samedi 30 novembre 2019

Hubble Detects Dynamic Galactic Duo

NASA - Hubble Space Telescope patch.

Nov. 30, 2019

Some galaxies are closer friends than others. While many live their own separate, solitary lives, others stray a little too close to a near neighbor and take their friendship even deeper.

The two galaxies in this image taken by the NASA/ESA Hubble Space Telescope, named NGC 6285 (left) and NGC 6286 (right), have done just that! Together, the duo is named Arp 293 and they are interacting, their mutual gravitational attraction pulling wisps of gas and streams of dust from them, distorting their shapes, and gently smudging and blurring their appearances on the sky — to Earth-based observers, at least.

Hubble has viewed a number of interacting pairs. These can have distinctive, beautiful, and downright odd shapes, ranging from sheet music to a spaceship entering a sci-fi-esque wormhole, a bouquet of celestial blooms and a penguin fiercely guarding its precious egg.

Arp 293 is located in the constellation of Draco (the Dragon) and lies over 250 million light-years from Earth.

Hubble Space Telescope (HST)

For more information about Hubble, visit:

Text Credits: ESA (European Space Agency)/NASA/Rob Garner/Image, Animation Credits: ESA/Hubble & NASA, K. Larson et al.


vendredi 29 novembre 2019

10 Questions You Might Have About Black Holes

NASA logo.

November 29, 2019

A black hole is an extremely dense object in space from which no light can escape. While black holes are mysterious and exotic, they are also a key consequence of how gravity works: When a lot of mass gets compressed into a small enough space, the resulting object rips the very fabric of space and time, becoming what is called a singularity. A black hole's gravity is so powerful that it will be able to pull in nearby material and "eat" it.

Image above: This artist concept illustrates a supermassive black hole with millions to billions times the mass of our Sun. Supermassive black holes are enormously dense objects buried at the hearts of galaxies. Image credits: NASA/JPL-Caltech.

Here are 10 things you might want to know about black holes:

Image above: Galaxy NGC 1068 is shown in visible light and X-rays in this composite image. High-energy X-rays (magenta) captured by NASA's Nuclear Spectroscopic Telescope Array, or NuSTAR, are overlaid on visible-light images from both NASA's Hubble Space Telescope and the Sloan Digital Sky Survey. The X-ray light is coming from an active supermassive black hole, also known as a quasar, in the center of the galaxy. This supermassive black hole has been extensively studied due to its relatively close proximity to our galaxy. Image Credits: NASA/JPL-Caltech/Roma Tre Univ.

1. How can we learn about black holes if they trap light, and can't actually be seen?

No light of any kind, including X-rays, can escape from inside the event horizon of a black hole, the region beyond which there is no return. NASA's telescopes that study black holes are looking at the surrounding environments of the black holes, where there is material very close to the event horizon. Matter is heated to millions of degrees as it is pulled toward the black hole, so it glows in X-rays. The immense gravity of black holes also distorts space itself, so it is possible to see the influence of an invisible gravitational pull on stars and other objects.

Image above: In 2015, researchers discovered a black hole named CID-947 that grew much more quickly than its host galaxy. The black hole at the galaxy’s center is nearly 7 billion times the mass of our Sun, placing it among the most massive black holes discovered. The galaxy’s mass, however, is considered normal. Because its light had to travel a very long distance, scientists were observing it at a period when the universe was less than 2 billion years old, just 14% of its current age (almost 14 billion years have passed since the Big Bang). Image credits: M. Helfenbein, Yale University / OPAC.

2. How long does it take to make a black hole?

A stellar-mass black hole, with a mass of tens of times the mass of the Sun, can likely form in seconds, after the collapse of a massive star. These relatively small black holes can also be made through the merger of two dense stellar remnants called neutron stars. A neutron star can also merge with a black hole to make a bigger black hole, or two black holes can collide. Mergers like these also make black holes quickly, and produce ripples in space-time called gravitational waves.

More mysterious are the giant black holes found at the centers of galaxies — the "supermassive" black holes, which can weigh millions or billions of times the mass of the Sun. It can take less than a billion years for one to reach a very large size, but it is unknown how long it takes them to form, generally.

Image above: Scientists obtained the first image of a black hole, seen here, using Event Horizon Telescope observations of the center of the galaxy M87. The image shows a bright ring formed as light bends due to the intense gravity around a black hole that is 6.5 billion times more massive than our Sun. Image credits: Event Horizon Telescope Collaboration.

3. How do scientists calculate the mass of a supermassive black hole?

The research involves looking at the motions of stars in the centers of galaxies. These motions imply a dark, massive body whose mass can be computed from the speeds of the stars. The matter that falls into a black hole adds to the mass of the black hole. Its gravity doesn't disappear from the universe.

Image above: This animation illustrates the activity surrounding a black hole. While the matter that has passed the black hole's event horizon can't be seen, material swirling outside this threshold is accelerated to millions of degrees and radiates in X-rays. Image credits: CXC/A.Hobart.

4. Is it possible for a black hole to "eat" an entire galaxy?

No. There is no way a black hole would eat an entire galaxy. The gravitational reach of supermassive black holes contained in the middle of galaxies is large, but not nearly large enough for eating the whole galaxy.

Image above: This illustration shows a glowing stream of material from a star disrupted as it was being devoured by a supermassive black hole. The black hole is surrounded by a ring of dust. When a star passes close enough to be swallowed by a black hole, the stellar material is stretched and compressed as it is pulled in, releasing an enormous amount of energy. Image credits: NASA/JPL-Caltech.

