vendredi 3 octobre 2014

Station Crew Wraps Up Week of Spacewalk Preps With Research












ISS - Expedition 41 Mission patch.

October 3, 2014

The six-person Expedition 41 crew of the International Space Station conducted a range of scientific experiments Friday to benefit life here on Earth, closing out a busy workweek primarily focused on gearing up for a series of spacewalks.

Flight Engineer Alexander Gerst of the European Space Agency worked with an experiment that’s looking for a way to repurpose a diabetes treatment drug into a cancer fighter. The Drug Metabolism experiment studies yeast cells to understand how drugs act on tumors to see if metaformin, a drug commonly used to treat type 2 diabetes, can serve as an anti-cancer drug. The German astronaut retrieved samples from the Commercial Generic Bioprocessing Apparatus and injected the test drugs into them.


Image above: European Space Agency astronaut Alexander Gerst, Expedition 41 flight engineer, is pictured in the Quest airlock of the International Space Station. Image Credit: NASA.

Gerst also transferred a seedling culture dish into the Cell Biology Experiment Facility for incubation. The Plant Gravity Sensing experiment is examining the cellular and molecular mechanisms that enable plants to sense gravity. The researchers behind this study hypothesize that the gravity sensitivity of plants here on Earth can be modified to make crops more resistant to the destructive forces of nature, thus maintaining yields even in areas struck by flooding or high winds.

Meanwhile in the Japanese Kibo laboratory, Flight Engineer Barry Wilmore of NASA performed some maintenance on the Aquatic Habitat currently housing a school of fish popularly known as zebra danios for the Zebrafish Muscle study. The goal of this experiment is to determine whether zebrafish muscles weaken in microgravity similarly to human muscles and, if so, isolate the cause. Results from the Zebrafish Muscle investigation may help identify molecular changes involved in the deterioration of muscles exposed to microgravity, which could provide benefits to patients confined to bed and astronauts on long-duration space missions.

Flight Engineer Reid Wiseman checked in on several experiments taking place aboard the orbiting laboratory. The NASA astronaut first placed test canisters from the Biological Research in Canisters-19 (BRIC-19) experiment into the Minus Eighty-degree Laboratory Freezer for ISS, or MELFI. This experiment is taking a look at the development in microgravity of Arabidopsis thaliana seedlings, commonly referred to as Mouse-ear cress.

Wiseman then transferred test samples for the Micro-8 experiment, which is investigating the Candida albicans yeast in order to help scientists better understand and control the infectious nature of this opportunistic pathogen.

After a marathon week of preparations for a pair of upcoming U.S. spacewalks, the three astronauts also had some welcome off-duty time Friday.

Station robotic arm

Image above: ESA astronaut Alexander Gerst took this image of the International Space Station’s robotic arm and the Dragon commercial supply spacecraft during his six-month Blue Dot mission. Image Credits: ESA/NASA.

During the first Expedition 41 spacewalk slated to begin around 8:10 a.m. Tuesday, Wiseman and Gerst will exit out the Quest airlock for a six-and-a-half hour excursion to transfer a degraded pump module to its long-term home on the External Stowage Platform-2. The two spacewalkers also will install the Mobile Transporter Relay Assembly that provides backup power options to the Mobile Transporter railcar system, which moves the Mobile Servicing System’s Canadarm2 and Special Purpose Dexterous Manipulator to worksites along the station’s truss.

Alexander testing spacesuit

Image above: ESA astronaut Alexander Gerst testing his spacesuit on the International Space Station in preparation for 7 October 2014 when he will venture into open space with NASA astronaut Reid Wiseman on a seven-hour spacewalk. Image Credits: ESA/NASA.

Wilmore, who will be inside the cupola to provide robotic support for the first spacewalk, will join Wiseman on Oct. 15 for another excursion outside the station. Wiseman and Wilmore will venture out to the station’s starboard truss to replace a voltage regulator, known as a sequential shunt unit, which failed back in May.

On the Russian side of the complex, Commander Max Suraev performed routine maintenance on the life-support system in the Zvezda service module. He later stowed trash and unneeded items in the ISS Progress 56 cargo craft, which is set to undock from the Pirs docking compartment on Oct. 27 to make way for the next Russian space freighter – ISS Progress 57 – launching on Oct. 29.

Flight Engineer Alexander Samokutyaev, who joined Suraev to replace a Payload Interface Monitoring Unit, also conducted a session with the Cardiovector health experiment, which takes a look at the adaptation of the heart to long-duration spaceflight.

Flight Engineer Elena Serova meanwhile manually mixed test samples within the bioreactor of the Kaskad cell cultivation experiment. Later she photographed and deployed new samples for the Calcium experiment, which examines the causes of the loss of bone density that occurs in a weightless environment. For this study, Russian researchers are looking at the solubility of calcium phosphates and bone samples in water in space.

Over the weekend, the station’s astronauts and cosmonauts will take care of weekly housekeeping chores as they wipe down surfaces and vacuum dust. They also will continue their daily 2.5-hour workouts to stay fit and to prevent the loss of muscle mass and bone density that occurs in microgravity.

The station's crew conducted scientific experiments Friday, closing out a busy week focused on gearing up for a series of spacewalks.

Related links:

Drug Metabolism experiment: http://www.nasa.gov/mission_pages/station/research/experiments/1072.html

Plant Gravity Sensing experiment: http://www.nasa.gov/mission_pages/station/research/experiments/1011.html

Zebrafish Muscle investigation: http://www.nasa.gov/mission_pages/station/research/experiments/65.html

Biological Research in Canisters-19 (BRIC-19) experiment: http://www.nasa.gov/mission_pages/station/research/experiments/1082.html

Micro-8 experiment: http://www.nasa.gov/mission_pages/station/research/news/micro_8/

For more information about the International Space Station (ISS), visit: http://www.nasa.gov/mission_pages/station/main/index.html

Images (mentioned), Text, Credits: NASA / ESA.

Cheers, Orbiter.ch

Rosetta Comet Fires Its Jets












ESA - Rosetta Mission patch.

3 October 2014

Rosetta Comet Fires Its Jets

The four images that make up this montage of comet 67P/Churyumov–Gerasimenko were taken on Sept. 26, 2014 by the European Space Agency’s Rosetta spacecraft. At the time, Rosetta was about 16 miles (26 kilometers), from the center of the comet.

In the montage, a region of jet activity can be seen at the neck of the comet. These jets, originating from several discrete locations, are a product of ices sublimating and gases escaping from inside the nucleus. 

The overlapping and slightly dissimilar angles of the four images that compose the montage are a result of the combined effect of the comet rotating between the first and last images taken in the sequence (about 10 degrees over 20 minutes), and the spacecraft movement during that same time.

Launched in March 2004, Rosetta was reactivated in January 2014 after a record 957 days in hibernation. Composed of an orbiter and lander, Rosetta's objectives since arriving at comet 67P/Churyumov-Gerasimenko earlier this month are to study the celestial object up close in unprecedented detail, prepare for landing a probe on the comet's nucleus in November, and after the landing track the comet's changes through 2015, as it sweeps past the sun.


