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Astronomy & Space

Cassini mosaic captures moon sculpting Saturn’s rings – Astronomy Now

June 14, 2019 • By
A mosaic made up of photographs in the course of the Cassini spacecraft’s last orbits of Saturn reveals new insights into how the small moon Daphnis gravitationally sculpts close by ring materials into rippling waves. Click on on the picture for a zoomed-in view. Picture: NASA/JPL-Caltech/Area Science Institute

NASA’s Cassini mission resulted in 2017 with a deliberate plunge into Saturn’s environment. However information and pictures captured in the course of the spacecraft’s last, closest-ever passes by the planet’s rings proceed to disclose new particulars in regards to the composition of the system and the way small moons gravitationally sculpt ring particles into delicate textures and patterns.

“It’s like turning the power up one more notch on what we could see in the rings,” stated Cassini Challenge Scientist Linda Spilker. “Everyone just got a clearer view of what’s going on. Getting that extra resolution answered many questions, but so many tantalising ones remain.”

The analysis, showing within the journal Science, applies not simply to the dynamics of Saturn’s rings. It additionally sheds gentle on how astrophysical disc type an evolve, together with the protoplanetary discs that give rise to total photo voltaic programs.

“These new details of how the moons are sculpting the rings in various ways provide a window into solar system formation, where you also have disks evolving under the influence of masses embedded within them,” stated lead writer and Cassini scientist Matt Tiscareno of the SETI Institute in Mountain View, California.

In a spectacular mosaic, Saturn’s tiny moon Daphnis could be seen embedded within the rings, its gravity clearing out a area generally known as the Keeler hole, trailing three waves within the hole’s periphery. The crests of the waves diminish in measurement the farther they’re from the moon as ring particles work together and collide.

A closeup displaying how probably the most distant crest within the waves trailing Daphnis breaks down as ring particles jostle about within the moon’s gravitational wake. Picture: NASA/JPL-Caltech/Area Science Institute

The sculpting generated by Daphnis already was effectively documented, however the brand new evaluation reveals a number of beforehand unseen options, together with skinny strands of ring materials spreading out because the extra distant crests diminish and break up. The pictures making up the mosaic have been captured at a distance of about 28,000 kilometres (17,000 miles) from Daphnis.

“This tells us the way the rings look is not just a function of how much material there is,” Tiscareno stated. “There has to be something different about the characteristics of the particles, perhaps affecting what happens when two ring particles collide and bounce off each other. And we don’t yet know what it is.”

Cassini’s Seen and Infrared Mapping Spectrometer revealed one more thriller, discovering a surprisingly weak sign for water ice in Saturn’s outermost A hoop, a extremely reflective area thought to include comparatively uncontaminated ice bands. As well as, no natural compounds have been detected and no detectable quantities of ammonia ice or methane ice.

“If organics were there in large amounts, at least in the main A, B and C rings, we’d see them,” stated Phil Nicholson, Cassini VIMS scientist of Cornell College. “I’m not convinced yet that they are a major component of the main rings.”


Astronomy & Space

Hubble screens galactic host of a number of supernova blasts – Astronomy Now

June 12, 2019 • By

Some 45 gentle years from Earth, the galaxy NGC 4051 was found within the constellation Ursa Main by John Herschel in 1788. It’s a part of a spiral-rich subset of the Virgo supercluster of galaxies that features the Milky Means. Categorised as a Seyfert galaxy, NGC 4051 hosts a supermassive black gap in its core with 1.7 million instances the mass of the Solar. A number of supernovae blasts have been noticed within the galaxy over the previous a number of a long time, the primary in 1983 and the latest in 2010 when the core of an enormous star that had already misplaced its outer layers of hydrogen and helium exploded in a sort 1c supernova. Such explosions are generally known as stripped core-collapse supernovae. This fantastically rendered view of NGC 4051 was captured by the Hubble House Telescope.

