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Nobel physics prize awarded to 3 scientists for discoveries relating to black holes –



Three scientists won this year’s Nobel Prize in Physics Tuesday for advancing our understanding of black holes, the all-consuming monsters that lurk in the darkest parts of the universe and that still confound astronomers.

Briton Roger Penrose, German Reinhard Genzel and American Andrea Ghez explained to the world these dead ends of the cosmos, where light and even time doesn’t escape. These staples of both science fact and fiction are still not completely understood, but they are deeply connected, somehow, to the creation of galaxies, where the stars and life exist.

Penrose, of the University of Oxford, received half of this year’s prize “for the discovery that black hole formation is a robust prediction of” Albert Einstein’s general theory of relativity, the Nobel Committee said.

Genzel, who is at both the Max Planck Institute in Germany and the University of California at Berkeley, and Ghez, of UCLA, received the second half of the prize “for the discovery of a supermassive compact object at the centre of our galaxy.” That object was also a black hole, albeit a giant one.

The prize celebrates what the Nobel Committee called “one of the most exotic objects in the universe” and ones that “still pose many questions that beg for answers and motivate future research.”

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Black holes are at the centre of every galaxy, and smaller ones are dotted around the universe. Nothing, not even light, can escape their incredible gravity. Time comes to a standstill as it gets closer.

Just their existence is mind-bending, taking what people experience every day on Earth — light and time — and warping them in such a way that seems unreal.

“Black holes, because they are so hard to understand, is what makes them so appealing,” Ghez told The Associated Press Tuesday morning. “I really think of science as a big, giant puzzle.”

Ghez, 55, went to college as a math major because the concept of infinity fascinated her. Because time slows and even stops in these black holes, Ghez said she is still studying infinity in a way.

“You get this mixing of space and time,” Ghez said, adding that’s what makes black holes so hard to understand.

Einstein laid foundation

Penrose, 89, proved with mathematics that the formation of black holes was possible, based heavily on Albert Einstein’s general theory of relativity.

“Einstein did not himself believe that black holes really exist, these super-heavyweight monsters that capture everything that enters them,” the committee said. “Nothing can escape, not even light.”

Martin Rees, the British astronomer royal, noted that Penrose triggered a “renaissance” in the study of relativity in the 1960s, and that, together with a young Stephen Hawking, he helped firm up evidence for the Big Bang and black holes.

British scientist Roger Penrose proved with mathematics that the formation of black holes was possible. (Danny Lawson/PA/The Associated Press)

“Penrose and Hawking are the two individuals who have done more than anyone else since Einstein to deepen our knowledge of gravity,” Rees said. “Sadly, this award was too much delayed to allow Hawking to share the credit.”

Hawking died in 2018, and Nobel prizes are only awarded to living scientists.

It wasn’t until the 1990s that Genzel, 68, and Ghez, each leading a group of astronomers, trained their sights on the dust-covered centre of our Milky Way galaxy, a region called Sagittarius A*, where something strange was going on.

They both found that there was “an extremely heavy, invisible object that pulls on the jumble of stars, causing them to rush around at dizzying speeds,” according to the committee.

Reinhard Genzel, astrophysicist at the Max Planck Institute for Extraterrestrial Physics, celebrates his Nobel Prize in Physics with his team in Garching, Germany, on Tuesday. (Matthias Balk/dpa/The Associated Press)

It was a black hole. Not just an ordinary black hole, but a supermassive black hole, four million times the mass of our sun.

The first image Ghez got was in 1995, using the Keck Telescope, which had just gone online. A year later, another image seemed to indicate that the stars near the centre of the Milky Way were circling something. A third image led Ghez and Genzel to think they were really on to something.

Now scientists know that all galaxies have supermassive black holes.

4th women to win Nobel for physics 

In 2019, scientists got the first optical image of a black hole, and Ghez, who was not involved, praised the discovery.

“Today we accept these objects are critical to the building blocks of the universe,” Ghez told an audience at the Royal Swedish Academy of Sciences by phone shortly after the announcement.

Ghez, who spoke from her home in Los Angeles, was woken by the call from the Nobel Committee at 2 a.m.

“For the first few minutes, I thought I was dreaming,” Ghez said in the AP interview.

Andrea Ghez said she hopes she can inspire other young women into the field after becoming the fourth woman to be awarded the Nobel Prize in Physics. (UCLA/The Associated Press)

Ghez is the fourth woman to be awarded the Nobel Prize in Physics, after Marie Curie in 1903, Maria Goeppert-Mayer in 1963 and Donna Strickland in 2018.

