samedi 8 février 2020

Hubble Captures Grand Spiral

NASA - Hubble Space Telescope patch.

Feb. 8, 2020

This eye-catching galaxy is known as NGC 5364.

Unmistakably a spiral, NGC 5364 is also something known as a grand design spiral galaxy — a descriptive name deserved by only one-tenth of spirals. While all spirals have a structure that is broadly similar, there is quite a bit of variation among individual galaxies; some have patchy, oddly shaped arms, some have bars of stars cutting through their core, some are colossal and radiant, and others are dim and diminutive. Grand designs like NGC 5364 are in many ways the archetype of a spiral galaxy. They are characterized by their prominent, well-defined arms, which circle outward from a clear core.

Despite being classified in this way, NGC 5364 is far from perfect. Its arms are asymmetrical compared to other grand design spirals — this is thought to be due to interactions with a nearby neighbor. This neighbor and NGC 5364 are tugging on one another, warping and moving their stars and gas around and causing this misshapen appearance.

Hubble Space Telescope (HST)

This image was captured by the NASA/ESA Hubble Space Telescope’s Advanced Camera for Surveys.

For more information about Hubble, visit:

Text Credits: ESA (European Space Agency)/NASA/Rob Garner/Image, Animation Credits: ESA/Hubble & NASA, L. Ho.


vendredi 7 février 2020

Space station to forge ultra-fast connections

ESA & DLR - Columbus Module patch.

Fev. 7, 2020

Astronauts aboard the International Space Station plan to install a high-speed radio link to enable almost real-time connections with Earth.

The upgrade to the ESA Columbus laboratory will relay data from experiments on the Station back to Earth almost instantaneously.

The fridge-sized device will fly to the Station aboard Northrop Grumman’s 12th Cygnus supply ship on 9 February.

Columbus over Earth

The device will send signals from the Station, which orbits at an altitude of 400 km above Earth, even further into space, where they will be picked up by European satellites in geostationary orbit 36 000 km above the surface.

These satellites – called the European Data Relay System – remain in constant communication with the same ground station on Earth, unlike the Station, which switches from one to another as it loops around the planet every 90 minutes.

Communications antenna for the Columbus module on the ISS

Dubbed ColKa for ‘Columbus Ka-band antenna’, the upgraded system will provide speeds of up to 50 Mbit/s for downlink and up to 2 Mbit/s for uplink. This will allow astronauts and researchers to benefit from a direct link with Europe at home broadband speeds – delivering a whole family’s worth of video streaming for science and communications.

A spacewalk later this year will be dedicated to upgrading the Columbus module. Two astronauts will take ColKa through the Station’s airlock and bolt it to the outside of Columbus. The antenna connects to a dedicated plug outside Columbus that feeds the data from the facilities and computers inside.

Northrop Grumman Antares CRS-13 Prelaunch

Columbus was conceived and designed over 20 years ago, when the internet was in its infancy. The laboratory was launched to the Station in 2008 and uses the Station’s network and NASA’s infrastructure for communications with the Columbus Control Centre.

The upgrade will ensure faster communications, independent from the NASA system, to relay data from more and more experiments allowing researchers on Earth to access their experiments at all times for another decade to come.

Colka was designed and built by British and Italian companies as prime contractors, using products from Norway, Belgium, France, Canada and Germany, some of which have been qualified under the ESA’s programme of Advanced Research in Telecommunications Systems (ARTES).

Colka will use the infrastructure for the European Data Relay System developed as a Partnership Project between ESA and Airbus, as part of ESA’s efforts to federate industry around large-scale programmes, stimulating technology developments to achieve economic benefits.

The know-how gained from designing, building and running ColKa will be instrumental for ESA’s communications package under the Esprit project that is being designed for the lunar Gateway – an outpost over 1000 times farther from Earth than the International Space Station.

Related links:

Telecommunications & Integrated Applications:

European Data Relay System:

Advanced Research in Telecommunications Systems (ARTES):

Images, Text, Credits: ESA/L. Parmitano, CC BY-SA 3.0 IGO.

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CHEOPS telescope took its first images

CHEOPS - CHaracterising ExOPlanet Satellite logo.

February 7, 2020

The Universities of Bern and Geneva welcomed this Friday the quality of the sky pictures taken by the CHEOPS space telescope.

The CHEOPS space telescope took its first images of the sky. A first analysis has shown that the pictures exceed expectations, announced the Universities of Bern and Geneva on Friday.

The decisive moment was the opening of the telescope cover on January 29. With the taking of images, a new stage was crossed.

Image above: Following the successful telescope cover opening last week, Cheops acquired the first image of its initial target star as part of its in-orbit commissioning.

Gathered not far from Madrid in front of a large screen, scientists and engineers awaited the first images of the space telescope. "The first images that were to appear were essential for us to be able to assess whether the optical elements of the telescope had emerged unscathed from the launch of the rocket," explains Willy Benz, professor of astrophysics at the University of Bern and responsible for the CHEOPS mission. , in a press release.

"He works!"

