Plant potatoes on the Moon? Why not!

Space Biology & Exobiology logo.

Oct. 3, 2018

What would we eat if we were to colonize Mars or the Moon one day? Scientists from the University of Zurich and the University of Lucerne are trying to answer this question.

An artist concept depicts a greenhouse on the surface of Mars

The moon is a celestial star very sad. It is composed of a thick layer of lunar dust, called lunar regolith in scientific jargon. There are few nutrients found in the soil. A team of Swiss researchers nevertheless wanted to know if it was possible to grow plants there, reports Friday "20 Minuten".

The group of scientists, led by Lorenzo Borghi from the University of Zurich and Marcel Egli from the University of Lucerne, wondered if it was possible to grow potatoes there. And if that were to be the case, how to go about it? "In order to grow tomatoes or potatoes on the moon, we need to promote the formation of mycorrhizae," says Borghi. The term mycorrhiza is used to refer to the symbiotic association between a plant and a mushroom.

It's gravity that's a problem

This symbiosis serves both the plant and the mushroom, says the researcher: "Some parts of the mushroom supply the roots of the plant in water, phosphates, nitrogen and trace elements from the soil. On the other hand, mushrooms take advantage of the sugars and fats produced by the plant. "

Swiss potato on the Moon, a small step for a potato, a giant step for space nutrition!

What is presently problematic is not only the soil poor in nutrients of the moon, but also the lower gravity which reigns there. That's why the researchers did a test with petunias and mycorrhizal fungi, in an environment simulating weightlessness (microgravity). Experience has shown that microgravity does have an impact on mycorrhizal formation. Fungi have not managed to "grab" enough of the plant's roots. Result: the symbiosis is weakened.

Vegetable hormone

Mycorrhizae fungi: The plant's secondary root system

The solution to this problem could however be called strigolactone, a plant hormone. The researchers have indeed treated the plants with this hormone ... with success! The operation promoted the formation of mycorrhizae. "These results are a promising foundation, which suggests that we can someday grow plants in space."

Related links:

University of Zurich: https://www.uzh.ch/en.html

University of Lucerne: https://www.unilu.ch/en/

Images, Animation, Text, Credits: GWA/NASA/Orbiter.ch Aerospace/Roland Berga.

Best regards, Orbiter.ch

New antimatter gravity experiments begin at CERN

CERN - European Organization for Nuclear Research logo.

3 Nov 2018

Image above: The ALPHA-g experiment being installed in CERN’s Antiproton Decelerator hall. (Image: CERN).

We learn it at high school: release two objects of different mass in the absence of friction forces and they fall down at the same rate in Earth’s gravity. What we haven’t learned, because it hasn’t been directly measured in experiments, is whether antimatter falls down at the same rate as ordinary matter or if it might behave differently. Two new experiments at CERN, ALPHA-g and GBAR, have now started their journey towards answering this question.

ALPHA-g is very similar to the ALPHA experiment, which makes neutral antihydrogen atoms by taking antiprotons from the Antiproton Decelerator (AD) and binding them with positrons from a sodium-22 source. ALPHA then confines the resulting neutral antihydrogen atoms in a magnetic trap and shines laser light or microwaves onto them to measure their internal structure. The ALPHA-g experiment has the same type of apparatus for making and trapping antiatoms, except that it is oriented vertically. With this vertical set-up, researchers can precisely measure the vertical positions at which the antihydrogen atoms annihilate with normal matter once they switch off the trap’s magnetic field and the atoms are under the sole influence of gravity. The values of these positions will allow them to measure the effect of gravity on the antiatoms.

The GBAR experiment, also located in the AD hall, takes a different tack. It plans to use antiprotons supplied by the ELENA deceleration ring and positrons produced by a small linear accelerator to make antihydrogen ions, consisting of one antiproton and two positrons. Next, after trapping the antihydrogen ions and chilling them to an ultralow temperature (about 10 microkelvin), it will use laser light to strip them of one positron, turning them into neutral antiatoms. At this point, the neutral antiatoms will be released from the trap and allowed to fall from a height of 20 centimetres, during which the researchers will monitor their behaviour.

After months of round-the-clock work by researchers and engineers to put together the experiments, ALPHA-g and GBAR have received the first beams of antiprotons, marking the beginning of both experiments. ALPHA-g began taking beam on 30 October, after receiving the necessary safety approvals. ELENA sent its first beam to GBAR on 20 July, and since then the decelerator and GBAR researchers have been trying to perfect the delivery of the beam. The ALPHA-g and GBAR teams are now racing to commission their experiments before CERN’s accelerators shut down in a few weeks for a two-year period of maintenance work. Jeffrey Hangst, spokesperson of the ALPHA experiments, says: “We are hoping that we’ll get the chance to make the first gravity measurements with antimatter, but it’s a race against time”. Patrice Pérez, spokesperson of GBAR, says: “The GBAR experiment is using an entirely new apparatus and an antiproton beam still in its commissioning phase. We hope to produce antihydrogen this year and are working towards being ready to measure the gravitational effects on antimatter when the antiprotons are back in 2021”.

Introducing ALPHA-g, a new experiment to measure the effect of gravity on antimatter

Video above: Jeffrey Hangst at the Antiproton Decelerator hall, explaining the ALPHA-g set-up in the run-up to the start of the experiment. (Video: Jacques Fichet/CERN).

Another experiment at the AD hall, AEgIS, which has been in operation for several years, is also working towards measuring the effect of gravity on antihydrogen using yet another approach. Like GBAR, AEgIS is also hoping to produce its first antihydrogen atoms this year.

Discovering any difference between the behaviour of antimatter and matter in connection with gravity could point to a quantum theory of gravity and perhaps cast light on why the universe seems to be made of matter rather than antimatter.

Note:

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 22 Member States.

Related article:

Chasing a particle that is its own antiparticle:
https://orbiterchspacenews.blogspot.com/2018/11/chasing-particle-that-is-its-own.html

Related links:

ALPHA experiment: https://home.cern/about/experiments/alpha

Antiproton Decelerator (AD): https://home.cern/about/accelerators/antiproton-decelerator

ELENA deceleration ring: https://home.cern/about/updates/2016/11/new-ring-slow-down-antimatter

Linear accelerator: https://home.cern/tags/linear-accelerator

Antimatter: https://home.cern/topics/antimatter

For more information about European Organization for Nuclear Research (CERN), Visit: https://home.cern/

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

Best regards, Orbiter.ch

Experience High-Res Science in First 8K Footage from Space

ISS - International Space Station logo.

Nov. 2, 2018

First 8K Video from Space - Ultra HD

Video above: Science gets scaled up with the first 8K ultra high definition (UHD) video from the International Space Station. Get closer to the in-space experience and see how the international partnership-powered human spaceflight is improving lives on Earth, while enabling humanity to explore the universe. Video Credit: NASA.