“I hope I can inspire other young women into the field. It’s a field that has so many pleasures. And if you’re passionate about the science, there’s so much that can be done,” Ghez said.

Canadian-born scientist won in 2019

It is common for several scientists who worked in related fields to share the prize. Last year’s prize went to Canadian-born cosmologist James Peebles for theoretical work about the early moments after the Big Bang, and Swiss astronomers Michel Mayor and Didier Queloz for discovering a planet outside our solar system.

The prestigious award comes with a gold medal and prize money of 10 million Swedish kronor ($1.5 million Cdn), courtesy of a bequest left 124 years ago by the prize’s creator, Swedish inventor Alfred Nobel. The amount was increased recently to adjust for inflation.

On Monday, the Nobel Committee awarded the prize for physiology and medicine to Americans Harvey J. Alter and Charles M. Rice and British-born scientist Michael Houghton for discovering the liver-ravaging hepatitis C virus.

The other prizes, to be announced in the coming days, are for outstanding work in the fields of chemistry, literature, peace and economics.

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SpaceX Starship Passes Static Fire Test With Three Raptor Engines, Finally Gets Nose Cone! – Universe Today



It’s beginning to look like SpaceX will attempt to make the 15 km (9.3 mi) hop test before Christmas! After two successful 150 m (~500 ft) hops with the SN5 and SN6 prototypes, engineers at SpaceX’s Boca Chica launch facility in South Texas rolled out the SN8 – the first Starship prototype to have three Raptor engines. But before the SN8 can conduct a high-altitude test flight, the engineers needed to run a static fire test.

This test is crucial to ensuring that the Starship‘s interior plumbing can handle its cryogenic propellants, and is the last milestone before the Starship can conduct a high-altitude flight. On the evening of Tuesday, October 20th, that’s exactly what they did! At 3:13 AM local time (01:13 AM PDT; 04:13 AM EDT), the SN8 fired up its three Raptor engines and kept firing them for several seconds straight.

Although SpaceX has not yet released a statement about the test, footage captured near the launch facility by NASA Spaceflight’s Mary McConnaughey (aka. @BocaChicaGal) would suggest that it was a success. The video of the event (posted below) shows the engine being ignited at 2h27m12s after several minutes of venting and remaining lit for several seconds.

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With this milestone achieved, the company appears ready to conduct the historic 15 km (9.3 mi) hop test. At this point, that seems likely to happen before the end of October or in early November. While the SN8 was receiving its three Raptor engines and preparing to test fire them, another team was busy assembling the nose cone in another part of the facility.

Not since the Starhopper test vehicle was in active service has a Starship prototype come with a nose cone. However, this segment was removed shortly after the Starhopper blew over in high winds in January of 2019. What remained, the single-engine lower section, went on to conduct a tethered hop test, followed by a first free-flight hop test to 20 meters (~65 ft).

In August of 2019, these tests culminated in a 150 meter (~500 ft) hop test, a feat that would not be accomplished again until a year later with the SN5 and SN7 prototype. Since then, the development of the SN8 has proceeded apace, which began with the core undergoing a series of proof tests (from Oct. 6th to Oct. 8th) to validate its stainless steel propellant tanks in preparation for its static fire test.

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What followed was the addition of the large maneuvering flaps to the core section and nose cone. The nose cone was then attached by crane to the SN8 fuselage on Thursday (Oct. 22nd), an event that was witnessed by multiple observers who took pictures and footage. Above is a time-lapse video of the stacking operation recorded by @LabPadre, which was made using their 24-hour live-coverage of the Boca Chica launch facility.

With the nose cone and flaps installed, the vehicle now looks like the finalized Starship design for the first time. With its three engines, nose cone, and maneuvering flaps integrated, the SN8 is about ready to attempt its 15 km (9.3 mi) hop test, which will include a “belly-flop” maneuver that will test its ability to glide back to its landing site using its maneuvering surfaces alone.

According to past statements by Musk, SpaceX hopes to conduct a suborbital hop test to an altitude of 200 km (~125 mi) sometime next year. For this final test, the Starship will be equipped with six Raptor engines – three optimized sea-level thrust and three optimized for the vacuum of space. The company is also busy working on the Super Heavy element of the launch system, which will have no less than 28 Raptor engines.

