Tuesday, September 12, 2017

Scientists Produce Unique Simulation of Magnetic Reconnection

Scientists Produce Unique Simulation of Magnetic Reconnection:



Northern lights in the night sky over Norway. Photo by Jan R. Olsen




Jonathan Ng, a Princeton University graduate student at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL), has for the first time applied a fluid simulation to the space plasma process behind solar flares northern lights and space storms. The model could lead to improved forecasts of space weather that can shut down cell phone service and damage power grids, as well as to better understanding of the hot, charged plasma gas that fuels fusion reactions.

The new simulation captures the physics of magnetic reconnection, the breaking apart and snapping together of the magnetic field lines in plasma that occurs throughout the universe. The simulations approximate kinetic effects in a fluid code, which treats plasma as a flowing liquid, to create a more detailed picture of the reconnection process. 

Previous simulations used fluid codes to produce simplified descriptions of reconnection that takes place in the vastness of space, where widely separated plasma particles rarely collide. However, this collisionless environment gives rise to kinetic effects on plasma behavior that fluid models cannot normally capture.

The new simulation estimates kinetic behavior. “This is the first application of this particular fluid model in studying reconnection physics in space plasmas,” said Ng, lead author of the findings reported in August in the journal Physics of Plasmas.

Ng and coauthors approximated kinetic effects with a series of fluid equations based on plasma density, momentum and pressure. They concluded the process through a mathematical technique called “closure” that enabled them to describe the kinetic mixing of particles from non-local, or large-scale, regions. The type of closure involved was originally developed by PPPL physicist Greg Hammett and the late Rip Perkins in the context of fusion plasmas, making its application to the space plasma environment an example of fruitful cross-fertilization.

The completed results agreed better with kinetic models as compared with simulations produced by traditional fluid codes. The new simulations could extend understanding of reconnection to whole regions of space such as the magnetosphere, the magnetic field that surrounds the Earth, and provide a more comprehensive view of the universal process.

Coauthoring the paper were physicists Ammar Hakim of PPPL and Amitava Bhattacharjee, head of the Theory Department at PPPL and a professor of astrophysical sciences at Princeton University, together with physicists Adam Stanier and William Daughton of Los Alamos National Laboratory. Support for this work comes from the DOE Office of Science, the National Science Foundation and NASA. Computation was performed at the National Energy Research Scientific Computer Center, a DOE Office of Science User Facility, and the University of New Hampshire.

Credit: pppl.gov

Are We Being Watched? Tens of Other Worlds Could Spot the Earth

Are We Being Watched? Tens of Other Worlds Could Spot the Earth:



Image showing where transits of our Solar System planets can be observed. Each line represents where one of the planets could be seen to transit, with the blue line representing Earth; an observer located here could detect us. Credit: 2MASS / A. Mellinger / R. Wells.




A group of scientists from Queen’s University Belfast and the Max Planck Institute for Solar System Research in Germany have looked at how an alien observer might be able to detect Earth using our own methods. They find that at least nine exoplanets are ideally placed to observe transits of Earth, in a new work published in the journal Monthly Notices of the Royal Astronomical Society.

Thanks to facilities and missions such as SuperWASP and Kepler, we have now discovered thousands of planets orbiting stars other than our Sun, worlds known as ‘exoplanets’. The vast majority of these are found when the planets cross in front of their host stars in what are known as ‘transits’, which allow astronomers to see light from the host star dim slightly at regular intervals every time the planet passes between us and the distant star.

In the new study, the authors reverse this concept and ask, “How would an alien observer see the Solar System?” They identified parts of the distant sky from where various planets in our Solar System could be seen to pass in front of the Sun – so-called ‘transit zones’ -- concluding that the terrestrial planets (Mercury, Venus, Earth, and Mars) are actually much more likely to be spotted than the more distant ‘Jovian’ planets (Jupiter, Saturn, Uranus, and Neptune), despite their much larger size.

”Larger planets would naturally block out more light as they pass in front of their star”, commented lead author Robert Wells, a PhD student at Queen’s University Belfast. ”However the more important factor is actually how close the planet is to its parent star – since the terrestrial planets are much closer to the Sun than the gas giants, they’ll be more likely to be seen in transit.”

To look for worlds where civilizations would have the best chance of spotting our Solar System, the astronomers looked for parts of the sky from which more than one planet could be seen crossing the face of the Sun. They found that three planets at most could be observed from anywhere outside of the Solar System, and that not all combinations of three planets are possible.

Katja Poppenhaeger, a co-author of the study, added: “We estimate that a randomly positioned observer would have roughly a 1 in 40 chance of observing at least one planet. The probability of detecting at least two planets would be about ten times lower, and to detect three would be a further ten times smaller than this.”

Of the thousands of known exoplanets, the team identified sixty-eight worlds where observers would see one or more of the planets in our Solar System transit the Sun. Nine of these planets are ideally placed to observe transits of Earth, although none of the worlds are deemed to be habitable.

In addition, the team estimate that there should be approximately ten (currently undiscovered) worlds which are favorably located to detect the Earth and are capable of sustaining life as we know it. To date however, no habitable planets have been discovered from which a civilization could detect the Earth with our current level of technology.

The ongoing K2 mission of NASA’s Kepler spacecraft is to continue to hunt for exoplanets in different regions of the sky for a few months at a time. These regions are centered close to the plane of Earth’s orbit, which means that there are many target stars located in the transit zones of the Solar System planets. The team’s plans for future work include targeting these transit zones to search for exoplanets, hopefully finding some which could be habitable.

Credit: qub.ac.uk

Large Asteroid to Fly by Earth Today

Large Asteroid to Fly by Earth Today:



asteroid-apophis-illustration.jpg




Large near-Earth object (NEO), designated 2017 OP68, will fly by our planet today, missing the Earth at a distance of about 19.9 lunar distances (LD), or 7.6 million kilometers. The close approach is expected to occur at 18:25 UTC, when the space rock will whiz by our planet with a velocity of 11.7 km/s.

2017 OP68 is an Amor-type asteroid first spotted on July 25, 2017 by NASA’s Wide-field Infrared Survey Explorer (WISE). WISE is infrared-wavelength astronomical space telescope that has discovered thousands of minor planets.