Image above: Rosetta orbiting comet 67P/Churyumov-Gerasimenko. Photo-montage by Orbiter.ch Aerospace, the distance and sizes between the comet and the probe are not realistic. Image credits: Orbiter.ch Aerospace/ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA.

Comets are time capsules containing primitive material left over from the epoch when the sun and its planets formed. Rosetta's lander will obtain the first images taken from a comet's surface and will provide comprehensive analysis of the comet's possible primordial composition by drilling into the surface. Rosetta also will be the first spacecraft to witness at close proximity how a comet changes as it is subjected to the increasing intensity of the sun's radiation. Observations will help scientists learn more about the origin and evolution of our solar system and the role comets may have played in seeding Earth with water, and perhaps even life.

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

For more information on the U.S. instruments aboard Rosetta, visit: http://rosetta.jpl.nasa.gov

More information about Rosetta is available at: http://www.esa.int/rosetta

Image Credit: ESA / Rosetta / NAVCAM.

Greetings, Orbiter.ch

NASA Releases Images of a Mid-level Solar Flare












NASA - Solar Dynamics Observatory (SDO) patch.

October 3, 2014

video
Twisting Solar Eruption and Flare

Video above: A solar flare erupted on the right side of the sun on Oct. 2, 2014, while a cloud of solar material just below was flung out into space. Video Credit: NASA/SDO/ Wiessinger.

The sun emitted a mid-level solar flare, peaking at 3:01 p.m. EDT on Oct. 2, 2014.  NASA's Solar Dynamics Observatory, which watches the sun 24-hours a day, captured images of the flare. Solar flares are powerful bursts of radiation. Harmful radiation from a flare cannot pass through Earth's atmosphere to physically affect humans on the ground, however -- when intense enough -- they can disturb the atmosphere in the layer where GPS and communications signals travel.


Image above: NASA's Solar Dynamics Observatory captured this image of a solar flare on Oct. 2, 2014. The solar flare is the bright flash of light on the right limb of the sun. A burst of solar material erupting out into space can be seen just below it. Image Credit: NASA/SDO.

To see how this event may affect Earth, please visit NOAA's Space Weather Prediction Center at http://spaceweather.gov, the U.S. government's official source for space weather forecasts, alerts, watches and warnings.

This flare is classified as an M7.3 flare. M-class flares are one-tenth as powerful as the most powerful flares, which are designated X-class flares.

Updates will be provided as needed.

What is a solar flare?
For answers to this and other space weather questions, please visit the Spaceweather Frequently Asked Questions page: http://www.nasa.gov/mission_pages/sunearth/spaceweather/index.html

Related Link:

View Past Solar Activity: http://www.nasa.gov/mission_pages/sunearth/multimedia/Solar-Events.html

NASA's SDO Watches Giant Filament on the Sun

A snaking, extended filament of solar material currently lies on the front of the sun-- some 1 million miles across from end to end. Filaments are clouds of solar material suspended above the sun by powerful magnetic forces. Though notoriously unstable, filaments can last for days or even weeks.


Images above: A dark snaking line in the upper right of these images on Sept. 30, 2014, show a filament of solar material hovering above the sun's surface. NASA's SDO captured the images in extreme UV light – different colors represent different wavelengths of light and different temperatures of solar material. Image Credit: NASA/SDO.

NASA's Solar Dynamics Observatory, or SDO, which watches the sun 24 hours a day, has observed this gigantic filament for several days as it rotated around with the sun. If straightened out, the filament would reach almost across the whole sun, about 1 million miles or 100 times the size of Earth.

SDO captured images of the filament in numerous wavelengths, each of which helps highlight material of different temperatures on the sun. By looking at any solar feature in different wavelengths and temperatures, scientists can learn more about what causes such structures, as well as what catalyzes their occasional giant eruptions out into space.

Look at the images to see how the filament appears in different wavelengths. The brownish combination image was produced by blending two wavelengths of extreme UV light with a wavelength of 193 and 335 Angstroms. The red image shows the 304 Angstrom wavelength of extreme UV light.

For more information about Solar Dynamics Observatory (SDO), visit: http://www.nasa.gov/mission_pages/sdo/main/index.html

Images (mentioned), Video (mentioned), Text, Credits: NASA's Goddard Space Flight Center/Karen C. Fox/Steele Hill.

Best regards, Orbiter.ch

CryoSat unveils secrets of the deep







ESA - Cryosat 2 Mission patch.

3 October 2014

ESA’s ice mission has been used to create a new gravity map, exposing thousands of previously unchartered ‘seamounts’, ridges and deep ocean structures. This vivid new picture of the least-explored part of the ocean offers fresh clues about how continents form and breakup.

Carrying a radar altimeter, CryoSat’s main role is to provide detailed measurements of the height of the world’s ice. This allows us to see how the thickness of the ice changes, seasonally and in response to climate change.

Gravity reveals seafloor

However, CryoSat works continuously, whether there is ice below or not. This means that the satellite can also measure the height of the surface of the sea. These measurements can be used to create global marine gravity models and, from them, maps of the seafloor.

Although invisible to the eye, the sea surface has ridges and valleys that echo the topography of the ocean floor, but on a greatly reduced scale.

The effect of the slight increase in gravity caused by the mass of rock in an undersea mountain is to attract a mound of water several metres high over the seamount. Deep ocean trenches have the reverse effect.

CryoSat

These features can only be detected by using radar altimetry from space.

Scientists from Scripps Institute of Oceanography at University California San Diego in the US and colleagues tapped into two new streams of satellite data to create a new gravity map mirroring features of the ocean floor – twice as accurate as the previous version produced nearly 20 years ago.

They used measurements that CryoSat has captured over the oceans during the last four years as well as measurements from the French–US Jason-1 satellite, which was retasked to map the gravity field during the last year of its 12-year mission.

Combined with existing data, the new map, described in the journal Science, reveals details of thousands of undersea mountains rising a kilometre or more from the bottom of the ocean.

The new map offers geophysics new tools to investigate little-studied remote ocean basins and processes such as seafloor spreading.

Atlantic bed imprinted in gravity

“The kinds of things you can see very clearly now are abyssal hills, which are the most common land form on the planet,” said David Sandwell, lead scientist of the paper and a geophysics professor at Scripps.

The authors of the study say the map provides a new window into the tectonics of the deep oceans.

Previously unseen features in the map include newly exposed continental connections across South America and Africa, and new evidence for seafloor spreading ridges at the Gulf of Mexico that were active 150 million years ago and are now buried by layers of sediment more than a kilometre thick.

One of the most important uses of this new marine gravity field will be to improve the estimates of seafloor depth in the 80% of the oceans that remains uncharted or is buried beneath thick sediment.

Indian Ocean bed imprinted in gravity

The new map will also provide the foundation for the upcoming new version of Google’s ocean maps to fill large voids between shipboard depth profiles.

ESA’s Richard Francis, co-author and project manager for the development of CryoSat, said, “Although CryoSat’s primary mission is in the cryosphere, we knew as soon as we selected its orbit that it would be invaluable for marine geodesy, and this work proves the point.”