Fans of science in space now can experience fast-moving footage in even higher definition as NASA and ESA (European Space Agency) deliver the first 8K ultra high definition (UHD) video of astronauts living, working and conducting research from the International Space Station. The same engineers who sent high-definition (HD) cameras, 3D cameras, and a camera capable of recording 4K footage to the space station now have delivered a new camera capable of recording images with four times the resolution than previously offered.

The Helium 8K camera by RED, a digital cinema company, is capable of shooting at resolutions ranging from conventional HDTV up to 8K, specifically 8192 x 4320 pixels. By comparison, the average HD consumer television displays up to 1920 x 1080 pixels of resolution, and digital cinemas typically project in resolutions of 2K to 4K.

“This new footage showcases the story of human spaceflight in more vivid detail than ever before,” said Dylan Mathis, communications manager for the International Space Station Program at NASA’s Johnson Space Center in Houston. “The world of camera technology continues to progress, and seeing our planet in high fidelity is always welcome. We're excited to see what imagery comes down in the future.”

Viewers can watch as crew members advance DNA sequencing in space with the BEST investigation, study dynamic forces between sediment particles with BCAT-CS, learn about genetic differences in space-grown and Earth-grown plants with Plant Habitat-1, observe low-speed water jets to improve combustion processes within engines with Atomization; and explore station facilities such as the MELFI, the Plant Habitat, the Life Support Rack, the JEM Airlock and the Canadarm2.

While the 4K camera brought beautiful footage of fluid behavior in the space station’s microgravity environment to the world, the new 8K video takes viewers through a variety of experiments and facilities aboard the orbiting outpost, which on Friday, Nov. 2 will celebrate the 18th anniversary of humans living continuously aboard and the 20th anniversary of the launch of the first two space station elements on Nov. 20 and Dec. 4, 1998, respectively. 

Delivered to the station in April aboard the 14th SpaceX cargo resupply mission through a Space Act Agreement between NASA and RED, this camera’s ability to record twice the pixels and at resolutions four times higher than the 4K camera brings science in orbit into the homes, laboratories and classrooms of everyone on Earth.

“We’re excited to embrace new technology that improves our ability to engage our audiences in space station research,” said David Brady, assistant program scientist for the International Space Station Program Science Office at Johnson. “Each improvement in imagery fidelity brings that person on Earth closer to the in-space experience, allowing them to see what human spaceflight is doing to improve their life, as well as enable humanity to explore the universe.”

The RED camera is the same brand used to record theatrical releases such as The Hobbit trilogy, Guardians of the Galaxy Volume 2, and television programs such as, Stranger Things, Maniac, and Lost in Space.

Image above: NASA astronaut Ricky Arnold does some filming on the International Space Station Oct. 3, 3018, with a Helium 8K camera, made by the digital cinema company RED. Image Credit: NASA.

Viewers can watch high-resolution footage from inside and outside the orbiting laboratory right on their computer screens. A screen capable of displaying 8K resolution is required for the full effect, but the imagery is shot at a higher fidelity and then down-converted, which results in higher-quality playback, even for viewers who do not have an 8K screen.   

Download the video in full resolution at: https://images.nasa.gov/details-First-8K-Video-from-Space.html

In addition to the new 8K video, NASA astronauts Andrew Feustel and Ricky Arnold and Russian space agency Roscosmos cosmonaut Oleg Artemyev recently took new images of the world’s unique orbital laboratory as they departed at the conclusion of their mission. The photos are available at: https://flic.kr/s/aHsmuLTSzb

Related links:

BEST: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7687

BCAT-CS: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7668

Plant Habitat-1: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=2032

Atomization: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=282

MELFI: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=56

Plant Habitat: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=2036

Life Support Rack: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=7751

JEM Airlock: https://www.youtube.com/watch?v=bNxZhrIrV78

Canadarm2: https://www.youtube.com/watch?v=dzE_i6h5NeI

Space Station Research and Technology: https://www.nasa.gov/mission_pages/station/research/index.html

International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html

Video (mentioned), Image (mentioned), Text, Credits: NASA/Karen Northon/Stephanie Schierholz/JSC/Dan Huot.

Best regards, Orbiter.ch

China launches first geostationary BeiDou-3 satellite

BeiDou Navigation Satellite System logo.

Nov. 2, 2018

Long March-3B carrying BeiDou-3 GEO-1 launch

A Long March-3B (Chang Zheng-3) rocket launched the first geostationary BeiDou-3 navigation satellite from the Xichang Satellite Launch Center, Sichuan Province, southwest China, on 1 November 2018, at 15:57 UTC (23:57 local time).

BeiDou-3 GEO-1 - the first geostationary BeiDou-3 satellite

BeiDou-3 GEO-1 is the 41st BeiDou navigation satellite and the first geostationary orbit satellite of the BeiDou-3 system. This is the 17th satellite for the BeiDou-3 system, with 18 BeiDou-3 satellites expected to be orbiting by the end of the year.

 BeiDou-3 GEO-1

The satellite will use its own engine to circularize its orbit over the equator in the coming weeks, settling into a position in geostationary orbit, where its speed will match the rate of Earth’s rotation, allowing the Beidou spacecraft to remain over the same geographic region.

Beidou Constellation

The Beidou network has provided regional navigation services over the Asia-Pacific since the end of 2012, and China plans to roll out a wider coverage zone stretching over Asia, Europe and most of Africa at the end of this year. Global service is planned around 2020 once the constellation contains more than 30 satellites.

For more information about China Aerospace Science and Technology Corporation (CASC), visit: http://english.spacechina.com/n16421/index.html

For more information about China National Space Administration (CNSA), visit: http://www.cnsa.gov.cn/

For more information about Beidou navigation system: http://www.beidou.gov.cn/

Images, Video, Text, Credits: CASC/CNSA/IGS/CCTV/SciNews.

Greetings, Orbiter.ch

Dramatic on-board video shows moment of Soyuz booster failure on October 11, 2018

ROSCOSMOS logo.

November 01, 2018

New video released by the Russian space agency Thursday shows the moment a Soyuz rocket ran into trouble around two minutes after liftoff with a two-man crew Oct. 11, when one of the vehicle’s four first stage boosters crashed into the Soyuz core stage.

Image above: The Soyuz MS-10 spacecraft launched Oct. 11, 2018, with Expedition 57 crew members Nick Hague of NASA and Alexey Ovchinin of Roscosmos. During the Soyuz spacecraft’s climb to orbit, an anomaly occurred, resulting in an abort downrange. The crew was quickly recovered in good condition. Image Credits: NASA/Roscosmos.

An on-board safety system immediately detected the malfunction, triggering an automatic abort with escape rockets that pushed the Soyuz MS-10 spacecraft with Russia cosmonaut Alexey Ovchinin and NASA astronaut Nick Hague safely away from the rocket.

The crew landed downrange on the steppe of Kazakhstan after the first use of the Soyuz crew escape system since 1983.

The video from a rear-facing camera on the Soyuz-FG rocket shows the kerosene-fueled launcher lifting off from the Baikonur Cosmodrome in Kazakhstan, followed by a sped-up video sequence during the rocket’s initial climb. The video then reverts to a real-time sequence before the separation of the four strap-on boosters from the core stage.

