Orbiter.ch Space News: 2018-08-05

samedi 11 août 2018

Space Station Science Highlights: Week of August 6, 2018

ISS - Expedition 56 Mission patch.

Aug. 11, 2018

The crew members aboard the International Space Station spent this week conducting science, helping out with student robotic competitions, and preparing for next week’s Russian spacewalk when cosmonauts Oleg Artemyev and Sergey Prokopyev will work outside the station’s Russian segment for about six hours of science and maintenance tasks.

International Space Station (ISS). Image Credit: NASA

Read more details about scientific work last week aboard your orbiting laboratory:

SPHERES investigations soar through the station

Synchronized Position Hold, Engage, Reorient, Experimental Satellites (SPHERES), three free-flying, bowling-ball sized spherical satellites used inside the space station to test a set of well-defined instructions for spacecraft performing autonomous rendezvous and docking maneuvers, are used for a variety of investigations aboard the orbiting lab.

The SPHERES-Zero-Robotics investigation provides an opportunity for high school students to conduct research aboard the station. As part of a competition, students write algorithms for the satellites to accomplish tasks relevant to potential future missions. The most promising designs are selected to operate the SPHERES satellites aboard the station as a part of the competition.

Animation above: Two of the free-flying spherical robots used by the SPHERES investigations. SPHERES-Zero-Robotics gives students the chance to develop software to guide robots through a virtual obstacle course aboard the space station. Animation Credit: NASA.

This week, the crew members conducted dry runs in preparation for the final competition, which occurred Friday.

The SPHERES Tether Slosh investigation combines fluid dynamics equipment with robotic capabilities aboard the station. In space, the fuels used by spacecraft can slosh around in unpredictable ways making space maneuvers difficult. This investigation uses two SPHERES robots tethered to a fluid-filled container covered in sensors to test strategies for safely steering spacecraft such as dead satellites that might still have fuel in the tank.

This week, crew members set up the hardware and cameras before executing an experiment run.

Crew members use sextant to identify stars for use in future navigation

A tool that has helped guide sailors across oceans for centuries is now being tested aboard the station as a potential emergency navigation tool for guiding future spacecraft across the cosmos. The Sextant Navigation investigation tests use of a hand-held sextant aboard the space station.

Sextants have a small telescope-like optical sight to take precise angle measurements between pairs of stars from land or sea, enabling navigation without computer assistance. Sextants have been used by sailors for centuries, and NASA’s Gemini missions conducted the first sextant sightings from a spacecraft. Designers built a sextant into Apollo vehicles as a navigation backup in the event the crew lost communications from their spacecraft, and Jim Lovell demonstrated on Apollo 8 that sextant navigation could return a space vehicle home. Astronauts conducted additional sextant experiments on Skylab.

Animation above: NASA astronaut Serena Auñón-Chancellor conducting a star identification session as a part of the Sextant Navigation investigation. Animation Credit: NASA.

This week, the crew calibrated the sextant and performed the second star identification and sighting session of the investigation with European Space Agency (ESA) astronaut Alexander Gerst and NASA astronaut Serena Auñón-Chancellor. This session placed an emphasis on position stabilization and sighting.

For more information about the investigation, click here: https://www.nasa.gov/mission_pages/station/research/news/Sextant_ISS

Investigation studies how Earth’s magnetic field interacts with electrical conductor; sample exchanges begin

The European Space Agency’s (ESA) MagVector investigation studies how Earth’s magnetic field interacts with an electrical conductor. Using extremely sensitive magnetic sensors placed around and above a conductor, researchers gain insight into ways that the magnetic field influences how conductors work. This research not only helps improve future experiments aboard the station and other electrical experiments, but it could offer insights into how magnetic fields influence electrical conductors in general, the backbone of our technology on Earth.

This week, crew members performed the last set of planned sample exchanges.

Replacements completed in preparation for CLD Flames

The Advanced Combustion Microgravity Experiment (ACME) investigation is a set of five independent studies of gaseous flames to be conducted in the Combustion Integration Rack (CIR), one of which being Coflow Laminar Diffusion Flame (CLD Flame). ACME’s goals are to improve fuel efficiency and reduce pollutant production in practical combustion on Earth and to improve spacecraft fire prevention through innovative research focused on materials flammability.

Image above: ESA astronaut Alexander Gerst working within the CIR on the ACME CLD Flame investigation. Image Credit: NASA.

This week, the crew replaced the CIR manifold bottles and an ACME controller in support of the second part of CLD Flames.

Space to Ground: A Star to Steer By: 08/10/2018

Perseids Meteor Shower Peaks This Weekend

NASA logo.

August 11, 2018

Theeey’re heeere!

The Perseid meteor shower is here! Perseid meteors, caused by debris left behind by the Comet Swift-Tuttle, began streaking across the skies in late July and will peak on August 12.

Tail of Comet Swift-Tuttle crossing Earth orbit. Animation Credit: Celestia

The Perseid meteor shower is often considered to be one of the best meteor showers of the year due to its high rates and pleasant late-summer temperatures. This year’s shower peak, however, has the added bonus of dark skies courtesy of an early-setting crescent Moon. Combine these ideal observing conditions and high rates (an average of 60 meteors per hour at the peak) with the fact that the best nights for viewing – August 11 to 12 and August 12 to 13 – occur on a weekend and you have a recipe for successfully viewing some celestial fireworks!

Image above: A Perseid meteor over Daytona Beach, FL. Perseids are known for being bright and fast, traveling 132,000 mph. Image Credits: NASA/MEO.

When Should I Look?

Make plans to stay up late or wake up early the nights of August 11 to 12 and August 12 to 13. The Perseids are best seen between about 2 a.m. your local time and dawn.

If those hours seem daunting, not to worry! You can go out after dark, around 9 p.m. local time, and see Perseids. Just know that you won’t see nearly as many as you would had you gone out during the early morning hours.

