vendredi 21 juillet 2017

Crew Conducts Research to Mitigate the Human Body’s Response to Spaceflight










ISS - Expedition 52 Mission patch.

July 21, 2017

International Space Station (ISS). Animation Credit: NASA

The crew of Expedition 52 wrapped up an intensive week of research on Friday, concentrating on studies in the field of human health and performance.

On Thursday, the crew conducted their second ultrasound for the Sprint investigation, which studies the use of high-intensity, low-volume exercise training to minimize the loss of muscle, bone and cardiovascular fitness during long-duration space excursions. Using meticulous thigh and calf scans through remote guidance from the ground team, these results will help determine what changes astronauts are experiencing in microgravity and how best to manage those fluctuations for future missions.


Image above: Flight Engineers Peggy Whitson and Jack Fischer assess spaceflight-induced changes in muscle volume with the Sprint study.

Flight Engineers Peggy Whitson and Jack Fischer today will gather and transfer Fluid Shifts hardware to the station’s Russian segment in preparation for Fluid Shifts Chibis (Lower Body Negative Pressure) operations that begin on Monday. Fluid Shifts investigates the causes for lasting physical changes to astronaut’s eyes—a side effect of human space exploration in a microgravity environment. It’s theorized that the headward fluid shift in space-faring explorers contributes to these changes. In response, a lower body negative pressure device is being evaluated to see if it can perhaps reverse this fluid shift. As an added bonus, what investigators glean from this study may contribute to the development of countermeasures against lasting changes in vision and prevention of eye damage.

The Expedition 52-53 crew that will lift off to the International Space Station within a week is finalizing preparations at the Baikonur Cosmodrome in Kazakhstan. Cosmonaut Sergey Ryazanskiy, along with astronauts Randy Bresnik and Paolo Nespoli, are slated to launch July 28 at 11:41 a.m. EDT for a six-hour journey to the orbiting laboratory. NASA TV will cover all the activities, so tune in.

Related links:

NASA TV: https://www.nasa.gov/multimedia/nasatv/index.html#public

Sprint: https://www.nasa.gov/mission_pages/station/research/experiments/972.html

Fluid Shifts: https://www.nasa.gov/mission_pages/station/research/experiments/1257.html

Expedition 52: https://www.nasa.gov/mission_pages/station/expeditions/expedition52/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

Animation (mentioned), Image (mentioned), Text, Credits: NASA/Catherine Williams.

Greetings, Orbiter.ch

Weekly Recap From the Expedition Lead Scientist, week of July 17, 2017










ISS - Expedition 52 Mission patch.

July 21, 2017

(Highlights: Week of July 17, 2017) - Crew members on the International Space Station spend a lot of time studying human physiology to keep future space travelers safe on long journeys and improve life for people on Earth.

Astronauts completed a session for the Effects of Long-Duration Microgravity on Fine Motor Skills (Fine Motor Skills) investigation. Fine motor skills are crucial for successfully interacting with touch-based technologies, repairing sensitive equipment and a variety of other tasks. The investigation is the first fine motor skills study to measure long-term microgravity exposure, different phases of microgravity adaptation, and sensorimotor recovery after returning to Earth’s gravity. The investigation involves a series of interactive tasks on a touchscreen tablet and may have wide-reaching benefits for elderly patients, people with motor disorders or patients with brain injuries on Earth undergoing rehabilitation for conditions that impair fine motor control.


Image above: NASA astronaut Peggy Whitson posted this image to her Twitter account (@AstroPeggy) of her storing blood samples in the International Space Station's ultra-cold freezer for eventual return to Earth. Image Credit: NASA.

NASA is studying how spaceflight changes the body's shape and size while in orbit. The Quantification of In-Flight Physical Changes – Anthropometry and Neutral Body Posture (Body Measures) investigation collects photos and videos as well as measurements of all body segments (i.e., chest, waist, hip, arms, legs, etc.) from astronauts before, during and after visits to the space station. Body mass is also recorded.