"When the first images of a star field appeared on the screen, everyone immediately understood: the telescope is working," he rejoices. The question now is to what extent.

According to a first analysis, the images exceed expectations. This does not mean that they are perfectly sharp, as the telescope has been purposely defocused. Thus, the collected light is distributed over numerous pixels, in order to attenuate the effect of the movements of the satellite on the images and to increase the photometric precision.

CHaracterising ExOPlanet Satellite or CHEOPS

"The icing on the cake, the blurred images received are nevertheless even smoother and symmetrical than what we had imagined based on our measurements in the laboratory", continues Willy Benz.

High precision is necessary to allow CHEOPS to observe small changes in the intensity of light received from a star caused by the passage of an exoplanet in front of it. As the changes in brightness are proportional to the surface of the exoplanet, CHEOPS will be able to measure its size. "These initial analyzes are promising and encouraging for the weeks to come," continues the researcher.

100 billion planets

CHEOPS (abbreviation of CHaracterising ExOPlanet Satellite) is a project of the European Space Agency (ESA) and Switzerland, under the leadership of the University of Bern in collaboration with that of Geneva. CHEOPS will compose "a family photo of exoplanets" while observing about 500.

CHaracterising ExOPlanet Satellite or CHEOPS

Today, it is estimated that there are at least as many planets as stars in the galaxy, or about 100 billion. More than 4000 exoplanets - orbiting a star other than the Sun - had been detected since the discovery of the first, 51 Pegasi b, 24 years ago by the 2019 Nobel Prize winners Michel Mayor and Didier Queloz of the University of Geneva.

Related article:

CHEOPS telescope cover is open

The opening of the CHEOPS lid postponed

Related links:

CHEOPS Mission Home Page:


Images, Animation, Text, Credits: ATS/ESA/UNIBE/Twitter/ Aerospace/Roland Berga.

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jeudi 6 février 2020

A new life for AMS

CERN - European Organization for Nuclear Research logo.

6 February, 2020

ESA astronaut Luca Parmitano has left the International Space Station after a six-month stay during which he contributed to repairing on the AMS experiment

Image above: ESA astronaut Luca Parmitano (middle) and NASA astronaut Drew Morgan (left) during their fourth spacewalk to service the Alpha Magnetic Spectrometer (AMS). Image Credit: ESA.

The voyage of ESA astronaut Luca Parmitano and his colleagues Alexander Skvortsov and Christina Koch aboard the International Space Station (ISS) ended this morning, as their capsule touched down just after 10 a.m. (CET) in Kazakhstan. Over the course of his six months on board the ISS (including four months as its commander), Luca Parmitano and his colleague Andrew Morgan of NASA carried out four spacewalks to maintain and repair the Alpha Magnetic Spectrometer (AMS-02). Assembled at CERN by an international team of scientists, the detector was installed on the ISS in 2011 and has since collected valuable cosmic-ray data.

The repairs carried out by Luca Parmitano and Andrew Morgan will extend the lifetime of the experiment, which is searching for dark matter and antimatter, to match that of the space station itself. In particular, during four difficult spacewalks, the two astronauts replaced the cooling system, which is essential to the operation of the cosmic-particle detector.

Watch our video on the spacewalk programme and the work carried out at CERN by scientists from the AMS collaboration in close contact with the astronauts:

Video above: A new cosmic data-taking era begins for the AMS experiment. Video Credit: CERN.


CERN, the European Organization for Nuclear Research, is one of the world’s largest and most respected centres for scientific research. Its business is fundamental physics, finding out what the Universe is made of and how it works. At CERN, the world’s largest and most complex scientific instruments are used to study the basic constituents of matter — the fundamental particles. By studying what happens when these particles collide, physicists learn about the laws of Nature.

The instruments used at CERN are particle accelerators and detectors. Accelerators boost beams of particles to high energies before they are made to collide with each other or with stationary targets. Detectors observe and record the results of these collisions.

Founded in 1954, the CERN Laboratory sits astride the Franco–Swiss border near Geneva. It was one of Europe’s first joint ventures and now has 23 Member States.

Related articles:

Astronauts Wrap Up Spacewalk Repair Job on Cosmic Ray Detector

Astronauts Wrap Up Third Spacewalk for Cosmic Particle Detector Repairs

Spacewalkers Complete First Excursion to Repair Cosmic Particle Detector

A very good start

Related links:

Alpha Magnetic Spectrometer (AMS-02):

International Space Station (ISS):

For more information about European Organization for Nuclear Research (CERN), Visit:

Image (mentioned), Video (mentioned), Text, Credits: CERN/Thomas Hortala.

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Flight ST27 - Soyuz lifts off from Baikonur Cosmodrome

ARIANESPACE - Soyuz / Flight ST27 -  OneWeb Mission poster.