How can you see the Perseids if the weather doesn’t cooperate where you are? A live broadcast of the meteor shower from a camera in Huntsville, AL (if our weather cooperates!) will be available on the NASA Meteor Watch Facebook starting around 8 p.m. CT and continuing until the early hours of August 13. Meteor videos recorded by the NASA All Sky Fireball Network are also available each morning; to identify Perseids in these videos, look for events labeled “PER.”

Why Are They Called Perseids?

All meteors associated with one particular shower have similar orbits, and they all appear to come from the same place in the sky, called the radiant. Meteor showers take their name from the location of the radiant. The Perseid radiant is in the constellation Perseus. Similarly, the Geminid meteor shower, observed each December, is named for a radiant in the constellation Gemini.

Image above: Most of the meteors seen in this composite are Perseids. Notice how they all appear to be streaking from the same direction? The Perseids appear to radiate from a point in the constellation Perseus. Image Credits: NASA/MEO.

How to Observe Perseids

If it’s not cloudy, pick an observing spot away from bright lights, lay on your back, and look up! You don’t need any special equipment to view the Perseids – just your eyes. (Note that telescopes or binoculars are not recommended.) Meteors can generally be seen all over the sky so don’t worry about looking in any particular direction.

Perseid meteor shower. Animation Credit: Unknown

While observing this month, not all of the meteors you’ll see belong to the Perseid meteor shower. Some are sporadic background meteors. And some are from other weaker showers also active right now, including the Alpha Capricornids, the Southern Delta Aquariids, and the Kappa Cygnids. How can you tell if you’ve seen a Perseid? If you see a meteor try to trace it backwards. If you end up in the constellation Perseus, there’s a good chance you’ve seen a Perseid. If finding constellations isn’t your forte, then note that Perseids are some of the fastest meteors you’ll see!

Pro tip: Remember to let your eyes become adjusted to the dark (it takes about 30 minutes) – you’ll see more meteors that way. Try to stay off of your phone too, as looking at devices with bright screens will negatively affect your night vision and hence reduce the number of meteors you see!

Happy viewing!

MSFC Meteoroid Environment Office: https://blogs.nasa.gov/Watch_the_Skies/category/msfc-meteoroid-environment-office/

All sky camera: https://blogs.nasa.gov/Watch_the_Skies/tag/all-sky-camera/

All Sky Fireball Network: https://blogs.nasa.gov/Watch_the_Skies/tag/all-sky-fireball-network/

Comet Swift-Tuttle: https://blogs.nasa.gov/Watch_the_Skies/tag/comet-swift-tuttle/

Perseids meteor shower: https://blogs.nasa.gov/Watch_the_Skies/tag/perseids-meteor-shower/

Images (mentioned) Animation (mentioned), Text, Credits: NASA's Marshall Space Flight Center.

Greetings, Orbiter.ch

vendredi 10 août 2018

Finding the Happy Medium of Black Holes

NASA - Chandra X-ray Observatory patch.

Aug. 10, 2018

Scientists have taken major steps in their hunt to find black holes that are neither very small nor extremely large. Finding these elusive intermediate-mass black holes could help astronomers better understand what the "seeds" for the largest black holes in the early Universe were.

The new research comes from two separate studies, each using data from NASA's Chandra X-ray Observatory and other telescopes.

Image above: The COSMOS Legacy Survey shows data that have provided evidence for the existence of intermediate-mass black holes (IMBHs). Image Credits: X-ray: NASA/CXC/ICE/M.Mezcua et al.; Infrared: NASA/JPL-Caltech; Illustration: NASA/CXC/A.Hobart.

Black holes that contain between about one hundred and several hundred thousand times the mass of the Sun are called "intermediate mass" black holes, or IMBHs. This is because their mass places them in between the well-documented and frequently-studied "stellar mass" black holes on one end of the mass scale and the "supermassive black holes" found in the central regions of massive galaxies on the other.

While several tantalizing possible IMBHs have been reported in recent years, astronomers are still trying to determine how common they are and what their properties teach us about the formation of the first supermassive black holes.

One team of researchers used a large campaign called the Chandra COSMOS-Legacy survey to study dwarf galaxies, which contain less than one percent the amount of mass in stars as our Milky Way does. (COSMOS is an abbreviation of Cosmic Evolution Survey.) The characterization of these galaxies was enabled by the rich dataset available for the COSMOS field at different wavelengths, including data from NASA and ESA telescopes.

The Chandra data were crucial for this search because a bright, point-like source of X-ray emission near the center of a galaxy is a telltale sign of the presence of a black hole. The X-rays are produced by gas heated to millions of degrees by the enormous gravitational and magnetic forces near the black hole.

"We may have found that dwarf galaxies are a haven for these missing middleweight black holes," said Mar Mezcua of the Institute of Space Sciences in Spain who led one of the studies. "We didn't just find a handful of IMBHs — we may have found dozens."

Her team identified forty growing black holes in dwarf galaxies. Twelve of them are located at distances more than five billion light years from Earth and the most distant is 10.9 billion light years away, the most distant growing black hole in a dwarf galaxy ever seen. One of the dwarf galaxies is the least massive galaxy found to host a growing black hole in its center.

Most of these sources are likely IMBHs with masses that are about ten thousand to a hundred thousand times that of the Sun. One crucial result of this research is that the fraction of galaxies containing growing black holes is smaller for less massive galaxies than for their more massive counterparts.

A second team led by Igor Chilingarian of the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Mass., found a separate, important sample of possible IMBHs in galaxies that are closer to us. In their sample, the most distant IMBH candidate is about 2.8 billion light years from Earth and about 90% of the IMBH candidates they discovered are no more than 1.3 billion light years away.

With data from the Sloan Digital Sky Survey (SDSS), Chilingarian and his colleagues found galaxies with the optical light signature of growing black holes and then estimated their mass. They selected 305 galaxies with properties that suggested a black hole with a mass less than 300,000 times that of the Sun was lurking in the central regions of each of these galaxies.

Only 18 members of this list contained high quality X-ray observations that would allow confirmation that the sources are black holes. Detections with Chandra and with XMM-Newton were obtained for ten sources, showing that about half of the 305 IMBH candidates are likely to be valid IMBHs. The masses for the ten sources detected with X-ray observations were determined to be between 40,000 and 300,000 times the mass of the Sun.