5. What would happen if you fell into a black hole?

It certainly wouldn't be good! But what we know about the interior of black holes comes from Albert Einstein's General Theory of Relativity.

For black holes, distant observers will only see regions outside the event horizon, but individual observers falling into the black hole would experience quite another "reality." If you got into the event horizon, your perception of space and time would entirely change. At the same time, the immense gravity of the black hole would compress you horizontally and stretch you vertically like a noodle, which is why scientists call this phenomenon (no joke) "spaghettification."

Fortunately, this has never happened to anyone — black holes are too far away to pull in any matter from our solar system. But scientists have observed black holes ripping stars apart, a process that releases a tremendous amount of energy.

Image above: NASA’s Chandra X-ray observatory detected record-breaking wind speeds coming from a disk around a black hole. This artist's impression shows how the strong gravity of the black hole, on the left, is pulling gas away from a companion star on the right. This gas forms a disk of hot gas around the black hole, and the wind is driven off this disk at 20 million mph, or about 3% the speed of light. Image credits: NASA/CXC/M.Weiss.

6. What if the Sun turned into a black hole?

The Sun will never turn into a black hole because it is not massive enough to explode. Instead, the Sun will become a dense stellar remnant called a white dwarf.

But if, hypothetically, the Sun suddenly became a black hole with the same mass as it has today, this would not affect the orbits of the planets, because its gravitational influence on the solar system would be the same. So, Earth would continue to revolve around the Sun without getting pulled in — although the lack of sunlight would be disastrous for life on Earth.

Image above: The central region of our galaxy, the Milky Way, contains an exotic collection of objects, including a supermassive black hole, called Sagittarius A*, weighing about 4 million times the mass of the Sun, clouds of gas at temperatures of millions of degrees, neutron stars and white dwarf stars tearing material from companion stars and beautiful tendrils of radio emission. The region around Sagittarius A* is shown in this composite image with Chandra data (green and blue) combined with radio data (red) from the MeerKAT telescope in South Africa, which will eventually become part of the Square Kilometer Array (SKA). Image credits: X-Ray: NASA/CXC/UMass/D. Wang et al.; Radio: SARAO/MeerKAT.

7. Have black holes had any influence on our planet?

Stellar-mass black holes are left behind when a massive star explodes. These explosions distribute elements such as carbon, nitrogen and oxygen that are necessary for life into space. Mergers between two neutron stars, two black holes, or a neutron star and black hole, similarly spread heavy elements around that may someday become part of new planets. The shock waves from stellar explosions may also trigger the formation of new stars and new solar systems. So, in some sense, we owe our existence on Earth to long-ago explosions and collision events that formed black holes.

On a larger scale, most galaxies seem to have supermassive black holes at their centers. The connection between the formation of these supermassive black holes and the formation of galaxies is still not understood. It is possible that a black hole could have played a role in the formation of our Milky Way galaxy. But this chicken-and-egg problem — that is, which came first, the galaxy or the black hole? — is one of the great puzzles of our universe.

Image above: This artist's concept shows the most distant supermassive black hole ever discovered. It is part of a quasar from just 690 million years after the Big Bang. Image credits: Robin Dienel/Carnegie Institution for Science.

8. What is the most distant black hole ever seen?

The most distant black hole ever detected is located in a galaxy about 13.1 billion light-years from Earth. (The age of the universe is currently estimated to be about 13.8 billion years, so this means this black hole existed about 690 million years after the Big Bang.)

This supermassive black hole is what astronomers call a “quasar,” where large quantities of gas are pouring into the black hole so rapidly that the energy output is a thousand times greater than that of the galaxy itself. Its extreme brightness is how astronomers can detect it at such great distances.

Image above: The central region of this image contains the highest concentration of supermassive black holes ever seen and about a billion over the entire sky. Made with over 7 million seconds of Chandra observing time, this 2017 image is part of the Chandra Deep Field-South. With its unprecedented look at the early universe in X-rays, it offers astronomers a look at the growth of black holes over billions of years starting soon after the Big Bang. In this image, low, medium and high-energy X-rays that Chandra detects are shown as red, green, and blue respectively. Image credits: NASA/CXC/Penn State/B.Luo et al.

9. If nothing can escape from a black hole, then won't the whole universe eventually be swallowed up?

The universe is a big place. In particular, the size of a region where a particular black hole has significant gravitational influence is quite limited compared to the size of a galaxy. This applies even to supermassive black holes like the one found in the middle of the Milky Way. This black hole has probably already "eaten" most or all of the stars that formed nearby, and stars further out are mostly safe from being pulled in. Since this black hole already weighs a few million times the mass of the Sun, there will only be small increases in its mass if it swallows a few more Sun-like stars. There is no danger of the Earth (located 26,000 light years away from the Milky Way's black hole) being pulled in.

Future galaxy collisions will cause black holes to grow in size, for example by merging of two black holes. But collisions won't happen indefinitely because the universe is big and because it's expanding, and so it's very unlikely that any sort of black hole runaway effect will occur.

Image above: In this illustration of a black hole and its surrounding disk, gas spiraling toward the black hole piles up just outside it, creating a traffic jam. The traffic jam is closer in for smaller black holes, so X-rays are emitted on a shorter timescale. Image credit: NASA.

10. Can black holes get smaller?

Yes. The late physicist Stephen Hawking proposed that while black holes get bigger by eating material, they also slowly shrink because they are losing tiny amounts of energy called "Hawking radiation."