Related links:

Science: New global marine gravity model from CryoSat-2 and Jason-1 reveals buried tectonic structure: http://www.sciencemag.org/content/346/6205/65

Scripps Institution of Oceanography: http://topex.ucsd.edu/index.html

Jason-1: http://science.nasa.gov/missions/jason-1/

Access CryoSat data: https://earth.esa.int/web/guest/missions/esa-operational-eo-missions/cryosat

Introducing CryoSat: http://www.esa.int/Our_Activities/Observing_the_Earth/CryoSat/Introducing_CryoSat

Images, Text, Credits: ESA/P. Carril/Scripps Institution of Oceanography.

Greetings, Orbiter.ch

jeudi 2 octobre 2014

Station Crew Conducts Biological Research, Assembles Hardware for Spacewalk












ISS - Expedition 41 Mission patch.

October 2, 2014

The six-person Expedition 41 crew of the International Space Station focused their attention Thursday on biological research and preparations for the first of three spacewalks planned for October, while the ground team worked to bring a newly installed weather monitoring instrument up to speed.

Late Wednesday, the International Space Station-Rapid Scatterometer, or ISS-RapidScat installed on the exterior of the Columbus module was activated by payload controllers at the Marshall Space Flight Center. The radar antenna of the device, which is designed to monitor ocean winds from the station’s vantage point, began spinning as planned, but the payload controllers decided to place the system in safe mode when they noted higher than expected temperatures in the instrument’s electronics. The antenna continues to spin normally while the ground team analyzes the data and learns how to manage the temperature.


Animation above: A video camera on the International Space Station captured this view of the the ISS-Rapid Scatterometer, or RapidScat, on Wednesday. Animation Credit: NASA.

ISS-RapidScat was among the nearly two-and-a-half tons of cargo delivered to the station by the SpaceX Dragon resupply craft Sept. 23. Robotics officers at Houston’s Mission Control Center remotely commanded the Canadarm2 robotic arm to remove ISS-RapidScat from Dragon’s trunk and attach it to its adapter on the station’s Columbus laboratory on Tuesday.

Meanwhile, Flight Engineers Reid Wiseman and Alexander Gerst spent much of Thursday assembling hardware and reviewing procedures for a spacewalk scheduled to begin on Tuesday around 8:10 a.m. EDT. During the six-and-a-half-hour excursion, Wiseman and Gerst will transfer a degraded pump module from its temporary stowage location to its long-term home on the External Stowage Platform-2. The two spacewalkers also will install the Mobile Transporter Relay Assembly (MTRA) that provides backup power options to the Mobile Transporter railcar system, which moves the Mobile Servicing System’s Canadarm2 and Special Purpose Dexterous Manipulator to worksites along the station’s truss.


Image above: Inside the International Space Station's Quest airlock, Flight Engineer Reid Wiseman works on the spacesuit that Flight Engineer Alexander Gerst will wear during Tuesday's spacewalk. Image Credit: NASA TV.

Flight Engineer Barry Wilmore, who will be at the controls of Canadarm2 inside the station cupola to provide support for Tuesday’s spacewalk, joined his astronaut crewmates for a review of the robotic operations.

Wilmore will be joining Wiseman on the second Expedition 41 spacewalk set for Oct. 15, to replace a voltage regulator that failed back in May. And on Oct. 22, Commander Max Suraev and Flight Engineer Alexander Samokutyaev will conduct the first Russian spacewalk of Expedition 41.

Wilmore performed some maintenance on the Aquatic Habitat currently housing a school of fish popularly known as zebra danios for the Zebrafish Muscle study. The goal of this experiment is to determine whether zebrafish muscles weaken in microgravity similarly to human muscles and, if so, isolate the cause. Results from the Zebrafish Muscle investigation may help identify molecular changes involved in the deterioration of muscles exposed to microgravity and could provide benefits to patients on extended bed rest and astronauts on long-duration missions in space.


Image above: One of the Expedition 41 crew members aboard the International Space Station, flying at an altitude of 222 nautical miles above a point in the Atlantic Ocean several hundred miles off the coast of Africa near the Tropic of Cancer, photographed this eye-catching panorama of the night sky on Sept. 27. Image Credit: NASA.

Gerst participated in a periodic fitness evaluation as he worked out on the station’s exercise bike – the Cycle Ergometer with Vibration Isolation and Stabilization. Wilmore assisted his German crewmate by initiating blood pressure and electrocardiogram measurements to help the flight surgeons benchmark the crew’s cardiovascular and musculoskeletal health.

Gerst also donned monitors to track his body’s core temperature over a 36-hour period for the Circadian Rhythms study. Because the station orbits the Earth every 92 minutes and experiences 16 sunrises and sunsets every day, the astronauts do not have the same day/night cues that people have on Earth. Results from this investigation will provide insights into the adaptations of the human autonomic nervous system in space and will help optimize crew schedules and workplace illumination.

Wiseman activated a botanical study known as Biological Research in Canisters-19, or BRIC-19. This experiment is taking a look at the development in microgravity of Arabidopsis thaliana seedlings, commonly referred to as Mouse-ear cress. The seedlings will be preserved and returned to Earth for genetic analysis and comparison with a control set of seedlings germinated in normal gravity.

On the Russian side of the complex, Flight Engineer Elena Serova participated in the Cardiovector experiment, which takes a look at the adaptation of the heart to long-duration spaceflight. Samokutyaev meanwhile performed the Virtual study, a Russian investigation into the human body’s sensory adaptations to weightlessness.

Commander Suraev spent part of his day transferring water from the Progress 56 cargo ship attached to the Pirs docking compartment. Progress 56, which is set to depart in late October, delivered nearly three tons of supplies when it docked to the station on July 23.

Related links:

International Space Station-Rapid Scatterometer, or ISS-RapidScat: http://www.jpl.nasa.gov/missions/iss-rapidscat/

Zebrafish Muscle study: http://www.nasa.gov/mission_pages/station/research/experiments/65.html

Circadian Rhythms study: http://www.nasa.gov/mission_pages/station/research/experiments/892.html

Biological Research in Canisters-19, or BRIC-19: http://www.nasa.gov/mission_pages/station/research/experiments/1082.html

For more information about the International Space Station (ISS), visit: http://www.nasa.gov/mission_pages/station/main/index.html

Images (mentioned), Animation (mentioned), Text, Credits: NASA.

Greetings, Orbiter.ch

New results from the AMS experiment in space















CERN - European Organization for Nuclear Research logo / ISS - AMS-02 Mission (STS-134) patch.

October 2, 2014

The Alpha Magnetic Spectrometer (AMS) collaboration has today presented its latest results. These are based on the analysis of 41 billion particles detected with the space-based AMS detector aboard the International Space Station. The results, presented during a seminar at CERN, provide new insights into the nature of the mysterious excess of positrons (antielectrons) observed in the flux of cosmic rays. The findings are published today in the journal Physical Review Letters.