NGC 4051. Picture: ESA/Hubble & NASA, D. Crenshaw and O. Fox


Astronomy & Space

Simulations deal with black hole-accretion disc alignment – Astronomy Now

June 10, 2019 • By

Essentially the most-detailed laptop simulations of a black gap to this point have lastly confirmed the innermost areas of a gap’s accretion disc – the encircling fuel and mud that orbit the singularity and finally fall in – is aligned with the outlet’s equator. Whereas that may appear obvious, it took greater than 4 a long time to convincingly resolve.

Computational astrophysicists from Northwestern College, the College of Amsterdam and the College of Oxford completed the feat utilizing graphical processing unites, or GPUs, to extra effectively course of big quantities of information.

The staff discovered that whereas the outer areas of an accretion disc can stay tilted, the innermost area aligns with the black gap’s equator with a clean “warp” connecting the 2 areas. In 1975, Jim Bardeen and Jacobus Petterson argued {that a} spinning black gap would consequence within the interior area aligned with the equatorial airplane, precisely what the pc simulations revealed.

“This groundbreaking discovery of Bardeen-Petterson alignment brings closure to a problem that has haunted the astrophysics community for more than four decades,” stated Northwestern’s Alexander Tchekhovskoy, a co-leader of the brand new analysis. “These details around the black hole may seem small, but they enormously impact what happens in the (host) galaxy as a whole. They control how fast the black holes spin and, as a result, what effect black holes have on their entire galaxies.”

Matthew Liska, a researcher on the College of Amsterdam and first creator of a paper outlining the outcomes, stated the simulations “not solely remedy a 40-year-old drawback, however they’ve demonstrated that, opposite to typical considering, it’s potential to simulate essentially the most luminous accretion disks in full basic relativity.

“This paves the way for a next generation of simulations, which I hope will solve even more important problems surrounding luminous accretion disks.”

A picture of a simulated black gap an a tilted accretion disc with a facet ration of 0.03, the thinnest ever simulation. The picture exhibits the interior areas of the disc are aligned with the spinning black gap’s equator as predicted greater than 40 years in the past. Picture: Liska/Tchekhovskoy et al

Black holes can’t be instantly noticed as a result of their concentrated gravity stop radiation from escaping. However fuel in an accretion disc will get heated to monumental temperatures because it spirals round a black gap, radiating throughout the electromagnetic spectrum and giving astronauts a direct have a look at the consequences of the outlet’s gravity.

Accretion discs management how briskly a black gap grows and how briskly it spins.

“Alignment affects how accretion disks torque their black holes,” Tchekhovskoy stated. “So it affects how a black hole’s spin evolves over time and launches outflows that impact the evolution of their host galaxies.”

Till now, simulations have been too simplified to pin down the Bardeen-Petterson alignment for 2 major causes. Near a black gap, materials within the accretion disc is shifting at greater and better relativistic velocities in an setting the place the outlet’s rotation is warping the material of space-time. As well as, magnetic results play a task.

Liska and Tchekhovskoy developed new computational methods that allowed them to mannequin a particularly skinny accretion disc, one with a height-to-radius ratio of 0.03. They instantly noticed the expected alignment subsequent to the black gap.

“The thinnest disks simulated before had a height-to-radius ratio of 0.05, and it turns out that all of the interesting things happen at 0.03,” Tchekhovskoy stated. “Nobody expected jets to be produced by these disks at such slight thicknesses. People expected that the magnetic fields that produce these jets would just rip through these really thin disks. But there they are. And that actually helps us resolve observational mysteries.”

The simulations have been carried out utilizing the Blue Waters supercomputers on the U.S. Nationwide Middle for Supercomputing Functions on the College of Illinois at Urbana-Champaign.