Hawking radiation occurs because empty space, or the vacuum, is not really empty. It is actually a sea of particles continually popping into and out of existence. Hawking showed that if a pair of such particles is created near a black hole, there is a chance that one of them will be pulled into the black hole before it is destroyed. In this event, its partner will escape into space. The energy for this comes from the black hole, so the black hole slowly loses energy, and mass, by this process.

Hawking radiation

Eventually, in theory, black holes will evaporate through Hawking radiation. But it would take much longer than the entire age of the universe for most black holes we know about to significantly evaporate. Black holes, even the ones around a few times the mass of the Sun, will be around for a really, really long time!

Black Holes, Neutron Stars, White Dwarfs, Space and Time

 Video above: A journey of simulations of Black Holes, Neutron Stars, White Dwarfs and Space and Time. Though, it is only a simulation, nothing more. Video Credit: Mentioned on video/ Music: Château - Rob Dougan.

Recent Discover -  Related article:

Discovery of a huge black hole

Black holes:

Images (mentioned), Animation, Video (mentioned), Text, Credits: NASA, By Elizabeth Landau.


Belated Thanksgiving Meal Ahead of Spacewalk and New Cargo Ships

ISS - Expedition 61 Mission patch.

November 29, 2019

The six-member Expedition 61 crew is relaxing today and enjoying a belated Thanksgiving meal after an intense week of biology research and spacewalk preparations. A Russian resupply ship also departed the International Space Station this morning as two more space freighters are poised to replenish the orbiting lab. The ISS Progress 73 cargo ship, loaded with trash, undocked from the Pirs Docking Compartment and was deorbited, burning up over the Pacific Ocean.

The four astronauts and two cosmonauts on the orbiting lab were off-duty today sharing a Thanksgiving meal together after working all day during the U.S. holiday. Most of the fixings that dress a turkey on a dining table on Earth were available aboard the station’s galley including cornbread, green beans, mashed potatoes and gravy.

Image above: NASA astronaut and spacewalker Andrew Morgan is pictured during the second spacewalk on Nov. 22, 2019, to repair the International Space Station’s cosmic particle detector, the Alpha Magnetic Spectrometer. Image Credit: NASA.

NASA astronauts Jessica Meir and Andrew Morgan were busy on Thursday finalizing research operations as they collected blood and cell samples from rodents. Commander Luca Parmitano and Flight Engineer Christina Koch also assisted the duo in Japan’s Kibo laboratory module. Scientists on Earth will observe the samples to gain insights into afflictions such as cancer and diabetes potentially designing advanced therapies for humans on Earth and in space.

Morgan and Parmitano now turn their attention to Monday’s spacewalk to continue the complex repair job on a cosmic particle detector on the station’s truss. They will be employing complex and innovative repair techniques never performed in space to replace a faulty cooling pump on the Alpha Magnetic Spectrometer. The spacewalkers will set their U.S. spacesuits to battery power at 6:50 a.m. EST on Monday signifying the start of their venture. NASA TV begins its live broadcast at 5:30 a.m.

International Space Station (ISS). Image Credit: NASA

Cosmonauts Alexander Skvortsov and Oleg Skripochka monitored the Progress 73 resupply ship as it undocked at 4:25 a.m. EST Friday completing its four-month mission at the station. It reentered the Earth’s atmosphere a few hours later and burned up safely over the south Pacific.

SpaceX is targeting Dec. 4 for the launch if its 19th commercial cargo mission to the space station. The Dragon space freighter would arrive on Dec. 7 delivering a variety of brand new research gear including Japan’s Hyperspectral Imager Suite, or HISUI.

Image above: SpaceX Falcon 9 rocket lifts off from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida at 6:01 p.m. EDT on July 25, 2019, carrying the Dragon spacecraft on the company's 18th Commercial Resupply Services mission to the International Space Station. Image Credits: NASA/Tony Gray & Kenny Allen.

Russia will follow SpaceX with the launch of its Progress 74 (74P) cargo craft on Dec. 6. The 74P will arrive on Dec. 9 for an automated docking to the Pirs docking compartment.

Related links:

Expedition 61:

Blood and cell samples:

Kibo laboratory module:

Alpha Magnetic Spectrometer (AMS):


Brand new research gear:

Hyperspectral Imager Suite (HISUI):

Pirs docking compartment:

Space Station Research and Technology:

International Space Station (ISS):

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


The CleanSpace One Selected by ESA

ClearSpace logo / EPFL - Space Center - eSpace logo.

Nov. 29, 2019

ClearSpace, a Swiss start-up, spin-off of the EPFL Space Center (eSpace), wants to clean up nearby Space (Low Earth Orbit), which is starting to be seriously cluttered with old, broken satellites and debris of all kinds.

The CleanSpace One Project. The space cleanup satellite will deploy a conical net to capture the small SwissCube satellite before destroying it in the atmosphere. It’s one of the solutions being tested for eliminating dangerous debris orbiting the Earth.

CleanSpace One: A giant Pac-Man to gobble up space debris

European Space Agency tapped ClearSpace to retrieve a rocket component, the company was focused on the CleanSpace-1 mission, shown here. Engineers were developing technology to capture a Swiss cubesat launched in 2009.

After an extensive review process, ESA selected ClearSpace from a field of about a dozen competitors including European aerospace prime contractors who went head-to-head with ClearSpace in the final round of the competition.