Chandra X-ray Observatory. Animation Credits: NASA/CXC

"This is the largest sample of intermediate mass black holes ever found," said Chilingarian. "This black hole bounty can be used to address one of the biggest mysteries in astrophysics."

IMBHs may be able to explain how the very biggest black holes, the supermassive ones, were able to form so quickly after the Big Bang. One leading explanation is that supermassive black holes grow over time from smaller black holes "seeds" containing about a hundred times the Sun's mass. Some of these seeds should merge to form IMBHs. Another explanation is that they form very quickly from the collapse of a giant cloud of gas with a mass equal to hundreds of thousands of times that of the Sun.

Mezcua and her team may be seeing evidence in favor of the direct collapse idea, because this theory predicts that the less massive galaxies in their sample should be less likely to contain IMBHs.

"Our evidence is only circumstantial because it's possible that the IMBHs are just as common in the smaller galaxies but they're not consuming enough matter to be detected as X-ray sources", says Mezcua's co-author Francesca Civano of the CfA.

Chilingarian's team has a different conclusion.

"We're arguing that just the presence of intermediate mass black holes in the mass range we detected suggests that smaller black holes with masses of about a hundred Suns exist," says Chilingarian's co-author Ivan Yu. Katkov of Moscow State University in Russia. "These smaller black holes could be the seeds for the formation of supermassive black holes."

Another possibility is that both mechanisms actually occur. Both teams agree that to make firm conclusions much larger samples of black holes are needed using data from future satellites. The paper by Mar Mezcua and colleagues was published in the August issue of the Monthly Notices of the Royal Astronomical Society and is available online. The paper by Igor Chilingarian was recently accepted for publication in The Astrophysical Journal and is available online.

NASA's Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, controls Chandra's science and flight operations.

Read more from NASA's Chandra X-ray Observatory: http://chandra.harvard.edu/photo/2018/imbhs/

For more Chandra images, multimedia and related materials, visit: http://www.nasa.gov/chandra

Royal Astronomical Society: https://arxiv.org/abs/1802.01567

Astrophysical Journal: https://arxiv.org/abs/1805.01467

Image (mentioned), Animation (mentioned), Text, Credits: NASA/Lee Mohon/NASA Marshall Space Flight Center/Molly Porter/Chandra X-ray Center/Megan Watzke.

Greetings, Orbiter.ch

Crew Ends Week With Spacesuit Checks, Sat Competition and Japan Cargo Mission Preps

ISS - Expedition 56 Mission patch.

August 10, 2018

A pair of cosmonauts are going into the weekend preparing for the seventh spacewalk this year from the International Space Station. The rest of the Expedition 56 crew set up a student satellite competition, made space for a cargo mission and checked combustion experiment gear.

Image above: Astronauts Drew Feustel (left) and Alexander Gerst work with science hardware that enables research into plant biology, microbiology, cell culture, tissue culture, and flow chemistry. Image Credit: NASA.

Cosmonauts Oleg Artemyev and Sergey Prokopyev are getting ready for a spacewalk Aug. 15 to conduct science and maintenance outside the station’s Russian segment. Artemyev, who has two previous spacewalks under his belt, and Prokopyev suited up Friday for a dry run of their upcoming spacewalk with assistance from NASA astronaut Serena Auñón-Chancellor. The duo will hand-deploy four tiny satellites, install antennas and cables and collect exposed science experiments.

Commander Drew Feustel and Flight Engineer Ricky Arnold set up a pair of tiny satellites, known as SPHERES, for operation during the SPHERES Zero Robotics student competition. Middle school students in the United States are competing to write the best algorithms to operate the SPHERES simulating a mission on Saturn’s moon Enceladus.

International Space Station (ISS). Animation Credit: NASA

Alexander Gerst of ESA joined Arnold before lunchtime making space for cargo due to be delivered in Sept. 14 aboard Japan’s H-II Transfer Vehicle. Gerst then opened up the Combustion Integrated Rack in the afternoon and took pictures of ACME (Advanced Combustion via Microgravity Experiments) gear that supports five independent gaseous flame studies.

Related links:

ACME (Advanced Combustion via Microgravity Experiments): https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=1651

SPHERES Zero Robotics: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=679

SPHERES: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=303

Expedition 56: https://www.nasa.gov/mission_pages/station/expeditions/expedition56/index.html

Spacewalks: https://www.nasa.gov/mission_pages/station/spacewalks

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

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

Image (mentioned), Animation (mentioned), Text, Credits: NASA/Mark Garcia.

Best regards, Orbiter.ch

NASA Finds Amazon Drought Leaves Long Legacy of Damage

NASA - ICESat-2 Mission patch.

August 10, 2018

A single season of drought in the Amazon rainforest can reduce the forest's carbon dioxide absorption for years after the rains return, according to a new study published in the journal Nature. This is the first study to quantify the long-term legacy of an Amazon drought.

A research team from NASA's Jet Propulsion Laboratory in Pasadena, California, and other institutions used satellite lidar data to map tree damage and mortality caused by a severe drought in 2005. In years of normal weather, the undisturbed forest can be a natural carbon "sink," absorbing more carbon dioxide from the atmosphere than it puts back into it. But starting with the drought year of 2005 and running through 2008 -- the last year of available lidar data -- the Amazon basin lost an average of 0.27 petagrams of carbon (270 million metric tons) per year, with no sign of regaining its function as a carbon sink.

Image above: This image, taken during a September 2010 drought, shows a line of dead and damaged trees after a surface fire in the Amazon rainforest in western Brazil. When dryer-than-normal conditions exist, fires from the open edges encroach on the forests and burn dry and stressed trees. Under normal conditions, when the rainforests are wetter, this is far less common. Image Credits: NASA/JPL-Caltech.

At about 2.3 million square miles (600 million hectares), the Amazon is the largest tropical forest on Earth. Scientists estimate that it absorbs as much as one-tenth of human fossil fuel emissions during photosynthesis. "The old paradigm was that whatever carbon dioxide we put up in [human-caused] emissions, the Amazon would help absorb a major part of it," said Sassan Saatchi of NASA's JPL, who led the study.