Astronomy & Space

Polarisation examine finds no new proof for cosmic “anomalies” – Astronomy Now

June 8, 2019 • By
On this visualisation of the polarisation of the Cosmic Microwave Background as seen by ESA’s Planck spacecraft, there are not any apparent indicators of large-scale “anomalies” seen in an earlier map based mostly on temperature. Picture: ESA and the Planck Collaboration

ESA’s Planck satellite tv for pc has discovered no new proof for the puzzling cosmic anomalies that appeared in its temperature map of the Universe. The newest examine doesn’t rule out the potential relevance of the anomalies however they do imply astronomers should work even more durable to know the origin of those puzzling options.

Planck’s newest outcomes come from an evaluation of the polarisation of the Cosmic Microwave Background (CMB) radiation – essentially the most historic gentle in cosmic historical past, launched when the Universe was simply 380 000 years outdated.

The satellite tv for pc’s preliminary evaluation, which was made public in 2013, targeting the temperature of this radiation throughout the sky. This enables astronomers to research the origin and evolution of the cosmos. Whereas it largely confirmed the usual image of how our Universe evolves, Planck’s first map additionally revealed a variety of anomalies which can be tough to clarify inside the usual mannequin of cosmology.

The anomalies are faint options on the sky that seem at giant angular scales. They’re positively not artefacts produced by the behaviour of the satellite tv for pc or the info processing, however they’re faint sufficient that they may very well be statistical flukes – fluctuations that are extraordinarily uncommon however not totally dominated out by the usual mannequin.

Alternatively, the anomalies may be an indication of ‘new physics’, the time period used for as-yet unrecognised pure processes that will lengthen the recognized legal guidelines of physics.
The historical past of the Universe

To additional probe the character of the anomalies, the Planck group regarded on the polarisation of the CMB, which was revealed after a painstaking evaluation of the multi-frequency knowledge designed to remove foreground sources of microwave emission, together with gasoline and mud in our personal Milky Method galaxy.

This sign is the very best measurement so far of the so-called CMB polarisation E-modes, and dates again to the time when the primary atoms shaped within the Universe and the CMB was launched. It’s produced by the way in which gentle scattered off electron particles simply earlier than the electrons have been gathered into hydrogen atoms.

Polarisation gives an virtually unbiased view of the CMB, so if the anomalies have been additionally to indicate up there, this is able to improve astronomers’ confidence that they may very well be attributable to new physics somewhat than being statistical flukes.

Whereas Planck was not initially designed to give attention to polarisation, its observations have been used to create essentially the most correct all-sky maps of the CMB polarisation so far. These have been printed in 2018, enormously enhancing the standard of Planck’s first polarisation maps, launched in 2015.
The CMB polarisation on giant angular scales

When the Planck group checked out this knowledge, they noticed no apparent signal of the anomalies. At finest, the evaluation, printed as we speak in Astronomy and Astrophysics, revealed some weak hints that among the anomalies could also be current.

“Planck’s polarisation measurements are fantastic,” says Jan Tauber, ESA Planck mission scientist. “Yet in spite of the great data we have, we don’t see any significant traces of anomalies.”


Astronomy & Space

Observers urged to observe Jupiter’s ‘unravelling’ Nice Pink Spot – Astronomy Now

June 6, 2019 • By

Dramatic modifications within the look of Jupiter’s Nice Pink Spot (GRS) in lower than three Earth Days. The GRS made seven circuits of the planet within the interval between these two pictures captured by Australian beginner astronomer Anthony Wesley on 25 and 28 Could (AEST dates). Interactions with Jupiter’s South Equatorial Belt (SEB) seem like peeling materials from the GRS on a roughly weekly foundation. These filaments, a few of that are 10,000 kilometres lengthy or extra, type a brief bridge between the GRS and the SEB. NASA’s Juno spacecraft presently orbiting Jupiter hopes to take a more in-depth look when it passes over the function in late July 2019. Picture credit: Anthony Wesley, AN animation: Ade Ashford.

The Nice Pink Spot (GRS) is the photo voltaic system’s largest identified storm, an Earth-sized anticyclone boasting wind speeds approaching 400 kilometres per hour that has raged within the ambiance of Jupiter for at the very least two centuries. However current observations from Earth and house recommend that this iconic Jovian function is present process monumental modifications that would herald the storm’s demise. With Jupiter presently so near Earth, there’s no higher time to search for these dramatic modifications your self.