Dramatic on-board video shows moment of Soyuz booster failure

The boosters are supposed to separate simultaneously, but one of the units appears to cling to the center stage in the video, before colliding with the core section, causing the rocket to veer out of control.

Russian investigators announced Thursday that the Oct. 11 failure was caused by a “deformed” sensor in the booster separation system. Read more details in our full story on the investigation’s results.

Roscosmos. Press-conference on the findings of the State Committee investigation of the Soyuz failure of October 11, 2018: http://en.roscosmos.ru/20752/

Related articles:

Rocket Investigation Complete; Russia, Japan Announce Mission Updates:
https://orbiterchspacenews.blogspot.com/2018/11/rocket-investigation-complete-russia.html

Crew in Good Condition After Booster Failure:
https://orbiterchspacenews.blogspot.com/2018/10/crew-in-good-condition-after-booster.html

Soyuz MS-10 - Emergency landing after a failure:
https://orbiterchspacenews.blogspot.com/2018/10/soyuz-ms-10-emergency-landing-after.html

Related links:

Roscosmos investigator report: https://www.youtube.com/watch?v=PzLBGGsOOps&t=31s

Roscosmos statement: https://www.roscosmos.ru/25664/

Roscosmos: https://www.roscosmos.ru/

NASA: https://www.nasa.gov/

Image (mentioned), Video, Text, Credits: Roscosmos/NASA/Spaceflight Now.com/Stephen Clark.

Greetings, Orbiter.ch

Chasing a particle that is its own antiparticle

CERN - European Organization for Nuclear Research logo.

November 1, 2018

Neutrinos weigh almost nothing: you need at least 250 000 of them to outweigh a single electron. But what if their lightness could be explained by a mechanism that needs neutrinos to be their own antiparticles? The ATLAS collaboration at CERN is looking into this, using data from high-energy proton collisions collected at the Large Hadron Collider (LHC).

One way to explain neutrinos’ extreme lightness is the so-called seesaw mechanism, a popular extension of the Standard Model of particle physics. This mechanism involves pairing up the known light neutrinos with hypothetical heavy neutrinos. The heavier neutrino plays the part of a larger child on a seesaw, lifting the lighter neutrino to give it a small mass. But for this mechanism to work, both neutrinos need to be “Majorana” particles: particles that are indistinguishable from their antimatter counterparts.

The ATLAS experiment at CERN. (Image: Maximilien Brice/CERN)

Antimatter particles have the same mass as their corresponding matter particles but have the opposite electric charge. So, for example, an electron has a negative electric charge and its antiparticle, the positron, is positive. But neutrinos have no electric charge, opening up the possibility that they could be their own antiparticles. Finding heavy Majorana neutrinos could not only help explain neutrino mass, it could also lead to a better understanding of why matter is much more abundant in the universe than antimatter.

In an extended form of the seesaw model, these heavy Majorana neutrinos could potentially be light enough to be detected in LHC data. In a new paper, the ATLAS collaboration describes the results of its latest search for hints of these particles.

ATLAS looked for instances in which both a heavy Majorana neutrino and a “right-handed” W boson, another hypothetical particle, could appear. They used LHC data from collision events that produce two “jets” of particles plus a pair of energetic electrons or a pair of their heavier cousins, muons.

The researchers compared the observed number of such events with the number predicted by the Standard Model. They found no significant excess of events over the Standard Model expectation, indicating that no right-handed W bosons and heavy Majorana neutrinos took part in these collisions.

Large Hadron Collider (LHC). Animation Credit: CERN

However, the researchers were able to use their observations to excludepossible masses for these two particles. They excluded heavy Majorana neutrino masses up to about 3 TeV, for a right-handed W boson with a mass of 4.3 TeV. In addition, they explored for the first time the hypothesis that the Majorana neutrino is heavier than the right-handed W boson, placing a lower limit of 1.5 TeV on the mass of Majorana neutrinos. Further studies should be able to put tighter limits on the mass of heavy Majorana neutrinos in the hope of finding them – if, indeed, they exist.

Note:

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 22 Member States.

Related links:

ATLAS collaboration paper: https://arxiv.org/pdf/1809.11105.pdf

ATLAS experiment: https://home.cern/about/experiments/atlas

Large Hadron Collider (LHC): https://home.cern/topics/large-hadron-collider

Standard Model: https://home.cern/about/physics/standard-model

Antimatter: https://home.cern/topics/antimatter

For more information about European Organization for Nuclear Research (CERN), Visit: https://home.cern/

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

Best regards, Orbiter.ch

Rocket Investigation Complete; Russia, Japan Announce Mission Updates

ISS - Expedition 57 Mission patch.

November 1, 2018

NASA is working closely with its International Space Station partner Roscosmos to move forward on crew launch plans. Roscosmos plans to launch the Progress 71 resupply mission on Nov. 16, and is targeting the launch of the Expedition 58 crew including NASA astronaut Anne McClain for Dec. 3, pending the outcome of the flight readiness review.

Image above: The Soyuz MS-10 spacecraft launched Oct. 11, 2018, with Expedition 57 crew members Nick Hague of NASA and Alexey Ovchinin of Roscosmos. During the Soyuz spacecraft’s climb to orbit, an anomaly occurred, resulting in an abort downrange. The crew was quickly recovered in good condition. Image Credits: NASA/Roscosmos.

Roscosmos completed an investigation into the loss of a Soyuz rocket last month that led to a suspension of Russian rocket launches to the station. One of four first stage rocket engines abnormally separated and hit the second stage rocket that led to the loss of stabilization of the Soyuz on Oct. 11. A statement from Roscosmos describes the cause…

“The reason for the abnormal separation is the non-opening of the nozzle cap of the “D” block oxidizer tank because of the deformation of the stem of the separation contact sensor (bending on 6 ˚ 45 ‘), which was admitted when assembling the “package” at the Baikonur Cosmodrome. The cause of the LV accident is of operational nature and extends to the backlog of the “Soyuz” type LV “package”.

Japan also announced today the release of its H-II Transfer Vehicle-7 (HTV-7) resupply ship, also called the Kounotori, from the station’s Harmony module. Commander Alexander Gerst will command the Canadarm2 robotic arm to release Kounotori Nov. 7 at 10:50 a.m. EDT as Flight Engineer Serena Auñón-Chancellor supports him.

Image above: A Japan Aerospace Exploration Agency (JAXA) Kounotori 5 H-II Transfer Vehicle (HTV-5) is seen through the window shortly before release from the International Space Station in September 2015. Image Credits: NASA/JAXA/Kimiya Yui.

Named “Kounotori,” or “white stork” in Japanese, the unpiloted cargo spacecraft delivered six new lithium-ion batteries and adapter plates to replace aging nickel-hydrogen batteries used in two power channels on the space station’s port truss. Flight controllers already have robotically removed the batteries and adapter plates from HTV-7 and stored them on the space station’s truss. The batteries will be replaced through a series of robotic operations and spacewalks that will be scheduled at a later date.