Further Reading: ArsTechnica

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First Habitable-Zone, Earth-Sized Exoplanet Discovered With Planet-Hunter TESS – SciTechDaily



TOI 700, a planetary system 100 light-years away in the constellation Dorado, is home to TOI 700 d, the first Earth-size habitable-zone planet discovered by NASA’s Transiting Exoplanet Survey Satellite. Credit: NASA’s Goddard Space Flight Center

TESS, the Transiting Exoplanet Survey Satellite, was launched in 2018 with the goal of discovering small planets around the Sun’s nearest neighbors, stars bright enough to allow for follow-up characterizations of their planets’ masses and atmospheres. TESS has so far discovered seventeen small planets around eleven nearby stars that are M dwarfs — stars that are smaller than the Sun (less than about 60% of the Sun’s mass) and cooler (surface temperatures less than about 3900 kelvin). In a series of three papers that appeared together this month, astronomers report that one of these planets, TOI-700d, is Earth-sized and also located in its star’s habitable zone; they also discuss its possible climate.

CfA astronomers Joseph Rodriguez, Laura Kreidberg, Karen Collins, Samuel Quinn, Dave Latham, Ryan Cloutier, Jennifer Winters, Jason Eastman, and David Charbonneau were on the teams that studied TOI-700d, one of three small planets orbiting one M dwarf star (its mass is 0.415 solar masses) located one hundred and two light-years from Earth. The TESS data analysis found the tentative sizes of the planets as being approximately Earth-sized, 1.04, 2.65 and 1.14 Earth-radii, respectively, and their orbital periods as 9.98, 16.05, and 37.42 days, respectively.

TOI 700 d Illustration

This illustration of TOI 700 d is based on several simulated environments for an ocean-covered version of the planet. Credit: NASA’s Goddard Space Flight Center

In our solar system, Mercury orbits the Sun in about 88 days; it is so close to the Sun that its temperature can reach over 400 Celsius. But because this M-dwarf star is comparatively cool the orbit of its third planet, even though much closer to the star than Mercury is to the Sun, places it in the habitable zone – the region within which the temperatures allow surface water (if any) to remain liquid when there is also an atmosphere. That makes this Earth-sized planet TOI-700d particularly interesting as a potential host for life.

The TESS detections were exciting but uncertain: the signals were faint and a small possibility remained that the TOI-700d detection was spurious. Because of the potential importance of finding a nearby Earth-sized planet in a habitable zone, the TESS scientists turned to the IRAC camera on the Spitzer Space Observatory for confirmation. Before being turned off by NASA in February 2020, the IRAC camera was by far the most sensitive near infrared camera in space.

TOI-700 Schematic

A schematic of the planets around the nearby M dwarf star TOI-700, discovered by TESS. The third (the farthest planet from the star), TOI-700d, lies within the star’s habitable zone (shown in green). Using the IRAC camera on Spitzer, the team refined the planet’s mass as 2.1 Earth-masses and 1.14 Earth-radii. (The scale shows 0.2 astronomical units; AU being the average Earth-Sun distance.) Credit: Rodriguez et al 2020

The TESS team observed TOI-700 with IRAC in October of 2019 and January of 2020, acquiring clear detections of the planets with about twice the signal-to-noise of TESS, enough to give a 61% improvement in the planet’s orbit and to significantly refine our knowledge of its other characteristics, refining the radius as above and finding the mass to be 2.1 Earth-masses. The results, especially when compared with other planets’ properties, suggest that this planet may be rocky and likely to be “tidally locked” with one side of the planet always facing the star.

If there were liquid water on the surface of TOI-700d, the astronomers argue, there would also be water-bearing clouds in the atmosphere, and the team uses climate system models to estimate its possible properties and what more sensitive measurements might find. They conclude, however, that pending space missions, including JWST, will probably lack the sensitivity to detect atmospheric features by a factor of ten or more. Their detailed climate studies will nevertheless help astronomers constrain the kinds of telescopes and instruments that will be needed to investigate this exciting new neighbor.

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NASA’s Transiting Exoplanet Survey Satellite (TESS) has discovered its first Earth-size planet in its star’s habitable zone, the range of distances where conditions may be just right to allow the presence of liquid water on the surface. Scientists confirmed the find, called TOI 700 d, using NASA’s Spitzer Space Telescope and have modeled the planet’s potential environments to help inform future observations. Credit: NASA’s Goddard Space Flight Center


“The First Habitable-zone Earth-sized Planet from TESS. I. Validation of the TOI-700 System” by Emily A. Gilbert, Thomas Barclay, Joshua E. Schlieder, Elisa V. Quintana, Benjamin J. Hord, Veselin B. Kostov, Eric D. Lopez, Jason F. Rowe, Kelsey Hoffman, Lucianne M. Walkowicz, Michele L. Silverstein, Joseph E. Rodriguez, Andrew Vanderburg, Gabrielle Suissa, Vladimir S. Airapetian, Matthew S. Clement, Sean N. Raymond, Andrew W. Mann, Ethan Kruse … Benjamin J. Shappee, Mackennae Le Wood and Jennifer G. Winters, 14 August 2020, The Astronomical Journal.
DOI: 10.3847/1538-3881/aba4b2

