Wednesday, November 19, 2014

Amazingly Detailed New Maps of Asteroid Vesta

Amazingly Detailed New Maps of Asteroid Vesta:



Artist's concept of the Dawn spacecraft arriving at Vesta. Image credit: NASA/JPL-Caltech


Artist’s concept of the Dawn spacecraft arriving at Vesta. Credit: NASA/JPL-Caltech
Vesta is one of the largest asteroids in the Solar System. Comprising 9% of the mass in the Asteroid Belt, it is second in size only to the dwarf-planet Ceres. And now, thanks to data obtained by NASA’s Dawn spacecraft, Vesta’s surface has been mapped out in unprecedented detail.
These high-resolution geological maps reveal the variety of Vesta’s surface features and provide a window into the asteroid’s history.

“The geologic mapping campaign at Vesta took about two-and-a-half years to complete, and the resulting maps enabled us to recognize a geologic timescale of Vesta for comparison to other planets,” said David Williams of Arizona State University.


Geological mapping is a technique used to derive the geologic history of a planetary object from detailed analysis of surface morphology, topography, color and brightness information. The team found that Vesta’s geological history is characterized by a sequence of large impact events, primarily by the Veneneia and Rheasilvia impacts in Vesta’s early history and the Marcia impact in its late history.

The geologic mapping of Vesta was made possible by the Dawn spacecraft’s framing camera, which was provided by the Max Planck Institute for Solar System Research of the German Max Planck Society and the German Aerospace Center.  This camera takes panchromatic images and seven bands of color-filtered images, which are used to create topographic models of the surface that aid in the geologic interpretation.

A team of 14 scientists mapped the surface of Vesta using Dawn data. The study was led by three NASA-funded participating scientists: Williams; R. Aileen Yingst of the Planetary Science Institute; and W. Brent Garry of the NASA Goddard Spaceflight Center.



This high-res geological map of Vesta is derived from Dawn spacecraft data. Brown colors represent the oldest, most heavily cratered surface. Credit: NASA/JPL-Caltech/ASU


This high-res geological map of Vesta is derived from Dawn spacecraft data. Credit: NASA/JPL-Caltech/ASU
The brown colored sections of the map represent the oldest, most heavily cratered surface. Purple colors in the north and light blue represent terrains modified by the Veneneia and Rheasilvia impacts, respectively. Light purples and dark blue colors below the equator represent the interior of the Rheasilvia and Veneneia basins. Greens and yellows represent relatively young landslides or other downhill movement and crater impact materials, respectively.

The map indicates the prominence of impact events – such as the Veneneia, Rheasilvia and Marcia impacts, respectively – in shaping the asteroid’s surface. It also indicates that the oldest crust on Vesta pre-dates the earliest Veneneia impact. The relative timescale is supplemented by model-based absolute ages from two different approaches that apply crater statistics to date the surface.

“This mapping was crucial for getting a better understanding of Vesta’s geological history, as well as providing context for the compositional information that we received from other instruments on the spacecraft: the visible and infrared (VIR) mapping spectrometer and the gamma-ray and neutron detector (GRaND),” said Carol Raymond, Dawn’s deputy principal investigator at NASA’s Jet Propulsion Laboratory in Pasadena, California.

The objective of NASA’s Dawn mission is to characterize the two most massive objects in the main asteroid belt between Mars and Jupiter – Vesta and the dwarf planet Ceres.



These Hubble Space Telescope images of Vesta and Ceres show two of the most massive asteroids in the asteroid belt, a region between Mars and Jupiter. Credit: NASA/European Space Agency


These Hubble Space Telescope images of Vesta and Ceres show two of the most massive asteroids in the asteroid belt. Credit: NASA/European Space Agency
Asteroids like Vesta are remnants of the formation of the solar system, giving scientists a peek at its early history. They can also harbor molecules that are the building blocks of life and reveal clues about the origins of life on Earth. Hence why scientists are eager to learn more about its secrets.

The Dawn spacecraft was launched in September of 2007 and orbited Vesta between July 2011 and September 2012. Using ion propulsion in spiraling trajectories to travel from Earth to Vesta, Dawn will orbit Vesta and then continue on to orbit the dwarf planet Ceres by April 2015.

The high resolution maps were included with a series of 11 scientific papers published this week in a special issue of the journal Icarus. The Dawn spacecraft is currently on its way to Ceres, the largest object in the asteroid belt, and will arrive at Ceres in March 2015.

Further Reading: NASA



About 

Author, freelance writer, educator, Taekwon-Do instructor, and loving hubby, son and Island boy!

Lunar Mission One Wants To Crowdfound A Robotic Moon Lander

Lunar Mission One Wants To Crowdfound A Robotic Moon Lander:

Just hours after announcing that it plans to put a robotic lander on the moon in the next decade, the British-led group Lunar Mission One is already a sixth of a way to its £600,000 (US$940,000) initial crowdfunding goal.

The money is intended to jumpstart the project and move it into more concrete stages after seven years of quiet, weekend work, the group said on its Kickstarter page.

“We’ve reached the limit of what we can do part-time. The next three years are going to be hard, full-time work to set the project up. We need to confirm and agree the lunar science and develop the instrument package,” the page read.



Artist's conception of Lunar Mission One's robotic lander touching down on the surface. Credit: Lunar Missions Ltd.


Artist’s conception of Lunar Mission One’s robotic lander touching down on the surface. Credit: Lunar Missions Ltd.
“We need to plan and research the online public archive. We need to get commercial partners on board to design and develop the lunar landing module and the drilling mechanism. We need to pilot the education programme. We need to prepare the sales and marketing campaign for our memory boxes. And we need to do all of this globally.”

Among the rewards is something called a “digital memory box”, where you can upload your favorite sounds to be placed on the spacecraft. The group also plans to offer a little bit of physical space to put a strand of your hair along with the small digital archive.

And what does the group want to do there? Drill. It would place the lander at the Moon’s south pole and push down at least 20 meters (65 feet), potentially as far as 100 meters (328 feet), to learn more about the Moon’s history.



Artist's conception of a moon drill that could potentially be used by Lunar Mission One's lunar lander. Credit: Lunar Missions Ltd.