Long-term changes in crewmembers’ bodies could require new designs for suits, clothing, and work stations to maximize health and efficiency during future space missions. The investigation also could help scientists understand the effects of prolonged bed rest, which produces physiological changes similar to those experienced in microgravity. Results could improve the Neutral Body Posture template, based on the normal curvature of the spine, which is used in a wide range of design standards for ergonomic equipment and medical care.

Space station astronauts continued more research into bone health, completing a set of ultrasounds for the Integrated Resistance and Aerobic Training Study (Sprint). This NASA Human Research Program study evaluates the use of high-intensity, low-volume exercise training to maintain the health of crew members -- minimizing muscle and bone loss and maintaining cardiovascular function during long-duration missions.


Image above: NASA astronaut Jack Fischer takes an ultrasound of his eyes during a routine medical check. Image Credit: NASA.

Ultrasound scans are used to evaluate spaceflight-induced changes in the muscle volume. When the study is complete, investigators expect to provide an integrated resistance and aerobic exercise training protocol capable of maintaining muscle, bone, and cardiovascular health while reducing total exercise time over the course of a long-duration spaceflight. This will provide valuable information in support of the long-term goal of protecting human fitness for even longer space exploration missions. Data gathered from the investigation also may help scientists develop treatments to aid in muscle, bone and heart health on Earth.

video
Space to Ground: A Giant Leap: 07/21/2017

Video above: NASA's Space to Ground is a weekly update on what is happening on the International Space Station. Social media users can post with #spacetoground to ask questions or make a comment. Video Credit: NASA.

Other investigations showing progress this week included Magnetic 3D Cell Culture for Biological Research in Microgravity (Magnetic 3D Cell Culturing), Capillary Structures for Exploration Life Support (Capillary Structures), Cardio Ox, MELFI-2, ISS-Ham Radio, Dose Tracker and Rodent Research-5.

Related links:

Fine Motor Skills: http://www.nasa.gov/mission_pages/station/research/experiments/1767.html

Body Measures: https://www.nasa.gov/mission_pages/station/research/experiments/1070.html

Sprint: http://www.nasa.gov/mission_pages/station/research/experiments/972.html

Magnetic 3D Cell Culturing: https://www.nasa.gov/mission_pages/station/research/experiments/1929.html

Capillary Structures: https://www.nasa.gov/mission_pages/station/research/experiments/2364.html

Cardio Ox: https://www.nasa.gov/mission_pages/station/research/experiments/931.html

MELFI-2: https://www.nasa.gov/mission_pages/station/research/experiments/MELFI.html

ISS-Ham Radio: https://www.nasa.gov/mission_pages/station/research/experiments/346.html

Dose Tracker: https://www.nasa.gov/mission_pages/station/research/experiments/1933.html

Rodent Research-5: https://www.nasa.gov/mission_pages/station/research/experiments/2283.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), Video (mentioned), Text, Credits: NASA/Kristine Rainey/Jorge Sotomayor, Lead Increment Scientist Expeditions 51 & 52.

Best regards, Orbiter.ch

Hubble’s Hunting Dog Galaxy












NASA - Hubble Space Telescope patch.

July 21, 2017


Tucked away in the small northern constellation of Canes Venatici (The Hunting Dogs) is the galaxy NGC 4242, shown here as seen by the NASA/ESA Hubble Space Telescope. The galaxy lies some 30 million light-years from us. At this distance from Earth, actually not all that far on a cosmic scale, NGC 4242 is visible to anyone armed with even a basic telescope, as British astronomer William Herschel found when he discovered the galaxy in 1788.

This image shows the galaxy’s bright center and the surrounding dimmer and more diffuse “fuzz.” Despite appearing to be relatively bright in this image, studies have found that NGC 4242 is actually relatively dim (it has a moderate-to-low surface brightness and low luminosity) and also supports a low rate of star formation. The galaxy also seems to have a weak bar of stars cutting through its asymmetric center, and a very faint and poorly-defined spiral structure throughout its disk. But if NGC 4242 is not all that remarkable, as with much of the Universe, it is still a beautiful and ethereal sight.