Historical past of commentary
Whereas it’s doable that the GRS is similar storm found by Italian astronomer Giovanni Cassini in 1665, the primary particular observations of the Nice Pink Spot date again to drawings made by German astronomer Samuel Heinrich Schwabe in 1831. The storm’s placing color in 1878 led American astronomer Carr W. Pritchett to coin the identify we use at this time, and the function has been noticed constantly since.

What’s the GRS?
The Nice Pink Spot is an anticyclone climate function that rotates counter-clockwise with a interval of about six Earth days. Different Jovian cloud layers intermittently cowl it resulting in modifications in color, however usually, the GRS cloud tops are colder and prolong 8 kilometres above their environment. The storm’s longevity is partly as a result of Jupiter has no land lots or strong floor to trigger it to lose power resulting from friction.

Altering measurement
Within the glory days of the Nice Pink Spot within the 19th century, the function was a big oval some 48,000 kilometres (30,000 miles) lengthy, nevertheless it was solely half that size by the point the Voyager spacecraft visited Jupiter 40 years in the past. The storm has develop into extra rounded in recent times, however its decline continues; it’s presently below 16,000 kilometres lengthy.

Why is the GRS crimson?
The explanation for the storm’s signature hue is unknown, however theories recommend that compounds of phosphorus and sulfur or the Solar’s ultraviolet gentle appearing on ammonium hydrosulfide and acetylene in Jupiter’s outer ambiance might create natural compounds referred to as tholins that may account for the crimson color.

What’s now taking place to the GRS?
The Nice Pink Spot lies south of Jupiter’s South Equatorial Belt (SEB), constrained to a latitude near 22 levels south of the planet’s equator by easterly jet streams to the north and a westerly jet to the south. Lately, observers have witnessed interactions with Jupiter’s SEB that seem like peeling materials from the GRS on a roughly weekly foundation. These filaments, a few of that are 10,000 kilometres lengthy or extra, type a brief bridge between the GRS and the SEB.

Picture credit score: Anthony Wesley, AN graphic: Ade Ashford.

Current footage captured by two famend beginner astroimagers, Anthony Wesley in Australia and Christopher Go within the Philippines, reveal that the Nice Pink Spot now sports activities a curved darkish bridge between Jupiter’s South Equatorial Belt and the Nice Pink Spot. However these occasions haven’t simply been seen on Earth. NASA’s Juno spacecraft presently orbiting Jupiter hopes to take a more in-depth have a look at the GRS when it passes over the function in late July 2019, however mission scientists have witnessed buildings described as flakes or blades detaching from the GRS with rising frequency since 2017.

When to see the Nice Pink Spot
Since Jupiter is a gaseous physique, it rotates quicker on the equator in comparison with the poles. On the southerly Jovian latitude of the Nice Pink Spot’s, cloud options make one rotation in regards to the planet about each 9h 56m. Nevertheless, the GRS is free to float in Jovian longitude in a considerably random method, so observations are used to refine predictions of when the function is finest positioned to see from Earth.

The Nice Pink Spot is best to view (tip: a blue filter in your telescope’s eyepiece helps) when it crosses the imaginary line becoming a member of Jupiter’s north and south poles. At such occasions we are saying that the GRS is ‘in transit’, although the storm is observable for as much as an hour or so both facet of the transit time.

The desk above lists predicted transits of Jupiter’s Nice Pink Spot (GRS) seen from Western Europe and the British Isles, with these finest seen from the UK highlighted in gray. Information credit score: Information 9.1.

For basic info on observing Jupiter, see this text.