But serious episodes of drought in 2005, 2010 and 2015 are causing researchers to rethink that idea. "The ecosystem has become so vulnerable to these warming and episodic drought events that it can switch from sink to source depending on the severity and the extent," Saatchi said. "This is our new paradigm."

Drought from the Ground

For scientists on the ground in the Amazon, "The first thing we see during a drought is that the trees may lose their leaves," Saatchi said. "These are rainforests; the trees almost always have leaves. So the loss of leaves is a strong indication the forest is stressed." Even if trees eventually survive defoliation, this damages their capacity to absorb carbon while under stress.

Observers on the ground also notice that droughts tend to disproportionately kill tall trees first. Without adequate rainfall, these giants can't pump water more than 100 feet up from their roots to their leaves. They die from dehydration and eventually fall to the ground, leaving gaps in the forest canopy far overhead.

Image above: This image, taken during a September 2010 drought, shows a dead tree in the Amazon rainforest in western Brazil. Image Credits: NASA/JPL-Caltech.

But any observer on the ground can monitor only a tiny part of the forest. There are only about hundred plots used for research and a few tower sites for long-term monitoring of the Amazon forests. "The detailed measurements in these sites are extremely important for understanding forest function, but we can never use them to say what this giant ecosystem is doing in a timely fashion," Saatchi said. To do that, he and his colleagues turned to satellite data.

Drought from Space

The research team used high-resolution lidar maps derived from the Geoscience Laser Altimeter System aboard the Ice, Cloud, and land Elevation Satellite (ICESat). These data reveal changes in canopy structure, including leaf damage and gaps. The researchers developed a new method of analysis to convert these structural changes into changes in aboveground biomass and carbon. They eliminated pixels showing burned or deforested areas to calculate the carbon impact of drought on intact forests alone.

They found that following drought, fallen trees, defoliation and canopy damage produced a significant loss in canopy height, with the most severely impacted region declining an average of about 35 inches (0.88 meters) in the year after the drought. Less severely affected regions of the forest declined less, but all continued to decline steadily throughout the remaining years of the data record.

Image above: This image, based on measurements taken by the Tropical Rainfall Measuring Mission (TRMM), shows the areas of the Amazon basin that were affected by the severe 2005 drought. Areas in yellow, orange, and red experienced light, moderate, and severe drought, respectively. Green areas did not experience drought. Image Credits: NASA/JPL-Caltech/Google.

Saatchi noted that half of the forest's rainfall is made by the forest itself -- water that transpires and evaporates from the vegetation and ground, rises into the atmosphere, and condenses and rains out during the dry season and the transition to the wet season. A drought that kills forest trees thus not only increases carbon emissions, it reduces rainfall and extends dry-season length. Those changes increase the likelihood of future drought.

If droughts continue to occur with the frequency and severity of the last three events in 2005, 2010 and 2015, Saatchi said, the Amazon could eventually change from a rainforest to a dry tropical forest. That would reduce the forest's carbon absorption capacity and its biological diversity.

Image above: NASA's Ice, Cloud and land Elevation Satellite (ICESat): Image Credits: NASA/JLP-Caltech.

The paper in Nature is titled "Post-drought Decline of the Amazon Carbon Sink." Co-authors are affiliated with UCLA, Boston University, Oregon State University in Corvallis, and the U.S. Forest Service's International Institute of Tropical Forestry in Rio Piedras, Puerto Rico.

Related link:

Ice, Cloud, and land Elevation Satellite (ICESat): https://icesat.gsfc.nasa.gov/

Images (mentioned), Text, Credits: NASA/JPL/Esprit Smith/NASA's Earth Science News Team, written by Carol Rasmussen.

Greetings, Orbiter.ch

jeudi 9 août 2018

Water Is Destroyed, Then Reborn in Ultrahot Jupiters

NASA - Spitzer Space Telescope patch.

Aug. 9, 2018

Imagine a place where the weather forecast is always the same: scorching temperatures, relentlessly sunny, and with absolutely zero chance of rain. This hellish scenario exists on the permanent daysides of a type of planet found outside our solar system dubbed an "ultrahot Jupiter." These worlds orbit extremely close to their stars, with one side of the planet permanently facing the star.

What has puzzled scientists is why water vapor appears to be missing from the toasty worlds' atmospheres, when it is abundant in similar but slightly cooler planets. Observations of ultrahot Jupiters by NASA's Spitzer and Hubble space telescopes, combined with computer simulations, have served as a springboard for a new theoretical study that may have solved this mystery.

Image above: These simulated views of the ultrahot Jupiter WASP-121b show what the planet might look like to the human eye from five different vantage points, illuminated to different degrees by its parent star. The images were created using a computer simulation being used to help scientists understand the atmospheres of these ultra-hot planets. Ultrahot Jupiters reflect almost no light, rather like charcoal. However, the daysides of ultrahot Jupiters have temperatures of between 3600°F and 5400°F (2000°C and 3000°C), so the planets produce their own glow, like a hot ember. The orange color in this simulated image is thus from the planet's own heat. The computer model was based on observations of WASP-121b conducted using NASA's Spitzer and Hubble space telescopes. Image Credits: NASA/JPL-Caltech/Vivien Parmentier/Aix-Marseille University (AMU).

According to the new study, ultrahot Jupiters do in fact possess the ingredients for water (hydrogen and oxygen atoms). But due to strong irradiation on the planet's daysides, temperatures there get so intense that water molecules are completely torn apart.

"The daysides of these worlds are furnaces that look more like a stellar atmosphere than a planetary atmosphere," said Vivien Parmentier, an astrophysicist at Aix Marseille University in France and lead author of the new study. "In this way, ultrahot Jupiters stretch out what we think planets should look like."