The AMS experiment is able to map the flux of cosmic rays with unprecedented precision and in the results published today, the collaboration presents new data at energies never before recorded. The AMS collaboration has analysed 41 billion primary cosmic-ray events among which 10 million have been identified as electrons and positrons. The distribution of these events in the energy range of 0.5 to 500 GeV shows a well-measured increase of positrons from 8 GeV with no preferred incoming direction in space. The energy at which the positron fraction ceases to increase has been measured to be 275±32 GeV.


Image above: View of the AMS detector on the International Space Station (Image credit: NASA).

This rate of decrease after the “cut-off energy” is very important to physicists as it could be an indicator that the excess of positrons is the signature of dark-matter particles annihilating into pairs of electrons and positrons. Although the current measurements could be explained by objects such as pulsars, they are also tantalizingly consistent with dark matter particles with mass of the order of 1 TeV.  Different models on the nature of dark matter predict different behaviour of the positron excess above the positron fraction expected from ordinary cosmic ray collisions. Therefore, results at higher energies will be of crucial importance in the near future to evaluate if the signal is from dark matter or from a cosmic source.

Editor notes:

The AMS detector is operated by a large international collaboration led by Nobel laureate Samuel Ting. AMS involves about 600 researchers from China, Denmark, Finland, France, Germany, Italy, Korea, Mexico, the Netherlands, Portugal, Spain, Switzerland, Taiwan, and the United-States. The AMS detector was assembled at CERN, tested at ESA’s ESTEC centre in the Netherlands and launched on 16 May 2011 onboard NASA’s Space Shuttle Endeavour. It is installed on the International Space Station where it tracks incoming charged particles such as protons, electrons and antimatter particles such as positrons, mapping the flux of cosmic rays with unprecedented precision.

CERN, the European Organization for Nuclear Research, is the world's leading laboratory for particle physics. It has its headquarters in Geneva. At present, its Member States are Austria, Belgium, Bulgaria, the Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Israel, Italy, the Netherlands, Norway, Poland, Portugal, Slovakia, Spain, Sweden, Switzerland and the United Kingdom. Romania is a Candidate for Accession. Serbia is an Associate Member in the pre-stage to Membership. India, Japan, the Russian Federation, the United States of America, Turkey, the European Commission and UNESCO have Observer Status.

Related links:

Physical Review Letters “High Statistics Measurement of the Positron Fraction in Primary Cosmic Rays of 0.5-500 GeV with the Alpha Magnetic Spectrometer on the International Space Station”: http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.113.121101

Physical Review Letters “Electron and Positron Fluxes in Primary Cosmic Rays Measured with the Alpha Magnetic Spectrometer on the International Space Station”: http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.113.121102

Alpha Magnetic Spectrometer (AMS): http://www.ams02.org/

More like this:

CERN’s ALPHA experiment measures charge of antihydrogen: http://orbiterchspacenews.blogspot.ch/2014/06/cerns-alpha-experiment-measures-charge.html

Antimatter experiment produces first beam of antihydrogen: http://home.web.cern.ch/about/updates/2014/01/antimatter-experiment-produces-first-beam-antihydrogen

For more information about CERN, visit: http://home.web.cern.ch

Image (mentioned), Text, Credits: CERN / Corinne Pralavorio.

Cheers, Orbiter.ch

mercredi 1 octobre 2014

Four candidate landing sites for ExoMars 2018








ESA / ROSCOSMOS - ExoMars Mission logo.

1 October 2014

Four possible landing sites are being considered for the ExoMars mission in 2018. Its rover will search for evidence of martian life, past or present.

ExoMars is a joint two-mission endeavour between ESA and Russia’s Roscosmos space agency. The Trace Gas Orbiter and an entry, descent and landing demonstrator module, Schiaparelli, will be launched in January 2016, arriving at Mars nine months later. The Rover and Surface Platform will depart in May 2018, with touchdown on Mars in January 2019.

Rover landing site candidates

The search for a suitable landing site for the second mission began in December 2013, when the science community was asked to propose candidates.

The eight proposals were considered during a workshop held by the Landing Site Selection Working Group in April. By the end of the workshop, there were four clear front-runners.

Following additional review by an ESA-appointed panel, the four sites have now been formally recommended for further detailed analysis.

The sites – Mawrth Vallis, Oxia Planum, Hypanis Vallis and Aram Dorsum – are all located relatively close to the equator.

“The present-day surface of Mars is a hostile place for living organisms, but primitive life may have gained a foothold when the climate was warmer and wetter, between 3.5 billion and 4 billion years ago,” says Jorge Vago, ESA’s ExoMars project scientist.

Mawrth Vallis

“Therefore, our landing site should be in an area with ancient rocks where liquid water was once abundant. Our initial assessment clearly identified four landing sites that are best suited to the mission’s scientific goals.”

The area around Mawrth Vallis and nearby Oxia Planum contains one of the largest exposures of rocks on Mars that are older than 3.8 billion years and clay-rich, indicating that water once played a role here. Mawrth Vallis lies on the boundary between the highlands and lowlands and is one of the oldest outflow channels on Mars.

Oxia Planum

The exposed rocks at both Mawrth Vallis and Oxia Planum have varied compositions, indicating a variety of deposition and wetting environments. In addition, the material of interest has been exposed by erosion only within the last few hundred million years, meaning the rocks are still well preserved against damage from the planet’s harsh radiation and oxidation environment.

By contrast, Hypanis Vallis lies on an exhumed fluvial fan, thought to be the remnant of an ancient river delta at the end of a major valley network. Distinct layers of fine-grained sedimentary rocks provide access to material deposited about 3.45 billion years ago.

Finally, the Aram Dorsum site receives its name from the eponymous channel, curving from northeast to west across the location. The sedimentary rocks around the channel are thought to be alluvial sediments deposited much like those around Earth’s River Nile.

Hypanis Vallis

This region experienced both sustained water activity followed by burial, providing protection from radiation and oxidation for most of Mars’ geological history, also making this a site with strong potential for finding preserved biosignatures.

“While all four sites are clearly interesting scientifically, they must also allow for the operational and engineering requirements for safe landing and roving on the surface,” adds Jorge.

“Technical constraints are satisfied to different degrees in each of these locations and, although our preliminary evaluation indicates that Oxia Planum has fewer problems compared to the other sites, verification is still on going.”

Aram Dorsum

The next stage of analysis will include simulations to predict the probability of landing success based on the entry profile, atmospheric and terrain properties at each of the candidate sites.

The aim is to complete the certification of at least one site by the second half of 2016, with a final decision on the landing site for the ExoMars 2018 rover to be taken sometime in 2017.

Notes for Editors:

Download the full report: Recommendation for the narrowing of ExoMars 2018 landing sites: http://exploration.esa.int/mars/54707

More ExoMars images, including digital terrain models of the candidate landing sites, are available here: http://exploration.esa.int/mars/44969-images-videos-archive/

Images, Text, Credits: ESA/Roscosmos/LSSWG/DLR/FU Berlin & NASA MGS MOLA Science Team.

Best regards, Orbiter.ch

Titan’s swirling polar cloud is cold and toxic












NASA / ESA - Cassini Mission to Saturn patch.

1 October 2014

The international Cassini mission has revealed that a giant, toxic cloud is hovering over the south pole of Saturn’s largest moon, Titan, after the atmosphere has cooled in a dramatic fashion.

