pm on November 19, 2014 Permalink | Reply
    Tags: , , , , , ESA Rosetta   

    From ESA: “Rosetta Continues into its Full Science Phase” 

    ESASpaceForEuropeBanner
    European Space Agency

    19 November 2014
    No Writer Credit

    With the Philae lander’s mission complete, Rosetta will now continue its own extraordinary exploration, orbiting Comet 67P/Churymov–Gerasimenko during the coming year as the enigmatic body arcs ever closer to our Sun.

    ESA Rosetta spacecraft
    ESA/Rosetta

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    Comet Churyumov–Gerasimenko as seen by Rosetta

    Last week, ESA’s Rosetta spacecraft delivered its Philae lander to the surface of the comet for a dramatic touchdown.

    ESA Rosetta Philae Lander
    Rosetta’s Philae Lander

    The lander’s planned mission ended after about 64 hours when its batteries ran out, but not before it delivered a full set of results that are now being analysed by scientists across Europe.

    Rosetta’s own mission is far from over and the spacecraft remains in excellent condition, with all of its systems and instruments performing as expected.

    “With lander delivery complete, Rosetta will resume routine science observations and we will transition to the ‘comet escort phase’,” says Flight Director Andrea Accomazzo.

    “This science-gathering phase will take us into next year as we go with the comet towards the Sun, passing perihelion, or closest approach, on 13 August, at 186 million kilometres from our star.”

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    Rosetta control room

    On 16 November, the flight control team moved from the large Main Control Room at ESA’s Space Operations Centre in Darmstadt, Germany, where critical operations during landing were performed, to a smaller Dedicated Control Room, from where the team normally flies the craft.

    Since then, Rosetta has performed a series of manoeuvres, using its thrusters to begin optimising its orbit around the comet for the 11 scientific instruments.

    “Additional burns planned for today, 22 and 26 November will further adjust the orbit to bring it up to about 30 km above the comet,” says Sylvain Lodiot, Spacecraft Operations Manager.

    From next week, Rosetta’s orbit will be selected and planned based on the needs of the scientific sensors. After arrival on 6 August, the orbit was designed to meet the lander’s needs.

    On 3 December, the craft will move down to height of 20 km for about 10 days, after which it will return to 30 km.

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    Rosetta path after 12 November

    With the landing performed, all future trajectories are designed purely with science as the driver, explained Laurence O’Rourke and Michael Küppers at the Rosetta Science Operations Centre near Madrid, Spain.

    “The desire is to place the spacecraft as close as feasible to the comet before the activity becomes too high to maintain closed orbits,” says Laurence.

    “This 20 km orbit will be used by the science teams to map large parts of the nucleus at high resolution and to collect gas, dust and plasma at increasing activity.”

    Planning the science orbits involves two different trajectories: ‘preferred’ and ‘high-activity’. While the intention is always to fly the preferred path, Rosetta will move to the high-activity trajectory in the event the comet becomes too active as it heats up.

    “This will allow science operations to continue besides the initial impact on science planning that such a move would entail,” adds Michael.

    “Science will now take front seat in this great mission. It’s why we are there in the first place!” says Matt Taylor, Rosetta Project Scientist.

    “The science teams have been working intensively over the last number of years with the science operations centre to prepare the dual planning for this phase.”

    When solar heat activates the frozen gases on and below the surface, outflowing gas and dust particles will create an atmosphere around the nucleus, known as the coma.

    Rosetta will become the first spacecraft to witness at close quarters the development of a comet’s coma and the subsequent tail streaming for millions of kilometres into space. Rosetta will then have to stay further from the comet to avoid the coma affecting its orbit.

    In addition, as the comet nears the Sun, illumination on its surface is expected to increase. This may provide sufficient sunlight for the DLR-operated Philae lander, now in hibernation, to reactivate, although this is far from certain.

    Early next year, Rosetta will be switched into a mode that allows it to listen periodically for beacon signals from the surface.


    Rosetta orbiting the comet

    Regular updates on Rosetta’s continuing mission and its scientific explorations will be posted in the mission blog, via http://blogs.esa.int/rosetta.

    See the full article, with video, here.