Hubble Space Telescope

For images and more information about Hubble, visit:

http://hubblesite.org/
http://www.nasa.gov/hubble
http://www.spacetelescope.org/

Image, Animation Credits: ESA/Hubble & NASA/Text Credits: European Space Agency/NASA/Karl Hille.

Best regards, Orbiter.ch

NASA Looks to Solar Eclipse to Help Understand Earth’s Energy System









NASA & NOAA - Deep Space Climate Observatory satellite (DSCOVR) patch.

July 21, 2017

It was midafternoon, but it was dark in an area in Boulder, Colorado on Aug. 3, 1998. A thick cloud appeared overhead and dimmed the land below for  more than 30 minutes. Well-calibrated radiometers showed that there were very low levels of light reaching the ground, sufficiently low that researchers decided to simulate this interesting event with computer models. Now in 2017, inspired by the event in Boulder, NASA scientists will explore the moon’s eclipse of the sun to learn more about Earth’s energy system.

video
A New View of Augusts Total Solar Eclipse

Video above: During the Aug. 21, 2017, total solar eclipse, scientists will use the Earth Polychromatic Imaging Camera (EPIC) on the Deep Space Climate Observatory satellite (DSCOVR), along with measurements taken from within the moon's shadow on the ground, to test a new model of Earth's energy budget. Video Credits: NASA/Katy Mersmann.

On Aug. 21, 2017, scientists are looking to this year’s total solar eclipse passing across America to improve our modelling capabilities of Earth’s energy. Guoyong Wen, a NASA scientist working for Morgan State University in Baltimore, is leading a team to gather data from the ground and satellites before, during and after the eclipse so they can simulate this year’s eclipse using an advanced computer model, called a 3-D radiative transfer model. If successful, Wen and his team will help develop new calculations that improve our estimates of the amount of solar energy reaching the ground, and our understanding of one of the key players in regulating Earth’s energy system, clouds.

Earth’s energy system is in a constant dance to maintain a balance between incoming radiation from the sun and outgoing radiation from Earth to space, which scientists call the Earth’s energy budget. The role of clouds, both thick and thin, is important in their effect on energy balance.

Like a giant cloud, the moon during the 2017 total solar eclipse will cast a large shadow across a swath of the United States. Wen and his team already know the dimensions and light-blocking properties of the moon, but will use ground and space instruments to learn how this large shadow affects the amount of sunlight reaching Earth’s surface, especially around the edges of the shadow.

 Deep Space Climate Observatory satellite (DSCOVR): Image Credits: NASA/NOAA

“This is the first time we’re able to use measurements from the ground and from space to simulate the moon’s shadow going across the face of Earth in the United States and calculating energy reaching the Earth,” said Wen. Scientists have made extensive atmospheric measurements during eclipses before, but this is the first opportunity to collect coordinated data from the ground and from a spacecraft that observes the entire sunlit Earth during an eclipse, thanks to the National Oceanic and Atmospheric Administration’s Deep Space Climate Observatory launched (DSCOVR) in February 2015.

Even though the moon blocking the sun during a solar eclipse and clouds blocking sunlight to Earth’s surface are two different phenomena, both require similar mathematical calculations to accurately understand their effects. Wen anticipates this experiment will help improve the current model calculations and our knowledge of clouds, specifically thicker, low altitude clouds that may cover about 30 percent of the planet at any given time.

In this experiment, Wen and his team will simulate the total solar eclipse in a 3-D radiative transfer model, which helps scientists understand how energy is propagated on Earth. Currently, models tend to depict clouds in one dimension. In many cases, these one dimensional calculations can create useful science models for understanding the atmosphere. Sometimes though, a three-dimensional calculation is needed to provide more accurate results. The big difference is that 3-D clouds reflect or scatter solar energy in many directions, from the top and bottom, and also out of the sides of clouds. This 3-D behavior results in different amounts of energy reaching the ground than a one-dimensional model could predict.