Feb. 6, 2020

Soyuz liftoff. (Illustration)

For Arianespace’s ST27 mission, a Soyuz-2.1b launched 34 OneWeb satellites from the Baikonur Cosmodrome in Kazakhstan, on 6 February 2020, at 21:42 GMT / UTC (7 February, at 03:42 local time). ST27 is the 27th Soyuz commercial mission from the Baikonur Cosmodrome performed by Arianespace. The 34 OneWeb satellites will be put into a near polar orbit at an altitude of 450 kilometers.

Soyuz-2.1b launches 34 OneWeb satellites

Soyuz has lifted off from Baikonur Cosmodrome, carrying the next 34 satellites to join OneWeb’s next-generation constellation – which will be deployed during a sequence lasting 3 hours and 45 minutes from liftoff to final separation.

Image above: Installed on their dispenser system, the OneWeb satellites are lowered for integration atop Soyuz’ Fregat upper stage. Flight ST27. 34 OneWeb satellites.

This 50th Soyuz mission conducted by Arianespace and its Starsem affiliate will be operated from the Baikonur Cosmodrome. It will pave the way for the constellation’s deployment phase − for which Arianespace is to perform 19 more medium-lift Soyuz launches from three spaceports (Kourou, Baikonur and Vostochny) during 2020 and 2021, without mentioning the Ariane 62 maiden flight.

OneWeb satellite

By operating this second flight on behalf of the global satellite operator OneWeb, Arianespace participates in the fulfillment of its customer’s ultimate ambition: providing internet access for everyone, everywhere.

Related links:



Images, Video, Text, Credits: ROSCOSMOS/ARIANESPACE/SciNews/OneWeb.


Update: Voyager 2 Resumes Taking Science Data

NASA - Voyager 1 & 2 Mission patch.

Feb. 6, 2020

Mission operators report that Voyager 2 continues to be stable and that communications between Earth and the spacecraft are good. The spacecraft has resumed taking science data, and the science teams are now evaluating the health of the instruments following their brief shutoff.

Image above: This artist's concept depicts one of NASA's Voyager spacecraft entering interstellar space, or the space between stars. Interstellar space is dominated by the plasma, or ionized gas, that was ejected by the death of nearby giant stars millions of years ago. Image Credits: NASA/JPL-Caltech.

Engineers for NASA's Voyager 2 spacecraft are working to return the mission to normal operating conditions after one of the spacecraft's autonomous fault protection routines was triggered. Multiple fault protection routines were programmed into both Voyager 1 and Voyager 2 in order to allow the spacecraft to automatically take actions to protect themselves if potentially harmful circumstances arise. At NASA's Jet Propulsion Laboratory in Pasadena, California, engineers are still communicating with the spacecraft and receiving telemetry.

Launched in 1977, Voyager 1 and Voyager 2 are both in interstellar space, making them the most distant human-made objects in the solar system. On Saturday, Jan. 25, Voyager 2 didn't execute a scheduled maneuver in which the spacecraft rotates 360 degrees in order to calibrate its onboard magnetic field instrument. Analysis of the telemetry from the spacecraft indicated that an unexplained delay in the onboard execution of the maneuver commands inadvertently left two systems that consume relatively high levels of power operating at the same time. This caused the spacecraft to overdraw its available power supply.

The fault protection software routine was designed to automatically manage such an event, and by design, it appears to have turned off Voyager 2's science instruments to make up for the power deficit. As of Jan. 28, Voyager engineers have successfully turned off one of the high-power systems and turned the science instruments back on but have not yet resumed taking data. The team is now reviewing the status of the rest of the spacecraft and working on returning it to normal operations.

Voyager's power supply comes from a radioisotope thermoelectric generator (RTG), which turns heat from the decay of a radioactive material into electricity to power the spacecraft. Due to the natural decay of the material inside the RTG, Voyager 2's power budget goes down by about 4 watts per year. Last year, engineers turned off the primary heater for the Voyager 2 cosmic ray subsystem instrument in order to compensate for this power loss, and the instrument continues to operate.

In addition to managing each Voyager's power supply, mission operators must also manage the temperature of certain systems on the spacecraft. If, for example, the spacecraft fuel lines were to freeze and break, Voyager would no longer be able to point its antenna back at Earth to send data and receive commands. The temperature of the spacecraft is maintained either through the use of heaters or by taking advantage of excess heat from other onboard instruments and systems.

It has taken the team several days to assess the current situation primarily because of Voyager 2's distance from Earth — about 11.5 billion miles (18.5 billion kilometers). Communications traveling at the speed of light take about 17 hours to reach the spacecraft, and it takes another 17 hours for a response from the spacecraft to return to Earth. As a result, mission engineers have to wait about 34 hours to find out if their commands have had the desired effect on the spacecraft.

Related article:

Voyager 2 Engineers Working to Restore Normal Operations

The Voyager spacecraft were built by JPL, which continues to operate both. JPL is a division of Caltech in Pasadena. The Voyager missions are a part of the NASA Heliophysics System Observatory, sponsored by the Heliophysics Division of the Science Mission Directorate in Washington. For more information about the Voyager spacecraft, visit:

Image (mentioned), Text, Credits: NASA/Tony Greicius/JPL/Calla Cofield.