Additional experiments and equipment delivered by HTV include a new sample holder for the Electrostatic Levitation Furnace (JAXA-ELF), a protein crystal growth experiment at low temperatures (JAXA LT PCG), an investigation that looks at the effect of microgravity on bone marrow (MARROW), a Life Sciences Glovebox, and additional EXPRESS Racks.

HTV-7 will re-enter the Earth’s atmosphere and burn up harmlessly over the South Pacific Ocean Nov. 10.

Related links:

Roscosmos statement: https://www.roscosmos.ru/25664/

Roscosmos: https://www.roscosmos.ru/

NASA: https://www.nasa.gov/

H-II Transfer Vehicle-7 (HTV-7): https://www.nasa.gov/feature/kounotori-htv-launches-arrivals-and-departures

JAXA-ELF: https://www.nasa.gov/mission_pages/station/research/experiments/1999.html

JAXA LT PCG: https://www.nasa.gov/mission_pages/station/research/experiments/2297.html

MARROW: https://www.nasa.gov/mission_pages/station/research/experiments/1931.html

Life Sciences Glovebox: https://www.nasa.gov/mission_pages/station/research/experiments/2723.html

EXPRESS Racks: https://www.nasa.gov/mission_pages/station/research/experiments/608.html

Expedition 57: https://www.nasa.gov/mission_pages/station/expeditions/expedition57/index.html

Space Station Research and Technology: https://www.nasa.gov/mission_pages/station/research/index.html

International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html

Images (mentioned), Text, Credits: NASA/Mark Garcia/Cheryl Warner/JSC/Dan Huot.

Best regards, Orbiter.ch

NASA’s Dawn Mission to Asteroid Belt Comes to End

NASA - Dawn Mission patch.

Nov. 1, 2018

NASA’s Dawn spacecraft has gone silent, ending a historic mission that studied time capsules from the solar system’s earliest chapter.

Dusk for Dawn: NASA Mission to the Asteroid Belt

Vvideo above: NASA’s Dawn spacecraft turned science fiction into science fact by using ion propulsion to explore the two largest bodies in the main asteroid belt, Vesta and Ceres. The mission will end this fall, when the spacecraft runs out of hydrazine, which keeps it oriented and in communication with Earth. Video Credits: NASA/JPL-Caltech.

Dawn missed scheduled communications sessions with NASA's Deep Space Network on Wednesday, Oct. 31, and Thursday, Nov. 1. After the flight team eliminated other possible causes for the missed communications, mission managers concluded that the spacecraft finally ran out of hydrazine, the fuel that enables the spacecraft to control its pointing. Dawn can no longer keep its antennas trained on Earth to communicate with mission control or turn its solar panels to the Sun to recharge.

Image above: This photo of Ceres and the bright regions of Occator Crater was one of the last views NASA's Dawn spacecraft transmitted before it completed its mission. This view, which faces south, was captured on Sept. 1, 2018, at an altitude of 2,340 miles (3,370 kilometers) as the spacecraft was ascending in its elliptical orbit. Image Credits: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA.

The Dawn spacecraft launched 11 years ago to visit the two largest objects in the main asteroid belt. Currently, it’s in orbit around the dwarf planet Ceres, where it will remain for decades.

“Today, we celebrate the end of our Dawn mission – its incredible technical achievements, the vital science it gave us, and the entire team who enabled the spacecraft to make these discoveries,” said Thomas Zurbuchen, associate administrator of NASA’s Science Mission Directorate in Washington. “The astounding images and data that Dawn collected from Vesta and Ceres are critical to understanding the history and evolution of our solar system.”

Dawn launched in 2007 on a journey that put about 4.3 billion miles (6.9 billion kilometers) on its odometer. Propelled by ion engines, the spacecraft achieved many firsts along the way. In 2011, when Dawn arrived at Vesta, the second largest world in the main asteroid belt, the spacecraft became the first to orbit a body in the region between Mars and Jupiter. In 2015, when Dawn went into orbit around Ceres, a dwarf planet that is also the largest world in the asteroid belt, the mission became the first to visit a dwarf planet and go into orbit around two destinations beyond Earth.

Image above: This photo of Ceres and one of its key landmarks, Ahuna Mons, was one of the last views Dawn transmitted before it completed its mission. This view, which faces south, was captured on Sept. 1, 2018, at an altitude of 2220 miles (3570 kilometers) as the spacecraft was ascending in its elliptical orbit. Image Credits: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA.

"The fact that my car's license plate frame proclaims, 'My other vehicle is in the main asteroid belt,' shows how much pride I take in Dawn," said Mission Director and Chief Engineer Marc Rayman at NASA's Jet Propulsion Laboratory (JPL). "The demands we put on Dawn were tremendous, but it met the challenge every time. It's hard to say goodbye to this amazing spaceship, but it’s time."

The data Dawn beamed back to Earth from its four science experiments enabled scientists to compare two planet-like worlds that evolved very differently. Among its accomplishments, Dawn showed how important location was to the way objects in the early solar system formed and evolved. Dawn also reinforced the idea that dwarf planets could have hosted oceans over a significant part of their history – and potentially still do.

“In many ways, Dawn’s legacy i­s just beginning,” said Princ­­ipal Investigator Carol Raymond at JPL. “Dawn’s data sets will be deeply mined by scientists working on how planets grow and differentiate, and when and where life could have formed in our solar system. Ceres and Vesta are important to the study of distant planetary systems, too, as they provide a glimpse of the conditions that may exist around young stars.”

Dawn Ceres. flyby Mage Credits: NASA/JPL-Caltech

Because Ceres has conditions of interest to scientists who study chemistry that leads to the development of life, NASA follows strict planetary protection protocols for the disposal of the Dawn spacecraft. Dawn will remain in orbit for at least 20 years, and engineers have more than 99 percent confidence the orbit will last for at least 50 years.

So, while the mission plan doesn't provide the closure of a final, fiery plunge – the way NASA’s Cassini spacecraft ended last year, for example – at least this is certain: Dawn spent every last drop of hydrazine making science observations of Ceres and radioing them back so we could learn more about the solar system we call home.

The Dawn mission is managed by JPL for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. JPL is responsible for overall Dawn mission science. Northrop Grumman in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, Max Planck Institute for Solar System Research, Italian Space Agency and Italian National Astrophysical Institute are international partners on the mission team.

Related article:

The Surprising Coincidence Between Two Overarchieving NASA Missions:
https://orbiterchspacenews.blogspot.com/2018/10/the-surprising-coincidence-between-two.html

Check out the Dawn media toolkit, with a mission timeline, images, video and quick facts, at:

https://dawn.jpl.nasa.gov/mission/toolkit

Watch the video “Dawn: Mission to Small Worlds,” with NASA Chief Scientist Jim Green, at:

https://www.youtube.com/watch?v=JrafypeEhTM

More information about Dawn is available at: https://www.nasa.gov/dawn

Images (mentioned), Video (mentioned), Text, Credits: NASA/Dwayne Brown/JoAnna Wendel/Karen Northon/JPL/Gretchen McCartney.