Astronomers reveal that 2017 OP68 has an absolute magnitude of 20.6 and a diameter between 150 and 470 meters. The asteroid has an orbital period of nearly four years and a semimajor axis of about 2.5 AU.

Next close approach of 2017 OP68 to Earth is expected to take place on July 17, 2021, when it will pass by our planet at a much larger distance of 131 LD (50.3 million kilometers).

On September 10, 2017, there were 1,803 potentially hazardous asteroids (PHAs) discovered to date. PHAs are space rocks larger than approximately 100 meters that can come closer to Earth than 19.5 LD. However, none of the known PHAs is on a collision course with our planet.

Explosive Birth of Stars Swells Galactic Cores

Explosive Birth of Stars Swells Galactic Cores:



Observation images of a galaxy 11 billion light-years away. Submillimeter waves detected with ALMA are shown in left, indicating the location of dense dust and gas where stars are being formed. Optical and infrared light seen with the Hubble Space Telescope are shown in the middle and right, respectively. A large galactic disk is seen in infrared, while three young star clusters are seen in optical light. Credit: ALMA (ESO/NAOJ/NRAO), NASA/ESA Hubble Space Telescope, Tadaki et al.




Astronomers found that active star formation upswells galaxies, like yeast helps bread rise. Using three powerful telescopes on the ground and in orbit, they observed galaxies from 11 billion years ago and found explosive formation of stars in the cores of galaxies. This suggests that galaxies can change their own shape without interaction with other galaxies.

"Massive elliptical galaxies are believed to be formed from collisions of disk galaxies," said Ken-ichi Tadaki, the lead author of two research papers and a postdoctoral researcher at the National Astronomical Observatory of Japan (NAOJ). "But, it is uncertain whether all the elliptical galaxies have experienced galaxy collision. There may be an alternative path."

Aiming to understand galactic metamorphosis, the international team explored distant galaxies 11 billion light-years away. Because it takes time for the light from distant objects to reach us, by observing galaxies 11 billion light-years away, the team can see what the Universe looked like 11 billion years ago, 3 billion years after the Big Bang. This corresponds the peak epoch of galaxy formation; the foundations of most galaxies were formed in this epoch.

Receiving faint light which has traveled 11 billion years is tough work. The team harnessed the power of three telescopes to anatomize the ancient galaxies. First, they used NAOJ's 8.2-m Subaru Telescope in Hawai`i and picked out 25 galaxies in this epoch. Then they targeted the galaxies for observations with NASA/ESA's Hubble Space Telescope (HST) and the Atacama Large Millimeter/submillimeter Array (ALMA). The astronomers used HST to capture the light from stars which tells us the "current" (as of when the light was emitted, 11 billion years ago) shape of the galaxies, while ALMA observed submillimeter waves from cold clouds of gas and dust, where new stars are being formed. By combining the two, we know the shapes of the galaxies 11 billion years ago and how they are evolving.

Thanks to their high resolution, HST and ALMA could illustrate the metamorphosis of the galaxies. With HST images the team found that a disk component dominates the galaxies. Meanwhile, the ALMA images show that there is a massive reservoir of gas and dust, the material of stars, so that stars are forming very actively. The star formation activity is so high that huge numbers of stars will be formed at the centers of the galaxies. This leads the astronomers to think that ultimately the galaxies will be dominated by the stellar bulge and become elliptical or lenticular galaxies.

"Here, we obtained firm evidence that dense galactic cores can be formed without galaxy collisions. They can also be formed by intense star formation in the heart of the galaxy." said Tadaki. The team used the European Southern Observatory's Very Large Telescope to observe the target galaxies and confirmed that there are no indications of massive galaxy collisions.

Almost 100 years ago, American astronomer Edwin Hubble invented the morphological classification scheme for galaxies. Since then, many astronomers have devoted considerable effort to understanding the origin of the variety in galaxy shapes. Utilizing the most advanced telescopes, modern astronomers have come one step closer to solving the mysteries of galaxies.

Galaxies Swell due to Explosive Action of New Stars

Galaxies Swell due to Explosive Action of New Stars:

In 1926, famed astronomer Edwin Hubble developed his morphological classification scheme for galaxies. This method divided galaxies into three basic groups – Elliptical, Spiral and Lenticular – based on their shapes. Since then, astronomers have devoted considerable time and effort in an attempt to determine how galaxies have evolved over the course of billions of years to become these shapes.

One of th most widely-accepted theories is that galaxies changed by merging, where smaller clouds of stars – bound by mutual gravity – came together, altering the size and shape of a galaxy over time. However, a new study by an international team of researchers has revealed that galaxies could actually assumed their modern shapes through the formation of new stars within their centers.

The study, titled “Rotating Starburst Cores in Massive Galaxies at z = 2.5“, was recently published in the Astrophysical Journal Letters. Led by Ken-ichi Tadaki – a postdoctoral researcher with the Max Planck Institute for Extraterrestrial Physics and the National Astronomical Observatory of Japan (NAOJ) – the team conducted observations of distant galaxies in order to get a better understanding of galactic metamorphosis.





Evolution diagram of a galaxy. First the galaxy is dominated by the disk component (left) but active star formation occurs in the huge dust and gas cloud at the center of the galaxy (center). Then the galaxy is dominated by the stellar bulge and becomes an elliptical (or lenticular) galaxy. Credit: NAOJ
This involved using ground-based telescopes to study 25 galaxies that were at a distance of about 11 billion light-years from Earth. At this distance, the team was seeing what these galaxies looked like 11 billion years ago, or roughly 3 billion years after the Big Bang. This early epoch coincides with a period of peak galaxy formation in the Universe, when the foundations of most galaxies were being formed. As Dr. Tadaki indicated in a NAOJ press release:

“Massive elliptical galaxies are believed to be formed from collisions of disk galaxies. But, it is uncertain whether all the elliptical galaxies have experienced galaxy collision. There may be an alternative path.”
Capturing the faint light of these distant galaxies was no easy task and the team needed three ground-based telescopes to resolve them properly. They began by using the NAOJ’s 8.2-m Subaru Telescope in Hawaii to pick out the 25 galaxies in this epoch. Then they targeted them for observations with the NASA/ESA Hubble Space Telescope (HST) and the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile.