Scientists analysing data from the mission found that this giant polar vortex contains frozen particles of the toxic compound hydrogen cyanide.

“The discovery suggests that the atmosphere of Titan’s southern hemisphere is cooling much faster than we expected,” says Remco de Kok of Leiden Observatory and SRON Netherlands Institute for Space Research, lead author of the study published in the journal Nature.

Spectral map of Titan

Unlike any other moon in the Solar System, Titan is shrouded by a dense atmosphere dominated by nitrogen, with small amounts of methane and other trace gases. Almost 10 times further from the Sun than Earth, Titan is very cold, allowing methane and other hydrocarbons to rain onto its surface to form rivers and lakes.

Like Earth, Titan experiences seasons as it makes its 29-year orbit around the Sun along with Saturn. Each of the four seasons lasts about seven Earth years and the most recent seasonal switch occurred in 2009, when summer transitioned to autumn in the southern hemisphere.

In May 2012, images from Cassini revealed a huge swirling cloud, several hundred kilometres across, taking shape at the south pole. 

Titan’s changing seasons

This polar vortex appears to be an effect of the change of season, with large amounts of air being heated by sunlight during the northern spring and flowing towards the southern hemisphere.

A puzzling detail about this swirling cloud is its altitude, some 300 km above Titan's surface, where scientists thought it was too warm for clouds to form.

“We really didn’t expect to see such a massive cloud so high in the atmosphere,” says Dr de Kok.

Keen to understand what could give rise to this mysterious cloud, the scientists turned to the rich data from Cassini. After careful scrutiny, they found an important clue in the spectrum of sunlight reflected by Titan’s atmosphere.

A spectrum splits the light from a celestial body into its constituent colours, revealing signatures of the elements and molecules that are present. The Visual and Infrared Mapping Spectrometer on Cassini takes spectra at many different points on Titan, mapping the distribution of the chemical compounds in its atmosphere and on its surface.

“The light coming from the polar vortex showed a remarkable difference with respect to other portions of Titan’s atmosphere,” says Dr de Kok. “We could clearly see a signature of frozen hydrogen cyanide molecules – HCN.”

As a gas, HCN is one of the molecules present in small amounts in the nitrogen-rich atmosphere of Titan. However, finding these molecules in the form of ice was very surprising, as HCN can condense to form frozen particles only if the atmosphere is as cold as –148ºC.

Vortex on Titan close up

“This is about 100ºC colder than predictions from current theoretical models of Titan’s upper atmosphere,” explains co-author Nick Teanby from the University of Bristol, UK.

“To check whether such low temperatures were actually possible, we investigated a second set of observations from Cassini’s Composite Infrared Spectrometer, which allows us to measure atmospheric temperature at different altitudes.”

Unfortunately, no such readings were taken in 2012 at this cloud’s altitude, but the scientists looked at data from other dates, probing the atmosphere above and below the vortex.

These data showed that the southern hemisphere has been cooling rapidly, making it possible to reach the low temperature needed to form the giant toxic cloud seen on the south pole.

This fast cooling of the southern atmosphere may be a consequence of the atmospheric circulation, which has been drawing large masses of gas towards the south ever since the change of season in 2009. As the HCN gas becomes more concentrated, its molecules shine brightly at infrared wavelengths, cooling the surrounding air in the process.

Artist's view of Cassini Titan flyby. Image Credits: NASA/JPL-Caltech

Another factor contributing to this cooling is the reduced exposure to sunlight on Titan’s southern hemisphere.

“This surprising result shows how much we are still learning about Titan’s weather and the complex dynamics of its atmosphere,” says Nicolas Altobelli, Cassini–Huygens Project Scientist at ESA. “We can look forward to more fascinating discoveries from Cassini in the next few years, as it continues to monitor the seasonal changes on Saturn and its moons.”

Notes for Editors:

“HCN ice in Titan’s high-altitude southern polar cloud,” by R. J. de Kok et al. is published in the journal Nature on 2 October 2014; doi: 10.1038/nature13789

The results are reported by R.J. de Kok, Leiden Observatory and SRON Netherlands Institute for Space Research, The Netherlands; N.A. Teanby, University of Bristol, UK; L. Maltagliati and S. Vinatier, LESIA-Observatoire de Paris, CNRS, UPMC Université Paris 06, Université Paris-Diderot, France; and P.G.J. Irwin, University of Oxford, UK.

The Cassini–Huygens mission is a cooperative project of NASA, ESA and Italy’s ASI space agency. Launched in 1997, Cassini arrived in the Saturn system in 2004 and is studying the ringed planet and its moons. The Huygens probe was released from the main spacecraft and, in 2005, parachuted through the atmosphere to the surface of Saturn’s largest moon, Titan.

Cassini’s initial four-year mission to explore the Saturn System covered the period July 2004 to June 2008, when Saturn and its moons were experiencing northern winter and southern summer. The first extended mission, called the ‘Cassini Equinox Mission’, was completed in September 2010. This included the spring equinox, on 11 August 2009, when winter was followed by spring in the northern hemisphere and summer was followed by autumn in the southern hemisphere.

A second extended mission, the ‘Cassini Solstice Mission’, will continue until September 2017. This will allow scientists to study the Saturnian system until after the next seasonal change, the summer solstice in May 2017, which will mean the arrival of northern summer and southern winter.

NASA’s Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA’s Science Mission Directorate, Washington, D.C., USA.

Related links:

Cassini-Huygens in depth: http://sci.esa.int/huygens

NASA JPL Cassini site: http://saturn.jpl.nasa.gov/

Italian Space Agency: http://www.asi.it/en

For more information about Cassini-Huygens mission, visit: http://www.esa.int/Our_Activities/Space_Science/Cassini-Huygens

ESA/AOES/NASA/JPL-Caltech/ASI/University of Arizona/SSI/Leiden Observatory & SRON/Space Science Institute.

Greetings, Orbiter.ch

NASA Mission Points to Origin of “Ocean of Storms” on Earth’s Moon











NASA - GRAIL Mission patch.

October 1, 2014

Using data from NASA’s Gravity Recovery and Interior Laboratory (GRAIL), mission scientists have solved a lunar mystery almost as old as the moon itself.

Early theories suggested the craggy outline of a region of the moon’s surface known as Oceanus Procellarum, or the Ocean of Storms, was caused by an asteroid impact. If this theory had been correct, the basin it formed would be the largest asteroid impact basin on the moon. However, mission scientists studying GRAIL data believe they have found evidence the craggy outline of this rectangular region -- roughly 1,600 miles (2,600 kilometers) across -- is actually the result of the formation of ancient rift valleys.

"The nearside of the moon has been studied for centuries, and yet continues to offer up surprises for scientists with the right tools," said Maria Zuber, principal investigator of NASA's GRAIL mission, from the Massachusetts Institute of Technology, Cambridge. "We interpret the gravity anomalies discovered by GRAIL as part of the lunar magma plumbing system -- the conduits that fed lava to the surface during ancient volcanic eruptions."