Greetings, Orbiter.ch

OSIRIS-REx Captures 'Super-Resolution' View of Bennu

NASA - OSIRIS-REx Mission patch.

Nov. 1, 2018

This "super-resolution” view of asteroid Bennu was created using eight images obtained by NASA’s OSIRIS-REx spacecraft on Oct. 29, 2018, from a distance of about 205 miles (330 km). The spacecraft was moving as it captured the images with the PolyCam camera, and Bennu rotated 1.2 degrees during the nearly one minute that elapsed between the first and the last snapshot. The team used a super-resolution algorithm to combine the eight images and produce a higher resolution view of the asteroid. Bennu occupies about 100 pixels and is oriented with its north pole at the top of the image.

OSIRIS-REx (Origins Spectral Interpretation Resource Identification Security Regolith Explorer): http://www.nasa.gov/mission_pages/osiris-rex/index.html

Image, Text, Credits: NASA/Karl Hille/Goddard/University of Arizona.

Greetings, Orbiter.ch

Physics, Combustion and Biology Science Ahead of Station’s 20th Anniversary

ISS - Expedition 57 Mission patch.

October 31, 2018

The three Expedition 57 crew members from the United States, Germany and Russia will soon be observing the 20th anniversary of the launch of the International Space Station’s first module. On Nov. 20, 1998, the Zarya cargo module was launched aboard a Russian rocket and placed into orbit beginning the era of station assembly.

In the meantime, the crew orbiting Earth since June worked on a variety of advanced science hardware today. The trio ensured the safe and ongoing research into combustion, physics and biology in microgravity to benefit humans on Earth and in space.

International Space Station (ISS). Animation Credit: NASA

NASA Astronaut Serena Auñón-Chancellor swapped cartridge holders inside the Electrostatic Levitation Furnace (ELF) that explores what happens to materials exposed to extremely high temperatures. The device located in Japan’s Kibo lab module measures the thermo-physical properties of samples that are melted and solidified and difficult to observe on the ground.

Commander Alexander Gerst from ESA (European Space Agency) worked on the new Life Sciences Glovebox launched to the space station aboard a Japanese cargo ship at the end of September. He is configuring the biology research facility for service inside the Kibo lab.

Building the International Space Station (ISS) 1998 - 2013. Image Credit: NASA

Image above: Dec. 6, 1998, International Space Station Assembly Begins. On Dec. 6, 1998, the crew of space shuttle mission STS-88 began construction of the International Space Station, attaching the U.S.-built Unity node and the Russian-built Zarya module together in orbit.6 déc. 2013.

Cosmonaut Sergey Prokopyev worked inside the U.S. Destiny lab module replacing the Combustion Integrated Rack’s (CIR) fuel bottles.  The CIR has been enabling research and observations into how fuels and flames burn in space on the orbital lab for over ten years. Results may guide the development of rocket engines and fire safety aboard spacecraft.

Related links:

Expedition 57: https://www.nasa.gov/mission_pages/station/expeditions/expedition57/index.html

Electrostatic Levitation Furnace (ELF): https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=1536

Life Sciences Glovebox: https://orbiterchspacenews.blogspot.com/2018/09/partnership-teamwork-enable-landmark.html

Combustion Integrated Rack’s (CIR): https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=317

Space Station Research and Technology: https://www.nasa.gov/mission_pages/station/research/index.html

International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html

Animation (mentioned), Image (mentioned), Text, Credits: NASA/Mark Garcia/Orbiter.ch Aerospace/Roland Berga.

Best regards, Orbiter.ch

Five Things to Know About InSight's Mars Landing

NASA - InSight Mission logo.

Oct. 31, 2018

Image above: This is an illustration showing a simulated view of NASA's InSight lander about to land on the surface of Mars. This view shows the underside of the spacecraft. Image Credits: NASA/JPL-Caltech.

Every Mars landing is a knuckle-whitening feat of engineering. But each attempt has its own quirks based on where a spacecraft is going and what kind of science the mission intends to gather.

On Nov. 26, NASA will try to safely set a new spacecraft on Mars. InSight is a lander dedicated to studying the deep interior of the planet – the first mission ever to do so.

Here are a few things to know about InSight's landing:

Landing on Mars is hard

Only about 40 percent of the missions ever sent to Mars – by any space agency – have been successful. The U.S. is the only nation whose missions have survived a Mars landing. The thin atmosphere – just 1 percent of Earth's – means that there's little friction to slow down a spacecraft. Despite that, NASA has had a long and successful track record at Mars. Since 1965, it has flown by, orbited, landed on and roved across the surface of the Red Planet.

InSight Landing on Mars

Video above: When NASA’s InSight descends to the Red Planet on Nov. 26, 2018, it is guaranteed to be a white-knuckle event. Rob Manning, chief engineer at NASA’s Jet Propulsion Laboratory, explains the critical steps that must happen in perfect sequence to get the robotic lander safely to the surface. Video Credits: NASA/JPL.

InSight uses tried-and-true technology

In 2008, NASA's Jet Propulsion Laboratory in Pasadena, California, successfully landed the Phoenix spacecraft at Mars' North Pole. InSight is based on the Phoenix spacecraft, both of which were built by Lockheed Martin Space in Denver. Despite tweaks to its heat shield and parachute, the overall landing design is still very much the same: After separating from a cruise stage, an aeroshell descends through the atmosphere. The parachute and retrorockets slow the spacecraft down, and suspended legs absorb some shock from the touchdown.

InSight is landing on "the biggest parking lot on Mars"

One of the benefits of InSight's science instruments is that they can record equally valuable data regardless of where they are on the planet. That frees the mission from needing anything more complicated than a flat, solid surface (ideally with few boulders and rocks). For the mission's team, the landing site at Elysium Planitia is sometimes thought as "the biggest parking lot on Mars."

InSight was built to land in a dust storm

InSight’s engineers have built a tough spacecraft, able to touch down safely in a dust storm if it needs to. The spacecraft's heat shield is designed to be thick enough to withstand being "sandblasted" by dust. Its parachute has suspension lines that were tested to be stronger than Phoenix's, in case it faces more air resistance due to the atmospheric conditions expected during a dust storm.

The entry, descent and landing sequence also has some flexibility to handle shifting weather. The mission team will be receiving daily weather updates from NASA's Mars Reconnaissance Orbiter in the days before landing so that they can tweak when InSight's parachute deploys and when it uses radar to find the Martian surface.

After landing, InSight will provide new science about rocky planets

InSight will teach us about the interior of planets like our own. The mission team hopes that by studying the deep interior of Mars, we can learn how other rocky worlds, including Earth and the Moon, formed. Our home planet and Mars were molded from the same primordial stuff more than 4.5 billion years ago but then became quite different. Why didn’t they share the same fate?