Astronomy & Space

Double asteroid tracked by VLT in planetary defence take a look at – Astronomy Now

June 4, 2019 • By
The left body reveals asteroid 1999 KW4 as imaged by the European Southern Observatory’s Very Massive Telescope and the SPHERE planet-hunting instrument. The picture on the proper is an artist’s impression of the double asteroid. Picture: ESO

The European Southern Observatory’s Very Massive Telescope participated in take a look at coordinated by the Worldwide Asteroid Warning Community, efficiently concentrating on, monitoring and imaging a double asteroid because it flew inside 5.2 million kilometres (3.2 million miles) of Earth on 25 Might.

Utilizing the delicate SPHERE planet-finding instrument connected to VLT’s Unit Three telescope, together with state-of-the-art adaptive optics, asteroid 1999 KW4’s two elements, separated by simply 2.6 kilometres (1.6 miles), had been clearly seen regardless of their fast monitor throughout the sky and considerably unstable air above the observatory.

The double asteroid was shifting by area at some 77,000 kilometres per hour (48,000 mph). Whereas the bigger member of the pair has a diameter of about 1.Three kilometres (0.eight mile), the duo’s orbit is well-known and there’s no danger of influence with Earth.

However by learning the passing asteroids with a wide range of devices, the IAWN marketing campaign goals to study extra about detecting, monitoring and learning threatening asteroids to offer engineers and scientists time to develop attainable countermeasures.

“These data, combined with all those that are obtained on other telescopes through the IAWN campaign, will be essential for evaluating effective deflection strategies in the event that an asteroid was found to be on a collision course with Earth,” mentioned ESO astronomer Olivier Hainaut.

“In the worst possible case, this knowledge is also essential to predict how an asteroid could interact with the atmosphere and Earth’s surface, allowing us to mitigate damage in the event of a collision.”

Imaging asteroid 1999 KW4 was a problem for the VLT given its distance and fast motion throughout the sky. Picture: ESO

Observing the fast-moving double asteroid was a serious problem for operators of ESO’s VLT.

“During the observations the atmospheric conditions were a bit unstable,” mentioned Mathias Jones, a VLT astronomer. “In addition, the asteroid was relatively faint and moving very fast in the sky, making these observations particularly challenging, and causing the AO system to crash several times. It was great to see our hard work pay off despite the difficulties.”

1999 KW4 is comparable in look to Didymos, a double asteroid made up of a 780-metre-wide (2,560-foot-wide) part – Didymos A – and a smaller sibling measuring 160 metres (525 toes) throughout.

Assuming funding questions are resolved, NASA’s Double Asteroid Redirection Check, or DART, spacecraft will intentionally crash into Didymos B in 2022 in an try to barely change its orbital velocity and in so doing, display the feasibility of deflecting a threatening asteroid. Observations like these of 1999 KW4 shall be carried out to doc the mission’s outcomes.


Astronomy & Space

NASA funds industrial moon landers for science, exploration – Astronomy Now

June 2, 2019 • By
An artist’s impression of a industrial moon lander. NASA is funding private-sector improvement of recent landers to hold devices and sensors to the moon to assist pave the way in which for astronaut landings in 2024. Picture: NASA

Below contracts valued at $253.5 million, NASA is funding three fast-track moon landers in a program meant to kick-start private-sector exploration and expertise improvement, key parts within the area company’s drive to return astronauts to the moon’s floor in 2024.

Orbit Past of Edison, New Jersey, was awarded $97 million to construct and launch its Z-01 spacecraft as a secondary payload on a SpaceX Falcon 9 rocket, touchdown on Mare Imbrium by September 2020.

Astrobotic of Pittsburgh, Pennsylvania, gained $79.5 million to develop its Peregrine lander to hold 14 NASA payloads to a landing at Lacus Mortis in July 2021. The corporate has not but specified a launcher.

Intuitive Machines of Houston, Texas, is receiving $77 million for its Nova-C spacecraft, certain for a touchdown in Oceanus Procellarum, additionally in July 2021. A Falcon 9 shall be used to launch the Nova-C.