Image above: Earth's moon as observed in visible light (left), topography (center, where red is high and blue is low), and the GRAIL gravity gradients (right). The Procellarum region is a broad region of low topography covered in dark mare basalt. The gravity gradients reveal a giant rectangular pattern of structures surrounding the region. Image Credit: NASA/GSFC/JPL/Colorado School of Mines/MIT.

The surface of the moon’s nearside is dominated by a unique area called the Procellarum region, characterized by low elevations, unique composition, and numerous ancient volcanic plains.

The rifts are buried beneath dark volcanic plains on the nearside of the moon and have been detected only in the gravity data provided by GRAIL. The lava-flooded rift valleys are unlike anything found anywhere else on the moon and may at one time have resembled rift zones on Earth, Mars and Venus.  The findings are published online in the journal Nature.

Another theory arising from recent data analysis suggests this region formed as a result of churning deep in the interior of the moon that led to a high concentration of heat-producing radioactive elements in the crust and mantle of this region. Scientists studied the gradients in gravity data from GRAIL, which revealed a rectangular shape in resulting gravitational anomalies.

"The rectangular pattern of gravity anomalies was completely unexpected," said Jeff Andrews-Hanna, a GRAIL co-investigator at the Colorado School of Mines in Golden, Colorado, and lead author of the paper. "Using the gradients in the gravity data to reveal the rectangular pattern of anomalies, we can now clearly and completely see structures that were only hinted at by surface observations."

Gravity Recovery and Interior Laboratory (GRAIL) spacecrafts. Image Credits: NASA/GSFC/JPL

The rectangular pattern, with its angular corners and straight sides, contradicts the theory that Procellarum is an ancient impact basin, since such an impact would create a circular basin. Instead, the new research suggests processes beneath the moon’s surface dominated the evolution of this region.

Over time, the region would cool and contract, pulling away from its surroundings and creating fractures similar to the cracks that form in mud as it dries out, but on a much larger scale.

The study also noted a surprising similarity between the rectangular pattern of structures on the moon, and those surrounding the south polar region of Saturn’s icy moon Enceladus. Both patterns appear to be related to volcanic and tectonic processes operating on their respective worlds.

"Our gravity data are opening up a new chapter of lunar history, during which the moon was a more dynamic place than suggested by the cratered landscape that is visible to the naked eye," said Andrews-Hanna. "More work is needed to understand the cause of this newfound pattern of gravity anomalies, and the implications for the history of the moon."

Launched as GRAIL A and GRAIL B in September 2011, the probes, renamed Ebb and Flow, operated in a nearly circular orbit near the poles of the moon at an altitude of about 34 miles (55 kilometers) until their mission ended in December 2012. The distance between the twin probes changed slightly as they flew over areas of greater and lesser gravity caused by visible features, such as mountains and craters, and by masses hidden beneath the lunar surface.

 On the West Coast of the Ocean of Storms (Artist's Concept)

Image above: A view of Earth's moon looking south across Oceanus Procellarum, representing how the western border structures may have looked while active. Image credit: NASA/Colorado School of Mines/MIT/JPL/GSFC.

The twin spacecraft flew in a nearly circular orbit until the end of the mission on Dec. 17, 2012, when the probes intentionally were sent into the moon’s surface. NASA later named the impact site in honor of late astronaut Sally K. Ride, who was America's first woman in space and a member of the GRAIL mission team.

GRAIL’s prime and extended science missions generated the highest resolution gravity field map of any celestial body. The map will provide a better understanding of how Earth and other rocky planets in the solar system formed and evolved.

The GRAIL mission was managed by NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, for NASA's Science Mission Directorate in Washington. The mission was part of the Discovery Program managed at NASA's Marshall Space Flight Center in Huntsville, Alabama. GRAIL was built by Lockheed Martin Space Systems in Denver.

For more information about GRAIL, visit: http://www.nasa.gov/grail

Images (mentioned), Text, Credit: NASA.

Cheers, Orbiter.ch

Wild Ducks Take Flight in Open Cluster












ESO - European Southern Observatory logo.

1 October 2014

The Wild Duck Cluster

The Wide Field Imager on the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory in Chile has taken this beautiful image, dappled with blue stars, of one of the most star-rich open clusters currently known — Messier 11, also known as NGC 6705 or the Wild Duck Cluster.

Messier 11 is an open cluster, sometimes referred to as a galactic cluster, located around 6000 light-years away in the constellation of Scutum (The Shield). It was first discovered by German astronomer Gottfried Kirch in 1681 at the Berlin Observatory, appearing as nothing more than a fuzzy blob through the telescope. It wasn’t until 1733 that the blob was first resolved into separate stars by the Reverend William Derham in England, and Charles Messier added it to his famous catalogue in 1764.

The open cluster Messier 11 in the constellation of Scutum

Messier was a comet hunter and the catalogue came into being as he was frustrated by constantly observing fixed, diffuse objects that looked like comets (for example, objects that we now know to be clusters, galaxies and nebulae). He wanted a record in order to avoid accidentally observing them again and confusing them with possible new comets. This particular stellar cluster was noted down as the eleventh such object — hence the name of Messier 11.

Open clusters are typically found lying in the arms of spiral galaxies or in the denser regions of irregular galaxies, where star formation is still common. Messier 11 is one of the most star-rich and compact of the open clusters, being almost 20 light-years across and home to close to 3000 stars. Open clusters are different to globular clusters, which tend to be very dense, tightly bound by gravity, and contain hundreds of thousands of very old stars — some of which are nearly as old as the Universe itself.

video
Zooming in on the open cluster Messier 11

Studying open clusters is great way to test theories of stellar evolution, as the stars form from the same initial cloud of gas and dust and are therefore very similar to one another — they all have roughly the same age, chemical composition, and are all the same distance away from Earth. However, each star in the cluster has a different mass, with the more massive stars evolving much faster than their lower mass counterparts as they use up all of their hydrogen much sooner.

In this way, direct comparisons between the different evolutionary stages can be made within the same cluster: for example, does a 10 million year old star with the same mass as the Sun evolve in a different way to another star that is the same age, but half as massive? In this sense, open clusters are the closest thing astronomers have to “laboratory conditions”.

video
Close-up view of the open cluster Messier 11

Because the stars within open clusters are very loosely bound to one another, individuals are very susceptible to being ejected from the main group due to the effect of gravity from neighbouring celestial objects. NGC 6705 is already at least 250 million years old, so in a few more million years it is likely that this Wild Duck formation will disperse, and the cluster will break up and merge into its surroundings [1].

This image was taken by the Wide Field Imager on the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory in northern Chile.

Notes:

[1] The alternative and evocative name for NGC 6705, the Wild Duck Cluster, came about in the 19th century. When the cluster was seen through a small telescope it was noticed that the brightest stars formed an open triangle pattern on the sky that resembled ducks flying in formation.

More information:

ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 15 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning the 39-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

Links:

Research papers on NGC 6705: http://adsabs.harvard.edu/cgi-bin/basic_connect?qsearch=NGC+6705&version=1

Photos of the MPG/ESO 2.2-m telescope: http://www.eso.org/public/images/archive/search/?adv=&subject_name=mpg

Photos of La Silla Observatory: http://www.eso.org/public/images/archive/category/lasilla/

Images, Text, Credits: ESO/IAU and Sky & Telescope/Videos: ESO/N. Risinger (skysurvey.org)/J. Bohanon. Music: movetwo.