Whereas the HST captured light from stars to discern the shape of the galaxies (as they existed 11 billion years ago), the ALMA array observed submillimeter waves  emitted by the cold clouds of dust and gas – where new stars are being formed. By combining the two, they were able to complete a detailed picture of how these galaxies looked 11 billion years ago when their shapes were still evolving.





Observation images of a galaxy 11 billion light-years away. Credit: ALMA (ESO/NAOJ/NRAO), NASA/ESA Hubble Space Telescope, Tadaki et al.
What they found was rather telling. The HST images indicated that early galaxies were dominated by a disk component, as opposed to the central bulge feature we’ve come to associate with spiral and lenticular galaxies. Meanwhile, the ALMA images showed that there were massive reservoirs of gas and dust near the centers of these galaxies, which coincided with a very high rate of star formation.

To rule out alternate possibility that this intense star formation was being caused by mergers, the team also used data from the European Southern Observatory’s Very Large Telescope (VLT) – located at the Paranal Observatory in Chile – to confirm that there were no indications of massive galaxy collisions taking place at the time. As Dr. Tadaki explained:

“Here, we obtained firm evidence that dense galactic cores can be formed without galaxy collisions. They can also be formed by intense star formation in the heart of the galaxy.”
These findings could lead astronomers to rethink their current theories about galactic evolution and howthey came to adopt features like a central bulge and spiral arms. It could also lead to a rethink of our models regarding cosmic evolution, not to mention the history of own galaxy. Who knows? It might even cause astronomers to rethink what might happen in a few billion years, when the Milky Way is set to collide with the Andromeda Galaxy.

As always, the further we probe into the Universe, the more it reveals. With every revelation that does not fit our expectations, our hypotheses are forced to undergo revision.

Further Reading: ALMAAstrophysical Journal Letters

The post Galaxies Swell due to Explosive Action of New Stars appeared first on Universe Today.

Astronomers create best ever image of star outside our Solar System

Astronomers create best ever image of star outside our Solar System:



VLTI reconstructed view of the surface of Antares


Using ESO’s Very Large Telescope Interferometer astronomers have constructed this image of the red supergiant star Antares. This is the most detailed image ever of this object, or any other star apart from the Sun. Image & Caption Credit: K. Ohnaka / ESO
A map of activity on the surface and in the atmosphere of the star Antares by a team of astronomers is considered to be the most detailed ever created for a star other than the Sun. The red supergiant is located some 550 light-years distant in the constellation Scorpius and is in its final stages of its existence. It will eventually die in a supernova explosion.

While Antares likely started its life with about 15 times the mass of our Sun, it is now shedding mass and is estimated to have lost about three solar masses. Its current diameter is approximately 700 times that of the Sun.

Researchers led by Keiichi Ohnaka of the Universidad Catolico del Norte in Chile used the European Southern Observatory’s (ESO) Very Large Telescope Interferometer (VLTI) at Paranal Observatory to map the surface of the luminous, low-density star and measure the speed at which surface material is moving.

The VLTI is an instrument composed of several telescopes that create the equivalent of a single large telescope with a mirror boasting a diameter up to 656 feet (200 meters). It combines the light from as many as four telescopes, including either the 26.9-foot (8.2-meter) Unit Telescopes or the 5.9-foot (1.8-meter) Auxiliary Telescopes, enabling scientists to view the star in incredible detail.



Artist’s impression of the red supergiant star Antares


This artist’s impression shows the red supergiant star Antares in the constellation of Scorpius. Image & Caption Credit: M. Kornmesser / ESO
Using three Auxiliary Telescopes along with the near-infrared AMBER instrument, astronomers imaged several locales on Antares’ surface in various infrared wavelengths to measure the speed at which gases are moving in these different regions and across the entire star. The technique yielded the most detailed map of surface activity by atmospheric gases on any star besides our Sun.

Ohnaka said a central goal of the study is to determine how stars like Antares lose so much mass at the end of their lives.

“The VLTI is the only facility that can directly measure the gas motions in the extended atmosphere of Antares – a crucial step towards clarifying this problem. The next challenge is to identify what’s driving the turbulent motions,” Ohnaka said.



VLTI velocity map of the surface of Antares


This is the first such velocity map of any star other than the Sun. In red regions, the material is moving away from Earth, and in the blue areas, the material is approaching. The empty region around the star is not a real feature but shows where velocity measurements were not possible. Image & Caption Credit: K. Ohnaka / ESO
Low-density gas was discovered extending much further from the star than the researchers expected, leading them to conclude it was brought there by a process other than convection, which involves the transfer of energy from a star’s core to its outer atmosphere. Just what that process is remains unknown.

Other stars of various types will need to be studied using the technique astronomers used to map Antares in the same degree of detail for scientists to determine what that process is, Ohnaka said.

“Our work brings stellar astrophysics to a new dimension and opens an entirely new window to observe stars,” Ohnaka said.

Ohnaka is the lead author of a paper on the study published in the journal Nature.



The bright red star Antares in the constellation of Scorpius


This chart shows the constellation of Scorpius. At the heart of this grouping of stars lies the bright red supergiant star Antares. Image & Caption Credit: ESO / IAU / Sky & Telescope


This article was updated at 16:55 EDT on Aug. 27, 2017, with distance to Antares.



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JPL proposes exploring Venus with a clockwork rover

JPL proposes exploring Venus with a clockwork rover:



Automaton Rover for Extreme Environments (AREE)


AREE is a clockwork rover inspired by mechanical computers. A JPL team is studying how this kind of rover could explore extreme environments, like the surface of Venus. Image & Caption Credit: NASA/JPL-Caltech
NASA’s Jet Propulsion Laboratory (JPL) proposes taking a page out of a Swiss watchmaker’s handbook to design a long-lived rover to explore Venus’ surface. Utilizing centuries-old mechanical computing concepts, but with a modern upgrade, engineers at JPL hope to design a rover capable of exploring the unforgiving Venusian terrain and returning data to Earth.

Today’s forecast: Cloudy with a high of 864 °F






The surface of Venus is perpetually shrouded from view by heavy cloud cover. Photo Credit: NASA
Though Venus has been called Earth’s sister due to the similarities in size and mass between the two, humanity knows comparatively little about the planet itself. Indeed, the Soviet Venera and Vega programs of the 1970s and 1980s have provided the only surface-based investigations of Earth’s nearest planetary neighbor.