Artist’s conception of a moon drill that could potentially be used by Lunar Mission One’s lunar lander. Credit: Lunar Missions Ltd.
“By doing this, we will access lunar rock dating back up to 4.5 billion years to discover the geological composition of the Moon, the ancient relationship it shares with our planet and the effects of asteroid bombardment,” the group wrote. “Ultimately, the project will improve scientific understanding of the early Solar System, the formation of our planet and the Moon, and the conditions that initiated life on Earth.”

Private ideas for bold missions is something we’ve heard about repeatedly in the last few years, with initiatives ranging from the Mars One mission to send people on a one-way mission to the Red Planet, to the potential asteroid-mining ventures Planetary Resources and Deep Space Initiatives. As with these other ventures, the nitty gritty in terms of costs, systems and mission plans is still being worked out. This coupled with the long timelines to get these ventures off the ground means that success is not necessarily a guarantee.

Lunar Mission One, however, does have an experienced space hand helping it out: RAL Space, who the Kickstarter campaign page says has helped out with 200 missions. That’s including the high-profile Philae lander that just landed on Comet 67P/Churyumov–Gerasimenko last week and did a brief surge of science before going into hibernation.

For more information on the mission, check out their leading team here and the official website here.



About 

Elizabeth Howell is the senior writer at Universe Today. She also works for Space.com, Space Exploration Network, the NASA Lunar Science Institute, NASA Astrobiology Magazine and LiveScience, among others. Career highlights include watching three shuttle launches, and going on a two-week simulated Mars expedition in rural Utah. You can follow her on Twitter @howellspace or contact her at her website.

Observing Challenge: Watch Asteroid 3 Juno Occult a +7th Magnitude Star Tonight

Observing Challenge: Watch Asteroid 3 Juno Occult a +7th Magnitude Star Tonight:



Stellarium


The position of 3 Juno on the morning of November 20th during the occultation as seen from Portland, Maine. Credit: Stellarium.
One of the better asteroid occultations of 2014 is coming right up tonight, and Canadian and U.S. observers in the northeast have a front row seat.

The event occurs in the early morning hours of Thursday, November 20th, when the asteroid 3 Juno occults the 7.4 magnitude star SAO 117176. The occultation kicks off in the wee hours as the 310 kilometre wide “shadow” of 3 Juno touches down and crosses North America from 6:54 to 6:57 Universal Time (UT), which is 12:54 to 12:57 AM Central, or 1:54 to 1:57 AM Eastern Standard Time.



Steve Preston


The path of tomorrow’s occultation along with the circumstances. Credit: Steve Preston’s Asteroid Occultation website.
The maximum predicted length of the occultation for observers based along the centerline is just over 27 seconds. Note that 3 Juno also shines at magnitude +8.5, so both it and the star are binocular objects. The event will sweep across Winnipeg and Lake of the Woods straddling the U.S. Canadian border, just missing Duluth Minnesota before crossing Lake Superior and over Ottawa and Montreal and passing into northern Vermont and New Hampshire. Finally, the path crosses over Portland Maine, and heads out to sea over the Atlantic Ocean.

Don’t live along the path? Observers worldwide will still see a close pass of 3 Juno and the +7th magnitude star as both do their best to impersonate a close binary pair. If you’ve never crossed spotting 3 Juno off of your astro-“life list,” now is a good time to try.

The position of the target star HIP43357/SAO 117176 is:

Right Ascension: 8 Hours 49’ 54”

Declination: +2° 21’ 44”



Starry Night


A finder chart for 3 Juno and HIP43357. Stars are noted down to +10th magnitude. Created using Starry Night Education software.
Generally, the farther east you are along the track, the higher the pair will be above the horizon when the event occurs, and the better your observing prospects will be in terms of altitude or elevation. From Portland Maine — the last port of call for the shadow of 3 Juno on dry land — the pair will be 35 degrees above the horizon in the constellation of Hydra.



NOAA


The projected sky cover at the time of the occultation. Credit: NWS/NOAA.
As always, the success in observing any astronomical event is at the whim of the weather, which can be fickle in North America in November. As of 48 hours out from the occultation, weather prospects look dicey, with 70%-90% cloud cover along the track. But remember, you don’t necessarily need a fully clear sky to make a successful observation… just a clear view near the head of Hydra asterism. Remember the much anticipated occultation of Regulus by the asteroid 163 Erigone earlier this year? Alas, it went unrecorded due to pesky but pervasive cloud cover. Perhaps this week’s occultation will fall prey to the same, but it’s always worth a try. In asteroid occultations as in free throws, you miss 100% of the shots that you don’t take!



IOTA


The path of the occcultation across eastern North America. Credit: Google Earth/BREIT IDEAS observatory.
Why study asteroid occultations? Sure, it’s cool to see a star wink out as an asteroid passes in front of it, but there’s real science to be done as well. Expect the star involved in Thursday’s occultation to dip down about two magnitudes (six times) in brightness. The International Occultation Timing Association (IOTA) is always seeking careful measurements of asteroid occultations of bright stars. If enough observations are made along the track, a shape profile of the target asteroid emerges. And the possible discovery of an “asteroid moon” is not unheard of using this method, as the background star winks out multiple times.



UT-Juno Occultation


3 Juno as imaged by the 100″ Hooker telescope at the Mt. Wilson observatory at different wavelengths using adaptive optics. Credit: NASA/JPL/The Harvard Smithsonian Center for Astrophysics.
3 Juno was discovered crossing Cetus by astronomer Karl Harding on September 1st, 1804 from the Lilienthal Observatory in Germany. The 3rd asteroid discovered after 1 Ceres and 2 Pallas, 3 Juno ranks 5th in size at an estimated 290 kilometres in diameter. In the early 19th century, 3 Juno was also considered a planet along with these other early discoveries, until the ranks swelled to a point where the category of asteroid was introduced. A denizen of the asteroid belt, 3 Juno roams from 2 A.U.s from the Sun at perigee to 3.4 A.U.s at apogee, and can reach a maximum brightness of +7.4th magnitude as seen from the Earth. No space mission has ever been dispatched to study 3 Juno, although we will get a good look at its cousin 1 Ceres next April when NASA’s Dawn spacecraft enters orbit around the king of the asteroids.