InSight landed, instruments and solar panels deployed. Image Credits: NASA/JPL-Caltech

When it comes to rocky planets, we’ve only studied one in detail: Earth. By comparing Earth's interior to that of Mars, InSight's team members hope to better understand our solar system. What they learn might even aid the search for Earth-like exoplanets, narrowing down which ones might be able to support life. So while InSight is a Mars mission, it’s also much more than a Mars mission.

You can read more about how the science of the mission is unique here: https://www.jpl.nasa.gov/news/news.php?feature=7067. A press kit released today includes additional information on the mission: https://www.jpl.nasa.gov/news/press_kits/insight

JPL manages InSight for NASA's Science Mission Directorate. InSight is part of NASA's Discovery Program, managed by the agency's Marshall Space Flight Center in Huntsville, Alabama. Lockheed Martin Space in Denver built the InSight spacecraft, including its cruise stage and lander, and supports spacecraft operations for the mission.

A number of European partners, including France's Centre National d'Études Spatiales (CNES) and the German Aerospace Center (DLR), are supporting the InSight mission. CNES provided the Seismic Experiment for Interior Structure (SEIS) instrument, with significant contributions from the Max Planck Institute for Solar System Research (MPS) in Germany, the Swiss Institute of Technology (ETH) in Switzerland, Imperial College and Oxford University in the United Kingdom, and JPL. DLR provided the Heat Flow and Physical Properties Package (HP3) instrument, with significant contributions from the Polish Space Agency (CBK) and Astronika in Poland. Spain’s Centro de Astrobiología (CAB) supplied the wind sensors.

Read more about InSight here: https://mars.nasa.gov/insight/

Image (mentioned), Video (mentioned), Text, Credits: NASA/Tony Greicius/JPL/Andrew Good.

Greetings, Orbiter.ch

Hubble reveals cosmic Bat Shadow in the Serpent’s Tail

ESA - Hubble Space Telescope logo.

31 October 2018

Cosmic shadow of HBC 672

The NASA/ESA Hubble Space Telescope has captured part of the wondrous Serpens Nebula, lit up by the star HBC 672. This young star casts a striking shadow — nicknamed the Bat Shadow — on the nebula behind it, revealing telltale signs of its otherwise invisible protoplanetary disc.

Serpens Nebula, seen by HAWK-1

The Serpens Nebula, located in the tail of the Serpent (Serpens Cauda) about 1300 light-years away, is a reflection nebula that owes most of its sheen to the light emitted by stars like HBC 672 —  a young star nestled in its dusty folds. In this image the NASA/ESA Hubble Space Telescope has exposed two vast cone-like shadows emanating from HBC 672.

Wide-field view of the Serpens Nebula (ground-based image)

These colossal shadows on the Serpens Nebula are cast by the protoplanetary disc surrounding HBC 672. By clinging tightly to the star the disc creates an imposing shadow, much larger than the disc — approximately 200 times the diameter of our own Solar System. The disc’s shadow is similar to that produced by a cylindrical lamp shade. Light escapes from the top and bottom of the shade, but along its circumference, dark cones of shadow form.

Bat Shadow

The disc itself is so small and far away from Earth that not even Hubble can detect it encircling its host star. However, the shadow feature — nicknamed the Bat Shadow — reveals details of the disc’s shape and nature. The presence of a shadow implies that the disc is being viewed nearly edge-on.

Whilst most of the shadow is completely opaque, scientists can look for colour differences along its edges, where some light gets through. Using the shape and colour of the shadow, they can determine the size and composition of dust grains in the disc.

Serpens Nebula from the ground and from space

The whole Serpens Nebula, of which this image shows only a tiny part, could host more of these shadow projections. The nebula envelops hundreds of young stars, many of which could also be in the process of forming planets in a protoplanetary disc.

Although shadow-casting discs are common around young stars, the combination of an edge-on viewing angle and the surrounding nebula is rare. However, in an unlikely coincidence, a similar looking shadow phenomenon can be seen emanating from another young star, in the upper left of the image.

Zoom on HBC 672

These precious insights into protoplanetary discs around young stars allow astronomers to study our own past. The planetary system we live in once emerged from a similar protoplanetary disc when the Sun was only a few million years old. By studying these distant discs we get to uncover the formation and evolution of our own cosmic home.

Pan across the Serpens Nebula

More information:

The Hubble Space Telescope is a project of international cooperation between ESA and NASA.

Links:

Images of Hubble: http://www.spacetelescope.org/images/archive/category/spacecraft/

Hubblesite release: http://hubblesite.org/news_release/news/2018-40

ESA Hubblesite: http://hubblesite.org/

Images Credits: NASA/ESA/Mathias Jäger/ESO/Digitized Sky Survey 2 (Acknowledgement: Davide De Martin)/STScI/Videos: NASA, ESA/Hubble, ESO/Digitized Sky Survey, Nick Risinger (skysurvey.org).

Greetings, Orbiter.ch

Galactic ghosts: Gaia uncovers major event in the formation of the Milky Way

ESA - Gaia Mission patch.

31 October 2018

ESA’s Gaia mission has made a major breakthrough in unravelling the formation history of the Milky Way.

Instead of forming alone, our Galaxy merged with another large galaxy early in its life, around 10 billion years ago. The evidence is littered across the sky all around us, but it has taken Gaia and its extraordinary precision to show us what has been hiding in plain sight all along.

Galactic merger

Gaia measures the position, movement and brightness of stars to unprecedented levels of accuracy.

Using the first 22 months of observations, a team of astronomers led by Amina Helmi, University of Groningen, The Netherlands, looked at seven million stars – those for which the full 3D positions and velocities are available – and found that some 30,000 of them were part of an ‘odd collection’ moving through the Milky Way. The observed stars in particular are currently passing by our solar neighbourhood.

We are so deeply embedded in this collection that its stars surround us almost completely, and so can be seen across most of the sky.

Even though they are interspersed with other stars, the stars in the collection stood out in the Gaia data because they all move along elongated trajectories in the opposite direction to the majority of the Galaxy’s other hundred billion stars, including the Sun.

Debris of galactic merger

They also stood out in the so-called Hertzprung-Russell diagram – which is used to compare the colour and brightness of stars – indicating that they belong to a clearly distinct stellar population.

The sheer number of odd-moving stars involved intrigued Amina and her colleagues, who suspected they might have something to do with the Milky Way’s formation history and set to work to understand their origins.

In the past, Amina and her research group had used computer simulations to study what happens to stars when two large galaxies merge. When she compared those to the Gaia data, the simulated results matched the observations.

“The collection of stars we found with Gaia has all the properties of what you would expect from the debris of a galactic merger,” says Amina, lead author of the paper published today in Nature.

In other words, the collection is what they expected from stars that were once part of another galaxy and have been consumed by the Milky Way. The stars now form most of our Galaxy’s inner halo – a diffuse component of old stars that were born at early times and now surround the main bulk of the Milky Way known as the central bulge and disc.

