lundi 27 mars 2017

Weekend Robotics Work Sets Up Thursday Spacewalk

ISS - Expedition 50 Mission patch.

March 27, 2017

International Space Station (ISS). Image Credit: NASA

The Pressurized Mating Adapter-3 (PMA-3) was robotically removed Sunday from the Tranquility module and attached to the Harmony module after being prepared during a successful spacewalk Friday. A second spacewalk is scheduled for Thursday at 8 a.m. EDT to finalize the PMA-3 cable connections on Harmony.

Download hi-res video of briefing animations depicting the activities of all three spacewalks:

Commander Shane Kimbrough disconnected cables from PMA-3 while still attached to Tranquility during a spacewalk on Friday. That work allowed ground controllers to use the Canadarm2 robotic arm to remotely grapple and remove PMA-3 from Tranquility and attach it to Harmony.

Image above: Astronaut Shane Kimbrough takes an out-of-this-world selfie during a spacewalk on March 24, 2017. Image Credit: NASA.

The relocation readies the PMA-3 for the future installation of the new International Docking Adapter-3 (IDA-3) set to be delivered on a future cargo mission. The IDA-3 will accommodate commercial crew vehicle dockings and provide the pressurized interface between the station and the adapter.

Thursday’s spacewalk will see Kimbrough and Peggy Whitson complete the PMA-3 attachment work on the Harmony’s space-facing port. The duo will also install computer relay boxes containing software upgrades to enable future commercial crew vehicle dockings at the International Space Station.

Related links:

Space Station Research and Technology:

International Space Station (ISS):

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

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Stars Born in Winds from Supermassive Black Holes

ESO - European Southern Observatory logo.

27 March 2017

ESO’s VLT spots brand-new type of star formation

Artist’s impression of stars born in winds from supermassive black holes

Observations using ESO’s Very Large Telescope have revealed stars forming within powerful outflows of material blasted out from supermassive black holes at the cores of galaxies. These are the first confirmed observations of stars forming in this kind of extreme environment. The discovery has many consequences for understanding galaxy properties and evolution. The results are published in the journal Nature.

A UK-led group of European astronomers used the MUSE and X-shooter instruments on the Very Large Telescope (VLT) at ESO’s Paranal Observatory in Chile to study an ongoing collision between two galaxies, known collectively as IRAS F23128-5919, that lie around 600 million light-years from Earth. The group observed the colossal winds of material — or outflows — that originate near the supermassive black hole at the heart of the pair’s southern galaxy, and have found the first clear evidence that stars are being born within them [1].

Such galactic outflows are driven by the huge energy output from the active and turbulent centres of galaxies. Supermassive black holes lurk in the cores of most galaxies, and when they gobble up matter they also heat the surrounding gas and expel it from the host galaxy in powerful, dense winds [2].

“Astronomers have thought for a while that conditions within these outflows could be right for star formation, but no one has seen it actually happening as it’s a very difficult observation,” comments team leader Roberto Maiolino from the University of Cambridge. “Our results are exciting because they show unambiguously that stars are being created inside these outflows.”

Artist’s impression of stars born in winds from supermassive black holes

The group set out to study stars in the outflow directly, as well as the gas that surrounds them. By using two of the world-leading VLT spectroscopic instruments, MUSE and X-shooter, they could carry out a very detailed study of the properties of the emitted light to determine its source.

Radiation from young stars is known to cause nearby gas clouds to glow in a particular way. The extreme sensitivity of X-shooter allowed the team to rule out other possible causes of this illumination, including gas shocks or the active nucleus of the galaxy.

The group then made an unmistakable direct detection of an infant stellar population in the outflow [3]. These stars are thought to be less than a few tens of millions of years old, and preliminary analysis suggests that they are hotter and brighter than stars formed in less extreme environments such as the galactic disc.

As further evidence, the astronomers also determined the motion and velocity of these stars. The light from most of the region’s stars indicates that they are travelling at very large velocities away from the galaxy centre — as would make sense for objects caught in a stream of fast-moving material.