While telescopes like Spitzer and Hubble can gather some information about the daysides of ultrahot Jupiters, the nightsides are difficult for current instruments to probe. The new paper proposes a model for what might be happening on both the illuminated and dark sides of these planets, based largely on observations and analysis of the ultrahot Jupiter known as WASP-121b, and from three recently published studies, coauthored by Parmentier, that focus on the ultrahot Jupiters WASP-103b, WASP-18b and HAT-P-7b, respectively. The new study suggests that fierce winds may blow the sundered water molecules into the planets' nightside hemispheres. On the cooler, dark side of the planet, the atoms can recombine into molecules and condense into clouds, all before drifting back into the dayside to be splintered again.

Water is not the only molecule that may undergo a cycle of chemical reincarnation on these planets, according to the new study. Previous detections of clouds by Hubble at the boundary between day and night, where temperatures mercifully fall, have shown that titanium oxide (popular as a sunscreen) and aluminum oxide (the basis for ruby, the gemstone) could also be molecularly reborn on the ultrahot Jupiters' nightsides. These materials might even form clouds and rain down as liquid metals and fluidic rubies.

Star-planet hybrids

Among the growing catalog of planets outside our solar system -- known as exoplanets -- ultrahot Jupiters have stood out as a distinct class for about a decade. Found in orbits far closer to their host stars than Mercury is to our Sun, the giant planets are tidally locked, meaning the same hemisphere always faces the star, just as the Moon always presents the same side to Earth. As a result, ultrahot Jupiters' daysides broil in a perpetual high noon. Meanwhile, their opposite hemispheres are gripped by endless nights. Dayside temperatures reach between 3,600 and 5,400 degrees Fahrenheit (2,000 and 3,000 degrees Celsius), ranking ultrahot Jupiters among the hottest exoplanets on record. Nightside temperatures are around 1,800 degrees Fahrenheit cooler (1,000 degrees Celsius), cold enough for water to re-form and, along with other molecules, coalesce into clouds.

Hot Jupiters, cousins to ultrahot Jupiters with dayside temperatures below 3,600 degrees Fahrenheit (2,000 Celsius), were the first widely discovered type of exoplanet, starting back in the mid-1990s. Water has turned out to be common in their atmospheres. One hypothesis for why it appeared absent in ultrahot Jupiters has been that these planets must have formed with very high levels of carbon instead of oxygen. Yet the authors of the new study say this idea could not explain the traces of water also sometimes detected at the dayside-nightside boundary.

To break the logjam, Parmentier and colleagues took a cue from well-established physical models of the atmospheres of stars, as well as "failed stars," known as brown dwarfs, whose properties overlap somewhat with hot and ultrahot Jupiters. Parmentier adapted a brown dwarf model developed by Mark Marley, one of the paper's coauthors and a research scientist at NASA's Ames Research Center in Silicon Valley, California, to the case of ultrahot Jupiters. Treating the atmospheres of ultrahot Jupiters more like blazing stars than conventionally colder planets offered a way to make sense of the Spitzer and Hubble observations.

"With these studies, we are bringing some of the century-old knowledge gained from studying the astrophysics of stars, to the new field of investigating exoplanetary atmospheres," said Parmentier.

Spitzer's observations in infrared light zeroed in on carbon monoxide in the ultrahot Jupiters' atmospheres. The atoms in carbon monoxide form an extremely strong bond that can uniquely withstand the thermal and radiational assault on the daysides of these planets. The brightness of the hardy carbon monoxide revealed that the planets' atmospheres burn hotter higher up than deeper down. Parmentier said verifying this temperature difference was key for vetting Hubble's no-water result, because a uniform atmosphere can also mask the signatures of water molecules.

"These results are just the most recent example of Spitzer being used for exoplanet science -- something that was not part of its original science manifest," said Michael Werner, project scientist for Spitzer at NASA’s Jet Propulsion Laboratory in Pasadena, California. "In addition, it’s always heartening to see what we can discover when scientists combine the power of Hubble and Spitzer, two of NASA’s Great Observatories."

Spitzer Space Telescope. Animation Credit: NASA

Although the new model adequately described many ultrahot Jupiters on the books, some outliers do remain, suggesting that additional aspects of these worlds' atmospheres still need to be understood. Those exoplanets not fitting the mold could have exotic chemical compositions or unanticipated heat and circulation patterns. Prior studies have argued that there is a more significant amount of water in the dayside atmosphere of WASP-121b than what is apparent from observations, because most of the signal from the water is obscured. The new paper provides an alternative explanation for the smaller-than-expected water signal, but more studies will be required to better understand the nature of these ultrahot atmospheres.

Resolving this dilemma could be a task for NASA’s next-generation James Webb Space Telescope, slated for a 2021 launch. Parmentier and colleagues expect it will be powerful enough to glean new details about the daysides, as well as confirm that the missing dayside water and other molecules of interest have gone to the planets’ nightsides.

"We now know that ultrahot Jupiters exhibit chemical behavior that is different and more complex than their cooler cousins, the hot Jupiters," said Parmentier. "The studies of exoplanet atmospheres is still really in its infancy and we have so much to learn."

The new study is forthcoming in the journal Astronomy and Astrophysics.

NASA's Jet Propulsion Laboratory, Pasadena, California, manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at Caltech in Pasadena. Spacecraft operations are based at Lockheed Martin Space, Littleton, Colorado. Data are archived at the Infrared Science Archive housed at IPAC at Caltech. Caltech manages JPL for NASA.

Hubble is a project of international cooperation between NASA and ESA. NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages Hubble. The Space Telescope Science Institute (STScI) in Baltimore conducts Hubble science operations.

Journal Astronomy and Astrophysics: https://arxiv.org/pdf/1805.00096.pdf

Space Telescope Science Institute (STScI): http://www.stsci.edu/

Spitzer Space Telescope: http://www.nasa.gov/mission_pages/spitzer/main/index.html

Hubble Space Telescope (HST): https://www.nasa.gov/mission_pages/hubble/main/index.html

Images (mentioned), Animation (mentioned), Text, Credits: NASA/Tony Greicius/JPL/Calla Cofield.

Greetings, Orbiter.ch

NASA’s Parker Solar Probe is About to Lift Off

NASA - Parker Solar Probe Mission patch.