Animation above: DSCOVR's Earth Polychromatic Imaging Camera (EPIC) will capture images similar to this one from the Lagrange 1 point, about a million miles away from Earth. Animation Credits: NASA/Katy Mersmann.

“We’re testing the ability to do a certain kind of complex calculation, a test of a 3-D mathematical technique, to see if this is an improvement over the previous technique,” said Jay Herman, scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and co-investigator of the project. “If this is successful, then we will have a better tool to implement in climate models and can use it to answer questions and the Earth’s energy budget and climate.”

For the upcoming eclipse, Wen and his team members will be stationed in Casper, Wyoming, and Columbia, Missouri to gather information on the amount of energy being transmitted to and from Earth before, during and right after the eclipse with several ground instruments.

A ground-based, NASA-developed Pandora Spectrometer Instrument will provide information on how much of any given wavelength of light is present, and a pyranometer will measure total solar energy from all directions coming down toward the surface. Immediately before and after the eclipse scientists will measure other information such as the amount of absorbing trace gases in the atmosphere, such as ozone, nitrogen dioxide and small aerosol particles to also use in the 3-D model.


Animation above: From a Million Miles: An EPIC Eclipse. This animation features shadow of the Moon on the Earth see by Deep Space Climate Observatory satellite (DSCOVR) using EPIC instrument. Animation Credit: NASA.

Meanwhile in space, NASA’s Earth Polychromatic Imaging Camera, or EPIC, instrument aboard the DSCOVR spacecraft, will observe the light leaving Earth and allow scientists to estimate of the amount of light reaching the earth’s surface. Additionally, NASA’s two MODIS satellite instruments, aboard the agency’s Terra and Aqua satellites, launched in 1999 and 2002, respectively, will provide observations of atmospheric and surface conditions at times before and after the eclipse. The scientists will then combine ground measurements with those observed by the spacecraft.

This experiment complements NASA’s decades-long commitment to observing and understanding contributions to Earth’s energy budget. For more than 30 years, NASA has measured and calculated the amount of solar energy hitting the top of our atmosphere, the amount of the sun’s energy reflected back to space and how much thermal energy is emitted by our planet to space. These measurements have been possible thanks to instruments and missions such as ACRIMSAT and SOLSTICE (launched in 1991), and SORCE, launched in 2003 as well as the series of CERES instruments flown aboard Terra, Aqua, and Suomi-NPP (launched in 2011).


Animation above: During the eclipse, scientists will take ground measurements in Casper, Wyoming, and Columbia, Missouri. Animation Credits: NASA/Katy Mersmann.

This fall, NASA will continue to monitor the sun-Earth relationship by launching the Total and Spectral Solar Irradiance Sensor-1, or TSIS-1, to the International Space Station and the sixth Clouds and the Earth’s Radiant Energy System CERES instrument, CERES FM6, to orbit later this year. Five CERES instruments are currently on orbit aboard three satellites.

Related links:

NASA’s Total Solar Eclipse page: https://eclipse2017.nasa.gov/

Total Solar Irradiance Spectral Solar Irradiance instrument: https://science.nasa.gov/missions/tsis-1

Information about the CERES instruments and data: https://ceres.larc.nasa.gov/

ACRIMSAT: https://www.jpl.nasa.gov/missions/active-cavity-irradiance-monitor-satellite-acrimsat/

SORCE: http://lasp.colorado.edu/home/sorce/

NASA & NOAA Deep Space Climate Observatory satellite (DSCOVR):
https://www.nesdis.noaa.gov/content/dscovr-deep-space-climate-observatory

Animations (mentioned), Image (mentioned), Video (mentioned), Text, Credits: NASA/Sara Blumberg/Goddard Space Flight Center, by Kasha Patel.

Greetings, Orbiter.ch

jeudi 20 juillet 2017

Russian Cargo Craft Departs Space Station











ROSCOSMOS - Russian Vehicles patch.