The components of the Milky Way

The Galactic disc itself is composed of two parts. There is the thin disc, which is a few hundred light years deep and contains the pattern of spiral arms made by bright stars. And there is the thick disc, which is a few thousand light years deep. It contains about 10–20 percent of the Galaxy’s stars yet its origins have been difficult to determine.

According to the team’s simulations, as well as supplying the halo stars, the accreted galaxy could also have disturbed the Milky Way’s pre-existing stars to help form the thick disc.

“We became only certain about our interpretation after complementing the Gaia data with addi-tional information about the chemical composition of stars, supplied by the ground-based APOGEE survey,” says Carine Babusiaux, Université Grenoble Alpes, France, and second author of the paper.

Stars that form in different galaxies have unique chemical compositions that match the conditions of the home galaxy. If this star collection was indeed the remains of a galaxy that merged with our own, the stars should show an imprint of this in their composition. And they did.

The astronomers called this galaxy Gaia-Enceladus after one of the Giants in ancient Greek mythology, who was the offspring of Gaia, the Earth, and Uranus, the Sky.

“According to the legend, Enceladus was buried under Mount Etna, in Sicily, and responsible for local earthquakes. Similarly, the stars of Gaia-Enceladus were deeply buried in the Gaia data, and they have shaken the Milky Way, leading to the formation of its thick disc,” explains Amina.

Gaia-Enceladus stars across the sky

Even though no more evidence was really needed, the team also found hundreds of variable stars and 13 globular clusters in the Milky Way that follow similar trajectories as the stars from Gaia-Enceladus, indicating that they were originally part of that system.

Globular clusters are groups of up to millions of stars, held together by their mutual gravity and orbiting the centre of a galaxy. The fact that so many clusters could be linked to Gaia-Enceladus is another indication that this must have once been a big galaxy in its own right, with its own entourage of globular clusters.

Further analysis revealed that this galaxy was about the size of one of the Magellanic Clouds – two satellite galaxies roughly ten times smaller than the current size of the Milky Way.

Gaia observatory

Ten billion years ago, however, when the merger with Gaia-Enceladus took place, the Milky Way itself was much smaller, so the ratio between the two was more like four to one. It was therefore clearly a major blow to our Galaxy.

“Seeing that we are now starting to unravel the formation history of the Milky Way is very exciting,” says Anthony Brown, Leiden University, The Netherlands, who is a co-author of the paper and also chair of the Gaia Data Processing and Analysis Consortium Executive.

Since the very first discussions about building Gaia 25 years ago, one of the mission’s key objectives was to examine the various stellar streams in the Milky Way, and reconstruct its early history. That vision is paying off.

Merger simulation

“Gaia was built to answer such questions,” says Amina. “We can now say this is the way the Galaxy formed in those early epochs. It’s fantastic. It’s just so beautiful and makes you feel so big and so small at the same time.”

“By reading the motions of stars scattered across the sky, we are now able to rewind the history of the Milky Way and discover a major milestone in its formation, and this is possible thanks to Gaia,” concludes Timo Prusti, Gaia project scientist at ESA.

Notes for editors:

“The merger that led to the formation of the Milky Way's inner stellar halo and thick disk” by A. Helmi et al is published in Nature: https://www.nature.com/articles/s41586-018-0625-x

Related links:

Gaia data: https://www.cosmos.esa.int/web/gaia/data-release-2

Hertzprung-Russell diagram: http://sci.esa.int/gaia-stellar-family-portrait/

Gaia: http://www.esa.int/Our_Activities/Space_Science/Gaia

Images, Animation, Video, Text, Credits: ESA (artist’s impression and composition); Koppelman, Villalobos and Helmi (simulation); NASA/ESA/Hubble (galaxy image), CC BY-SA 3.0 IGO/ESA/Markus Bauer/Timo Prusti/Leiden Observatory, Leiden University/Anthony Brown/Université Grenoble Alpes, CNRS, IPAG/Carine Babusiaux/Kapteyn Astronomical Institute/University of Groningen/Amina Helmi/ATG medialab/NASA/JPL-Caltech/Gaia/DPAC; A. Helmi et al 2018/Video: Koppelman, Villalobos & Helmi, Kapteyn Astronomical Institute, University of Groningen, The Netherlands.

Best regards, Orbiter.ch

Most Detailed Observations of Material Orbiting close to a Black Hole

ESO - European Southern Observatory logo.

31 October 2018

Simulation of Material Orbiting close to a Black Hole

ESO’s exquisitely sensitive GRAVITY instrument has added further evidence to the long-standing assumption that a supermassive black hole lurks in the centre of the Milky Way. New observations show clumps of gas swirling around at about 30% of the speed of light on a circular orbit just outside its event horizon — the first time material has been observed orbiting close to the point of no return, and the most detailed observations yet of material orbiting this close to a black hole.

Sagittarius A* in the constellation of Sagittarius

ESO’s GRAVITY instrument on the Very Large Telescope (VLT) Interferometer has been used by scientists from a consortium of European institutions, including ESO [1], to observe flares of infrared radiation coming from the accretion disc around Sagittarius A*, the massive object at the heart of the Milky Way. The observed flares provide long-awaited confirmation that the object in the centre of our galaxy is, as has long been assumed, a supermassive black hole. The flares originate from material orbiting very close to the black hole’s event horizon — making these the most detailed observations yet of material orbiting this close to a black hole.

Wide-field view of the centre of the Milky Way

While some matter in the accretion disc — the belt of gas orbiting Sagittarius A* at relativistic speeds [2] — can orbit the black hole safely, anything that gets too close is doomed to be pulled beyond the event horizon. The closest point to a black hole that material can orbit without being irresistibly drawn inwards by the immense mass is known as the innermost stable orbit, and it is from here that the observed flares originate.

The centre of the Milky Way*

"It’s mind-boggling to actually witness material orbiting a massive black hole at 30% of the speed of light," marvelled Oliver Pfuhl, a scientist at the MPE. "GRAVITY’s tremendous sensitivity has allowed us to observe the accretion processes in real time in unprecedented detail."

These measurements were only possible thanks to international collaboration and state-of-the-art instrumentation [3]. The GRAVITY instrument which made this work possible combines the light from four telescopes of ESO’s VLT to create a virtual super-telescope 130 metres in diameter, and has already been used to probe the nature of Sagittarius A*.

Simulation of Material Orbiting close to a Black Hole

Earlier this year, GRAVITY and SINFONI, another instrument on the VLT, allowed the same team to accurately measure the close fly-by of the star S2 as it passed through the extreme gravitational field near Sagittarius A*, and for the first time revealed the effects predicted by Einstein’s general relativity in such an extreme environment. During S2’s close fly-by, strong infrared emission was also observed.

Zooming into Sagittarius A*

"We were closely monitoring S2, and of course we always keep an eye on Sagittarius A*,"  explained Pfuhl. "During our observations, we were lucky enough to notice three bright flares from around the black hole — it was a lucky coincidence!"