3 Juno reaches opposition and its best observing position on January 29th, 2015.

3 Juno also has an interesting place in the history of asteroid occultations. The first ever predicted and successfully observed occultation of a star by an asteroid involved 3 Juno on February 19th, 1958. Another occultation involving the asteroid on December 11th, 1979 was even more widely observed. Only a handful of such events were caught prior to the 1990s, as it required ultra-precise computation and knowledge of positions and orbits. Today, dozens of asteroid occultations are predicted each month worldwide.

Observing an asteroid occultation can be challenging but rewarding. You can watch Thursday’s event with binoculars, but you’ll want to use a telescope to make a careful analysis. You can either run video during the event, or simply watch and call out when the star dims and brightens as you record audio. Precise timing and pinpointing your observing location via GPS is key, and human reaction time plays a factor as well. Be sure to locate the target star well beforehand. For precise time, you can run WWV radio in the background.

And finally, you also might see… nothing. Asteroid paths have a small amount of uncertainty to them, and although these negative observations aren’t as thrilling to watch, they’re important to the overall scientific effort.

Good luck, and let us know of your observational tales of anguish and achievement!



About 

David Dickinson is an Earth science teacher, freelance science writer, retired USAF veteran & backyard astronomer. He currently writes and ponders the universe from Tampa Bay, Florida.

“Spotters Guide” for Detecting Black Hole Collisions

“Spotters Guide” for Detecting Black Hole Collisions:



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


Black holes are a region in spacetime where intense gravity prevents anything, even light, from escaping. Credit: NASA/JPL-Caltech
When it comes to the many mysteries of the Universe, a special category is reserved for black holes. Since they are invisible to the naked eye, they remain visibly undetected, and scientists are forced to rely on “seeing” the effects their intense gravity has on nearby stars and gas clouds in order to study them.

That may be about to change, thanks to a team from Cardiff University. Here, researchers have achieved a breakthrough that could help scientists discover hundreds of black holes throughout the Universe.



Led by Dr. Mark Hannam from the School of Physics and Astronomy, the researchers have built a theoretical model which aims to predict all potential gravitational-wave signals that might be found by scientists working with the Laser Interferometer Gravitational-Wave Observatory (LIGO) detectors.

These detectors, which act like microphones, are designed to search out remnants of black hole collisions. When they are switched on, the Cardiff team hope their research will act as a sort of “spotters guide” and help scientists pick up the faint ripples of collisions – known as gravitational waves – that took place millions of years ago.



X-ray/radio composite image of two supermassive black holes spiral towards each other near the center of a galaxy cluster named Abell 400. Credit: X-ray: NASA/CXC/AIfA/D.Hudson & T.Reiprich et al.; Radio: NRAO/VLA/NRL


X-ray/radio composite image of two supermassive black holes spiraling towards each other near the center of Abell 400 galaxy cluster. Credit: X-ray: NASA/CXC/AIfA/D.Hudson & T.Reiprich et al.; Radio: NRAO/VLA/NRL
Made up of postdoctoral researchers, PhD students, and collaborators from universities in Europe and the United States, the Cardiff team will work with scientists across the world as they attempt to unravel the origins of the Universe.

“The rapid spinning of black holes will cause the orbits to wobble, just like the last wobbles of a spinning top before it falls over,” Hannam said. “These wobbles can make the black holes trace out wild paths around each other, leading to extremely complicated gravitational-wave signals. Our model aims to predict this behavior and help scientists find the signals in the detector data.”

Already, the new model has been programmed into the computer codes that LIGO scientists all over the world are preparing to use to search for black-hole mergers when the detectors switch on.

Dr Hannam added: “Sometimes the orbits of these spinning black holes look completely tangled up, like a ball of string. But if you imagine whirling around with the black holes, then it all looks much clearer, and we can write down equations to describe what is happening. It’s like watching a kid on a high-speed spinning amusement park ride, apparently waving their hands around. From the side lines, it’s impossible to tell what they’re doing. But if you sit next to them, they might be sitting perfectly still, just giving you the thumbs up.”



Researchers crunched Einstein's theory of general relativity on the Columbia supercomputer at the NASA Ames Research Center to create a three-dimensional simulation of merging black holes. Image Credit: Henze, NASA


Researchers crunched Einstein’s theory of general relativity on the Columbia supercomputer at the NASA Ames Research Center to create a three-dimensional simulation of merging black holes. Credit: Henze, NASA
But of course, there’s still work to do: “So far we’ve only included these precession effects while the black holes spiral towards each other,” said Dr. Hannam. “We still need to work our exactly what the spins do when the black holes collide.”

For that they need to perform large computer simulations to solve Einstein’s equations for the moments before and after the collision. They’ll also need to produce many simulations to capture enough combinations of black-hole masses and spin directions to understand the overall behavior of these complicated systems.

In addition, time is somewhat limited for the Cardiff team. Once the detectors are switched on, it will only be a matter of time before the first gravitational wave-detections are made. The calculations that Dr. Hannam and his colleagues are producing will have to ready in time if they hope to make the most of them.

But Dr. Hannam is optimistic. “For years we were stumped on how to untangle the black-hole motion,” he said. “Now that we’ve solved that, we know what to do next.”

Further Reading: News Center – Cardiff U



About 

Author, freelance writer, educator, Taekwon-Do instructor, and loving hubby, son and Island boy!

Tuesday, November 18, 2014

Macro View Makes Dark Matter Look Even Stranger

Macro View Makes Dark Matter Look Even Stranger:



New research suggests that Dark Matter may exist in clumps distributed throughout our universe. Credit: Max-Planck Institute for Astrophysics


New research suggests that Dark Matter may exist in clumps distributed throughout our universe. Credit: Max-Planck Institute for Astrophysics
We know dark matter exists. We know this because without it and dark energy, our Universe would be missing 95.4% of its mass. What’s more, scientists would be hard pressed to explain what accounts for the gravitational effects they routinely see at work in the cosmos.

For decades, scientists have sought to prove its existence by smashing protons together in the Large Hadron Collider. Unfortunately, these efforts have not provided any concrete evidence.

Hence, it might be time to rethink dark matter. And physicists David M. Jacobs, Glenn D. Starkman, and Bryan Lynn of Case Western Reserve University have a theory that does just that, even if it does sound a bit strange.