Swiss Cube

ClearSpace is a Spin-Off from the EPFL Space Center. The company founded by Luc Piguet, Muriel Richard & Catherine Johnson was born to host the design team for the CleanSpace One mission, out of the realization that the cost-effective in space removals is a critical building block of the future of space operations. The ClearSpace team unified around the CleanSpace One mission is focused on building a viable and affordable solution to remove failed satellites left in space and ensure the long-term sustainability of space operations... Cost-effective service to remove failed satellites and debris from space.

CleanSpace One is a pioneering mission to demonstrate the removal of a satellite in space. The CleanSpace One chaser will remove the first, the SwissCube.

What happens when satellites fail?

Satellites may fail during their operational life, causing ground communication with them to be degraded or severed entirely.

A lost satellite continues to orbit aimlessly in space and presents a risk of collision for other objects. Failures most often occur during the first few months a satellite is in space.

Why do we need space recycling right now?

Today, satellites are not built to be reused or recycled in space. According to the European Space Agency (ESA), it is estimated that there are more 8,100 metric tonnes of known man-made objects in space. The cost of launching a 1 kg object into space can vary between USD 3,000 and USD 50,000.

Despite the fact that the costs of launch are decreasing, it is becomingly increasingly logical and necessary to reuse or recycle structures or satellites in space. Our mission is one of the stepping stones necessary to pave the way for such services as in space re-use and recycling.

How do we proceed to capture orbital debris?

SwissCube is a non-cooperative satellite, meaning that it has been designed with no intention of retrieval once in orbit. It does not have a GPS or any sensor on board to facilitate either an approach or capture, and is likely to be tumbling out of control.

To illustrate this, imagine a cooperative rendez-vous in space being akin to two train wagons drawing closer to one another on invisible rails and seamlessly connecting; whereas a non-cooperative rendez-vous is akin to trying to catch a car that is tumbling across the motorway. The selection of the capture mechanism and the sensors for this operation required years of research and multiple iterations.

What is our solution to remove those debris?

Once captured, SwissCube will be secured close to the chaser’s body in order to ensure an effective and controlled re-entry of the entire system – the chaser and the target.

In a controlled re-entry, the area of the chaser and the target’s re-entry into Earth’s atmosphere is precisely chosen in order to eliminate any risk to human life or air traffic. The satellites decompose in the upper atmosphere due to heat generated as they re-enter the earth atmosphere at orbital speeds.

As they decompose, several break-up pieces follow their own trajectory, making a relatively long footprint. CleanSpace One is a microsatellite of relatively small size (like a small washing machine), and thus all of its break-up pieces will be burnt before touching the ground.

Related link & articles:


EPFL Swiss Space Center:

ESA Clean Space Progamme:

ClearSpace, a public interest undertaking for our cognosphere

Cleaning up Earth's orbit: A Swiss satellite tackles space debris

Images, Video, Text, Credits: CleanSpace/Kerbal Space Program/ESA/ID&Sense/ONiRiXEL/EPFL/ Aerospace/Roland Berga.

Best regards,

Space Station Science Highlights: Week of November 25, 2019

ISS - Expedition 61 Mission patch.

Nov. 29, 2019

Current scientific research conducted aboard the International Space Station includes investigations on maintaining human health in space, the body’s circatidal cycle and growing moss in microgravity. Crew members prepared for the third in a series of spacewalks to repair the Alpha Magnetic Spectrometer (AMS-02), scheduled to be conducted by Luca Parmitano of the ESA (European Space Agency) and NASA’s Andrew Morgan on Dec. 2. In addition, the crew made ready for the arrival of additional scientific experiments aboard the 19th SpaceX Commercial Resupply Services (CRS-19), scheduled to blast off from Cape Canaveral Air Force Station, Florida, on Dec. 4, 2019.

Image above: NASA astronaut Christina Koch and ROSCOSMOS cosmonaut Oleg Skripochka assisted NASA astronaut Andrew Morgan and ESA astronaut Luca Parmitano with their second spacewalk to repair the Alpha Magnetic Spectrometer. Image Credit: NASA.

The space station is now in its 20th year of continuous human presence. Learning to live and work in space is one of the biggest challenges of long-duration spaceflight, and experience gained on the space station supports Artemis, NASA’s program to go forward to the Moon and on to Mars.

Here are details on some of the science under way on the orbiting lab:

Measuring how the body adapts to space

Standard Measures captures an ongoing, optimized set of measures from crew members in order to characterize how their bodies adapt to living in space. Ground teams perform analyses for metabolic and chemistry panels, immune function, microbiome, and other measures to create a repository of the data. This repository enables high-level monitoring of the effectiveness of countermeasures and more meaningful interpretation of health and performance outcomes. The investigation also supports future research on planetary missions. The crew performed pre-sleep questionnaire data collection.

Testing microgravity’s effects on the 12-hour body clock

Image above: This image taken from the space station shows the Mediterranean Sea looking toward the Gulf of Suez. Scientists use images of Earth such as this one for research in a variety of fields. Image Credit: NASA.

Throughout the week, crew members performed Rodent Research-14 science sessions. This investigation uses mice to examine the effects of microgravity on the body’s circatidal rhythm or sleep/wake cycle on a cellular and key organ level. The body’s 12-hour clock is an important mechanism for controlling stress-responsive pathways. The space station makes it possible to expose cellular systems in mice to the stress of microgravity and study both cellular adaptation and organismal behavior responses to that stress.

Tiny plants, big potential

Image above: These Mizuna mustard greens growing aboard the International Space Station support development of food production in space agriculture to provide fresh food for crews on deep space missions. The Veg-04B investigation focuses on the effects of red-to-blue lighting on the plants. Image Credit: NASA.