Record-breaking spacewalker returns from orbit

ROSCOSMOS - Soyuz MS-13 Mission patch.

February 6, 2020

Soyuz MS-13 hatch closure

ESA astronaut Luca Parmitano returned to Earth today alongside NASA astronaut Christina Koch and Roscosmos cosmonaut Alexander Skvortsov, marking the end of his second six-month International Space Station mission known as ‘Beyond’.

Luca, Christina and Alexander in Soyuz MS-13

Returning in the same Soyuz MS-13 spacecraft that flew Luca, Alexander and NASA astronaut Andrew Morgan to the Space Station on 20 July 2019, the trio touched down in about 30 cm of snow in the Kazakh Steppe on 6 February at 09:12 GMT (10:12 CET), as scheduled. The Soyuz landed upright and all three crew members emerged from the module smiling and looking well.

Image above: Astronaut Christina Koch smiles as she gives a “thumbs up” sign shortly after being extracted from the Soyuz MS-13 crew ship that brought her home after 328 days in space. Image Credit: NASA TV.

Koch’s first journey into space became a 328-day mission in which she orbited Earth 5,248 times, a journey of 139 million miles, roughly the equivalent of 291 trips to the Moon and back. She conducted and supported more than 210 investigations during Expeditions 59, 60, and 61, including as a research subject volunteer to provide scientists the opportunity to observe effects of long-duration spaceflight on a woman as the agency plans to return to the Moon under the Artemis program and prepare for human exploration of Mars.

Soyuz MS-13 undocking and departure

For Parmitano and Skvortsov, this landing completed a 201-day stay in space, 3,216 orbits of Earth and a journey of 85.2 million miles.

Luca will now fly directly to Cologne, Germany, where he will continue to be monitored by ESA’s space medicine team as he readapts to Earth’s gravity at ESA’s European Astronaut Centre (EAC) and DLR’s ‘:envihab’ facility.


Luca’s return to Earth marks the successful conclusion of his Beyond mission. During this mission Luca became the third European and first Italian in command of the International Space Station, performed four complex spacewalks to maintain the cosmic-ray-detecting Alpha Magnetic Spectrometer AMS-02, gained the European record for most cumulative hours spent spacewalking at 33 hours and 9 minutes, remotely operated a rover in the Netherlands as part of the Analog-1 experiment, delivered an important climate change message to leaders at the UN climate change conference in Madrid, and supported over 50 European experiments as well as 200 international experiments in space.

Luca will now fly directly to Cologne, Germany, where he will continue to be monitored by ESA’s space medicine team as he readapts to Earth’s gravity at ESA’s European Astronaut Centre (EAC) and DLR’s ‘:envihab’ facility.

Soyuz MS-13 landing

Luca’s return to Earth marks the successful conclusion of his Beyond mission. During this mission Luca became the third European and first Italian in command of the International Space Station, performed four complex spacewalks to maintain the cosmic-ray-detecting Alpha Magnetic Spectrometer AMS-02, gained the European record for most cumulative hours spent spacewalking at 33 hours and 9 minutes, remotely operated a rover in the Netherlands as part of the Analog-1 experiment, delivered an important climate change message to leaders at the UN climate change conference in Madrid, and supported over 50 European experiments as well as 200 international experiments in space.

He also played the first ever DJ set in space and shared numerous images of our planet and his activities on the Station.

DJ Luca in space

Thursday 6 February marked day 201 of his Beyond mission and Luca has now spent 367 noncumulative days in space across two missions – this is the longest of any ESA astronaut.

Intense ‘Beyond’ mission for Luca

Back on Earth, Luca will continue working with European researchers on experiments including Acoustic Diagnostics that looks into the impact of the Space Station environment on astronaut hearing, the TIME experiment that looks at whether astronauts judge time differently in space, and two experiments known as Grip and GRASP that look into the physiology behind eye-hand coordination and the role of gravity in regulating grip force, among others. 

Luca back from Beyond mission

The findings of research conducted as part of Luca’s Beyond mission will help shape the future of human and robotic exploration while enhancing technological developments on Earth.

Related article:

Best regards,

mercredi 5 février 2020

NASA & ESA TV's Broadcasts Return of Christina Koch and Expedition 61 Crewmates

ISS - Expedition 61 Mission patch.

February 5, 2020

Record-setting astronaut Christina Koch, along with Alexander Skvortsov of Roscosmos and Luca Parmitano of ESA (European Space Agency) are preparing to depart the International Space Station just after midnight for their return to Earth early Thursday morning. Earlier today Expedition 61 Commander Parmitano passed control of the station to Oleg Skripochka of Roscosmos.

Tune in to NASA Television and the agency’s website tonight at 9 p.m. EST as Koch, Skvortsov, and Parmitano say farewell and board their Soyuz MS-13 spacecraft in preparation for their undocking and return to Earth.

Image above: Expedition 61 Commander Luca Parmitano (front left) handed over control of the station today to Oleg Skripochka (front right). In the back row (from left) are Flight Engineers Christina Koch, Alexander Skvortsov, Jessica Meir and Andrew Morgan. Image Credit: NASA.