In their new study, they argue that instead of dark matter consisting of elementary particles that are invisible and do not emit or absorb light and electromagnetic radiation, it takes the form of chunks of matter that vary widely in terms of mass and size.

As it stands, there are many leading candidates for what dark matter could be, which range from Weakly-Interacting Massive Particles (aka WIMPs) to axions. These candidates are attractive, particularly WIMPs, because the existence of such particles might help confirm supersymmetry theory – which in turn could help lead to a working Theory of Everything (ToE).



According to supersymmetry, dark-matter particles known as neutralinos (which are often called WIMPs) annihilate each other, creating a cascade of particles and radiation that includes medium-energy gamma rays. If neutralinos exist, the LAT might see the gamma rays associated with their demise. Credit: Sky & Telescope / Gregg Dinderman.


According to supersymmetry, dark-matter particles known as neutralinos (aka WIMPs) annihilate each other, creating a cascade of particles and radiation. Credit: Sky & Telescope / Gregg Dinderman.
But so far, no evidence has been obtained that definitively proves the existence of either. Beyond being necessary in order for General Relativity to work, this invisible mass seems content to remain invisible to detection.

According to Jacobs, Starkman, and Lynn, this could indicate that dark matter exists within the realm of normal matter. In particular, they consider the possibility that dark matter consists of macroscopic objects – which they dub “Macros” – that can be characterized in units of grams and square centimeters respectively.

Macros are not only significantly larger than WIMPS and axions, but could potentially be assembled out of particles in the Standard Model of particle physics – such as quarks and leptons from the early universe – instead of requiring new physics to explain their existence. WIMPS and axions remain possible candidates for dark matter, but Jacobs and Starkman argue that there’s a reason to search elsewhere.

“The possibility that dark matter could be macroscopic and even emerge from the Standard Model is an old but exciting one,” Starkman told Universe Today, via email. “It is the most economical possibility, and in the face of our failure so far to find dark matter candidates in our dark matter detectors, or to make them in our accelerators, it is one that deserves our renewed attention.”

After eliminating most ordinary matter – including failed Jupiters, white dwarfs, neutron stars, stellar black holes, the black holes in centers of galaxies, and neutrinos with a lot of mass – as possible candidates, physicists turned their focus on the exotics.



Particle Collider


Ongoing experiments at the Large Hadron Collider have so far failed to produce evidence of WIMPs. Credit: CERN/LHC/GridPP
Nevertheless, matter that was somewhere in between ordinary and exotic – relatives of neutron stars or large nuclei – was left on the table, Starkman said. “We say relatives because they probably have a considerable admixture of strange quarks, which are made in accelerators and ordinarily have extremely short lives,” he said.

Although strange quarks are highly unstable, Starkman points out that neutrons are also highly unstable. But in helium, bound with stable protons, neutrons remain stable.

“That opens the possibility that stable strange nuclear matter was made in the early Universe and dark matter is nothing more than chunks of strange nuclear matter or other bound states of quarks, or of baryons, which are themselves made of quarks,” said Starkman.

Such dark matter would fit the Standard Model.

This is perhaps the most appealing aspect of the Macros theory: the notion that dark matter, which our cosmological model of the Universe depends upon, can be proven without the need for additional particles.

Still, the idea that the universe is filled with a chunky, invisible mass rather than countless invisible particles does make the universe seem a bit stranger, doesn’t it?

Further Reading: Case Western



About 

Author, freelance writer, educator, Taekwon-Do instructor, and loving hubby, son and Island boy!

Whittling Away At SN1987A

Whittling Away At SN1987A:



Left Panel: SNR1987A as seen by the Hubble Space Telescope in 2010.Middle Panel: SNR1987A as seen by the Australia Telescope Compact Array (ATCA) in New South Wales and the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile. Right Panel: A computer generated visualisation of the remnant showing the possible location of a Pulsar. Credit: ATCA & ALMA Observations & data - G. Zanardo et al. / HST Image: NASA, ESA, K. France (University of Colorado, Boulder), P. Challis and R. Kirshner (Harvard-Smithsonian Center for Astrophysics)


Left Panel: SNR1987A as seen by the Hubble Space Telescope in 2010.Middle Panel: SNR1987A as seen by the Australia Telescope Compact Array (ATCA) in New South Wales and the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile. Right Panel: A computer generated visualization of the remnant showing the possible location of a Pulsar. Credit: ATCA & ALMA Observations & data – G. Zanardo et al. / HST Image: NASA, ESA, K. France (University of Colorado, Boulder), P. Challis and R. Kirshner (Harvard-Smithsonian Center for Astrophysics)
A team of Australian astronomers has been busy utilizing some of the world’s leading radio telescopes located in both Australia and Chile to carve away at the layered remains of a relatively new supernova. Designated as SN1987A, the 28 year-old stellar cataclysm came to Southern Hemisphere observer’s attention when it sprang into action at the edge of the Large Magellanic Cloud some two and a half decades ago. Since then, it has provided researchers around the world with a ongoing source of information about one of the Universe’s “most extreme events”.

Representing the University of Western Australia node of the International Centre for Radio Astronomy Research, PhD Candidate Giovanna Zanardo led the team focusing on the supernova with the Australia Telescope Compact Array (ATCA) in New South Wales. Their observations took in the wavelengths spanning the radio to the far infrared.

“By combining observations from the two telescopes we’ve been able to distinguish radiation being emitted by the supernova’s expanding shock wave from the radiation caused by dust forming in the inner regions of the remnant,” said Giovanna Zanardo of the International Centre for Radio Astronomy Research (ICRAR) in Perth, Western Australia.

“This is important because it means we’re able to separate out the different types of emission we’re seeing and look for signs of a new object which may have formed when the star’s core collapsed. It’s like doing a forensic investigation into the death of a star.”

“Our observations with the ATCA and ALMA radio telescopes have shown signs of something never seen before, located at the centre or the remnant. It could be a pulsar wind nebula, driven by the spinning neutron star, or pulsar, which astronomers have been searching for since 1987. It’s amazing that only now, with large telescopes like ALMA and the upgraded ATCA, we can peek through the bulk of debris ejected when the star exploded and see what’s hiding underneath.”