The Japan Aerospace Exploration Agency (JAXA) Space Moss investigation grows mosses aboard the space station, and simultaneously on Earth, to determine how microgravity affects their growth, development, gene expression, photosynthetic activity and other features. Tiny plants without roots, mosses grow in a very small area, which represents an advantage for their potential use on long space voyages and future bases on the Moon or Mars. Crew members prepped the Plant Observation Dishes, which incubate for one, two and three days and then are placed in the JAXA Fluorescence Microscope for observation. Teams on the ground control all observations and downlink image data.

Other investigations on which the crew performed work:

- Analog-1 tests operating an exploration rover on Moon-like terrain on Earth from the space station. It is part of the METERON project, an ESA (European Space Agency) initiative to help prepare for human-robotic exploration on future missions.

- Food Acceptability examines changes in the appeal of food aboard the space station during long-duration missions. “Menu fatigue” from repeatedly consuming a limited choice of foods may contribute to the loss of body mass often experienced by crew members, potentially affecting astronaut health, especially as mission length increases.

- Veg-04B, part of a phased research project to address the need for fresh food production in space, focuses on the effects of light quality and fertilizer on a leafy crop, Mizuna mustard greens. The final harvest for this investigation occurred on Thanksgiving Day, Nov. 28.

- NutrISS, an investigation by the Italian Space Agency (ASI), assesses the body composition of crew members during spaceflight using a device that measures long-term energy balance modification over time. Adjusting diet to maintain a near-neutral energy balance and/or increasing protein intake may limit microgravity-induced bone and muscle loss.

Space to Ground: Keeping it Cool: 11/29/2019

Related links:

Expedition 61:

Alpha Magnetic Spectrometer (AMS-02):


Standard Measures:

Rodent Research-14:

Space Moss:

Spot the Station:

Space Station Research and Technology:

International Space Station (ISS):

Images (mentioned), Video (NASA), Text, Credits: NASA/Michael Johnson/John Love, Lead Increment Scientist Expedition 61.

Best regards,

Black Hole Nurtures Baby Stars a Million Light-Years Away

NASA - Chandra X-ray Observatory patch.

Nov. 29, 2019

Black holes are famous for ripping objects apart, including stars. But now, astronomers have uncovered a black hole that may have sparked the births of stars over a mind-boggling distance, and across multiple galaxies.

If confirmed, this discovery, made with NASA’s Chandra X-ray Observatory and other telescopes, would represent the widest reach ever seen for a black hole acting as a stellar kick-starter. The black hole seems to have enhanced star formation more than one million light-years away. (One light year is equal to 6 trillion miles.)

“This is the first time we’ve seen a single black hole boost star birth in more than one galaxy at a time,” said Roberto Gilli of the National Institute of Astrophysics (INAF) in Bologna, Italy, lead author of the study describing the discovery. “It’s amazing to think one galaxy’s black hole can have a say in what happens in other galaxies millions of trillions of miles away.”

A black hole is an extremely dense object from which no light can escape. The black hole's immense gravity pulls in surrounding gas and dust, but particles from a small amount of that material can also get catapulted away instead at nearly the speed of light. These fast-moving particles form two narrow beams or "jets" near the poles of the black hole.

The supermassive black hole scientists observed in the new study is located in the center of a galaxy about 9.9 billion light-years from Earth. This galaxy has at least seven neighboring galaxies, according to observations with the European Southern Observatory's Very Large Telescope (VLT) and the Large Binocular Telescope (LBT).

Using the National Science Foundation's Karl Jansky Very Large Array, scientists had previously detected radio-wave emission from a jet of high-energy particles that is about a million light-years long. The jet can be traced back to the supermassive black hole, which Chandra detected as a powerful source of X-rays produced by hot gas swirling around the black hole. Gilli and colleagues also detected a diffuse cloud of X-ray emission surrounding one end of the radio jet. This X-ray emission is most likely from a gigantic bubble of hot gas heated by the interaction of the energetic particles in the radio jet with surrounding matter.

As the hot bubble expanded and swept through four neighboring galaxies, it could have created a shock wave that compressed cool gas in the galaxies, causing stars to form.  All four galaxies are approximately the same distance, about 400,000 light years, from the center of the bubble. The authors estimate that the star formation rate is between about two to five times higher than typical galaxies with similar masses and distance from Earth.

Chandra X-ray Observatory

“The story of King Midas talks of his magic touch that can turn metal into gold,” said co-author Marco Mignoli, also of INAF in Bologna, Italy. “Here we have a case of a black hole that helped turn gas into stars, and its reach is intergalactic.”

Astronomers have seen many cases where a black hole affects its surroundings through “negative feedback” – in other words, curtailing the formation of new stars. This can occur when the black hole's jets inject so much energy into the hot gas of a galaxy, or galaxy cluster, that the gas can't cool down enough to make large numbers of stars.

In this newly discovered collection of galaxies, astronomers have found a less common example of “positive feedback,” where the black hole’s effects increase star formation. Moreover, when astronomers previously encountered positive feedback, it either involved increases in the star formation rate of 30% or less, or it occurred over scales of only about 20,000 to 50,000 light years on a nearby companion galaxy. Whether the feedback is positive or negative depends on a delicate balance between the heating rate and cooling rate of a cloud. That is because clouds that are initially cooler when hit by a shock wave are more prone to experience positive feedback, and form more stars.

“Black holes have a well-earned reputation for being powerful and deadly, but not always," said co-author Alessandro Peca, formerly at INAF in Bologna and now a Ph.D. student at the University of Miami. “This is a prime example that they sometimes defy that stereotype and can be nurturing instead.”