Koch was a crew member for Expeditions 59, 60 and 61, spending 328 days living and working aboard the International Space Station.

Soyuz's spacecrafts docked to ISS. Animation Credits: NASA/ISS HD Live Now

During Koch’s 11-month mission, she participated in more than 210 investigations, helping advance NASA’s goals to return to the Moon under the Artemis program and prepare for human exploration of Mars. Koch participated in a number of studies to support those future exploration missions, including research into how the human body adjusts to weightlessness, isolation, radiation and the stress of long-duration spaceflight.

Related article:

Astronaut Christina Koch’s Space Station Science Scrapbook

Related links:

Expedition 61:

Expedition 62:

Artemis program:


ESA’s Web TV:

Space Station Research and Technology:

International Space Station (ISS):

Image (mentioned), Animation (mentioned), Text, Credits: NASA/Mark Garcia.

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The science behind and beyond Luca's mission

ESA - Beyond Mission logo.

5 February 2020

As ESA astronaut Luca Parmitano marks his 200 days in space as part of his Beyond mission, it is time to pack up a few experiments, wrap up science reports and give way to further research that will continue beyond his second spaceflight.

Science in microgravity

When Luca lands tomorrow in the steppes of Kazakhstan, he will have supported over 200 experiments, of which over 50 are European.

Together with Roscosmos’ Alexander Skvortsov and NASA’s Christina Koch, Luca will share the ride back home in the Soyuz MS-13 spacecraft with 14 radiation dosimeters and a hard drive full of data on the behavior of dusty plasmas.

Radiation devices down to Earth

Ionising radiation is an invisible hazard that poses a major health risk to people in space. Away from the protection of Earth’s magnetic field, astronauts are exposed to significantly higher doses on the International Space Station than an airline pilot or a radiology nurse.

For the last 15 years, all European astronauts have used a device called the European Crew Personal Dosimeter to measure the radiation dose during their stay in orbit. Luca wore it around his waist throughout his seven-month mission – and even during his four spacewalks.

Back on Earth, scientists will analyse the radiation levels he has been exposed to.

Space risks – Fighting radiation

Luca is also bringing back 12 passive radiation detector packages that mapped the radiation environment in Europe’s Columbus laboratory. These are part of the Dosis 3D experiment, and you can now virtually navigate through the space lab, spot the devices and check the dose measured in each location during past missions on this website.

The results will help build a clearer picture of astronauts’ radiation environment and prepare for deep-space missions to come.

Columbus cartoon: Episode 14


Last week, a Cygnus space freighter departed the Space Station after nearly three months with hardware from two other European experiments.

The disposal of cables from the Vessel-ID experiment marks the end of an era for this long-running  technology demonstration. Outside the Columbus laboratory, the Vessel-ID antenna has been receiving shipping signals since June 2010, and even helped save the life of a Norwegian sailor caught in violent sea weather.

Outside the Columbus laboratory, the Vessel-ID antenna has been receiving shipping signals since June 2010 and even helped save the life of a Norwegian sailor caught in violent sea weather.

ISS Benefits for Humanity: Found at Sea

Luca deactivated the experiment on Friday 25 October 2019. A successor is ready for launch on a cubesat this year.

Floating around in weightlessness, astronauts lose muscle function and bone mass. Myotones is an experiment designed to measure the muscle tone, stiffness and elasticity.

Christina Koch with science freezer

Christina Koch was the second astronaut to take part in this research, and the first female test subject. Scans of her muscle resting tone, blood draws and ultrasound imaging are helping scientists gain a better picture of what happened to her body in space.

Used Myotones consumables, mainly for blood sampling, were disposed during Cygnus’ destructive reentry into Earth’s atmosphere.

Wrapping up

Luca wrapped up the final sessions of several experiments covering nutrition, time perception, energy balance and motor adaptation in space. The astronaut completed all tests for the Time, Acoustic Diagnostics, NutrISS, Grip and Grasp experiments.

Columbus Flight Director during Myotones experiment

Running in the background were two small cubes with ambitious goals. ESA’s first commercial facility for research on the International Space Station, ICE Cubes, is looking into contingency measures against the impacts of space radiation and enhancing cybersecurity for future space missions, while maintaining an interactive art installation.

In the final reports, scientists on ground and User Support and Operation Centres throughout Europe reiterated their “big thank you” to Luca and the other astronauts for “their commitment to science and the high quality of the data we have received.”

To be continued

Other experiments that will continue to run unattended after Luca’s departure are collecting bacteria for cleaner spacecraft, monitoring thunderstorms from space and understanding heat transfer in space bubbles.

Related links:

Dusty plasmas:

Invisible hazard:

Dosis 3D experiment:






ICE Cubes:

User Support and Operation Centres:

Collecting bacteria:

Monitoring thunderstorms:

Space bubbles:

Human and Robotic Exploration:

International Space Station (ISS):

Images, Video, Text, Credits: ESA/NASA/Ed Grace.