A video compilation showing Supernova Remnant 1987A as seen by the Hubble Space Telescope in 2010, and by radio telescopes located in Australia and Chile in 2012. The piece ends with a computer generated visualization of the remnant showing the possible location of a Pulsar. Credit: Dr Toby Potter, ICRAR-UWA, Dr Rick Newton, ICRAR-UWA

But, there is more. Not long ago, researchers published another paper which appeared in the Astrophysical Journal. Here they made an effort to solve another unanswered riddle about SN1987A. Since 1992 the supernova appears to be “brighter” on one side than it does the other! Dr. Toby Potter, another researcher from ICRAR’s UWA node took on this curiosity by creating a three-dimensional simulation of the expanding supernova shockwave.

“By introducing asymmetry into the explosion and adjusting the gas properties of the surrounding environment, we were able to reproduce a number of observed features from the real supernova such as the persistent one-sidedness in the radio images”, said Dr. Toby Potter.

So what’s going on? By creating a model which spans over a length of time, researchers were able to emulate an expanding shock front along the eastern edge of the supernova remnant. This region moves away more quickly than its counterpart and generates more radio emissions. When it encounters the equatorial ring – as observed by the Hubble Space Telescope – the effect becomes even more pronounced.

A visualization showing how Supernova1987A evolves between May of 1989 and July of 2014. Credit: Dr Toby Potter, ICRAR-UWA, Dr Rick Newton, ICRAR-UWA

“Our simulation predicts that over time the faster shock will move beyond the ring first. When this happens, the lop-sidedness of radio asymmetry is expected to be reduced and may even swap sides.”

“The fact that the model matches the observations so well means that we now have a good handle on the physics of the expanding remnant and are beginning to understand the composition of the environment surrounding the supernova – which is a big piece of the puzzle solved in terms of how the remnant of SN1987A formed.”

Original Story Source: Astronomers dissect the aftermath of a Supernova – International Centre for Radio Astronomy Research News Release.



About 

Tammy is a professional astronomy author, President Emeritus of Warren Rupp Observatory and retired Astronomical League Executive Secretary. She’s received a vast number of astronomy achievement and observing awards, including the Great Lakes Astronomy Achievement Award, RG Wright Service Award and the first woman astronomer to achieve Comet Hunter's Gold Status.

Chaotic Wombs May Birth Wrong-way Planets

Chaotic Wombs May Birth Wrong-way Planets:



Turbulent somethings lead to something. Image Credit: Vob


Turbulent conditions lead to retrograde exoplanets. Image Credit: Vorobyov
We’ve heard it time and time again. When it comes to new exoplanet findings, our conventional wisdom never holds. So the surprise that a batch of extrasolar planets are moving retrograde, orbiting in directions opposite to the way their stars are spinning, shouldn’t come as a surprise.

Then again, maybe it should. These discoveries turned the long-standing view of how planets form on its head. Now Eduard Vorobyov at the University of Vienna and colleagues argue that chaotic conditions in the planetary system’s gaseous wombs may be to blame.

Theorists have long assumed that stars and their planetary companions assemble from spinning disks of gas and dust. This causes the star to spin in one direction, while its planetary companions follow suit. “In some fundamental sense, the cloud carries a ‘genetic code’ that obligates the formation of corotating stars and planets,” Vorobyov told Universe Today.

So how do these wrong-way exoplanets get out of whack? Some theorists have postulated that the gravitational tugs from neighbors might change their direction of rotation. But this is pretty difficult for massive planets.

So Vorobyov and his colleagues took a second look at the initial clouds in which stars and their corotating planets form. Initially, astronomers thought that clouds evolve in relative isolation. Recent simulations, however, suggest that “clouds form within a turbulent environment and move like bees in a hive from one place to another,” said Vorobyov.

So a moving cloud might end up in an environment that’s quite different from the one it had at birth. It could even find itself surrounded by gas that’s swirling opposite to its spin.

Vorobyov and colleagues ran simulations that place clouds into environments with various characteristics. Sure enough when a gas cloud is surrounded by gas that’s swirling in the opposite direction, the inner disk continues to rotate in the same direction of the star, but the outer disk flips and starts to rotate in the opposite direction.

Over time, grains glom together in both disks until they ultimately form planets. Any inner planets will rotate with the star and any outer planets will rotate opposite the star.



ALMA image of the protoplanetary disc around HL Tauri


ALMA image of the protoplanetary disc around HL Tauri. Image Credit: ALMA / ESO / NOAJ / NRAO / NSF
But there are a few interesting byproducts. The first is that there’s a gap between the two counter-rotating disks. So whenever we see gaps in protoplanetary disks (like the one ALMA spotted a few weeks ago), these gaps might not be the result of a forming planet, but instead a null space between two counter-rotating disks.

The second is that the outer disk produces shock waves, which can trigger early planet formation. “The idea that planets would naturally form in the first very short (100,000 to 400,000 years) lifetime of the protostar would be profound, even if some of the planets were later destroyed,” expert Joel Green from the University of Texas told Universe Today.

This stands in contrast to the idea that planets collect their mass from collisions. It’s a process that astronomers think takes millions of years. But Green isn’t completely convinced by the simulations just yet as there seems to be no physical reason for the outer disks to end up counter rotating.

It all really comes down to the question of nature vs. nurture. “In some philosophical sense, the nurture (external environment) may completely change the nature of planet-forming disks,” said Vorobyov.

The results will be published in Astronomy & Astrophysics and are available online.



About 

Shannon Hall is a freelance science journalist. She holds two B.A.'s from Whitman College in physics-astronomy and philosophy, and an M.S. in astronomy from the University of Wyoming. Currently, she is working toward a second M.S. from NYU's Science, Health and Environmental Reporting program. You can follow her on Twitter @ShannonWHall.