While the landers returned valuable data, they operated for no more than a couple hours before succumbing to the intense heat and pressure of Venus’ atmosphere. With an average surface temperature of 864 degrees Fahrenheit (462 degrees Celsius) – hot enough to melt lead – and an atmospheric pressure more than 90 times that of Earth’s, even modern hardware would have difficulty operating for very long.

With the hellish surface conditions being a major hurdle to overcome, scientists have had to be content with observations from above the cloud tops.

Tick-tock goes the… rover?


Although technology has made great strides since the Soviet landers, heat is just as deadly to modern electronics as it was in the 1980s. Faced with the difficulty of designing hardware to operate on Venus’ surface, conventional wisdom seemed to dictate one of two paths: developing a cooling system that would work in such extreme conditions, or designing high-temperature electronics.

With a cooling system costing billions of dollars to develop, and heat-tolerant hardware exceeding the design tolerances of a rover, neither seemed a viable path for some designers.

Enter Jonathan Sauder, a mechatronics engineer at JPL and the inspiration behind the Automaton Rover for Extreme Environments (AREE) program. Sauder believes mechanical computing is the key to designing a long-lasting Venusian rover.

“Venus is too inhospitable for kind of complex control systems you have on a Mars rover,” Sauder stated in a release issued by JPL. “But with a fully mechanical rover, you might be able to survive as long as a year.”

Mechanically driven devices have been around for centuries. Some, like the Antikythera mechanism, were used to compute astronomical events. Others were designed as works of art. Though seemingly less-advanced than electronic devices, mechanical computers have the advantage of being able to operate under conditions that would cripple their modern counterparts.

“When you think of something as extreme as Venus, you want to think really out there,” stated Evan Hilgemann, a JPL engineer working on high-temperature designs for AREE, in the same release.



AREE-tech20170825b.jpg
AREE-tech20170825c-1.jpg


RIGHT IMAGE: A look inside the AREE rover (next to an astronaut for scale). Wind would be channeled through the rover’s body for primary power. Rotating targets on top could be “pinged” by radar, sending data as Morse code. (Click to enlarge) Images & Caption Credit: NASA / JPL-Caltech
Not only would the rover operate under mechanical guidance, but its communication system would be similarly basic.

Utilizing a mechanism that would re-orient radar-reflective panels, the rover could communicate with an orbiting spacecraft. Far overhead, the spacecraft would beam down a radar signal that would bounce off the rover’s reflective panels. These panels could be oriented in a fashion to allow for simple communication between the two explorers, thus enabling the relaying of data back to Earth.

The program is now in its second phase of development, with engineers determining which components of the concept should be refined and further advanced.



Automaton Rover for Extreme Environments (AREE)
Video courtesy of Jonathan Sauder / JPL / NASA


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Johnson Space Center closed through Labor Day to evaluate safety after Harvey

Johnson Space Center closed through Labor Day to evaluate safety after Harvey:



Tropical Storm Harvey as seen by the crew of the International Space Station on Aug. 29, 2017. Photo Credit: Randy Bresnik / NASA


Tropical Storm Harvey as seen by the crew of the International Space Station on Aug. 29, 2017. Photo Credit: Randy Bresnik / NASA
Hurricane Harvey, now a tropical storm, has prompted NASA to cancel an in-flight question and answer session with Expedition 52 astronaut Peggy Whitson, who is currently aboard the International Space Station. Additionally, the Johnson Space Center will remain closed until Sept. 5, 2017, to all but mission mission-essential personnel while officials evaluate the safety of the center.

A 30-minute news conference with Whitson, who has been residing at the outpost since November 2016 and will return to Earth this weekend, was planned for Aug. 30. However, because of the Johnson Space Center’s closure, mission-essential staff will not be able to support the in-flight event.

Moreover, live satellite interviews with NASA astronauts Mark Vande Hei and Joe Acaba, who are in Russia, have also been canceled. The U.S. space agency originally cited a change in the crew’s training schedule for the cancellation, but because the event was planned for Sept. 1, there will also be no staff to support the event.

Vande Hei and Acaba will launch to the space station with cosmonaut Alexander Misurkin on Sept. 12 inside their Soyuz MS-06 spacecraft. Liftoff is scheduled for 5:17 p.m. EDT (21:17 GMT). They will remain at the outpost until February 2018.

Harvey made its first landfall near Corpus Christi, Texas, on Aug. 26 with maximum sustained winds of 130 mph (210 km/h): a Category 4 hurricane. The 280-mile (450-kilometer) wide storm soon stalled over the state before moving back out into the Gulf of Mexico. It made a second landfall on Aug. 30 near the Texas-Louisiana border, this time as a tropical storm with sustained winds of 45 mph (73 km/h).

So far, the storm has dropped more than 50 inches of rain, including in Houston where Johnson Space Center is located, resulting in floods impacting hundreds of thousands of homes and displacing more than 30,000 people. Harvey has caused at least 21 deaths in the United States. Preliminary economic losses are estimated to be between $10 billion to $160 billion.

While the Johnson Space Center originally closed on Aug. 25, sheltering in place were mission-essential personnel. This included flight controllers who maintain constant contact with the International Space Station.

Johnson Space Center’s leadership is continuing to monitor weather conditions as well as the overall situation in Houston. Teams will prepare a full assessment of the center’s status after the storm fully passes.

“Our primary concern is the safety of our employees and all our fellow Houstonians,” said Johnson Director Ellen Ochoa in a statement on NASA’s website. “We’re taking these measures to ensure the members of our team and their families can take care of themselves and their neighbors.”

According to NASA, closing the center will allow employees to avoid flooded roads and attend to the needs of their families. Additionally, it allows for essential employees to focus on the highest-priority missions, including the landing of three ISS crew members over the Labor Day weekend. The trio – Whitson, NASA astronaut Jack Fischer, and cosmonaut Fyodor Yurchikhin – will land in their Soyuz MS-04 spacecraft at 9:22 p.m. EDT Sept. 2 (01:22 GMT Sept. 3), 2017, in Kazakhstan.