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  • richardmitnick 9:31 pm on November 18, 2014 Permalink | Reply
    Tags: , , , , , ESA Rosetta   

    From BBC- “Comet landing: Organic molecules detected by Philae” 

    BBC
    BBC

    18 November 2014
    Paul Rincon

    The Philae lander has detected organic molecules on the surface of its comet, scientists have confirmed.

    p67

    Carbon-containing “organics” are the basis of life on Earth and may give clues to chemical ingredients delivered to our planet early in its history.

    The compounds were picked up by a German-built instrument designed to “sniff” the comet’s thin atmosphere.

    Other analyses suggest the comet’s surface is largely water-ice covered with a thin dust layer.

    The European Space Agency (ESA) craft touched down on the Comet 67P on 12 November after a 10-year journey.

    Dr Fred Goessmann, principal investigator on the Cosac instrument, which made the organics detection, confirmed the find to BBC News. But he added that the team was still trying to interpret the results.

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    Cosac instrument from Max Planck Institute for Solar System Research

    It has not been disclosed which molecules have been found, or how complex they are.

    But the results are likely to provide insights into the possible role of comets in contributing some of the chemical building blocks to the primordial mix from which life evolved on the early Earth.

    Preliminary results from the Mupus instrument, which deployed a hammer to the comet after Philae’s landing, suggest there is a layer of dust 10-20cm thick on the surface with very hard water-ice underneath.

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    Mupus instrument from DLR Institute of Planetary Research

    The ice would be frozen solid at temperatures encountered in the outer Solar System – Mupus data suggest this layer has a tensile strength similar to sandstone.

    “It’s within a very broad spectrum of ice models. It was harder than expected at that location, but it’s still within bounds,” said Prof Mark McCaughrean, senior science adviser to ESA, told BBC News.

    Philae has gone into standby because of low power.

    He explained: “You can’t rule out rock, but if you look at the global story, we know the overall density of the comet is 0.4g/cubic cm. There’s no way the thing’s made of rock.

    “It’s more likely there’s sintered ice at the surface with more porous material lower down that hasn’t been exposed to the Sun in the same way.”

    After bouncing off the surface at least twice, Philae came to a stop in some sort of high-walled trap.

    “The fact that we landed up against something may actually be in our favour. If we’d landed on the main surface, the dust layer may have been even thicker and it’s possible we might not have gone down [to the ice],” said Prof McCaughrean.

    Scientists had to race to perform as many key tests as they could before Philae’s battery life ran out at the weekend.

    On re-charge

    A key objective was to drill a sample of “soil” and analyse it in Cosac’s oven. But, disappointingly, the latest information suggest no soil was delivered to the instrument.

    Prof McCaughrean explained: “We didn’t necessarily see many organics in the signal. That could be because we didn’t manage to pick up a sample. But what we know is that the drill went down to its full extent and came back up again.”

    “But there’s no independent way to say: This is what the sample looks like before you put it in there.”

    Scientists are hopeful however that as Comet 67P/Churyumov-Gerasimenko approaches the Sun in coming months, Philae’s solar panels will see sunlight again. This might allow the batteries to re-charge, and enable the lander to perform science once more.

    “There’s a trade off – once it gets too hot, Philae will die as well. There is a sweet spot,” said Prof McCaughrean.

    He added: “Given the fact that there is a factor of six, seven, eight in solar illumination and the last action we took was to rotate the body of Philae around to get the bigger solar panel in, I think it’s perfectly reasonable to think it may well happen.

    “By being in the shadow of the cliff, it might even help us, that we might not get so hot, even at full solar illumination. But if you don’t get so hot that you don’t overheat, have you got enough solar power to charge the system.”

    The lander’s Alpha Particle X-ray Spectrometer (APXS) , designed to provide information on the elemental composition of the surface, seems to have partially seen a signal from its own lens cover – which could have dropped off at a strange angle because Philae was not lying flat.

    alp
    Alpha Particle X-ray Spectrometer (APXS) from NASA/JPL

    See the full article here.

    [I gotta say, I am not sure if the results in the story match the headline. But, hey, I am not a rocket scientist.]

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