July 20, 2017

The unpiloted Russian Progress 66 cargo craft departed the International Space Station today after a five-month stay. Loaded with trash and other items no longer needed by the Expedition 52 crew, the Progress automatically undocked from the Pirs Docking Compartment on the Earth-facing side of the Russian segment of the complex at 1:46 p.m. EDT. With its mission completed, the cargo craft, which first arrived at the complex on Feb. 24, used its engines to conduct a separation maneuver, allowing it to move to a safe distance away from the station. 


Image above: An unpiloted Russian Progress resupply ship undocks from the International Space Station. Image Credit: NASA.

The Progress’ engines will execute a deorbit burn at 4:58 p.m. to enable it to drop out of orbit for its entry back to Earth where it will burn up harmlessly in the atmosphere over the Pacific Ocean. 

The next Russian Progress resupply ship is scheduled to launch to the station in mid-October.

Related link:

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

Image (mentioned), Text, Credits: NASA/Catherine Williams.

Best regards, Orbiter.ch

From Mars Rover: Panorama Above 'Perseverance Valley'











NASA - Mars Exploration Rover B (MER-B) patch.

July 20, 2017

Panorama Above 'Perseverance Valley'. Image Credits: NASA/JPL-Caltech

NASA's Mars Exploration Rover Opportunity recorded a panoramic view before entering the upper end of a fluid-carved valley that descends the inner slope of a large crater's rim.

The scene includes a broad notch in the crest of the crater's rim, which may have been a spillway where water or ice or wind flowed over the rim and into the crater.  Wheel tracks visible in the area of the notch were left by Opportunity as the rover studied the ground there and took images into the valley below for use in planning its route.


Image above: This mosaic scene combining five images from the navigation camera (Navcam) on NASA's Mars Exploration Rover Opportunity shows a view from inside the upper end of "Perseverance Valley" on the inner slope of Endeavour Crater's western rim. Image Credits: NASA/JPL-Caltech.

"It is a tantalizing scene," said Opportunity Deputy Principal Investigator Ray Arvidson of Washington University in St. Louis. "You can see what appear to be channels lined by boulders, and the putative spillway at the top of Perseverance Valley. We have not ruled out any of the possibilities of water, ice or wind being responsible."

Opportunity's panoramic camera (Pancam) took the component images of the scene during a two-week driving moratorium in June 2017 while rover engineers diagnosed a temporary stall in the left-front wheel's steering actuator. The wheel was pointed outward more than 30 degrees, prompting the team to call the resulting vista Pancam's "Sprained Ankle" panorama. Both ends of the scene show portions of Endeavour Crater's western rim, extending north and south, and the center of the scene shows terrain just outside the crater.


Image above: This image from the navigation camera (Navcam) on the mast of NASA's Mars Exploration Rover Opportunity provides a look back to the crest of Endeavour Crater's rim after the rover began descending "Perseverance Valley" on the rim's inner slope. Image Credits: NASA/JPL-Caltech.

The team was able to straighten the wheel to point straight ahead, and now uses the steering capability of only the two rear wheels. The right-front wheel's steering actuator has been disabled since 2006. Opportunity has driven 27.95 miles (44.97 kilometers) since landing on Mars in 2004.

(Click on the image for enlarge)

Image above: Enhanced Color Panorama Above 'Perseverance Valley' on Mars. Image Credits: NASA/JPL-Caltech/Cornell/Arizona State Univ.

On July 7, 2017, Opportunity drove to the site within upper Perseverance Valley where it will spend about three weeks without driving while Mars passes nearly behind the sun from Earth's perspective, affecting radio communications. The rover's current location is just out of sight in the Sprained Ankle panorama, below the possible spillway. Opportunity is using Pancam to record another grand view from this location.

Mars Exploration Rover (MER). Image Credits: NASA/JPL-Caltech

After full communications resume in early August, the team plans to drive Opportunity farther down Perseverance Valley, seeking to learn more about the process that carved it.