Video courtesy of NOAA


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NASA Glenn experiments shedding new light on Venus’ shrouded surface

NASA Glenn experiments shedding new light on Venus’ shrouded surface:



The planet Venus


The planet Venus is permanently shrouded by cloud cover. Photo Credit NASA
CLEVELAND, Ohio — A special NASA test chamber apparatus is helping scientists explore the mysteries of Venus right here on Earth. The chamber is located at NASA’s Glenn Research Center in Cleveland, Ohio. It is hoped that this new vessel will help prepare the space agency for missions to extreme worlds.

GEER, the Glenn Extreme Environment Rig, is a high-tech pressure vessel capable of simulating the pressure, temperature, and atmospheric gas mix of Venus, or any other extreme planetary environment, for an extended period. Engineers at the NASA Glenn Research Center where GEER is housed, as well as scientists from nearby Case Western Reserve University, recently conducted a long-duration experiment in GEER that could yield important new information about the Venus environment.



Venus – Computer Simulated Global View Centered at 180 Degrees East Longitude


A computer generated global view of Venus, centered at 180° East longitude, based on the Magellan probe’s radar mapping. (Click to enlarge) Image Credit: NASA/JPL
The recent test, completed in mid-July, lasted for some 80 days; it served as the follow-up to a 40-day test that was conducted in GEER about two years ago.

“This is more about planetary science than spaceflight,” Ralph Harvey, a Professor in the department of Earth Environment and Planetary Science at Case Western Reserve University, told Spaceflight Insider. “We decided GEER gives us the opportunity to do a large volume experiment […] and that we would simulate the most reactive situation I could think of between the crust of Venus and the atmosphere. And that situation is when new rock is exposed – when volcanoes spit out a bit of lava.”

Surface radar images of Venus and the resulting topographic maps show an abundance of volcanoes and lava flows on the planet’s surface. Harvey and his graduate student Brandon Radoman-Shaw, in cooperation with researchers and engineers at NASA Glenn, conceived of an experiment in which they took a suite of minerals that represent the key minerals in basaltic volcanic rocks – pyroxene, olivine, feldspars, and others – as well as some glasses, and placed them inside the GEER chamber. There, the minerals were exposed to a high-fidelity simulation of Venus’ surface conditions – not only of the physical conditions but also of the atmospheric composition as well.

“The GEER chamber is an unparalleled thing,” Harvey said. “Other people have done experiments simulating the Venus surface, but they were always limited in terms of their own technology. Often the vessel in which they simulated the Venus surface conditions was the size of a soda can or a thermos bottle. Or their experiments had been limited in terms of the temperatures or pressures they could reach.”

The GEER chamber is much larger than a soda can. It is cylindrical in shape, 3-feet (91 cm) in diameter by 4-feet (122 cm) long. The complex apparatus surrounding the pressure vessel allows researchers to carefully create and monitor the simulated pressure, temperature, and gas mix conditions at Venus’ surface.

“It is the surface and the near surface where we know the least about Venus,” Harvey said. “Yet it has clearly played a major role in how the planet has evolved. If the rock is all reacted and weathered there at the surface, that would be really important to know about as you are designing instruments and analytical techniques to study that.”

The recent 80-day experiment, as well as the previous 40-day experiment, is designed to help understand how the Venus atmosphere and fresh rock might interact. The most recent experiment is still under fresh analysis, but some upcoming research abstracts suggest some of the early implications of the experiments.

Harvey said: “What we are learning so far is that, in spite of the fact that CO2 is the greenhouse gas that everyone pays a lot of attention to, it is probably sulfur that is the real mover and shaker. We don’t see a lot of activity of carbon. In fact, it doesn’t look like CO2-bearing or carbonate minerals are very stable at all. It looks like they go away rather than form.”

The effect of CO2 on Venus has long been a topic of debate among scientists, given immediacy by the greenhouse effects of CO2 and its possible connections to climate change on Earth. The lack of new data from Venus on the subject has kept the debate alive for decades. The new data from the recent GEER experiment may add a new and unforeseen twist to the debate.

“Sulfur looks like a much bigger player than CO2,” Harvey said. “Even though the atmosphere is mostly CO2 and that’s the big greenhouse gas you read about in all the papers, sulfur is a much more active greenhouse gas, and it forms a really nasty, very reactive acid. Even though sulfur is a minor component of that atmosphere, it is a major player in how rocks on Venus interact with the atmosphere.”

The analysis of the 80-day experiment is just beginning. It will be some time before its findings are included in papers for publication. Nevertheless, Harvey already believes the experiment is likely to provide a new perspective from which to approach future studies of the Venus surface environment.

“In some ways, we’re kind of wiping the slate clean,” he said. “We’re going to figure out what reactions are more important and which ones are less important. We’re not going to be super quantitative or come up with reaction rates or describe the history of Venus hour by hour for the next billion years. However, on the other hand, it creates a new starting point for more sophisticated modeling and more experiments.”



NASA-Glenn-engineer-Kyle-Phillips-GEER_r
GEER-samples_rsz-1600x1068.jpg


LEFT: Kyle Phillips, NASA Glenn engineer, removes samples from GEER after they were exposed to Venus surface conditions for 80 days. RIGHT: Professor Ralph Harvey and graduate student Brandon Radoman-Shaw of Case Western Reserve University inspect mineral samples used in the 80-day simulated Venus surface environment test in the GEER chamber at NASA Glenn Research Center in Cleveland, Ohio. Photos Credit: NASA
The recent 80-day experiment would not have been possible without some significant redesigns to the systems of GEER. Simulating the 863 °F (462 °C) temperatures and the extreme atmospheric pressure 90 times that of Earth that exists at Venus’ surface is a challenge to materials and engineering.

“We pretty much redesigned our entire process system, and that is everything but the GEER vessel itself,” Leah Nakely, Chemical Test Engineer and Lead Engineer for the GEER Project, told Spaceflight Insider. “All of the components, the lines, the subsystems were redesigned and checked out before the test.”

The GEER team did a materials study that was spread out over three different tests. The tests were over 10-day, 20-day, and 40-day periods. Those tests demonstrated what kind of component materials worked best to facilitate a Venus environment test, and they made their selection of component materials based on those results. The components included valves, heaters, sensors, gas mixers, flow meters, and tubing.