NASA’s RapidScat Ocean Wind Watcher Starts Earth Science Operations at Space Station

NASA’s RapidScat Ocean Wind Watcher Starts Earth Science Operations at Space Station:



ISS-RapidScat data on a North Atlantic extratropical cyclone, as seen by the National Centers for Environmental Prediction Advanced Weather Interactive Processing System used by weather forecasters at the National Oceanic and Atmospheric Administration's Ocean Prediction Center. Image Credit: NASA/JPL-Caltech/NOAA


ISS-RapidScat data on a North Atlantic extratropical cyclone, as seen by the National Centers for Environmental Prediction Advanced Weather Interactive Processing System used by weather forecasters at the National Oceanic and Atmospheric Administration’s Ocean Prediction Center. Image Credit: NASA/JPL-Caltech/NOAA
Barely two months after being launched to the International Space Station (ISS), NASA’s first science payload aimed at conducting Earth science from the station’s exterior has started its ocean wind monitoring operations two months ahead of schedule.

Data from the ISS Rapid Scatterometer, or ISS-RapidScat, payload is now available to the world’s weather and marine forecasting agencies following the successful completion of check out and calibration activities by the mission team.

Indeed it was already producing high quality, usable data following its power-on and activation at the station in late September and has monitored recent tropical cyclones in the Atlantic and Pacific Oceans prior to the end of the current hurricane season.

RapidScat is designed to monitor ocean winds for climate research, weather predictions, and hurricane monitoring for a minimum mission duration of two years.

“RapidScat is a short mission by NASA standards,” said RapidScat Project Scientist Ernesto Rodriguez of JPL.

“Its data will be ready to help support U.S. weather forecasting needs during the tail end of the 2014 hurricane season. The dissemination of these data to the international operational weather and marine forecasting communities ensures that RapidScat’s benefits will be felt throughout the world.”



ISS-RapidScat instrument, shown in this artist's rendering, was launched to the International Space Station aboard the SpaceX CRS-4 mission on Sept. 21, 2014 and attached at ESA’s Columbus module. It will measure ocean surface wind speed and direction and help improve weather forecasts, including hurricane monitoring. Credit: NASA/JPL-Caltech/Johnson Space Center.


ISS-RapidScat instrument, shown in this artist’s rendering, was launched to the International Space Station aboard the SpaceX CRS-4 mission on Sept. 21, 2014, and attached at ESA’s Columbus module. It will measure ocean surface wind speed and direction and help improve weather forecasts, including hurricane monitoring. Credit: NASA/JPL-Caltech/Johnson Space Center.
The 1280 pound (580kilogram) experimental instrument was developed by NASA’s Jet Propulsion Laboratory. It’s a cost-effective replacement to NASA’s former QuikScat satellite.

The $26 million remote sensing instrument uses radar pulses reflected from the ocean’s surface at different angles to calculate the speed and direction of winds over the ocean for the improvement of weather and marine forecasting and hurricane monitoring.

The RapidScat, payload was hauled up to the station as part of the science cargo launched aboard the commercial SpaceX Dragon CRS-4 cargo resupply mission that thundered to space on the company’s Falcon 9 rocket from Space Launch Complex-40 at Cape Canaveral Air Force Station in Florida on Sept. 21.

ISS-RapidScat is NASA’s first research payload aimed at conducting near global Earth science from the station’s exterior and will be augmented with others in coming years.



ISS-RapidScat viewed the winds within post-tropical cyclone Nuri as it moved parallel to Japan on Nov. 6, 2014 05:30 UTC. Image Credit: NASA/JPL-Caltech


ISS-RapidScat viewed the winds within post-tropical cyclone Nuri as it moved parallel to Japan on Nov. 6, 2014, 05:30 UTC. Image Credit: NASA/JPL-Caltech
It was robotically assembled and attached to the exterior of the station’s Columbus module using the station’s robotic arm and DEXTRE manipulator over a two day period on Sept 29 and 30.

Ground controllers at Johnson Space Center intricately maneuvered DEXTRE to pluck RapidScat and its nadir adapter from the unpressurized trunk section of the Dragon cargo ship and attached it to a vacant external mounting platform on the Columbus module holding mechanical and electrical connections.

The nadir adapter orients the instrument to point its antennae at Earth.

The couch sized instrument and adapter together measure about 49 x 46 x 83 inches (124 x 117 x 211 centimeters).

“The initial quality of the RapidScat wind data and the timely availability of products so soon after launch are remarkable,” said Paul Chang, ocean vector winds science team lead at NOAA’s National Environmental Satellite, Data and Information Service (NESDIS)/Center for Satellite Applications and Research (STAR), Silver Spring, Maryland.

“NOAA is looking forward to using RapidScat data to help support marine wind and wave forecasting and warning, and to exploring the unique sampling of the ocean wind fields provided by the space station’s orbit.”



A SpaceX Falcon 9 rocket carrying a Dragon cargo capsule packed with science experiments and station supplies blasts off from Space Launch Complex 40 at Cape Canaveral Air Force Station, Florida, at 1:52 a.m. EDT on Sept. 21, 2014 bound for the ISS. Credit: Ken Kremer/kenkremer.com


A SpaceX Falcon 9 rocket carrying a Dragon cargo capsule packed with science experiments and station supplies blasts off from Space Launch Complex 40 at Cape Canaveral Air Force Station, Florida, at 1:52 a.m. EDT on Sept. 21, 2014, bound for the ISS. Credit: Ken Kremer/kenkremer.com
This has been a banner year for NASA’s Earth science missions. At least five missions will be launched to space within a 12 month period, the most new Earth-observing mission launches in one year in more than a decade.

ISS-RapidScat is the third of five NASA Earth science missions scheduled to launch over a year.

NASA has already launched the of the Global Precipitation Measurement (GPM) Core Observatory, a joint mission with the Japan Aerospace Exploration Agency, in February and the Orbiting Carbon Observatory-2 (OCO-2) carbon observatory in July 2014.

Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.

Ken Kremer



About 

Dr. Ken Kremer is a speaker, scientist, freelance science journalist (Princeton, NJ) and photographer whose articles, space exploration images and Mars mosaics have appeared in magazines, books, websites and calanders including Astronomy Picture of the Day, NBC, BBC, SPACE.com, Spaceflight Now and the covers of Aviation Week & Space Technology, Spaceflight and the Explorers Club magazines. Ken has presented at numerous educational institutions, civic & religious organizations, museums and astronomy clubs. Ken has reported first hand from the Kennedy Space Center, Cape Canaveral and NASA Wallops on over 40 launches including 8 shuttle launches. He lectures on both Human and Robotic spaceflight - www.kenkremer.com. Follow Ken on Facebook and Twitter

Monday, November 17, 2014

Black Hole Powered Jets Plow Into Galaxy

Black Hole Powered Jets Plow Into Galaxy:



4C+29.30


This composite image
of a galaxy illustrates how the intense gravity of a supermassive
black hole can be tapped to generate immense power. The image
contains X-ray data from NASA's Chandra X-ray Observatory (blue),
optical light obtained with the Hubble Space Telescope (gold) and
radio waves from the NSF's Very Large Array (pink).