Rosetta and the chameleon comet

ESA - Rosetta Mission patch.

5 February 2020

A grand synthesis of Rosetta data has shown how its target comet repeatedly changed colour during the two years it was watched by the spacecraft. The chameleon comet’s nucleus became progressively less red as it made its close pass around the Sun, and then red again as it returned to deep space.

Colour changes at Rosetta's comet

Just like a chameleon changes its colour depending on its environment, so too did comet 67P/Churyumov-Gerasimenko. Unlike a chameleon, the colour changes on 67P/C-G reflect the amount of water ice that is exposed on the surface and in the surroundings of the comet.

At the beginning of Rosetta’s mission, the spacecraft rendezvoused with the comet while it was still a long way from the Sun. At such distances, the surface was covered in layers of dust and little ice was visible. This meant the surface appeared red when analysed with the VIRTIS (Visible and Infrared Thermal Imaging Spectrometer) instrument.

Comet on 7 July 2015 – NavCam

As the comet drew closer it crossed an important boundary, known as the frost line. Occurring at a distance around three times further from the Sun than the Earth, anything within the frostline will be heated sufficiently by the Sun that the ice will turn into a gas, a process called sublimation.

As Rosetta followed 67P/C-G across the frostline, VIRTIS began to notice the colour of the comet change. As the comet approached the Sun, the heating increased and the hidden water ice began to sublime pushing away the dust grains too. This revealed layers of pristine ice, which made the nucleus turn bluer in colour as seen by VIRTIS.

Around the comet’s nucleus, the situation was reversed. When the comet was far from the Sun, there was little dust surrounding the comet, but what there was contained water ice and so appeared bluer. This surrounding dust cloud is called the coma.

Colour changes at Rosetta's comet

As the comet crossed the frostline, the ice in the dust grains surrounding the nucleus sublimed quickly, leaving just the dehydrated dust grains. And so the coma turned redder as it approached perihelion, its closest approach to the Sun.

Once the comet was heading back into the outer solar system, VIRTIS showed the colour situation reverse again, so the nucleus became redder and the coma bluer.

To track the way the comet evolved, the VIRTIS team had to analyse more than 4000 separate observations spanning across two years of the Rosetta mission.

“To answer the big question of how does a comet work it is very important to have a long time series such as this,” says Gianrico Filacchione from Italy’s INAF-IAPS Istituto di Astrofisica e Planetologia Spaziali, who led the study.

The reason is that comets are extremely dynamic environments. Jets tend to swiftly appear on their surfaces and then decrease just as suddenly. Therefore, comparing occasional snap shots risks our understanding of the comet’s long-term evolution being biased by the transient changes. Having such a large quantity of measurements, however, means that even short timescale changes can be tracked.

Comet on 5 August 2014 - NavCam

This is because ground observations cannot resolve a comet’s nucleus, which in the case of 67P/CG is only about 3 km in size. Now that the team can describe and understand both the long-term evolution of the comet, and the steps it took along the way, it means that the readings from the other instruments onboard Rosetta can be placed into context.

But that does not mean we know everything about comets. Spectral analysis shows that the red colour of the dust is created by so-called organic molecules. These are molecules made of carbon, and there is a rich variety of them on the comet. Scientists believe that they are important for understanding how life formed on Earth.

In order to study them up close and identify these molecules, however, would require a sample of the comet’s surface to be returned to Earth.

“Bringing back to Earth a piece of the comet is really the Holy Grail for a cometary mission,” says Gianrico.

Until that is possible, however, he will continue to use the VIRTIS data to investigate 67P/C-G’s organics.

“There are definitely more exciting results to come,” says Matt Taylor, ESA Project Scientist for Rosetta, “The data collection may be over, but the analysis and the results will continue for years yet, adding to the rich legacy of cometary knowledge provided by Rosetta.”

“The correlation of what is happening on the nucleus is something completely new that cannot be done from Earth,” says Gianrico.

Notes for editors:

“An orbital water-ice cycle on comet 67P from colour changes,” by G. Filacchione et al is published in Nature.

Related links:

Visible and Infrared Thermal Imaging Spectrometer (VIRTIS):


Images, Text, Credits: ESA/Matt Taylor/Rosetta/NAVCAM – CC BY-SA IGO 3.0/INAF-IAPS, Institute for Space Astrophysics and Planetology/Fabrizio Capaccioni/Gianrico Filacchione.


NASA's ECOSTRESS Mission Sees Plants 'Waking Up' From Space

ISS - ECOSTRESS Mission logo.

February 5, 2020

Like many people, plants are less active at night. The agency's 'space botanist' can see when they begin to stir, and start their day.

Image above: The image shows plants "waking up" near Lake Superior. Red areas began to wake up at around 7 a.m. local time; green areas awoke around 8 a.m.; and blue areas, at about 9 a.m. The data was acquired by ECOSTRESS during the summer season.