Co-author Helen Russell (Institute of Astronomy, Cambridge, UK) expands: “The stars that form in the wind close to the galaxy centre might slow down and even start heading back inwards, but the stars that form further out in the flow experience less deceleration and can even fly off out of the galaxy altogether.”

The discovery provides new and exciting information that could better our understanding of some astrophysics, including how certain galaxies obtain their shapes [4]; how intergalactic space becomes enriched with heavy elements [5]; and even from where unexplained cosmic infrared background radiation may arise [6].

Maiolino is excited for the future: “If star formation is really occurring in most galactic outflows, as some theories predict, then this would provide a completely new scenario for our understanding of galaxy evolution.”


[1] Stars are forming in the outflows at a very rapid rate; the astronomers say that stars totalling around 30 times the mass of the Sun are being created every year. This accounts for over a quarter of the total star formation in the entire merging galaxy system.

[2] The expulsion of gas through galactic outflows leads to a gas-poor environment within the galaxy, which could be why some galaxies cease forming new stars as they age. Although these outflows are most likely to be driven by massive central black holes, it is also possible that the winds are powered by supernovae in a starburst nucleus undergoing vigorous star formation.

[3] This was achieved through the detection of signatures characteristic of young stellar populations and with a velocity pattern consistent with that expected from stars formed at high velocity in the outflow.

[4] Spiral galaxies have an obvious disc structure, with a distended bulge of stars in the centre and surrounded by a diffuse cloud of stars called a halo. Elliptical galaxies are composed mostly of these spheroidal components. Outflow stars that are ejected from the main disc could give rise to these galactic features.

[5] How the space between galaxies — the intergalactic medium — becomes enriched with heavy elements is still an open issue, but outflow stars could provide an answer. If they are jettisoned out of the galaxy and then explode as supernovae, the heavy elements they contain could be released into this medium.

[6] Cosmic-infrared background radiation, similar to the more famous cosmic microwave background, is a faint glow in the infrared part of the spectrum that appears to come from all directions in space. Its origin in the near-infrared bands, however, has never been satisfactorily ascertained. A population of outflow stars shot out into intergalactic space may contribute to this light.

More information:

This research was presented in a paper entitled “Star formation in a galactic outflow” by Maiolino et al., to appear in the journal Nature on 27 March 2017.

The team is composed of R. Maiolino (Cavendish Laboratory; Kavli Institute for Cosmology, University of Cambridge, UK), H.R. Russell (Institute of Astronomy, Cambridge, UK), A.C. Fabian (Institute of Astronomy, Cambridge, UK), S. Carniani (Cavendish Laboratory; Kavli Institute for Cosmology, University of Cambridge, UK), R. Gallagher (Cavendish Laboratory; Kavli Institute for Cosmology, University of Cambridge, UK), S. Cazzoli (Departamento de Astrofisica-Centro de Astrobiología, Madrid, Spain), S. Arribas (Departamento de Astrofisica-Centro de Astrobiología, Madrid, Spain), F. Belfiore ((Cavendish Laboratory; Kavli Institute for Cosmology, University of Cambridge, UK), E. Bellocchi (Departamento de Astrofisica-Centro de Astrobiología, Madrid, Spain), L. Colina  (Departamento de Astrofisica-Centro de Astrobiología, Madrid, Spain), G. Cresci (Osservatorio Astrofisico di Arcetri, Firenze, Italy), W. Ishibashi (Universität Zürich, Zürich, Switzerland), A. Marconi (Università di Firenze, Italy; Osservatorio Astrofisico di Arcetri, Firenze, Italy), F. Mannucci (Osservatorio Astrofisico di Arcetri, Firenze, Italy), E. Oliva (Osservatorio Astrofisico di Arcetri, Firenze, Italy), and E. Sturm (Max-Planck-Institut für Extraterrestrische Physik, Garching, Germany).

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 16 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile. 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 a major partner in ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre European Extremely Large Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.