“This is a new era for the moon,” John Thornton, Astrobotic CEO, mentioned when the contracts have been introduced 31 Might. “It’s been almost 50 years since we’ve been back as a country. Now we’re going back, we’re going to have regular, routine access to the moon in ways we’ve never experienced before. Our scientists are going to get really, really smart about that’s up there. This is a whole new era, an incredibly exciting time.”

The contracts are managed by NASA’s Industrial Lunar Payload Companies, or CLPS, program, which has authority to award as much as $2.6 billion in contracts over a 10-year interval. The objective is to fund non-public improvement of area methods and infrastructure that NASA can then use to ship science payloads to lunar orbit or the floor.

Future contracts are anticipated to fund missions that may ship landers to the moon’s south polar area to discover ice deposits in completely shadowed areas the place future astronauts could possibly extract air, water and even rocket gasoline. That’s the place NASA plans to ship the primary crew within the new Artemis moon program.

“These CLPS providers are really leading the way for our return to the moon as part of the Artemis program, these are precursor missions prior to us landing the first woman and the next man on the surface of the moon in 2024,” mentioned Steve Clarke, deputy affiliate administrator for exploration at NASA Headquarters.

“NASA is one of many customers,” he mentioned of the landers. “We are buying a ride, essentially. … We are looking for these providers to deliver our payloads to the surface. They are responsible for the launch, the lander itself, landing it and making sure we can operate our instruments on the surface of the moon.”

Officers with all three firms mentioned the preliminary touchdown missions will set the stage for extra intensive industrial improvement within the years forward.

“I think it’s going to create a new era, a new ecosystem for commercial companies to really explore space,”mentioned Kam Ghaffarian, govt chairman of Intuitive Machines. “I truly believe commercial space in general, whether it’s low Earth orbit or deeper space exploration is just beginning. It’s going to be a truly exciting journey.”


Astronomy & Space

Curiosity confirms clay deposits on slopes of Mount Sharp – Astronomy Now

May 31, 2019 • By
A selfie captured by the Curiosity Mars rover on 12 Might is made up of 57 photos taken by the Mars Hand Lens Imager digital camera on the top of the automobile’s robotic arm. Two current drill holes, referred to as Aberlady and Kilmarie, are seen simply in entrance of the rover at decrease left. Picture: NASA/JPL-Caltech/MSSS

NASA’s Curiosity Mars rover has confirmed the presence of clay deposits on the slopes of Mount Sharp the place orbiting spacecraft first detected their presence. Curiosity lately drilled and picked up two samples from rock formations referred to as Aberlady and Kilmarie exhibiting the best quantities of clay minerals but detected by the rover’s Chemistry and Mineralogy instrument, or CheMin.

Each drill targets are seen in a self portrait of Curiosity assembled from 57 photos taken taken on 12 Might, the rover’s 2,405th day, or sol, on Mars.

Clay usually kinds within the presence of water – a key ingredient for the evolution of life as it’s identified on Earth – and Curiosity’s newest findings add extra proof {that a} vital quantity of water as soon as pooled and flowed in Gale Crater. Whereas the small print stay a topic of debate, it’s probably that rocks within the space Curiosity is exploring initially fashioned as layers of mud in historic lakes.

As Curiosity climbs greater up the slopes of Mount Sharp, it’s anticipated to maneuver into youthful areas with geology reflecting an environmental change to a drier local weather. How Mars transitioned from a hotter, wetter world into the chilly, arid planet seen right this moment is a significant space of curiosity to planetary scientists.

So is the martian climate. Together with gathering soil samples for evaluation, Curiosity used its black-and-white Navigation Cameras, or NAVCAMs, to {photograph} drifting clouds above Mount Sharp. The clouds are considered made up of water ice crystals at an altitude of about 30 kilometres (19 miles) above the floor.

Curiosity photographed noctilucent water-ice clouds drifting 30 kilometres (19 miles) overhead on 17 Might, excessive sufficient for the clouds to be illuminated by daylight though the rover was in nighttime darkness on the floor. Picture: NASA/JPL-Caltech