The researchers used a total of six days of Chandra observing time spread out over five months.

"It's only because of this very deep observation that we saw the hot gas bubble produced by the black hole," said co-author Colin Norman of the Johns Hopkins University in Baltimore, Maryland. "By targeting objects similar to this one, we may discover that positive feedback is very common in the formation of groups and clusters of galaxies."

A paper describing these results has been published in the most recent issue of the journal “Astronomy and Astrophysics” and is available online:

NASA's Marshall Space Flight Center manages the Chandra program. The Smithsonian Astrophysical Observatory's Chandra X-ray Center controls science and flight operations from Cambridge and Burlington, Massachusetts.

Read more from NASA's Chandra X-ray Observatory:

For more Chandra images, multimedia and related materials, visit:

Image, Animation, Text,  Credits: X-ray: NASA/CXC/INAF/R. Gilli et al.; Radio NRAO/VLA; Optical: NASA/STScI/NASA/Lee Mohon.


jeudi 28 novembre 2019

Space is key to monitoring ocean acidification

ESA - SMOS Mission logo.

Nov. 28, 2019

This week, the UN World Meteorological Organization announced that concentrations of greenhouse gases in the atmosphere have reached yet another high. This ongoing trend is not only heating up the planet, but also affecting the chemical composition of our oceans. Until recently, it has been difficult to monitor ‘ocean acidification’, but scientists are exploring new ways to combine information from different sources, including from ESA’s SMOS mission, to shed new light on this major environmental concern.

SMOS in orbit

As the amount of atmospheric carbon dioxide continues to rise, our oceans are playing an increasingly important role in absorbing some of this excess. In fact, it was reported recently that the global ocean annually draws down about a third of the carbon released into the atmosphere by human activities.

While this long-term absorption means that the planet isn’t as hot as it would be otherwise, the process is causing the ocean’s carbonate chemistry to change: seawater is becoming less alkaline – a process commonly known as ocean acidification.

In turn, this is altering bio-geo-chemical cycles and having a detrimental effect on ocean life.

Sea butterfly

Pteropods, tiny marine snails known as ‘sea butterflies’, are an example of a particularly vulnerable species, where shell damage has been observed already in portions of the Arctic and Southern Ocean. Pteropods are hugely important in the polar food web, serving as a key food source for important fisheries species, such as salmon and cod.

With the damaging effects of ocean acidification already becoming evident, it is vital that the current shift in pH is monitored closely. Covering over 70% of Earth’s surface, ocean wellbeing also has a bearing on the health and balance of the rest of the planet.

Recent advances in data capture have included state-of-the-art pH instruments on ships and floats, but we can gain a global view by taking measurements from space. However, at present there aren’t any spaceborne sensors that can measure pH directly.

The use of satellites has not yet been thoroughly explored as an option for routinely observing ocean surface chemistry, but a paper published recently in Remote Sensing of Environment describes how scientists are testing new ways of merging different datasets to estimate and ultimately monitor ocean acidification.

The changing chemistry of our oceans

The animation above illustrates how marine chemistry can be studied using four parameters: partial pressure of carbon dioxide in the water, dissolved inorganic carbon, alkalinity and pH. Any two of these parameters, along with measurements of salinity and temperature, allow us to understand the complete carbon chemistry of the ocean.

ESA’s SMOS mission and NASA’s Aquarius mission, which both provide information on ocean salinity, have been key to the research. The work was made possible through access to thousands of collated and quality controlled measurements collected by the international community from ships and research campaigns.

Lead author, Peter Land, from the Plymouth Marine Laboratory, UK, said, “The advent of salinity measurements from space, pioneered by SMOS, has opened up the exciting possibility of continuously monitoring the ocean carbonate chemistry, identifying areas most at risk, and helping us to understand this threat to our oceans.”

Jamie Shutler, from the University of Exeter, UK, added, “We were able to carry out this research through ESA’s Earth Observation Science for Society programme.  We hope that the view from space can be used to help understand how ocean acidification is likely affecting our fisheries and marine ecosystems, on which we rely for food, health and tourism.”

This work is now being continued within the ESA's Ocean SODA project as part of the ESA Ocean Science Cluster.

Related links:

Observing the Earth:

UN World Meteorological Organization statement:

Remote Sensing of Environment:


Images, Video, Text, Credits: ESA/AOES Medialab/NOAA.


CASC - Long March-4C launches Gaofen-12

CASC - China Aerospace Science and Technology Corporation logo.

Nov. 28, 2019

Long March-4C launches Gaofen-12

A Long March-4C launch vehicle launched the Gaofen-12 Earth observation satellite from the Taiyuan Satellite Launch Center, Shanxi Province, northern China, on 27 November 2019, at 23:52 UTC (28 November, at 07:52 local time).

The satellite, Gaofen-12, launched aboard a Long March-4C carrier rocket, entered the planned orbit successfully. It was the 320th flight mission of the Long March carrier rocket series.

Long March-4C launches Gaofen-12

Gaofen-12 (高分十二) is a microwave remote sensing satellite capable of providing photographs with a resolution of better than a meter. According to official sources, it will be used in land surveys, urban planning, road network design, crop yield estimate, disaster relief and can also serve projects along the Belt and Road.


Both the satellite and the carrier rocket were developed by the Shanghai Academy of Spaceflight Technology under the China Aerospace Science and Technology Corporation.