“So all of the components, the lines, the subsystems, were redesigned and checked out before the test,” Nakely said. “Some of the new capabilities we added were real-time gas analysis. And that’s a big one. That allows us to take gas samples directly from the GEER vessel and analyze them in just a couple of minutes, and know exactly what the gas composition is, and from there we can adjust it, add more gas, or adjust the chemical composition. That’s a big addition we made.”

That new capability was essential to extending the Venus surface condition test to an 80-day experiment. And the redesign with the severe service parts helped make that real-time gas analysis capability possible.

“Some materials that perform really well on Earth do not perform well on Venus,” Nakely said. “No one really knows what will perform well on Venus. That’s what GEER is for.”

“I can guarantee you every time we run something in GEER we see something that makes our jaws drop,” Harvey added. “Things just aren’t behaving in the way your intuition based on Earth would lead you to expect. And whether you are a scientist or an engineer, that’s always cool.”



GEER, the Glenn Extreme Environment Rig


GEER, the Glenn Extreme Environment Rig, with its chamber open prior to an experiment. A 40-day test in simulated Venus surface conditions was conducted in the chamber two years ago, and an 80-day test was completed this past July. Scientists at Case Western Reserve University in Cleveland, Ohio, exposed a number of basaltic volcanic minerals to the simulated Venus environment to observe and analyze their reaction. An experiment in GEER’s simulated Venus environment was also completed earlier this year, testing the durability of silicon carbide semiconductor circuits, which may be used in instrumentation for future missions to Venus’ surface. Photo Credit: NASA Glenn


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Ariane 5 to launch 2 satellites to geostationary transfer orbit

Ariane 5 to launch 2 satellites to geostationary transfer orbit:



Intelsat37e is one of two satellites an Ariane 5 will send into orbit for the mission designated VA239. Image Credit: Arianespace


Intelsat37e is one of two satellites an Ariane 5 will send into orbit for the mission designated VA239. Image Credit: Arianespace
For the fifth time in 2017, Arianespace will send an Ariane 5 rocket into space. The flight will orbit commercial communication satellites for two international customers: Intelsat and Broadcasting Satellite System Corporation (B-SAT), a leading broadcasting satellite operator in Japan.

The Intelsat 37e satellite will support Africa, Europe, Central Africa, and Latin America, while BSAT-4a will provide Direct-to-Home (DTH) television service in Japan.

Improving satcom capabilities


Stationed in geosynchronous orbit at 342° E longitude, Intelsat 37e will be situated over the mid-Atlantic. Weighing in at a hefty 14,193 pounds (6,438 kilograms), the satellite is the fifth of Intelsat’s EpicNG series of high-throughput satellites built by Boeing.

Intelsat 37e includes fixed C-band, and steerable spot Ku-band and Ka-band beams, which allows the spacecraft to optimize its services to meet the requirements of its regional customers. It is the first satellite to offer interconnectivity between three different bands. Additionally, the next-generation satellite will be used in wireless backhaul, enterprise Very Small Aperture Terminal (VSAT), and mobility networks.

The satellite Intelsat 37e is replacing, Intelsat 901, was launched in 2001 and has exceeded its estimated 13-year service life.

BSAT-4a is Arianespace’s ninth launch for B-SAT and its 30th launch contract for a geostationary commercial satellite in Japan. The 7,760-pound (3,520-kilogram) satellite, which will be stationed over the equator at 110° E, carries 24 Ku-band transponders. It will expand the availability of high-definition and 4K/8K ultra-high-definition television in that country. The spacecraft bus is based on SSLSSL 1300 platform.

Both satellites are designed to provide service for 15 years or longer.

Ready to go


On Sept. 1, 2017, the Ariane 5 ECA flight, designated VA239 by Arianespace, was cleared for launch. The rocket will roll out from the Guiana Space Centre’s Final Assembly Building in Kourou, French Guiana Sept. 4 to the ELA-3 launch zone.

Liftoff will occur Sept. 5, with a 33-minute launch window opening at 6:51 p.m. local time in French Guiana (5:51 p.m. EDT / 21:51 GMT). After achieving an initial orbit, Intelsat 37e, as the top payload “passenger”, will be deployed first, followed by BSAT-4a.



BSAT-4a is one of two satellites an Ariane 5 will send into orbit for the mission designated VA239. Image Credit: Arianespace


BSAT-4a is one of two satellites an Ariane 5 will send into orbit for the mission designated VA239. Image Credit: Arianespace


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FINESSE mission to investigate atmospheres of hundreds of alien worlds

FINESSE mission to investigate atmospheres of hundreds of alien worlds:



FINESSE spacecraft


Artist’s concept of the FINESSE spacecraft. Image Credit: NASA / JPL
One of NASA’s proposed missions, known as the Fast INfrared Exoplanet Spectroscopy Survey Explorer (FINESSE), could greatly improve our understanding of extrasolar worlds. If selected for development, the spacecraft will investigate at least 500 exoplanet atmospheres, providing detailed information about climate processes on distant alien planets.

FINESSE has been recently chosen by NASA for concept studies and evaluations. It is one of the agency’s six astrophysics Explorers Program proposals that could be selected by 2019 to proceed with construction and launch.

The mission’s main objective is to study the processes that govern planet formation and global climate. It will investigate the mechanisms that establish the atmospheric chemical composition of exoplanets as well as the processes involved in atmospheric evolution.

“FINESSE will spectroscopically observe the atmospheres of many hundreds of transiting exoplanets to measure their molecular abundances and thermal profiles,” Robert Zellem, FINESSE science team member at NASA’s Jet Propulsion Laboratory (JPL), told Astrowatch.net.

In order to conduct the planned studies, FINESSE will use the transit method. It will measure how a planet’s atmosphere absorbs light from its host star as a function of wavelength. This will allow it to infer the molecules in the planet’s atmosphere.

“By doing this for hundreds of planets, FINESSE will determine how planets form and the crucial factors that establish planetary climate,” Zellem said.

These observations will require a proper imaging system. That is why the FINESSE spacecraft will be equipped with a telescope with a 75-centimeter (29.5-inch) primary mirror and a spectrometer that will observe planets in the visible and infrared wavelengths (from 0.5 to 5 microns).

According to Zellem, wide spectral coverage will enable FINESSE to measure the abundances of molecules such as water, methane, carbon dioxide, and carbon monoxide as well as look for the presence of clouds and hazes.