Although plants don't sleep in the same way humans do, they have circadian rhythms - internal clocks that, like our own internal clocks, tell them when it's night and when it's day. And like many people, plants are less active at night. When the Sun comes up, they kick into gear, absorbing sunlight to convert carbon dioxide they draw from the air and water they draw from the soil into food, a process called photosynthesis. They also "sweat" excess water through pores on their leaves to cool themselves down, a process called evapotranspiration.

NASA's ECOsystem Spaceborne Thermal Radiometer on Space Station (ECOSTRESS) can see when plants "wake up" and begin these processes from space. The image above shows plants waking up (as evidenced by evapotranspiration) west of Lake Superior near the U.S.-Canada border. Plants in the red and pink areas began to awake at around 7 a.m. local time. Those in green areas awoke closer to 8 a.m., and those in blue areas, closer to 9 a.m.

ECOSTRESS launched to the International Space Station in June 2018. The space station's unique orbit enables the instrument to capture data over the same areas at different times of day. When the mission team analyzes the data, they gain new insight into how plants behave throughout the course of a day.

International Space Station (ISS)

For this image, the mission team collected and combined all of ECOSTRESS's morning data for the summer season. In doing so, they observed that the earliest risers were near the lake, with plant activity spreading gradually northwestward as the morning progressed.

ECOSTRESS' ability to detect plant behavior in this way can be especially helpful to resource managers and farmers, who can use the data to determine how much water their crops need, which ones are most water-efficient and which ones aren't getting enough water, even before they show visible signs of dehydration. What's more, the instrument can provide this data on a global scale over areas as small as a football field.

NASA's Jet Propulsion Laboratory in Pasadena, California, built and manages the ECOSTRESS mission for the Earth Science Division in the Science Mission Directorate at NASA Headquarters in Washington. ECOSTRESS is an Earth Venture Instrument mission; the program is managed by NASA's Earth System Science Pathfinder program at NASA's Langley Research Center in Hampton, Virginia.

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More information about ECOSTRESS is available here:

Image, Animation, Text, Credits: NASA/Written by Esprit Smith, NASA's Earth Science News team/JPL/Rexana Vizza.


ALMA catches beautiful outcome of stellar fight

ALMA - Atacama Large Millimeter/submillimeter Array logo.

5 February 2020

ALMA image of HD101584

Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA), in which ESO is a partner, have spotted a peculiar gas cloud that resulted from a confrontation between two stars. One star grew so large it engulfed the other which, in turn, spiralled towards its partner provoking it into shedding its outer layers.

Like humans, stars change with age and ultimately die. For the Sun and stars like it, this change will take it through a phase where, having burned all the hydrogen in its core, it swells up into a large and bright red-giant star. Eventually, the dying Sun will lose its outer layers, leaving behind its core: a hot and dense star called a white dwarf.

Location of HD101584 in the constellation of Centaurus

“The star system HD101584 is special in the sense that this ‘death process’ was terminated prematurely and dramatically as a nearby low-mass companion star was engulfed by the giant,” said Hans Olofsson of the Chalmers University of Technology, Sweden, who led a recent study, published in Astronomy & Astrophysics, of this intriguing object.

Thanks to new observations with ALMA, complemented by data from the ESO-operated Atacama Pathfinder EXperiment (APEX), Olofsson and his team now know that what happened in the double-star system HD101584 was akin to a stellar fight. As the main star puffed up into a red giant, it grew large enough to swallow its lower-mass partner. In response, the smaller star spiralled in towards the giant’s core but didn’t collide with it. Rather, this manoeuvre triggered the larger star into an outburst, leaving its gas layers dramatically scattered and its core exposed.

Wide-field view of the region of the sky where HD101584 is located

The team says the complex structure of the gas in the HD101584 nebula is due to the smaller star’s spiralling towards the red giant, as well as to the jets of gas that formed in this process. As a deadly blow to the already defeated gas layers, these jets blasted through the previously ejected material, forming the rings of gas and the bright bluish and reddish blobs seen in the nebula.

A silver lining of a stellar fight is that it helps astronomers to better understand the final evolution of stars like the Sun. “Currently, we can describe the death processes common to many Sun-like stars, but we cannot explain why or exactly how they happen. HD101584 gives us important clues to solve this puzzle since it is currently in a short transitional phase between better studied evolutionary stages. With detailed images of the environment of HD101584 we can make the connection between the giant star it was before, and the stellar remnant it will soon become,” says co-author Sofia Ramstedt from Uppsala University, Sweden.

Co-author Elizabeth Humphreys from ESO in Chile highlighted that ALMA and APEX, located in the country’s Atacama region, were crucial to enabling the team to probe “both the physics and chemistry in action” in the gas cloud. She added: “This stunning image of the circumstellar environment of HD101584 would not have been possible without the exquisite sensitivity and angular resolution provided by ALMA.”

While current telescopes allow astronomers to study the gas around the binary, the two stars at the centre of the complex nebula are too close together and too far away to be resolved. ESO’s Extremely Large Telescope, under construction in Chile’s Atacama Desert, “will provide information on the ‘heart’ of the object,” says Olofsson, allowing astronomers a closer look at the fighting pair.