ESOcast 101 Light: Stars found in black hole blasts

Research paper in Nature:

Photos of the VLT:

ESO's Very Large Telescope (VLT):

MUSE instrument:

X-shooter instrument:

Image, Video, Text, Credits: ESO/Richard Hook/Cavendish Laboratory, Kavli Institute for Cosmology University of Cambridge/Roberto Maiolino/M. Kornmesser.

Best regards,

NuSTAR Probes Puzzling Galaxy Merger

NASA - Nuclear Spectroscopic Telescope Array (NuSTAR) logo.

March 27, 2017

A supermassive black hole inside a tiny galaxy is challenging scientists' ideas about what happens when two galaxies become one.

Was 49 is the name of a system consisting of a large disk galaxy, referred to as Was 49a, merging with a much smaller "dwarf" galaxy called Was 49b. The dwarf galaxy rotates within the larger galaxy's disk, about 26,000 light-years from its center. Thanks to NASA's Nuclear Spectroscopic Telescope Array (NuSTAR) mission, scientists have discovered that the dwarf galaxy is so luminous in high-energy X-rays, it must host a supermassive black hole much larger and more powerful than expected.

"This is a completely unique system and runs contrary to what we understand of galaxy mergers," said Nathan Secrest, lead author of the study and postdoctoral fellow at the U.S. Naval Research Laboratory in Washington.

Data from NuSTAR and the Sloan Digital Sky Survey suggest that the mass of the dwarf galaxy's black hole is huge, compared to similarly sized galaxies, at more than 2 percent of the galaxy's own mass.

"We didn't think that dwarf galaxies hosted supermassive black holes this big," Secrest said. "This black hole could be hundreds of times more massive than what we would expect for a galaxy of this size, depending on how the galaxy evolved in relation to other galaxies.”

Image above: This optical image shows the Was 49 system, which consists of a large disk galaxy, Was 49a, merging with a much smaller "dwarf" galaxy Was 49b. Image Credits: DCT/NRL.

The dwarf galaxy's black hole is the engine of an active galactic nucleus (AGN), a cosmic phenomenon in which extremely high-energy radiation bursts forth as a black hole devours gas and dust. This particular AGN appears to be covered by a donut-shaped structure made of gas and dust. NASA's Chandra and Swift missions were used to further characterize the X-ray emission.

Normally, when two galaxies start to merge, the larger galaxy's central black hole becomes active, voraciously gobbling gas and dust, and spewing out high-energy X-rays as matter gets converted into energy. That is because, as galaxies approach each other, their gravitational interactions create a torque that funnels gas into the larger galaxy's central black hole. But in this case, the smaller galaxy hosts a more luminous AGN with a more active supermassive black hole, and the larger galaxy's central black hole is relatively quiet.

An optical image of the Was 49 system, compiled using observations from the Discovery Channel Telescope in Happy Jack, Arizona, uses the same color filters as the Sloan Digital Sky Survey. Since Was 49 is so far away, these colors are optimized to separate highly-ionized gas emission, such as the pink-colored region around the feeding supermassive black hole, from normal starlight, shown in green. This allowed astronomers to more accurately determine the size of the dwarf galaxy that hosts the supermassive black hole.

The pink-colored emission stands out in a new image because of the intense ionizing radiation emanating from the powerful AGN. Buried within this region of intense ionization is a faint collection of stars, believed to be part of the galaxy surrounding the enormous black hole. These striking features lie on the outskirts of the much larger spiral galaxy Was 49a, which appears greenish in the image due to the distance to the galaxy and the optical filters used.

Scientists are still trying to figure out why the supermassive black hole of dwarf galaxy Was 49b is so big. It may have already been large before the merger began, or it may have grown during the very early phase of the merger.

Nuclear Spectroscopic Telescope Array or NuSTAR. Image Credit:NASA

"This study is important because it may give new insight into how supermassive black holes form and grow in such systems," Secrest said. “By examining systems like this, we may find clues as to how our own galaxy’s supermassive black hole formed.”