This multi-wavelength view shows 4C+29.30, a galaxy
located some 850 million light years from Earth. The radio emission
comes from two jets of particles that are speeding at millions of
miles per hour away from a supermassive black hole at the center of
the galaxy. The estimated mass of the black hole is about 100
million times the mass of our Sun. The ends of the jets show larger
areas of radio emission located outside the galaxy.

The X-ray data show a different aspect of this galaxy,
tracing the location of hot gas. The bright X-rays in the center of
the image mark a pool of million-degree gas around the black hole.
Some of this material may eventually be consumed by the black hole,
and the magnetized, whirlpool of gas near the black hole could in
turn, trigger more output to the radio jet.

Most
of the low-energy X-rays from the vicinity of the black hole are
absorbed by dust and gas, probably in the shape of a giant doughnut
around the black hole. This doughnut, or torus blocks all the
optical light produced near the black hole, so astronomers refer to
this type of source as a hidden or buried black hole. The optical
light seen in the image is from the stars in the galaxy.

The bright spots in X-ray and radio emission on the outer
edges of the galaxy, near the ends of the jets, are caused by
extremely high energy electrons following curved paths around
magnetic field lines. They show where a jet generated by the black
hole has plowed into clumps of material in the galaxy (mouse over
the image for the location of these bright spots). Much of the
energy of the jet goes into heating the gas in these clumps, and
some of it goes into dragging cool gas along the direction of the
jet. Both the heating and the dragging can limit the fuel supply
for the supermassive black hole, leading to temporary starvation
and stopping its growth. This feedback process is thought to cause
the observed correlation between the mass of the supermassive black
hole and the combined mass of the stars in the central region or
bulge of a galaxy.

More at http://chandra.harvard.edu/photo/2013/4c2930/

-Megan Watzke, CXC



NASA X-ray Telescopes Find Black Hole May Be a Neutrino Factory

NASA X-ray Telescopes Find Black Hole May Be a Neutrino Factory:



Sagittarius A*


The supermassive black hole at the center of the Milky Way, seen in this image from NASA's Chandra X-ray Observatory, may be producing mysterious particles called neutrinos, as described in our latest press release. Neutrinos are tiny particles that have virtually no mass and carry no electric charge. Unlike light or charged particles, neutrinos can emerge from deep within their sources and travel across the Universe without being absorbed by intervening matter or, in the case of charged particles, deflected by magnetic fields.

While the Sun produces neutrinos that constantly bombard the Earth, there are also other neutrinos with much higher energies that are only rarely detected. Scientists have proposed that these higher-energy neutrinos are created in the most powerful events in the Universe like galaxy mergers, material falling onto supermassive black holes, and the winds around dense rotating stars called pulsars.

Using three NASA X-ray telescopes, Chandra, Swift, and NuSTAR, scientists have found evidence for one such cosmic source for high-energy neutrinos: the 4-million-solar-mass black hole at the center of our Galaxy called Sagittarius A* (Sgr A*, for short). After comparing the arrival of high-energy neutrinos at the underground facility in Antarctica, called IceCube, with outbursts from Sgr A*, a team of researchers found a correlation. In particular, a high-energy neutrino was detected by IceCube less than three hours after astronomers witnessed the largest flare ever from Sgr A* using Chandra. Several flares from neutrino detections at IceCube also appeared within a few days of flares from the supermassive black hole that were observed with Swift and NuSTAR.

This Chandra image shows the region around Sgr A* in low, medium, and high-energy X-rays that have been colored red, green, and blue respectively. Sgr A* is located within the white area in the center of the image. The blue and orange plumes around that area may be the remains of outbursts from Sgr A* that occurred millions of years ago. The flares that are possibly associated with the IceCube neutrinos involve just the Sgr A* X-ray source.

More information at http://chandra.harvard.edu/photo/2014/sgra/index.html

-Megan Watzke, CXC

NASA Holds Telecon on Rocket Experiment Results

NASA Holds Telecon on Rocket Experiment Results:

Spitzer Spies Spectacular Sombrero
The Sombrero galaxy as seen by NASA's Spitzer and Hubble space telescopes in a combined visible- and infrared-light view. Image credit: NASA/JPL-Caltech/University of Arizona

› Full image and caption
NASA will host a news teleconference at 11 a.m. PST (2 p.m. EST) Thursday, Nov. 6, to announce discoveries from a sub-orbital rocket experiment that are redefining what we think of as galaxies.

The results are embargoed by the journal Science until 11 a.m. PST (2 p.m. EST) Nov. 6.

The briefing participants are:

-- Michael Garcia, program scientist, NASA Headquarters, Washington

-- James Bock, astronomer, NASA's Jet Propulsion Laboratory and California Institute of Technology, Pasadena, California

-- Michael Zemcov, astronomer, Caltech and JPL

-- Karoline Gilbert, assistant astronomer, Space Telescope Science Institute, Baltimore, Maryland

Audio of the teleconference will be streamed live at:

http://www.nasa.gov/newsaudio

Visuals will be posted at the start of the event at:

http://www.nasa.gov/mission_pages/sounding-rockets/

Audio and supporting visuals will be streamed live at:

http://www.ustream.tv/NASAJPL2

For more information, visit:

http://www.nasa.gov

Media Contact

Whitney Clavin

Jet Propulsion Laboratory, Pasadena, Calif.

818-354-4673

whitney.clavin@jpl.nasa.gov

Felicia Chou
NASA Headquarters, Washington
202-358-0257
felicia.chou@nasa.gov

2014-379

NASA Rolls Out Enhanced, Mobile-Friendly Climate Site

NASA Rolls Out Enhanced, Mobile-Friendly Climate Site:

NASA's Global Climate Change website tracks key indicators of climate change
NASA's Global Climate Change website tracks key indicators of climate change, include the retreat of glaciers and the shrinking of ice sheets around the world. Image credit: Shutterstock

› Larger image
NASA has relaunched its Webby Award-winning website, Global Climate Change, with enhanced interactive features that play on any mobile device, state-of-the-art visuals, and new sections on climate change solutions and the people behind the science.