Aug. 9, 2018

At 3:33 a.m. EDT on Aug. 11, while most of the U.S. is asleep, NASA’s Kennedy Space Center in Florida will be abuzz with excitement. At that moment, NASA’s Parker Solar Probe, the agency’s historic mission to touch the Sun, will have its first opportunity to lift off.

Launching from Cape Canaveral Air Force Station in Florida, Parker Solar Probe will make its journey all the way to the Sun’s atmosphere, or corona — closer to the Sun than any spacecraft in history.

Image above: NASA’s Parker Solar Probe inside one half of its 62.7-foot-tall fairing. Image Credits: NASA/Johns Hopkins APL/Ed Whitman.

“Eight long years of hard work by countless engineers and scientists is finally paying off,” said Adam Szabo, the mission scientist for Parker Solar Probe at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

Nestled atop a United Launch Alliance Delta IV Heavy — one of the world’s most powerful rockets — with a third stage added, Parker Solar Probe will blast off toward the Sun with a whopping 55 times more energy than is required to reach Mars. About the size of a small car, it weighs a mere 1,400 pounds.

“That’s a relatively light spacecraft,” said Andy Driesman, project manager for the mission at the Johns Hopkins Applied Physics Lab. “And it needs to be, because it takes an immense amount of energy to get to our final orbit around the Sun.”

Zooming through space in a highly elliptical orbit, Parker Solar Probe will reach speeds up to 430,000 miles per hour — fast enough to get from Philadelphia to Washington, D.C., in a second — setting the record for the fastest spacecraft in history. During its nominal mission lifetime of just under 7 years, Parker Solar Probe will complete 24 orbits of the Sun — reaching within 3.8 million miles of the Sun’s surface at closest approach.

“We’ll be going where no spacecraft has dared go before — within the corona of a star,” said project scientist Nicky Fox of APL. “With each orbit, we’ll be seeing new regions of the Sun’s atmosphere and learning things about stellar mechanics that we’ve wanted to explore for decades.”

But getting so close to the Sun requires slowing down — for which Parker will use the gravity of our neighbor planet, Venus.

Animation above: Parker uses a highly elliptical orbit with Venus gravity assists to get closer to the Sun. Animation Credits: NASA/JPL/WISPR Team.

“Parker Solar Probe uses Venus to adjust its course and slow down in order to put the spacecraft on the best trajectory,” said Driesman. “We will fly by Venus seven times throughout the mission. Each time we fly by we get closer and closer to the Sun.”

In an orbit this close to the Sun, the real challenge is to keep the spacecraft from burning up.

“NASA was planning to send a mission to the solar corona for decades, however,
we did not have the technology that could protect a spacecraft and its instruments from the heat,” said Szabo. “Recent advances in materials science gave us the material to fashion a heat shield in front of the spacecraft not only to withstand the extreme heat of the Sun, but to remain cool on the backside.”

The heat shield is made of a 4.5-inch thick carbon composite foam material between two carbon fiber face sheets. While the Sun-facing side simmers at 2,500 degrees Fahrenheit, behind the shield the spacecraft will be a cozy 85 degrees Fahrenheit.

Parker Solar Probe is also the first NASA mission to be named after a living individual: Dr. Eugene Parker, famed solar physicist who in 1958 first predicted the existence of the solar wind, the stream of charged particles and magnetic fields that flow continuously from the Sun, bathing Earth. The spacecraft’s path through the corona allows it to observe the acceleration of the very solar wind that Parker predicted, right as it makes a critical transition from slower than the speed of sound to faster than it.

Image above: An illustration of Parker Solar Probe approaching the Sun. Image Credits: NASA/Johns Hopkins APL/Steve Gribben.

The corona is also where the solar material is heated to millions of degrees and where the most extreme events on the Sun occur, such as solar flares and coronal mass ejections — accelerating particles to a fraction of the speed of light. These explosions create space weather events that can pummel Earth with high energy particles, endangering astronauts, interfering with GPS and communications satellites and, at their worst, disrupting our power grid.

This will be the first time that solar scientists can see the objects of their study up close and personal.

“All of our data on the corona so far have been remote,” said Nicholeen Viall, solar physicist at Goddard. “We have been very creative to get as much as we can out of our data, but there is nothing like actually sticking a probe in the corona to see what’s happening there.”

And scientists aren’t the only ones along for the adventure — the spacecraft holds a microchip carrying the names of more than 1.1 million participants who signed up to send their name to the Sun. Sometime between Aug. 11 and 23, the close of the launch period, these names and 1,400 pounds of solar protection and science equipment will begin their journey to the center of our solar system.

Animation above: Parker Solar Probe will travel closer to the Sun than any spacecraft before it. Animation Credit: NASA/Johns Hopkins APL.

Three months later, Parker Solar Probe will reach its first close approach of the Sun in November 2018, and will send the data back in December.

“For scientists like myself, the reward of the long, hard work will be the unique set of measurements returned by Parker,” said Szabo. “The solar corona is one of the last places in the solar system where no spacecraft has visited before. It gives me the sense of excitement of an explorer.”

Stay tuned — Parker is about to take flight.

Related article:

New Views of Sun: 2 Missions Will Go Closer to Our Star Than Ever Before
https://orbiterchspacenews.blogspot.com/2018/05/new-views-of-sun-2-missions-will-go.html

Related links:

Parker Solar Probe: https://www.nasa.gov/solarprobe

Why Won’t Parker Solar Probe Melt?: https://www.nasa.gov/feature/goddard/2018/traveling-to-the-sun-why-won-t-parker-solar-probe-melt

Parker Solar Probe and the Birth of the Solar Wind: https://www.nasa.gov/feature/goddard/2018/parker-solar-probe-and-the-birth-of-the-solar-wind

The Curious Case of the Sun’s Hot Corona: https://www.nasa.gov/feature/goddard/2018/nasa-s-parker-solar-probe-and-the-curious-case-of-the-hot-corona

Images (mentioned), Animation (mentioned), Text, Credits: NASA/Rob Garner/Goddard Space Flight Center, by Miles Hatfield.