In several hundred million years, the black holes of the large and small galaxies will merge into one enormous beast.

NuSTAR is a Small Explorer mission led by Caltech and managed by JPL for NASA's Science Mission Directorate in Washington. NuSTAR was developed in partnership with the Danish Technical University and the Italian Space Agency (ASI). The spacecraft was built by Orbital Sciences Corp., Dulles, Virginia. NuSTAR's mission operations center is at UC Berkeley, and the official data archive is at NASA's High Energy Astrophysics Science Archive Research Center. ASI provides the mission's ground station and a mirror archive. JPL is managed by Caltech for NASA.

For more information on NuSTAR, visit:

Images (mentioned), Text, Credits: NASA/Martin Perez/JPL/Elizabeth Landau.


Checking in on Bleriot

NASA - Cassini Mission to Saturn patch.

March 27, 2017

What appears as a pair of bright dashes at the center of this image is one of the features rings scientists have dubbed "propellers." This particular propeller, named Bleriot, marks the presence of a body that is much larger than the particles that surround it, yet too small to clear out a complete gap in the rings (like Pan and Daphnis) and become a moon in its own right. Although the moonlet at the core of the propeller is itself too small to see, the disturbances in the rings caused by its gravity betray its presence.

Cassini scientists have been tracking propeller features like this one for years in order to learn how their orbits change over time. From this, they hope to gain insight into how forming planets migrate in the disks in which they form.

For more on Bleriot, see PIA12792.

This view looks toward the sunlit side of the rings from about 59 degrees above the ring plane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Jan. 9, 2017.

The view was acquired at a distance of approximately 223,000 miles (359,000 kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 73 degrees. Image scale is 1.2 miles (2 kilometers) per pixel.

The Cassini mission is a cooperative project of NASA, ESA (the European Space Agency) and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colorado.

Related link:


For more information about the Cassini-Huygens mission visit and . The Cassini imaging team homepage is at and

Image, Text, Credits: NASA/Martin Perez/JPL-Caltech/Space Science Institute.


NASA Spacecraft Investigate Clues in Radiation Belts

NASA - Van Allen Probes logo.

March 27, 2017

High above Earth, two giant rings of energetic particles trapped by the planet’s magnetic field create a dynamic and harsh environment that holds many mysteries — and can affect spacecraft traveling around Earth. NASA’s Van Allen Probes act as space detectives, to help study the complex particle interactions that occur in these rings, known as the Van Allen radiation belts. Recently, the spacecraft were in just the right place, at just the right time, to catch an event caused by the fallout of a geomagnetic storm as it happened. They spotted a sudden rise in particles zooming in from the far side of the planet, improving our understanding of how particles travel in near-Earth space.

The two twin Van Allen Probe spacecraft orbit one behind the other, investigating clues in a way a single spacecraft never could. On one typical day, as the first instrument traveled around Earth, it spotted nothing unusual, but the second, following just an hour later, observed an increase in oxygen particles speeding around Earth’s dayside — the side nearest the sun. Where did these particles come from? How had they become so energized?

Animation above: The twin Van Allen Probes orbit one behind the other, investigating clues in a way a single spacecraft never could. In this model, the trailing spacecraft saw an increase in injected oxygen particles (blue), which was unobserved by the first. The increase in particles was due to a geomagnetic storm front that moved across the path of the orbit after the first spacecraft passed. Animation Credits: NASA’s Goddard Space Flight Center/Mike Henderson/Joy Ng, Producer.

Scientists scoured the clues to figure out what was happening. With the help of computer models, they deduced that the particles had originated on the night side of Earth before being energized and accelerated through interactions with Earth’s magnetic field. As the particles journeyed around Earth, the lighter hydrogen particles were lost in collisions with the atmosphere, leaving an oxygen-rich plasma. The findings were presented in a recent paper in Geophysical Review Letters.