Best regards, Orbiter.ch

Provision of Emergency Data on Mt. Ontake Observed by DAICHI-2












JAXA - Advanced Land Observing Satellite-2 (ALOS-2) patch.

1 October 2014

The Japan Aerospace Exploration Agency (JAXA) captured images of depressions and deposition of falling ash following Mt. Ontake's volcanic eruption on Sept. 27 through emergency observations by the Advanced Land Observing Satellite-2 "DAICHI-2" (ALOS-2). The satellite was launched in May this year.

The observations were conducted according to a request from the Coordinating Committee for Prediction of Volcanic Eruptions (Secretariat: Japan Meteorological Agency) and the Cabinet Office (Disaster Management) under the agreement with ministries related to disaster management. The acquired data was provided for confirming geographical changes and the accumulation of falling ash.

JAXA continues to observe Mt. Ontake in cooperation with disaster management agencies.


Figure 1: Comparison before and after the eruption near the peak of Mt. Ontake. (Left: after eruption) No depression was found prior to the eruption in the area circled yellow.

Figure 1 shows a comparison between the images near the peak of Mt. Ontake taken on Aug. 18, prior to the volcanic eruption (right), and on Sept. 29 (left) after the eruption. The images were shot by the L-band Synthetic Aperture Radar-2 (PALSAR-2) aboard the DAICHI-2. The PALSAR-2 can capture the status of the volcanic crater without being hampered by fumes by seeing through them thanks to its long radio wave length of L-band (1.2 GHz bandwidth.)

In the left image (after the eruption), a new depression measuring 210 meters in length and 70 meters in width was newly created due to the eruption. This seems to be an exhaust vent hole (volcanic orifice) freshly formed this time.


Figure 2: Accumulation of falling ash at Mt. Ontake peak observed by PALSAR-2. The observation was performed facing the right side (west to east) from the ascending node orbit (moving over Japan from south to north.)

Figure 2 is an extraction of changes observed from the observation images near Mt. Ontake peak taken from the same orbit on Aug. 18 and Sept. 29. Changes are colored in purple. It is estimated that falling ash has been accumulated near the peak crater through the satellite images.

References:

Daichi Bosai Web: https://bousai.jaxa.jp/

Earth Observation Research Center: http://www.eorc.jaxa.jp/en/index.html

For more information about DAICHI-2 (ALOS-2): http://global.jaxa.jp/projects/sat/alos2/

Images, Text, Credits: Japan Aerospace Exploration Agency (JAXA).

Greetings, Orbiter.ch

mardi 30 septembre 2014

NASA's Swift Mission Observes Mega Flares from a Mini Star












NASA - Swift Mission patch.

September 30, 2014

On April 23, NASA's Swift satellite detected the strongest, hottest, and longest-lasting sequence of stellar flares ever seen from a nearby red dwarf star. The initial blast from this record-setting series of explosions was as much as 10,000 times more powerful than the largest solar flare ever recorded.

"We used to think major flaring episodes from red dwarfs lasted no more than a day, but Swift detected at least seven powerful eruptions over a period of about two weeks," said Stephen Drake, an astrophysicist at NASA's Goddard Space Flight Center in Greenbelt, Maryland, who gave a presentation on the "superflare" at the August meeting of the American Astronomical Society’s High Energy Astrophysics Division. "This was a very complex event."

At its peak, the flare reached temperatures of 360 million degrees Fahrenheit (200 million Celsius), more than 12 times hotter than the center of the sun.

video
Swift Catches Mega Flares from a Mini Star

Video above: In April 2014, NASA's Swift mission detected a massive superflare from a red dwarf star in the binary system DG CVn, located about 60 light-years away. Astronomers Rachel Osten of the Space Telescope Science Institute and Stephen Drake of NASA Goddard discuss this remarkable event. Video Credit: NASA's Goddard Space Flight Center/S. Wiessinger.

The "superflare" came from one of the stars in a close binary system known as DG Canum Venaticorum, or DG CVn for short, located about 60 light-years away. Both stars are dim red dwarfs with masses and sizes about one-third of our sun's. They orbit each other at about three times Earth's average distance from the sun, which is too close for Swift to determine which star erupted.

"This system is poorly studied because it wasn't on our watch list of stars capable of producing large flares," said Rachel Osten, an astronomer at the Space Telescope Science Institute in Baltimore and a deputy project scientist for NASA's James Webb Space Telescope, now under construction. "We had no idea DG CVn had this in it."

Most of the stars lying within about 100 light-years of the solar system are, like the sun, middle-aged. But a thousand or so young red dwarfs born elsewhere drift through this region, and these stars give astronomers their best opportunity for detailed study of the high-energy activity that typically accompanies stellar youth. Astronomers estimate DG CVn was born about 30 million years ago, which makes it less than 0.7 percent the age of the solar system.

Swift's X-Ray Telescope. Image Credit: NASA

Stars erupt with flares for the same reason the sun does. Around active regions of the star's atmosphere, magnetic fields become twisted and distorted. Much like winding up a rubber band, these allow the fields to accumulate energy. Eventually a process called magnetic reconnection destabilizes the fields, resulting in the explosive release of the stored energy we see as a flare. The outburst emits radiation across the electromagnetic spectrum, from radio waves to visible, ultraviolet and X-ray light.

At 5:07 p.m. EDT on April 23, the rising tide of X-rays from DG CVn's superflare triggered Swift's Burst Alert Telescope (BAT). Within several seconds of detecting a strong burst of radiation, the BAT calculates an initial position, decides whether the activity merits investigation by other instruments and, if so, sends the position to the spacecraft. In this case, Swift turned to observe the source in greater detail, and, at the same time, notified astronomers around the globe that a powerful outburst was in progress.

"For about three minutes after the BAT trigger, the superflare's X-ray brightness was greater than the combined luminosity of both stars at all wavelengths under normal conditions," noted Goddard's Adam Kowalski, who is leading a detailed study on the event. "Flares this large from red dwarfs are exceedingly rare."

The star's brightness in visible and ultraviolet light, measured both by ground-based observatories and Swift's Optical/Ultraviolet Telescope, rose by 10 and 100 times, respectively. The initial flare's X-ray output, as measured by Swift's X-Ray Telescope, puts even the most intense solar activity recorded to shame.


Image above: DG CVn, a binary consisting of two red dwarf stars shown here in an artist's rendering, unleashed a series of powerful flares seen by NASA's Swift. At its peak, the initial flare was brighter in X-rays than the combined light from both stars at all wavelengths under typical conditions.
Image Credit: NASA's Goddard Space Flight Center/S. Wiessinger.

The largest solar explosions are classified as extraordinary, or X class, solar flares based on their X-ray emission. "The biggest flare we've ever seen from the sun occurred in November 2003 and is rated as X 45," explained Drake. "The flare on DG CVn, if viewed from a planet the same distance as Earth is from the sun, would have been roughly 10,000 times greater than this, with a rating of about X 100,000."