Zooming into HD101584

More information:

This research was presented in a paper published in Astronomy & Astrophysics.

The team is composed of H. Olofsson (Department of Space, Earth and Environment, Chalmers University of Technology, Onsala Space Observatory, Sweden [Chalmers]), T. Khouri (Chalmers), M. Maercker (Chalmers), P. Bergman (Chalmers), L. Doan (Department of Physics and Astronomy, Uppsala University, Sweden [Uppsala]), D. Tafoya (National Astronomical Observatory of Japan), W. H. T. Vlemmings (Chalmers), E. M. L. Humphreys (European Southern Observatory [ESO], Garching, Germany), M. Lindqvist (Chalmers), L. Nyman (ESO, Santiago, Chile), and S. Ramstedt (Uppsala).

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of ESO, the U.S. National Science Foundation (NSF) and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI). ALMA construction and operations are led by ESO on behalf of its Member States; by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America; and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It has 16 Member States: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Ireland, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile and with Australia as a Strategic Partner. 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 and its world-leading Very Large Telescope Interferometer as well as two survey telescopes, VISTA working in the infrared and the visible-light VLT Survey Telescope. Also at Paranal ESO will host and operate the Cherenkov Telescope Array South, the world’s largest and most sensitive gamma-ray observatory. ESO is also a major partner in two facilities on Chajnantor, APEX and ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre Extremely Large Telescope, the ELT, which will become “the world’s biggest eye on the sky”.


ESOcast 216 Light: ALMA Catches Beautiful Outcome of Stellar Fight

Research paper:

Photos of ALMA:

Atacama Large Millimeter/submillimeter Array (ALMA):

Atacama Pathfinder EXperiment (APEX):

Images, Text, Credits: ALMA/ESO/NAOJ/NRAO, Olofsson et al. Acknowledgement: Robert Cumming/IAU and Sky & Telescope/Digitized Sky Survey 2. Acknowledgement: Davide De Martin/ESO/Bárbara Ferreira/Elizabeth Humphreys/Chalmers University of Technology Onsala/Hans Olofsson/Uppsala University/Sofia Ramstedt/Video: ALMA (ESO/NAOJ/NRAO), Olofsson et al. Acknowledgement: Robert Cumming; N. Risinger (, Digitized Sky Survey 2. Music: Astral Electronic.


mardi 4 février 2020

Station Crew Splits Up Thursday before Next Cargo Mission

ISS - Expedition 61 Mission patch.

February 4, 2020

The crew aboard the International Space Station is preparing to split up while also getting ready for a U.S. space delivery.

NASA astronaut Christina Koch is packing up and cleaning her crew quarters today ahead of her return to Earth early Thursday. She will board the Soyuz MS-13 crew ship on Wednesday about 9:30 p.m. EST with crewmates Alexander Skvortsov of Roscosmos and Luca Parmitano of ESA (European Space Agency).

Image above: Clockwise from left are, NASA astronauts Christina Koch, Andrew Morgan and Jessica Meir and ESA (European Space Agency) astronaut Luca Parmitano. Parmitano is the Expedition 61 Commander leading Flight Engineers Koch, Morgan and Meir aboard the International Space Station. Image Credit: NASA.

The trio will undock Thursday at 12:50 a.m. then parachute to a landing in Kazakhstan at 4:12 a.m. (3:12 p.m. Kazakh time). NASA TV and ESA Web TV begins its live coverage Wednesday at 9 p.m. when the departing crew says farewell to their station counterparts and closes the Soyuz hatch.

Image above: Soyuz MS spacecraft infographic - Modules and Specs. Image Credit: ESA.

This will cap a 328-day-long mission for Koch that began on March 14. She is now in second place for the single longest spaceflight by a U.S. astronaut surpassed only by former astronaut Scott Kelly with 340 days during his final station mission.

Expedition 62 will officially begin when Koch and her Expedition 61 crewmates undock from the Poisk module. Continuing their stay in space will be Commander Oleg Skripochka of Roscosmos and NASA Flight Engineers Jessica Meir and Andrew Morgan. They will end their stay aboard the orbiting lab and return to Earth in April.

Image above: Soyuz MS-13 docked at the Inaternational Space Station (ISS). Image Credits: ESA/L. Parmitano, CC BY-SA 3.0 IGO

Meir and Morgan are getting ready for another mission that begins Sunday when Northrop Grumman’s Cygnus cargo craft lifts off at 5:39 p.m. It will rendezvous with the station Tuesday where the duo will be in the cupola to capture Cygnus at 3:30 a.m. with the Canadarm2 robotic arm.

Ground controllers will then remotely command the Canadarm2 to install Cygnus to the Unity module where it will stay for 90 days. Cygnus will be delivering over 8,000 pounds of new research gear and crew supplies.

Related links:

Expedition 61:

Expedition 62:

Soyuz MS-13:

Poisk module:


ESA’s Web TV:


Space Station Research and Technology:

International Space Station (ISS):

Images (mentioned), Text, Credits: NASA/Mark Garcia.

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