Van Allen Probes in orbit. Image Credits: NASA/JPL

The unique double observations of the Van Allen Probes help untangle the complex workings of Earth’s magnetic environment. Such information has provided the very first view of these harsh belts from the inside — and it helps us better protect satellites and astronauts traveling through the region.

Related Links:

Learn more about NASA’s Van Allen Probes:

Geophysical Review Letters:

Animation (mentioned, Image (mentioned), Text, Credits: NASA’s Goddard Space Flight Center, by Mara Johnson-Groh/Rob Garner.


samedi 25 mars 2017

CryoSat reveals Antarctica in 3D

ESA - CRYOSAT Mission logo.

25 March 2017

Around 250 million measurements taken by ESA’s CryoSat over the last six years have been used to create a unique 3D view of Antarctica, offering a snapshot of the undulating surface of this vast ice sheet.

Antarctica in 3D

CryoSat’s radar altimeter detects tiny variations in the height of the ice across the entire continent, including on the steeper continental margins where the vast majority of ice losses occur.

Importantly, the satellite’s orbit takes it to latitudes within 200 km of the north and south poles – closer than other Earth observation satellites.

Naturally, the mission is also used to map changes in the thickness of ice floating in the polar oceans, which is particularly important for the Arctic.

This new ‘digital elevation model’ was revealed at this week’s gathering of CryoSat scientists in Banff, Canada.

Tom Slater, researcher at the UK Centre for Polar Observation and Modelling (CPOM), said, “We used around 250 million measurements taken by CryoSat between 2010 and 2016 to create the most comprehensive picture of Antarctic ice elevation currently available.”

It offers wide range of applications – showing the surface of Antarctica in such detail means it can be used in anything from planning fieldwork to modelling the ice sheet. 

Ice height

It also allows scientists to distinguish between changes in topography and ice motion when working with other satellite measurements, such as those used to calculate the balance between how much the ice sheet is gaining by accumulating snow and losing through melting and creating icebergs.

The model will soon be freely available via the CPOM portal, which already provides information on sea-ice volume and thickness, ice velocity and, shortly, ice sheets. In the meantime, however, the model can be downloaded here:

CPOM Director Andrew Shepherd added, “We want the digital elevation model to be accessible to anyone who uses ice-sheet surface topography measurements in their work.

“This should benefit not only studies of the Antarctic ice sheet, but also projections of future sea-level rise.”

ESA's ice mission

ESA’s CryoSat mission manager, Tommaso Parrinello, said, “We are hearing some great results from our mission at the meeting here in Banff.

“It’s now widely recognised that dwindling polar ice is one of the first casualties of climate change, but it’s important to provide the hard facts – and this we can do with CryoSat.

“It’s equally important to make sure the satellite’s data are correct and so we have a huge international field campaign just started in the Arctic to take ‘ground  truth’ measurements from aircraft and on the ice to compare with those of CryoSat. It’s a tough environment – so we wish them lots of luck.”

Related links:

Antarctica digital elevation model:


Access CryoSat data:

CryoSat Science Meeting:

Centre for Polar Observation and Modelling:

CPOM data portal:

Natural Environment Research Council:

Images, Text, Credits: ESA/CPOM/AOES Medialab.

Best regards,

vendredi 24 mars 2017

Weekly Recap From the Expedition Lead Scientist, week of March 13, 2017

ISS - Expedition 50 Mission patch.

March 24, 2017

(Highlights: Week of March 13, 2017) - Crew members on the International Space Station worked on a pair of investigations into water that could result in cleaner water on Earth.

Image above: This long-exposure image captures a pair of Russian Soyuz capsules attached to the International Space Station as the outpost flies over the night lights of Earth at 17,500 mph. Image Credit: NASA.

ESA (European Space Agency) astronaut Thomas Pesquet sampled filtered water on the space station as part of the Water Monitoring Suite experiment. This new technology can quickly detect and identify potentially harmful microorganisms in the station's water supply. If successful, it will ensure that crew members can perform real time tests and monitor the safety of their water on future missions.