Greetings, Orbiter.ch

Facebook hopes to launch an internet satellite in early 2019

Facebook logo.

August 9, 2018

Facebook has cooperated on internet satellite initiatives (with less-than-ideal results), but there's been precious little word of plans to make its own satellite beyond high-level promises. Now, however, there's something tangible. Both publicly disclosed FCC emails and a direct confirmation to Wired have revealed that Facebook aims to launch an internally developed satellite, Athena, sometime in early 2019. A spokesperson didn't share details, but the shell organization Facebook used to keep filings hidden (PointView Tech LLC) talked about offering broadband to "unserved and underserved" areas with a low Earth orbit satellite on a "limited duration" mission.

Facebook to Launch Athena, a Satellite-Based ISP

This is likely just an experiment rather than a full-fledged deployment. Low Earth orbit satellite internet would require a large cloud of satellites to provide significant coverage, similar to SpaceX's planned Starlink network. However, it shows that the company isn't done building its own high-altitude hardware now that it has stopped work on its internet drone.

Whatever Athena shapes up to be, Facebook's motives likely remain the same. As with Alphabet's Loon internet balloons, there's a strong commercial incentive to connect underserved regions. Even if Facebook doesn't charge a thing for access, it could benefit by adding millions of new users who'd view ads and use services (including through Instagram and WhatsApp). It would also look good to investors, as Facebook would keep its audience growing at a time when there's seemingly no more room to grow.

Facebook: https://www.facebook.com/

Image, Text, Credits: Yahoo/Orbiter.ch Aerospace/Roland Berga.

Best regards, Orbiter.ch

New Satellite Map Shows Ground Deformation After Indonesian Quake

JPL - Jet Propulsion Laboratory logo.

August 9, 2018

Scientists with NASA/Caltech's Advanced Rapid Imaging and Analysis project (ARIA) used new satellite data to produce a map of ground deformation on the resort island of Lombok, Indonesia, following a deadly 6.9-magnitude earthquake on August 5.

The false-color map shows the amount of permanent surface movement that occurred, almost entirely due to the quake, over a 6-day period between satellite images taken on July 30 and August 5.

Image above: Scientists with NASA/Caltech's Advanced Rapid Imaging and Analysis project (ARIA) used new satellite data to produce a map of ground deformation on the resort island of Lombok, Indonesia following a deadly, 6.9 magnitude earthquake on August 5. Image Credits: NASA/JPL-Caltech/Copernicus/ESA.

From the pattern of deformation in the map, scientists have determined that the earthquake fault slip was on a fault beneath the northwestern part of Lombok Island, and it caused as much as 10 inches (25 centimeters) of uplift of the ground surface. White areas in the image are places where the radar measurement was not possible, largely due to dense forests in the middle of the islands.

Through these maps, NASA and its partners are contributing important observations and expertise that can assist with response to earthquakes and other natural or human-produced hazards.

Sentinel-1A satellite. Image Credit: ESA

The deformation map is produced from automated interferometric processing of synthetic aperture radar (SAR) data from the European Union's Copernicus Sentinel-1A and -1B satellites using the JPL-Caltech ARIA data system. The European Space Agency operates the Sentinel-1A and -1B satellites.

This and similar products were developed in support of the NASA Disasters Program. More information on them and on the Disasters Program is available at the following links:

https://disasters.nasa.gov/lombok-indonesia-earthquake-2018

https://disasters.nasa.gov

More information about ARIA is available here: https://aria.jpl.nasa.gov/

Images (mentioned), Text, Credits: NASA/JPL/Esprit Smith.

Greetings, Orbiter.ch

mercredi 8 août 2018

New measurement of particle’s lifetime intrigues physicists

CERN - European Organization for Nuclear Research logo.

8 Aug 2018

A new measurement of one of a particle’s properties can sometimes throw up a value that, intriguingly, is very different from previous values. In a paper posted online and submitted to the journal Physical Review Letters, the LHCb collaboration at CERN reports precisely that for the lifetime of the so-called charmed omega. Using data from proton–proton collisions, the LHCb researchers have obtained a value for the particle’s lifetime that is nearly four times larger than previous measurements. New studies are already being planned to unravel this intriguing discrepancy, at LHCb and other experiments.

The charmed omega belongs to a family of particles known as baryons. These particles, of which protons and neutrons are examples, comprise three smaller particles called quarks. But unlike protons, which contain three light quarks and are stable, the charmed omega contains two relatively light quarks and a heavier charm quark (the third heaviest of the six known types of quark), and eventually decays into other particles. Measurements of the lifetimes of charmed particles, and more generally of particles containing heavy quarks, are important because they test models of quantum chromodynamics – the theory that describes how quarks are stuck together by gluons.

Image above: A proton–proton collision event detected by LHCb earlier this year. Image Credits: CERN/LHCb.

The lifetime of the charmed omega was measured more than a decade ago by the E687 and FOCUS collaborations at Fermilab in the US and by the WA89 collaboration at CERN. These collaborations measured the lifetime of the charmed omega by examining some dozens of charmed-omega decays in experiments in which a beam of particles strikes the nuclei in a fixed target. The average of the values measured by these experiments, which are all relatively close to one another, is 69 ± 12 femtoseconds (one femtosecond is a millionth of a billionth of a second).

The new LHCb measurement is based on proton–proton collision data comprising about 1000 charmed-omega decays. The LHCb researchers determined the particle’s lifetime by comparing these decays with those of another particle whose lifetime is known very precisely; a similar approach was recently used by the team to determine the lifetime of a “doubly charmed” particle. The charmed-omega result – a lifetime of 268 ± 26 femtoseconds – is much larger than the average of the older values.

However, none of these measurements contradicts the theoretical estimates of the charmed omega’s lifetime, which rely on subtle calculations based on quantum chromodynamics and include predictions ranging from 60 to 520 femtoseconds. The jury is therefore out on whether the older values or the new one will stand, but the discrepancy between the values will no doubt prompt researchers to make new measurements and revise the theoretical estimates.