China Aerospace Science and Technology Corporation (CASC):

Images, Video, Text, Credits: China Central Television (CCTV)/SciNews/VCG Photo/Xinhua News Agency.


mercredi 27 novembre 2019

The plot thickens for a hypothetical “X17” particle

CERN - European Organization for Nuclear Research logo.

27 November, 2019

Additional evidence of an unknown particle from a Hungarian lab gives a new impetus to NA64 searches

The NA64 experiment at CERN (Image: CERN)

Fresh evidence of an unknown particle that could carry a fifth force of nature gives the NA64 collaboration at CERN a new incentive to continue searches.

In 2015, a team of scientists spotted an unexpected glitch, or “anomaly”, in a nuclear transition that could be explained by the production of an unknown particle. About a year later, theorists suggested that the new particle could be evidence of a new fundamental force of nature, in addition to electromagnetism, gravity and the strong and weak forces. The findings caught worldwide attention and prompted, among other studies, a direct search for the particle by the NA64 collaboration at CERN.

A new paper from the same team, led by Attila Krasznahorkay at the Atomki institute in Hungary, now reports another anomaly, in a similar nuclear transition, that could also be explained by the same hypothetical particle.

The first anomaly spotted by Krasznahorkay’s team was seen in a transition of beryllium-8 nuclei. This transition emits a high-energy virtual photon that transforms into an electron and its antimatter counterpart, a positron. Examining the number of electron–positron pairs at different angles of separation, the researchers found an unexpected surplus of pairs at a separation angle of about 140º. In contrast, theory predicts that the number of pairs decreases with increasing separation angle, with no excess at a particular angle. Krasznahorkay and colleagues reasoned that the excess could be interpreted by the production of a new particle with a mass of about 17 million electronvolts (MeV), the “X17” particle, which would transform into an electron–positron pair.

The latest anomaly reported by Krasznahorkay’s team, in a paper that has yet to be peer-reviewed, is also in the form of an excess of electron–positron pairs, but this time the excess is from a transition of helium-4 nuclei. “In this case, the excess occurs at an angle 115º but it can also be interpreted by the production of a particle with a mass of about 17 MeV,” explained Krasznahorkay. “The result lends support to our previous result and the possible existence of a new elementary particle,” he adds.

Sergei Gninenko, spokesperson for the NA64 collaboration at CERN, which has not found signs of X17 in its direct search, says: “The Atomki anomalies could be due to an experimental effect, a nuclear physics effect or something completely new such as a new particle. To test the hypothesis that they are caused by a new particle, both a detailed theoretical analysis of the compatibility between the beryllium-8 and the helium-4 results as well as independent experimental confirmation is crucial.”

The NA64 collaboration searches for X17 by firing a beam of tens of billions of electrons from the Super Proton Synchrotron accelerator onto a fixed target. If X17 did exist, the interactions between the electrons and nuclei in the target would sometimes produce this particle, which would then transform into an electron–positron pair. The collaboration has so far found no indication that such events took place, but its datasets allowed them to exclude part of the possible values for the strength of the interaction between X17 and an electron. The team is now upgrading their detector for the next round of searches, which are expected to be more challenging but at the same time more exciting, says Gninenko.

Among other experiments that could also hunt for X17 in direct searches are the LHCb experiment and the recently approved FASER experiment, both at CERN. Jesse Thaler, a theoretical physicist from the Massachusetts Institute of Technology, says: “By 2023, the LHCb experiment should be able to make a definitive measurement to confirm or refute the interpretation of the Atomki anomalies as arising from a new fundamental force. In the meantime, experiments such as NA64 can continue to chip away at the possible values for the hypothetical particle’s properties, and every new analysis brings with it the possibility (however remote) of discovery.”


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 links:

The latest anomaly reported by Krasznahorkay’s team:

Super Proton Synchrotron (SPS):

LHCb experiment:

FASER experiment:


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

Image (mentioned), Text, Credits: CERN/Ana Lopes.


Discovery of a huge black hole

Astrophysics logo.

Nov. 27, 2019

Scientists have discovered a huge black hole in the Milky Way.

Image above: The Milky Way, of which our solar system is a part, contains some 100 million stellar black holes. (Photo: archive / photo illustration).

The black hole discovered by scientists is so important that it challenges existing theories of star evolution, according to the researchers.

The LB-1, a stellar black hole located 15'000 light-years from Earth, which the journal "Nature" describes for the first time, has a mass 70 times greater than that of the Sun.

"Black holes of such a mass should not even exist in our galaxy, according to most current theories of stellar evolution," said Liu Jifeng, a professor at the Chinese National Astronomical Observatory, head of the team of researchers who studied LB-1.

"We thought that very massive stars, whose chemical composition is typical of our galaxy, had to spill most of their gas into powerful stellar winds as they near the end of their lives," and therefore not leave behind they have such a massive black hole, said Liu Jifeng.

Abundance of black holes

While the Milky Way, of which our solar system is a part, contains some 100 million stellar black holes, LB-1 has a mass twice as large as scientists thought possible. "Now theorists will have to take up the challenge of explaining how it was formed," said Liu Jifeng in a statement.

Super massive black holes in the center of galaxies. (Illustration image)

For researcher David Reitze of the California Institute of Technology, who has not been involved in LB-1 work, astronomers "are just beginning to understand the abundance of black holes and the mechanisms of their formation." "In general, stellar black holes appear after supernova explosions, but according to current theories, they have a mass less than 50 to 60 times that of the sun," he said. The larger mass of LB-1 would therefore indicate that the black hole could not have been produced by a supernova.