Using current technology, it can take a week to search for harmful bacteria. With the Water Monitoring Suite – part of the Microbial Monitoring System on the station – it could take less than an hour. This would be invaluable to travelers in space where water is a very limited and precious commodity, and could also help millions of people on Earth who do not have access to clean water. Equipment that is fast and simple to use can improve water quality monitoring in remote areas.

Image above: NASA astronaut Shane Kimbrough loads organic samples into the Minus Eighty Degree Laboratory Freezer for ISS (MEFLI) in preparation of sending them back to Earth on the SpaceX 10 Dragon capsule. Image Credit: NASA.

Pesquet worked on a separate investigation into clean water on the station, injecting water into a pair of Aquapads and leaving them to incubate at ambient temperature inside the orbiting laboratory. After two days, he took photographs of the resulting bacterial contamination in the cotton-based petri dish.

The water astronauts drink on the station is recycled by up to 80 percent from their sweat, urine, and other reclaimed wastewater sources. Recycling water reduces the number of supply missions needed to run the station, and building a self-sufficient spacecraft is necessary for future missions traveling farther from our planet. Using a device that consists of a simple absorbent cotton -- injected with 1 milliliter of water -- and a tablet computer application, ESA’s Aquapad aims to improve the speed and efficiency of water tests in orbit. This quick and simple analysis of water could also help test drinking water on Earth in countries where access to safe water to drink is a constant problem. Aquapad could also be used to diagnose the state of the water after natural disasters.

Pesquet packed samples of the study of gravity-controlled growth and development in plants using true microgravity conditions (Auxin Transport) for delivery back to Earth on the SpaceX 10 Dragon capsule. The JAXA (Japan Aerospace Exploration Agency) investigation seeks new insight into how gravity – or the lack of it – affects plant development. The study focuses on auxins – a plant hormone discovered by observing how plants respond to light.

Image above: ESA astronaut Thomas Pesquet initiated the ESA-sponsored Aquapad technology demonstration and sampling using the Microbial Monitoring System (MMS) portion of the Water Monitoring Suite (WMS) experiment. Image Credit: NASA.

Scientists will study the role auxins play in pea and corn seedlings grown in microgravity. Future space travelers will require plant and oxygen production during long space missions and scientists need to understand how to grow plants in microgravity, where there is no clear distinction between up and down. This investigation develops new techniques for controlling plant growth direction by using plant hormones, including auxins, involved in plant development. Results may provide new techniques for efficiently growing and watering seedlings in microgravity, benefiting future life sciences investigations as well as plant cultivation in space. This research can also provide additional insight on how to utilize plants to provide more suitable and comfortable environmental conditions on Earth.

Human research investigations conducted this week include At Home in Space, Fine Motor Skills, Energy, Habitability, Space Headaches, and Dose Tracker.

Progress was made on other investigations, outreach activities, and facilities this week, including APEX-4, CASIS PCG 5, Tangolab-1, Simple Solar Neutron Detector, Google Street View, Meteor, Tropical Cyclone, Microgravity Expanded Stem Cells, Rodent Research-4, ISS Ham Radio, Group Combustion, SODI-DCMIX #3, Multi-Gas Monitor, MAGVECTOR, BEAM, Radi-N2, Manufacturing Device, ExHAM #2 and NanoRacks Science Box, NanoRacks Modules 9 & 71.

Related links:

Water Monitoring Suite:


Auxin Transport:

At Home in Space:

Fine Motor Skills:



Space Headaches:

Dose Tracker:




Tropical Cyclone:

Microgravity Expanded Stem Cells:

Rodent Research-4:

ISS Ham Radio:

Group Combustion:


Multi-Gas Monitor:




Space Station Research and Technology:

International Space Station (ISS):

Images (mentioned), Text, Credits: NASA/Kristine Rainey/Jorge Sotomayor, Lead Increment Scientist Expeditions 49 & 50.

Best regards,