“The First Habitable-zone Earth-sized Planet from TESS. II. Spitzer Confirms TOI-700 d” by Joseph E. Rodriguez, Andrew Vanderburg, Sebastian Zieba, Laura Kreidberg, Caroline V. Morley, Jason D. Eastman, Stephen R. Kane, Alton Spencer, Samuel N. Quinn, Ryan Cloutier, Chelsea X. Huang, Karen A. Collins, Andrew W. Mann, Emily Gilbert, Joshua E. Schlieder, Elisa V. Quintana, Thomas Barclay, Gabrielle Suissa, Ravi kumar Kopparapu … Philip S. Muirhead, Elisabeth Newton, Mark E. Rose, Joseph D. Twicken and Jesus Noel Villaseñor, 14 August 2020, The Astronomical Journal.
DOI: 10.3847/1538-3881/aba4b3

“The First Habitable-zone Earth-sized Planet from TESS. III. Climate States and Characterization Prospects for TOI-700 d” by Gabrielle Suissa, Eric T. Wolf, Ravi kumar Kopparapu, Geronimo L. Villanueva, Thomas Fauchez, Avi M. Mandell, Giada Arney, Emily A. Gilbert, Joshua E. Schlieder, Thomas Barclay, Elisa V. Quintana, Eric Lopez, Joseph E. Rodriguez and Andrew Vanderburg, 14 August 2020, The Astronomical Journal.
DOI: 10.3847/1538-3881/aba4b4

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Scientists Peer Inside an Asteroid – Is Bennu in the Process of Spinning Itself Into Pieces? – SciTechDaily



OSIRIS REx Arrives at Asteroid Bennu

This series of images taken by the OSIRIS-REx spacecraft shows Bennu in one full rotation from a distance of around 50 miles (80 km). The spacecraft’s PolyCam camera obtained the thirty-six 2.2-millisecond frames over a period of four hours and 18 minutes. Credit: NASA’s Goddard Space Flight Center/University of Arizona

New findings from NASA’s OSIRIS-REx mission suggest that the interior of the asteroid Bennu could be weaker and less dense than its outer layers—like a crème-filled chocolate egg flying though space.

The results appear in a study published in the journal Science Advances and led by the University of Colorado Boulder’s OSIRIS-REx team, including professors Daniel Scheeres and Jay McMahon. The findings could give scientists new insights into the evolution of the solar system’s asteroids—how bodies like Bennu transform over millions of years or more.  

OSIRIS-REx rendezvoused with Bennu, an asteroid orbiting the sun more than 200 million miles from Earth, in late 2018. Since then, the spacecraft, built by Colorado-based Lockheed Martin, has studied the object in more detail than any other asteroid in the history of space exploration.

So far, however, one question has remained elusive: What’s Bennu like on the inside?

Bennu Orbit Diagram

Diagram of the orbit of Bennu in relation to Earth and other planets. Credit: NASA/Goddard/University of Arizona/Lockheed Martin

Scheeres, McMahon and their colleagues on the mission’s radio science team now think that they have an answer—or at least part of one. Using OSIRIS-REx’s own navigational instruments and other tools, the group spent nearly two years mapping out the ebbs and flows of Bennu’s gravity field. Think of it like taking an X-ray of a chunk of space debris with an average width about the height of the Empire State Building.

“If you can measure the gravity field with enough precision, that places hard constraints on where the mass is located, even if you can’t see it directly,” said Andrew French, a coauthor of the new study and a former graduate student at CU Boulder, now at NASA’s Jet Propulsion Laboratory (JPL).

What the team has found may also spell trouble for Bennu. The asteroid’s core appears to be weaker than its exterior, a fact that could put its survival at risk in the not-too-distant future.

“You could imagine maybe in a million years or less the whole thing flying apart,” said Scheeres, a distinguished professor in the Ann and H.J. Smead Department of Aerospace Engineering Sciences.

Evolution of asteroids

Of course, that’s part of the fun of studying asteroids. Scheeres explained that Bennu belongs to a class of smaller bodies that scientists call “rubble pile” asteroids—which, as their name suggests, resemble loosely held-together mounds of debris. 

Asteroids also change over time more than people think. 

“None of them have sat out there unchanging since the dawn of the solar system,” Scheeres said. “They’re being changed by things like sunlight affecting how they spin and collisions with other asteroids.”