Data collected by the spacecraft are expected to provide important information that could improve our knowledge about various exoplanets, from rocky terrestrial planets to gas giants like Jupiter. FINESSE could help us discover what these alien worlds are like, determining what makes them they way they are, and allowing this knowledge to be applied in the broader planetary context, including the search for life outside of the Solar System.

If selected for the development, FINESSE is targeted for the launch around 2023. Zellem hopes that during its operational lifetime of two years it will carry out important observations of even more than 1,000 extrasolar worlds.

“FINESSE has the capability in its two-year mission to observe the atmospheres of over 1000 transiting exoplanets,” he concluded.

Video courtesy of NASA / JPL


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Original enclosures:
Transit-method-single-planet.mp4

Second GPS III satellite completes strenuous launch environment test

Second GPS III satellite completes strenuous launch environment test:



GPS III satellite. Image Credit: Lockheed Martin


Artist’s rendering of a GPS III satellite. Image Credit: Lockheed Martin
Before a satellite can begin its operational life on orbit, it must first survive the extreme sound pressure and punishing vibrations caused by over 700,000 pounds-force (3,110 kilonewtons) of rocket thrust. On July 13, 2017, Lockheed Martin‘s second GPS III satellite (GPS III SV02) successfully completed acoustic environmental testing.

During the acoustic testing, the GPS III SV02 satellite was blasted by high-powered horns capable of producing sound up to 140 decibels. This is about as noisy as an aircraft carrier deck and is loud enough to shake loose anything on the satellite not properly attached.

“With this launch-simulation test, we are talking about sophisticated, advanced satellite technology and electronics enduring tremendous forces and then working flawlessly afterward,” said Mark Stewart, Lockheed Martin’s vice president for Navigation Systems. “Passing this test with GPS III SV02 further validates the robustness of our GPS III design. We credit this success and risk-retirement to all the pathfinding work we accomplished early in the program.”

The GPS III SV02 satellite is part of the U.S. Air Force’s next generation of GPS satellites. GPS III will have three times greater accuracy than current GPS satellites and up to eight times improved anti-jamming capabilities. The satellites have a designed life expectancy of up to 15 years – 25 percent longer than the latest GPS satellites currently in orbit.

The GPS III satellites will broadcast the new L1C civil signal that will make them the first GPS satellites to be interoperable with other international global navigational systems. The L1C signal will achieve full operational potential when broadcast from at least 24 GPS III satellites, currently projected for the late 2020s.



GPS III SV02 acoustic test


On July 13, 2017, the U.S. Air Force’s second GPS III space vehicle (GPS III SV 02) successfully completed acoustic testing. The test simulated the extreme sound wave pressure and pounding vibrations generated by more than 700,000 lbf of thundering rocket thrust during launch. During acoustic testing, the GPS III SV02 satellite was continuously blasted with deafening sound reaching 140 decibels in a specialized test chamber equipped with high-powered horns. Passing this test [has] further validated the robustness of Lockheed Martin’s GPS III design. Photo & Caption Credit: Lockheed Martin
GPS III SV02 is Lockheed Martin’s second GPS III satellite to complete acoustic testing. GPS III SV01 completed acoustic testing in fall 2015 and is currently in storage awaiting its expected 2018 launch.

The GPS III SV02 satellite is currently being prepared for Thermal Vacuum (TVAC) testing, where it will be subjected to extreme heat and cold in zero atmospheres, simulating conditions on-orbit. The satellite is expected to be delivered to the U.S. Air Force in early 2018.

GPS III SV02 is the second of 10 GPS satellites that Lockheed Martin is manufacturing for the Air Force at the company’s GPS III processing facility near Denver, Colorado. The $128 million factory includes a specialized cleanroom and testing chambers designed to streamline spacecraft production.

GPS III satellite design includes a modular architecture that allows for the addition of new technology as it becomes available or as mission needs change. Satellites using this design are compatible with both the Air Force’s next-generation Operational Control System (OTX) and the existing GPS constellation.



Video courtesy of Lockheed Martin 


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New Horizons sets flight plan for 2nd target; IAU accepts Pluto system names

New Horizons sets flight plan for 2nd target; IAU accepts Pluto system names:



New Horizons 2014 MU69 flyby


Artist’s concept of NASA’s New Horizons spacecraft flying by a possible binary 2014 MU69 on Jan. 1, 2019. Early observations of MU69 hint at the Kuiper Belt object being either a binary orbiting pair or a contact (stuck together) pair of nearly like-sized bodies with diameters near 20 and 18 kilometers (12 and 11 miles). Image & Caption Credit: Carlos Hernandez / NASA
NASA’s New Horizons mission has filed a flight plan for its January 1, 2019, flyby of Kuiper Belt Object (KBO) 2014 MU69, which will bring the spacecraft three times closer to its second target than it came to Pluto during the upcoming encounter.

New Horizons’ flyby of MU69


At a distance of more than four billion miles (6.5 billion kilometers) from Earth and approximately one billion miles (1.5 billion kilometers) beyond Pluto, the flyby will be the furthest ever encounter between a spacecraft and a planetary body.

The plan calls for the probe to pass within just 2,175 miles (3,500 kilometers) of the KBO, allowing the spacecraft’s cameras to capture images and data at higher resolutions than those taken at Pluto.



Artist’s concept #1 of Kuiper Belt Object 2014 MU69,


An artist’s concept of Kuiper Belt Object 2014 MU69, the next flyby target for NASA’s New Horizons mission. This binary concept is based on telescope observations made at Patagonia, Argentina, on July 17, 2017, when MU69 passed in front of a star. New Horizons scientists theorize that it could be a single body with a large chunk taken out of it, or two bodies that are close together or even touching. Image & Caption Credit: Alex Parker / NASA / JHU-APL / SwRI 
New Horizons’ highest-resolution camera, the Long Range Reconnaissance Imager (LORRI), has imaged details as small as 600 feet (183 meters) in diameter on Pluto’s surface; however, on MU69, it will be able to resolve details down to a diameter of 230 feet (70 meters).

“We’re planning to fly closer to MU69 than to Pluto to get even higher resolution imagery and other datasets. The science should be spectacular,” emphasized mission Principal Investigator Alan Stern of the Southwest Research Institute (SwRI) in Boulder, Colorado.