"That means we're dealing with a new kind of black hole, created by another physical mechanism," insisted David Reitze.

"Nothing less than fantastic"

The LB-1 was discovered using the Chinese telescope LAMOST (Large Field Optical Fiber Spectroscopic Telescope) by an international team of Chinese, American and European scientists. Scientists first used this telescope to search for stars in orbit around invisible objects, a sign that the star could be orbiting a black hole.

Other images of the world's largest optical telescopes - the Spanish telescope Gran Telescopio Canarias and the Keck I telescope in the United States - have confirmed the size of the LB-1. The National Astronomical Observatory of China has described it in a statement of "nothing less than fantastic".

Related links:

Chinese telescope LAMOST:

Gran Telescopio Canarias:

W. M. Keck Observatory:

Images, Text, Credits: ATS/LAMOST/Gran Telescopio Canarias/Keck Observatory/ Aerospace/Roland Berga.

Best regards,

ISRO - PSLV-C47 / Cartosat-3 Mission Success

ISRO -  Indian Space Research Organisation logo.

Nov. 27, 2019

PSLV-C47 / Cartosat-3 Liftoff

India’s PSLV-C47 successfully launched Cartosat-3 and 13 commercial nanosatellites from Satish Dhawan Space Centre (SDSC) SHAR, Sriharikota.

PSLV-XL launches Cartosat-3

For ISRO’s PSLV-C47 mission, a Polar Satellite Launch Vehicle (PSLV) in “XL” configuration (with 6 solid strap-on motors) launched Cartosat-3 and 13 commercial nanosatellites into Sun Synchronous orbit from the Second Launch Pad (SLP) of Satish Dhawan Space Centre (SDSC) SHAR, Sriharikota, on 27 November 2019, at 03:58 UTC (09:28 IST). The Cartosat-3 satellite is a third generation advanced satellite wih high resolution imaging capabilities.

PSLV-C47 lifted-off at 09:28Hrs (IST) on November 27, 2019 from the Second Launch Pad of SDSC SHAR, Sriharikota. PSLV-C46 was the 74th launch vehicle mission from SDSC SHAR, Sriharikota. This is the 21st flight of PSLV in 'XL' configuration (with 6 solid strap-on motors).


About 17 minutes and 38 seconds after lift-off, Cartosat-3 was injected into an orbit of 509 km at an inclination of 97.5 degree to the equator.

Cartosat-3 satellite is a third generation agile advanced satellite having high resolution imaging capability.

13 Commercial Nanosatellites from USA were also successfully injected into designated orbit. These satellites were launched under commercial arrangement with NewSpace India Limited (NSIL), the commercial arm of Indian Space Research Organisation (ISRO).

Indian Space Research Organisation (ISRO):

Images, Video, Text, Credits: Indian Space Research Organisation (ISRO)/SciNews/Günter Space Page.


Thanksgiving Bringing Harvest, Spacewalk Preps and Disease Research

ISS - Expedition 61 Mission patch.

November 27, 2019

The Expedition 61 crew is heading into Thanksgiving with more blood and cell research to improve human health. There will also be a harvest on the U.S. holiday as spacewalk preparations continue.

Rodents living aboard the International Space Station are being observed this week with their blood and cell samples being collected and stowed in science freezers. Doctors are exploring how microgravity affects the cellular level systems of mice to gain insights into afflictions such as cancer and diabetes. Results may inform the development of advanced therapies for Earth-bound and space-caused ailments.

Image above: Astronaut and spacewalker Luca Parmitano of ESA (European Space Agency) takes a photograph with a camera protected from the hazards of microgravity by shielding. Image Credit: NASA.

NASA astronauts Jessica Meir and Christina Koch are conducting the advanced biomedical research in Japan’s Kibo laboratory module. Flight Engineer Andrew Morgan and Commander Luca Parmitano have been assisting the duo while also practicing repair techniques for the next spacewalk on Monday.

Morgan and Parmitano will set their U.S. spacesuits to battery power at 6:50 a.m. EST on Monday signifying the start of their spacewalk. They will use new tools and techniques never performed in space for the intricate task of replacing the Alpha Magnetic Spectrometer’s thermal control system. NASA TV begins its live broadcast at 5:30 a.m.

Image above: Right now, half of the crew members on board the International Space Station are American astronauts who are getting ready to celebrate Thanksgiving, and they have a message for us. View the video to see what the holiday means to NASA’s Christina Koch, Jessica Meir and Andrew Morgan and get a look at what Thanksgiving in space will be like in 2019: Expedition 61 Thanksgiving message. Image Credit: NASA.

The crew will be busy on Thanksgiving with more disease therapy studies and a space crop harvest as well. Koch and Meir will be harvesting Mizuna mustard greens and sharing the leaves with the crew for a taste test on Thursday. The rest of the crop will be packed in a lab freezer for later analysis.

Cosmonauts Alexander Skvortsov and Oleg Skripochka are readying the Progress 73 resupply ship for its undocking on Friday at 5:25 a.m. This will clear the Pirs docking compartment for the Progress 74 cargo craft to arrive Dec. 9 after its launch on Dec. 6. Skvortsov also investigated space cardiology today while Skripochka explored using acoustics to locate micrometeoroid impacts on the station.

Related links:

Expedition 61:

Expedition 61 Thanksgiving message:

Kibo laboratory module:


Mizuna mustard greens:

Progress 73:

Pirs docking compartment:

Space cardiology:

Micrometeoroid impacts:

Space Station Research and Technology:

International Space Station (ISS):

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

Best regards,