First launched in 2008, the Global Climate Change website provides easy-to-understand information about the causes and effects of climate change and the ways NASA studies them, along with the latest climate news from the agency, graphics and visualizations. The URL is:

http://climate.nasa.gov

Highlights of the redesign include:

-- An improved Vital Signs dashboard, providing interactive charts with continuously updated data on atmospheric carbon dioxide, sea level rise, Arctic ice extent, global temperature and other key indicators of climate change

-- Visualizations of change over time from NASA's Scientific Visualization Studio

-- A section that focuses on science and technology advances that are providing essential data for adapting to and mitigating the effects of climate change

-- Making a Difference, a section that highlights NASA's climate researchers and the work they do

The updated site retains popular features of the earlier version, including the Images of Change gallery, the Climate Time Machine and the Eyes on the Earth data visualization tool.

The website is optimized for most mobile devices, including smartphones and tablets.

"NASA is a world leader in Earth system science and climate research, and it's important that we make the content of our work accessible to the general public," said Peg Luce, deputy director of NASA's Earth Science Division. "The continuing popularity and recognition of this site underscores the need for credible resources with timely climate change information."

For more information on NASA's Earth Science Program, visit:

http://science.nasa.gov/earth-science/ and

http://www.nasa.gov/earthrightnow/

Media Contact

Alan Buis

818-354-0474

Jet Propulsion Laboratory, Pasadena, California

Alan.Buis@jpl.nasa.gov

Written by Carol Rasmussen
NASA Earth Science News Team

2014-384

Jupiter's Red Spot is Likely a Sunburn, Not a Blush

Jupiter's Red Spot is Likely a Sunburn, Not a Blush:

Research suggests effects of sunlight produce the color of Jupiter's Great Red Spot.
Research suggests effects of sunlight produce the color of Jupiter's Great Red Spot. The feature's clouds are much higher than those elsewhere on the planet, and its vortex nature confines the reddish particles once they form. Image credit: NASA/JPL-Caltech/ Space Science Institute

› Larger image
The ruddy color of Jupiter's Great Red Spot is likely a product of simple chemicals being broken apart by sunlight in the planet's upper atmosphere, according to a new analysis of data from NASA's Cassini mission. The results contradict the other leading theory for the origin of the spot's striking color -- that the reddish chemicals come from beneath Jupiter's clouds.

The results are being presented this week by Kevin Baines, a Cassini team scientist based at NASA's Jet Propulsion Laboratory, Pasadena, California, at the American Astronomical Society's Division for Planetary Science Meeting in Tucson, Arizona.

Baines and JPL colleagues Bob Carlson and Tom Momary arrived at their conclusions using a combination of data from Cassini's December 2000 Jupiter flyby and laboratory experiments.

In the lab, the researchers blasted ammonia and acetylene gases -- chemicals known to exist on Jupiter -- with ultraviolet light, to simulate the sun's effects on these materials at the extreme heights of clouds in the Great Red Spot. This produced a reddish material, which the team compared to the Great Red Spot as observed by Cassini's Visible and Infrared Mapping Spectrometer (VIMS). They found that the light-scattering properties of their red concoction nicely matched a model of the Great Red Spot in which the red-colored material is confined to the uppermost reaches of the giant cyclone-like feature.

"Our models suggest most of the Great Red Spot is actually pretty bland in color, beneath the upper cloud layer of reddish material," said Baines. "Under the reddish 'sunburn' the clouds are probably whitish or grayish." A coloring agent confined to the top of the clouds would be inconsistent with the competing theory, which posits that the spot's red color is due to upwelling chemicals formed deep beneath the visible cloud layers, he said. If red material were being transported from below, it should be present at other altitudes as well, which would make the red spot redder still.

Jupiter is composed almost entirely of hydrogen and helium, with just a sprinkling of other elements. Scientists are interested in understanding what combinations of elements are responsible for the hues seen in Jupiter's clouds, as this would provide insights into the giant planet's make-up.

Baines and colleagues initially set out to determine if the Great Red Spot's color might derive from sun-induced breakdown of a more complex molecule, ammonium hydrosulfide, which makes up one of Jupiter's main cloud layers. They quickly found that instead of a red color, the products their experiment produced were a brilliant shade of green. This surprising negative result prompted the researchers to try simple combinations of ammonia with hydrocarbons that are common at Jupiter's high altitudes. Breaking down ammonia and acetylene with ultraviolet light turned out to best fit the data collected by Cassini.

The Great Red Spot is a long-lived feature in Jupiter's atmosphere that is as wide as two earths. Jupiter possesses three main cloud layers, which occupy specific altitudes in its skies; from highest to lowest they are: ammonia, ammonium hydrosulfide and water clouds.

As for why the intense red color is seen only in the Great Red Spot and a few much smaller spots on the planet, the researchers think altitude plays a key role. "The Great Red Spot is extremely tall," Baines said. "It reaches much higher altitudes than clouds elsewhere on Jupiter."

The team thinks the spot's great heights both enable and enhance the reddening. Its winds transport ammonia ice particles higher into the atmosphere than usual, where they are exposed to much more of the sun's ultraviolet light. In addition, the vortex nature of the spot confines particles, preventing them from escaping. This causes the redness of the spot's cloud tops to increase beyond what might otherwise be expected.

Other areas of Jupiter display a mixed palette of oranges, browns and even shades of red. Baines says these are places where high, bright clouds are known to be much thinner, allowing views to depths in the atmosphere where more colorful substances exist.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL, a division of the California Institute of Technology, Pasadena, manages the mission for NASA's Science Mission Directorate in Washington. The VIMS team is based at the University of Arizona in Tucson.

More information about Cassini is available at the following sites:

http://www.nasa.gov/cassini

http://saturn.jpl.nasa.gov

Media Contact

Preston Dyches

Jet Propulsion Laboratory, Pasadena, Calif.

818-354-5011

preston.dyches@jpl.nasa.gov

2014-391