MU69, which will become the farthest world ever visited by a spacecraft, will be studied with all seven of New Horizons’ science instruments, which will study its geology, geophysics, and composition as well as search for an atmosphere and possible moons.

Observations of the KBO conducted in July when it passed in front of a star suggest that it could be a binary system composed of two objects or a single object with two lobes.

New Horizons will look down on the KBO’s celestial north as it cruises by the object(s).

As done for the Pluto flyby, mission scientists and engineers have prepared an alternate flight plan that will be followed if debris is detected near MU69.

Even if the contingency plan has to be used, the probe will still come within 6,000 miles (10,000 kilometers) of the KBO, in contrast to 7,800 miles (12,500 kilometers) for Pluto.

NASA Planetary Science Director Jim Green praised New Horizons for repeatedly pushing the boundaries of what is possible in robotic space exploration.

“I couldn’t be more excited about this encore performance from New Horizons,” he said.

In deciding on this flight path, the mission team considered a variety of factors, including MU69’s size and shape, the desire for high-quality images, the possibility of hazardous debris nearby, and the capabilities of the spacecraft and its seven science instruments, noted team member John Spencer, also of SwRI.

On Monday, September 11, the spacecraft will be woken up from a five-month hibernation in preparation for its 16-month journey to MU69.

Names of features on Pluto officially adopted


While the spacecraft speeds toward its second target, the International Astronomical Union (IAU) has announced its formal adoption of 14 names for features on Pluto, Charon, and the system’s four small moons.



The Rich Color Variations of Pluto


NASA’s New Horizons spacecraft captured this high-resolution enhanced color view of Pluto on July 14, 2015. (Click to enlarge) Image Credit: NASA / JHU-APL / SwRI
These include Tombaugh Regio for the “heart” feature on Pluto’s surface, Sputnik Planitia for the icy plain on the left side of the heart, Burney crater for a crater west of the heart, Voyager Terra for a region northwest of the heart, and several more.

Tombaugh Regio is named for American astronomer Clyde Tombaugh, who discovered Pluto in 1930. Sputnik Planitia is named for the first satellite ever in space, the former Soviet Union’s Sputnik 1.

Burney crater honors Venetia Burney Phair, a British girl who, as an 11-year-old in 1930, suggested the name “Pluto” for the new discovery.

Voyager Terra honors NASA’s twin Voyager spacecraft, launched 40 years ago.

The many names assigned to mountain ranges, plains, regions, craters, and valleys on Pluto and its moons came from public input solicited as part of the “Our Pluto” project, a joint effort between the New Horizons mission, the IAU, and the SETI Institute of Mountain View, California, just prior to the Pluto flyby.

Names were sought for a variety of themes, including key space missions, underworld mythology, historic explorers, engineers, and scientists connected to Pluto and the Kuiper Belt, and even fictional locations from popular fantasy and science fiction literature, television, and movies.

“The approved designations honor many people and space missions who paved the way for the historic exploration of Pluto and the Kuiper Belt, the farthest worlds ever explored,” Stern said.

Rita Schultz, chair of the IAU Working Group for Planetary System Nomenclature, thanked both the public and members of the mission team for the name suggestions.

Along with Stern, mission scientists Mark Showalter, Ross Beyer, Will Grundy, William McKinnon, Jeff Moore, Cathy Olkin, Paul Schenk, and Amanda Zangari participated in New Horizons’ Nomenclature Working Group, which worked in concert with the IAU group.

“I’m delighted that most of the approved names were originally recommended by members of the public,” said Showalter of the SETI Institute.

The 14 names approved are only the first proposed by the mission team. Many more will be submitted by New Horizons scientists to the IAU in the near future.

The following names have been approved:

Tombaugh Regio honors Clyde Tombaugh (1906–1997), the U.S. astronomer who discovered Pluto in 1930 from Lowell Observatory in Arizona.
Burney crater honors Venetia Burney (1918–2009) who, as an 11-year-old schoolgirl, suggested the name “Pluto” for Clyde Tombaugh’s newly discovered planet. Later in life, she taught mathematics and economics.
Sputnik Planitia is a large plain named for Sputnik 1, the first space satellite, launched by the Soviet Union in 1957.
Tenzing Montes and Hillary Montes are mountain ranges honoring Tenzing Norgay (1914–1986) and Sir Edmund Hillary (1919–2008), the Indian/Nepali Sherpa and New Zealand mountaineer were the first to reach the summit of Mount Everest and return safely.
Al-Idrisi Montes honors Ash-Sharif al-Idrisi (1100–1165/66), a noted Arab mapmaker and geographer whose landmark work of medieval geography is sometimes translated as “The Pleasure of Him Who Longs to Cross the Horizons.”
Djanggawul Fossae defines a network of long, narrow depressions named for the Djanggawuls, three ancestral beings in indigenous Australian mythology who traveled between the island of the dead and Australia, creating the landscape and filling it with vegetation.
Sleipnir Fossa is named for the powerful, eight-legged horse of Norse mythology that carried the god Odin into the underworld.
Virgil Fossae honors Virgil, one of the greatest Roman poets and Dante’s fictional guide through hell and purgatory in the Divine Comedy.
Adlivun Cavus is a deep depression named for Adlivun, the underworld in Inuit mythology.
Hayabusa Terra is a large land mass saluting the Japanese spacecraft and mission (2003–2010) that performed the first asteroid sample return.
Voyager Terra honors the pair of NASA spacecraft, launched in 1977, that performed the first “grand tour” of all four giant planets. The twin Voyager spacecraft are now probing the boundary between the Sun and interstellar space.
Tartarus Dorsa is a ridge named for Tartarus, the deepest, darkest pit of the underworld in Greek mythology.
Elliot crater recognizes James L. Elliot (1943–2011), an MIT researcher who pioneered the use of stellar occultations to study the Solar System – leading to discoveries such as the rings of Uranus and the first detection of Pluto’s thin atmosphere.


Pluto features map


Pluto’s first official surface-feature names are marked on this map, compiled from images and data gathered by NASA’s New Horizons spacecraft during its flight through the Pluto system in 2015. Image & Caption Credit: NASA / JHU-APL / SwRI / Ross Beyer


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