Note:

CERN, the European Organization for Nuclear Research, is one of the world’s largest and most respected centres for scientific research. Its business is fundamental physics, finding out what the Universe is made of and how it works. At CERN, the world’s largest and most complex scientific instruments are used to study the basic constituents of matter — the fundamental particles. By studying what happens when these particles collide, physicists learn about the laws of Nature.

The instruments used at CERN are particle accelerators and detectors. Accelerators boost beams of particles to high energies before they are made to collide with each other or with stationary targets. Detectors observe and record the results of these collisions.

Founded in 1954, the CERN Laboratory sits astride the Franco–Swiss border near Geneva. It was one of Europe’s first joint ventures and now has 22 Member States.

Related article:

Long live the doubly charmed particle
https://orbiterchspacenews.blogspot.com/2018/05/long-live-doubly-charmed-particle.html

Related links:

Physical Review Letters: https://arxiv.org/abs/1807.02024

LHCb: https://home.cern/about/experiments/lhcb

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

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

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

Best regards, Orbiter.ch

Health, Physics Research During Preps for Spacewalk and Japan Cargo Mission

ISS - Expedition 56 Mission patch.

August 8, 2018

The Expedition 56 crew members explored how human health and physical processes are affected off the Earth today. The orbital residents are also configuring the International Space Station for a Russian spacewalk next week and a Japanese cargo craft mission in September.

A long-running human research study is helping doctors understand the impacts of microgravity shifting fluids upward in an astronaut’s body. Two astronauts, Serena Auñón-Chancellor of NASA and Alexander Gerst of ESA, joined forces today for that study using an ultrasound device for eye scans with assistance from specialists on Earth. The experiment aims to help researchers prevent the upward fluid shifts that put pressure on an astronaut’s eyes potentially affecting vision in space and back on Earth after a mission.

Image above: Cosmonauts Oleg Artemyev (left) and Sergey Prokopyev will conduct a six-hour, 10-minute spacewalk on Aug. 15, 2018. Image Credit: NASA.

The orbital complex enables research into a variety of space physics including the observation of atoms nearly frozen still when exposed to the coldest temperatures in the universe. The Cold Atom Lab (CAL), which chills atoms to about one ten billionth of a degree above absolute zero, had its fiber cables inspected by NASA astronaut Ricky Arnold today during troubleshooting operations. CAL was delivered to the station in May aboard the Cygnus space freighter then installed in the Columbus laboratory module shortly after.

A spacewalk is scheduled for Aug. 15 when cosmonauts Oleg Artemyev and Sergey Prokopyev will work outside the station’s Russian segment for about 6 hours of science and maintenance tasks. The duo spent Wednesday afternoon checking their Orlan spacesuits in a pressurized configuration. They also installed U.S. lights and video cameras on the suits ahead of next week’s excursion.

Image above: Flying over Australia coast (Brisbane), seen by EarthCam on ISS, speed: 27'587 Km/h, altitude: 414,08 Km, image captured by Roland Berga (on Earth in Switzerland) from International Space Station (ISS) using ISS-HD Live application with EarthCam's from ISS on August 8, 2018 at 22:13 UTC. Image Credits: Orbiter.ch Aerospace/Roland Berga.

The Japan Aerospace Exploration Agency (JAXA) is planning a Sept. 10 launch of its H-II Transfer Vehicle (HTV) for capture and installation to the space station. HTV will be carrying cargo and new lithium ion batteries for installation on the station’s Port-4 truss power system. Commander Drew Feustel partnered with Gerst and Arnold throughout the day readying JAXA’s Kibo laboratory module for the upcoming delivery mission.

Related links:

Fluid shifts: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=1126

Cold Atom Lab (CAL): https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=7396

Expedition 56: https://www.nasa.gov/mission_pages/station/expeditions/expedition56/index.html

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

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

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

Best regards, Orbiter.ch

40 Years Ago, Pioneer Venus Multiprobe Launched to Study the Cloud-Shrouded Planet Venus

NASA - Pioneer 10-11 Mission patch.

Aug. 8, 2018

On August 8, 1978, the Pioneer Venus Multiprobe spacecraft launched to study Venus, a planet that has an atmosphere 100 times denser than Earth’s atmosphere and is hotter than the melting point of zinc and lead. Pioneer Venus Multiprobe was composed of five components: the main spacecraft, the large probe and three identical small probes named North, Day and Night. Built by the Hughes Company in El Segundo, California, and launched on an Atlas-Centaur rocket from Cape Canaveral Air Force Station in Florida, the Pioneer Venus Multiprobe project was managed by NASA’s Ames Research Center in California’s Silicon Valley.

Illustration of Pioneer Venus Multiprobe approaching Venus. Image Credit: NASA

Carrying seven experiments and fitted with a parachute to slow its descent into the atmosphere, the large probe studied the composition of Venus’ atmosphere and clouds. In addition, the large probe measured the distribution of infrared and solar radiation. The three small probes were designed without parachutes, each carrying six experiments. Each probe targeted different parts of Venus. North entered Venus at the high northern latitudes, Night targeted the night side at mid-southern latitudes, and Day targeted the day side at mid-southern latitudes. The main spacecraft carried an additional two experiments designed to study Venus’ upper atmosphere. The five probes collected detailed information about atmospheric composition, circulation and energy balance.

Image above: Venus Day/Night illustration showing solar wind, bow shock, magnetosheath, clouds and streamers Pioneer Venus SP-461 fig 6-28 Interaction of the solar wind with the atmosphere of Venus as determined from Pioner Venus experiments and observations. Image Credit: NASA.

The large probe separated from the main spacecraft 123 days after launch, on November 16, followed by the small probes on November 20, reaching and entering Venus’ atmosphere December 9. While not expected to survive their fiery descent into the dense Venusian atmosphere, all four of the probes transmitted data down to the surface with the Day probe transmitting from the surface for over an hour.

Pioneer: https://www.nasa.gov/pioneer/

Pioneer Venus: http://www.nasa.gov/mission_pages/pioneer-venus/

Images (mentioned), Text, Credits: NASA/Danielle Carmichael.

Greetings, Orbiter.ch