This emission, from highly energetic electrons very close to the black hole, was visible as three prominent bright flares, and exactly matches theoretical predictions for hot spots orbiting close to a black hole of four million solar masses [4]. The flares are thought to originate from magnetic interactions in the very hot gas orbiting very close to Sagittarius A*.

Simulation of the orbits of stars around the black hole at the centre of the Milky Way

Reinhard Genzel, of the Max Planck Institute for Extraterrestrial Physics (MPE) in Garching, Germany, who led the study, explained: "This always was one of our dream projects but we did not dare to hope that it would become possible so soon." Referring to the long-standing assumption that Sagittarius A* is a supermassive black hole, Genzel concluded that "the result is a resounding confirmation of the massive black hole paradigm."

Notes:

[1] This research was undertaken by scientists from the Max Planck Institute for Extraterrestrial Physics (MPE), the Observatoire de Paris, the Université Grenoble Alpes, CNRS, the Max Planck Institute for Astronomy, the University of Cologne, the Portuguese CENTRA – Centro de Astrofisica e Gravitação and ESO.

[2] Relativistic speeds are those which are so great that the effects of Einstein’s Theory of Relativity become significant. In the case of the accretion disc around Sagittarius A*, the gas is moving at roughly 30% of the speed of light.

[3] GRAVITY was developed by a collaboration consisting of the Max Planck Institute for Extraterrestrial Physics (Germany), LESIA of Paris Observatory–PSL/CNRS/Sorbonne Université/Univ. Paris Diderot and IPAG of Université Grenoble Alpes/CNRS (France), the Max Planck Institute for Astronomy (Germany), the University of Cologne (Germany), the CENTRA–Centro de Astrofísica e Gravitação (Portugal) and ESO.

[4] The solar mass is a unit used in astronomy. It is equal to the mass of our closest star, the Sun, and has a value of 1.989 × 1030 kg. This means that Sgr A* has a mass 1.3 trillion times greater than the Earth.

More information:

This research was presented in a paper entitled "Detection of Orbital Motions Near the Last Stable Circular Orbit of the Massive Black Hole SgrA*", by the GRAVITY Collaboration, published in the journal Astronomy & Astrophysics on 31 October 2018.

The GRAVITY Collaboration team is composed of: R. Abuter (ESO, Garching, Germany), A. Amorim (Universidade de Lisboa, Lisbon, Portugal), M. Bauböck (Max Planck Institute for Extraterrestrial Physics, Garching, Germany [MPE]), J.P. Berger (Univ. Grenoble Alpes, CNRS, IPAG, Grenoble, France [IPAG]; ESO, Garching, Germany), H. Bonnet (ESO, Garching, Germany), W. Brandner (Max Planck Institute for Astronomy, Heidelberg, Germany [MPIA]), Y. Clénet (LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ. Paris 06, Univ. Paris Diderot, Meudon, France [LESIA])), V. Coudé du Foresto (LESIA), P. T. de Zeeuw (Sterrewacht Leiden, Leiden University, Leiden, The Netherlands; MPE), C. Deen (MPE), J. Dexter (MPE), G. Duvert (IPAG), A. Eckart (University of Cologne, Cologne, Germany; Max Planck Institute for Radio Astronomy, Bonn, Germany), F. Eisenhauer (MPE), N.M. Förster Schreiber (MPE), P. Garcia (Universidade do Porto, Porto, Portugal; Universidade de Lisboa Lisboa, Portugal), F. Gao (MPE), E. Gendron (LESIA), R. Genzel (MPE; University of California, Berkeley, California, USA), S. Gillessen (MPE), P. Guajardo (ESO, Santiago, Chile), M. Habibi (MPE), X. Haubois (ESO, Santiago, Chile), Th. Henning (MPIA), S. Hippler (MPIA), M. Horrobin (University of Cologne, Cologne, Germany), A. Huber (MPIA), A. Jimenez Rosales (MPE), L. Jocou (IPAG), P. Kervella (LESIA; MPIA), S. Lacour (LESIA), V. Lapeyrère (LESIA), B. Lazareff (IPAG), J.-B. Le Bouquin (IPAG), P. Léna (LESIA), M. Lippa (MPE), T. Ott (MPE), J. Panduro (MPIA), T. Paumard (LESIA), K. Perraut (IPAG), G. Perrin (LESIA), O. Pfuhl (MPE), P.M. Plewa (MPE), S. Rabien (MPE), G. Rodríguez-Coira (LESIA), G. Rousset (LESIA), A. Sternberg (School of Physics and Astronomy, Tel Aviv University, Tel Aviv, Israel, Center for Computational Astrophysics, Flatiron Institute, New York, USA), O. Straub (LESIA), C. Straubmeier (University of Cologne, Cologne, Germany), E. Sturm (MPE), L.J. Tacconi (MPE), F. Vincent (LESIA), S. von Fellenberg (MPE), I. Waisberg (MPE), F. Widmann (MPE), E. Wieprecht (MPE), E. Wiezorrek (MPE), J. Woillez (ESO, Garching, Germany), S. Yazici (MPE; University of Cologne, Cologne, Germany).

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. 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".

Links:

ESOcast 181 Light: Most Detailed Observations of Material Orbiting close to a Black Hole: https://www.eso.org/public/videos/eso1835a/

Research paper: https://www.eso.org/public/archives/releases/sciencepapers/eso1835/eso1835a.pdf

Photos of the VLT: http://www.eso.org/public/images/archive/category/paranal/

SO Photos of the Galactic Centre: https://www.eso.org/public/images/?search=Galactic+Centre

Very Large Telescope (VLT): https://www.eso.org/public/teles-instr/paranal-observatory/vlt/

GRAVITY: https://www.eso.org/public/teles-instr/paranal-observatory/vlt/vlt-instr/gravity/

Max Planck Institute for Extraterrestrial Physics (MPE): http://www.mpe.mpg.de/2169/en

Observatoire de Paris: https://www.obspm.fr/-observatoire-de-paris-.html?lang=en

Université Grenoble Alpes: https://www.univ-grenoble-alpes.fr/en/home-page-136826.kjsp

CNRS: https://www.cnrs.fr/

Max Planck Institute for Astronomy: http://www.mpia.de/en

University of Cologne: https://www.portal.uni-koeln.de/uoc_home.html?L=1

Portuguese CENTRA – Centro de Astrofisica e Gravitação: https://centra.tecnico.ulisboa.pt/

Images: ESO/Gravity Consortium/L. Calçada/S. Gillessen et al./IAU and Sky & Telescope/Digitized Sky Survey 2. Acknowledgment: Davide De Martin and S. Guisard (www.eso.org/~sguisard)/Text; ESO/Calum Turner/Xavier Haubois/Max Planck Institute for Extraterrestrial Physics/Hannelore Hämmerle/Jason Dexter/Oliver Pfuhl/CNRS/Thibaut Paumard/Videos: ESO/Gravity Consortium/L. Calçada/N. Risinger (skysurvey.org).

Best regards, Orbiter.ch