To study how Bennu and other similar asteroids may change, however, he and his colleagues needed to take a peek inside.

Asteroid Bennu Particles

OSIRIS-REx observed small bits of material leaping off the surface of the asteroid Bennu on January 19, 2019. Credit: NASA/Goddard/University of Arizona/Lockheed Martin

This is where the team got lucky. When OSIRIS-REx first arrived at Bennu, the spacecraft spotted something unusual: Over and over again, tiny bits of material, some just the size of marbles, seemed to pop off the asteroid and into space. In many cases, those particles circled Bennu before falling back down to the surface. Members of the mission’s radio science team at JPL were able to witness how the body’s gravity worked first-hand—a bit like the apocryphal story of Isaac Newton inferring the existence of gravity after observing an apple falling on his head. 

“It was a little like someone was on the surface of the asteroid and throwing these marbles up so they could be tracked,” Scheeres said. “Our colleagues could infer the gravity field in the trajectories those particles took.”

Squishy center

In the new study, Scheeres and his colleagues combined those records of Bennu’s gravity at work with data from OSIRIS-REx itself—precise measurements of how the asteroid tugged on the spacecraft over a period of months. They discovered something surprising: Before the mission began, many scientists had assumed that Bennu would have a homogenous interior. As Scheeres put it, “a pile of rocks is a pile of rocks.” 

But the gravity field measurements suggested something different. To explain those patterns, certain chunks of Bennu’s interior would likely need to be more tightly packed together than others. And some of the least dense spots in the asteroid seemed to lie around the distinct bulge at its equator and at its very core.

“It’s as if there is a void at its center, within which you could fit a couple of football fields,” Scheeres said.

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Now, thanks to laser altimetry data and high-resolution imagery from OSIRIS-REx, we can take a tour of Bennu’s remarkable terrain. Credit: NASA’s Goddard Space Flight Center

The asteroid’s spin may be responsible for that void. Scientists know that the asteroid is spinning faster and faster over time. That building momentum could, Scheeres said, be slowly pushing material away from the asteroid’s center and toward its surface.  Bennu, in other words, may be in the process of spinning itself into pieces.

“If its core has a low density, it’s going to be easier to pull the entire asteroid apart,” Scheeres said.

For the scientist, the new findings are bittersweet: After measuring Bennu’s gravity field, Scheeres and his team have mostly wrapped up their work on the OSIRIS-REx mission. 

Their results have contributed to the mission’s sample analysis plan—currently in development. The returned sample will be analyzed to determine the cohesion between grains—a key physical property that affects the mass distribution observed in their study.

“We were hoping to find out what happened to this asteroid over time, which can give us better insight into how all of these small asteroids are changing over millions, hundreds of millions or even billions of years,” Scheeres said. “Our findings exceeded our expectations.”

Read Asteroid Bennu Secrets Unlocked by NASA’s OSIRIS-REx Ahead of Historic Heist for more on this and related research.

“Heterogeneous mass distribution of the rubble-pile asteroid (101955) Bennu” by D. J. Scheeres, A. S. French, P. Tricarico, S. R. Chesley, Y. Takahashi, D. Farnocchia, J. W. McMahon, D. N. Brack, A. B. Davis, R.-L. Ballouz, E. R. Jawin, B. Rozitis, J. P. Emery, A. J. Ryan, R. S. Park, B. P. Rush, N. Mastrodemos, B. M. Kennedy, J. Bellerose, D. P. Lubey, D. Velez, A. T. Vaughan, J. M. Leonard, J. Geeraert, B. Page, P. Antreasian, E. Mazarico, K. Getzandanner, D. Rowlands, M. C. Moreau, J. Small, D. E. Highsmith, S. Goossens, E. E. Palmer, J. R. Weirich, R. W. Gaskell, O. S. Barnouin, M. G. Daly, J. A. Seabrook, M. M. Al Asad, L. C. Philpott, C. L. Johnson, C. M. Hartzell, V. E. Hamilton, P. Michel, K. J. Walsh, M. C. Nolan and D. S. Lauretta, 8 October 2020, Science Advances.
DOI: 10.1126/sciadv.abc3350

The University of Arizona leads science operations for OSIRIS-REx. NASA’s Goddard Space Flight Center in Maryland manages the overall mission.

Other coauthors on the new study include researchers at the Jet Propulsion Laboratory, Smithsonian Institution, The Open University, Northern Arizona University, KinetX Aerospace, Inc., NASA Goddard Space Flight Center, University of Maryland, Johns Hopkins University, York University, University of British Columbia, Southwest Research Institute, Université Côte d’Azur and University of Arizona.

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