But it wasn't over yet. Three hours after the initial outburst, with X-rays on the downswing, the system exploded with another flare nearly as intense as the first. These first two explosions may be an example of "sympathetic" flaring often seen on the sun, where an outburst in one active region triggers a blast in another.

Over the next 11 days, Swift detected a series of successively weaker blasts. Osten compares the dwindling series of flares to the cascade of aftershocks following a major earthquake. All told, the star took a total of 20 days to settle back to its normal level of X-ray emission.

How can a star just a third the size of the sun produce such a giant eruption? The key factor is its rapid spin, a crucial ingredient for amplifying magnetic fields. The flaring star in DG CVn rotates in under a day, about 30 or more times faster than our sun. The sun also rotated much faster in its youth and may well have produced superflares of its own, but, fortunately for us, it no longer appears capable of doing so.

Astronomers are now analyzing data from the DG CVn flares to better understand the event in particular and young stars in general. They suspect the system likely unleashes numerous smaller but more frequent flares and plan to keep tabs on its future eruptions with the help of NASA's Swift.

Related Links:

Download the video in HD formats and print-resolution images from NASA Goddard's Scientific Visualization Studio: http://svs.gsfc.nasa.gov/goto?11531

Swift Detection of a Superflare from DG CVn: http://www.astronomerstelegram.org/?read=6121

X-Class: A Guide to Solar Flares: https://www.youtube.com/watch?v=oOXVZo7KikE

The Mouse That Roared: Pipsqueak Star Unleashes Monster Flare: http://www.nasa.gov/centers/goddard/news/topstory/2008/pipsqueak_star.html

For more information about Swift mission, visit: http://www.nasa.gov/mission_pages/swift/main/

Images (mentioned, Video (mentioned), Text, Credits: NASA's Goddard Space Flight Center/Francis Reddy.

Greetings, Orbiter.ch

lundi 29 septembre 2014

Newly Expanded Station Crew Tackles Research, Spacewalk Preps












ISS - Expedition 41 Mission patch.

September 29, 2014

The International Space Station’s Expedition 41 crew, which doubled the number of humans in space when three new crew members arrived last week, began its first full workweek as a six-person crew Monday with biological research and preparations for a pair of U.S. spacewalks.

Flight Engineers Barry Wilmore, Alexander Samokutyaev and Elena Serova joined their Expedition 41 crewmates on the station early Friday following a six-hour, four-orbit trek aboard their Soyuz TMA-14M spacecraft from the launch site at the Baikonur Cosmodrome in Kazakhstan. Wilmore, Samokutyaev and Serova are slated to spend 5 ½ months aboard the station. Commander Max Suraev and Flight Engineers Reid Wiseman and Alexander Gerst, who arrived on May 28, will return to Earth in November.

Read more about launch and docking of new station trio: http://orbiterchspacenews.blogspot.ch/2014/09/expedition-41-welcomes-new-trio-aboard.html

Shortly after the usual 2 a.m. EDT reveille, the entire crew conducted body mass measurements, inspected their orbital home and participated in a daily planning conference with the flight control teams around the world to review the day’s activities.


Image above: Flight Engineer Reid Wiseman posted this Twitter photo showing Flight Engineers Barry Wilmore (left) and Alexander Gerst at work in the Kibo laboratory of the International Space Station. Image Credit: NASA.

For Wiseman, Gerst and Wilmore, most of those activities were centered primarily on gearing up for their upcoming spacewalks. During an Oct. 7 excursion outside the station, Wiseman and Gerst will transfer a previously uninstalled pump module from its temporary stowage location to the External Stowage Platform-2. The two spacewalkers also will install the Mobile Transporter Relay Assembly that adds the capability to provide “keep-alive” power to the Mobile Servicing System when the Mobile Transporter is moving between worksites.

Wiseman and Gerst spent some time reviewing the procedures for that spacewalk and later participated in a conference call with spacewalk specialists on the ground.

Wilmore meanwhile began “scrubbing” the cooling loops of the U.S. spacesuits, including the Liquid Cooling and Ventilation Garment that he will wear under his own spacesuit when he joins Wiseman for the second Expedition 41 spacewalk on Oct. 15. Wiseman completed the spacesuit water recharge in the afternoon.

Gerst also checked in on the Zebrafish Muscle study as he assessed the water condition inside the Aquatic Habitat, which is housing a school of spacefaring fish popularly known in the aquarium trade as zebra danios. The goal of the study is to determine whether zebrafish muscles weaken in microgravity similarly to human muscles and, if so, isolate the cause. Results from the Zebrafish Muscle investigation may help identify molecular changes involved in the deterioration of muscles exposed to microgravity. The findings could potentially benefit patients on extended bed rest or with limited mobility. In addition, this information would aid researchers in developing countermeasures for muscle weakness in astronauts living in microgravity during extended missions.

On the Russian side of the complex, Serova transferred test samples from the Kaskad cell cultivation experiment, while Samokutyaev performed a study of hardware designed to provide aseptic conditions for biotechnological experiments.

Meanwhile, Commander Suraev stowed trash and unneeded items for disposal inside the Progress 56 cargo ship currently attached to the Pirs docking compartment. The Russian space freighter, which delivered nearly three tons of cargo when it docked to the station’s Pirs docking compartment on July 23, will undock from the station in late October for a destructive re-entry over the Pacific Ocean.


Image above: Flight Engineer Reid Wiseman tweeted this photo of the International Space Station's Canadarm2 and the Special Purpose Dexterous Manipulator preparing to remove external cargo from the SpaceX Dragon resupply vehicle. Image Credit: NASA.

All six crew members teamed up in the afternoon for a review of their roles and responsibilities during an emergency aboard the station.

As the newest crew members, Wilmore, Samokutyaev and Serova also had an hour set aside on their own to learn the ropes of their orbiting home.

While the crew worked inside the station, the robotics officer at Houston’s Mission Control Center maneuvered the Canadarm2 robotic arm and its Special Purpose Dexterous Manipulator to the trunk of the recently arrived SpaceX Dragon cargo ship attached to the Earth-facing port of the Harmony node. There the arm was commanded to grapple and extract an adapter mechanism from Dragon’s trunk and install it to a bracket on the front of the Columbus module. On Tuesday, the ISS-Rapid Scatterometer, or RapidScat, will be removed robotically from the trunk for installation on the adapter device.

Designed to monitor ocean winds from the station’s vantage point, RapidScat is a space-based scatterometer that uses radar pulses reflected from the ocean's surface from different angles to calculate surface wind speed and direction. This information will be useful for weather forecasting and hurricane monitoring.

Related links:

Zebrafish Muscle study: http://www.nasa.gov/mission_pages/station/research/experiments/65.html

ISS-Rapid Scatterometer, or RapidScat: http://www.nasa.gov/mission_pages/station/research/experiments/1067.html

For more information about the International Space Station (ISS), visit: http://www.nasa.gov/mission_pages/station/main/index.html

Images (mentioned), Video, Text, Credits: NASA.

Cheers, Orbiter.ch