For more information about Opportunity's adventures on Mars, visit: https://mars.nasa.gov/mer

Mars Exploration Rovers (Spirit and Opportunity): https://www.nasa.gov/mission_pages/mer/index.html

Images (mentioned), Text, Credits: NASA/Laurie Cantillo/Dwayne Brown/Jon Nelson/JPL/Guy Webster.

Greetings, Orbiter.ch

Hubble Sees Martian Moon Orbiting the Red Planet











NASA - Hubble Space Telescope patch.

July 20, 2017

The sharp eye of NASA's Hubble Space Telescope has captured the tiny moon Phobos during its orbital trek around Mars. Because the moon is so small, it appears star-like in the Hubble pictures.

Over the course of 22 minutes, Hubble took 13 separate exposures, allowing astronomers to create a time-lapse video showing the diminutive moon's orbital path. The Hubble observations were intended to photograph Mars, and the moon's cameo appearance was a bonus.

Phobos Photobombs Hubble’s Picture of Mars

Video above: When the Hubble Space Telescope observed Mars near opposition in May, 2016, a sneaky companion photobombed the picture. Phobos, the Greek personification of fear, is one of two tiny moons orbiting Mars. In 13 exposures over 22 minutes, Hubble captured a timelapse of Phobos moving through its 7-hour 39-minute orbit. Image Credits: NASA's Goddard Space Flight Center.

A football-shaped object just 16.5 miles by 13.5 miles by 11 miles, Phobos is one of the smallest moons in the solar system. It is so tiny that it would fit comfortably inside the Washington, D.C. Beltway.

The little moon completes an orbit in just 7 hours and 39 minutes, which is faster than Mars rotates. Rising in the Martian west, it runs three laps around the Red Planet in the course of one Martian day, which is about 24 hours and 40 minutes. It is the only natural satellite in the solar system that circles its planet in a time shorter than the parent planet's day.

About two weeks after the Apollo 11 manned lunar landing on July 20, 1969, NASA's Mariner 7 flew by the Red Planet and took the first crude close-up snapshot of Phobos. On July 20, 1976 NASA's Viking 1 lander touched down on the Martian surface. A year later, its parent craft, the Viking 1 orbiter, took the first detailed photograph of Phobos, revealing a gaping crater from an impact that nearly shattered the moon.


Image above: Over the course of 22 minutes, Hubble took 13 separate exposures, allowing astronomers to create a time-lapse image showing the tiny moon Phobos during its orbital trek (white dots) around Mars. This image is a composite of separate exposures acquired by NASA's Hubble WFC3/UVIS instrument. Banner Animation: The animation at the top of the page was made from these images. Image Credits: NASA, ESA, and Z. Levay (STScI), Acknowledgment: J. Bell (ASU) and M. Wolff (Space Science Institute).

Phobos was discovered by Asaph Hall on August 17, 1877 at the U.S. Naval Observatory in Washington, D.C., six days after he found the smaller, outer moon, named Deimos. Hall was deliberately searching for Martian moons.

Both moons are named after the sons of Ares, the Greek god of war, who was known as Mars in Roman mythology. Phobos (panic or fear) and Deimos (terror or dread) accompanied their father into battle.

Close-up photos from Mars-orbiting spacecraft reveal that Phobos is apparently being torn apart by the gravitational pull of Mars. The moon is marred by long, shallow grooves that are probably caused by tidal interactions with its parent planet. Phobos draws nearer to Mars by about 6.5 feet every hundred years. Scientists predict that within 30 to 50 million years, it either will crash into the Red Planet or be torn to pieces and scattered as a ring around Mars.

Orbiting 3,700 miles above the Martian surface, Phobos is closer to its parent planet than any other moon in the solar system. Despite its proximity, observers on Mars would see Phobos at just one-third the width of the full moon as seen from Earth. Conversely, someone standing on Phobos would see Mars dominating the horizon, enveloping a quarter of the sky.

From the surface of Mars, Phobos can be seen eclipsing the sun. However, it is so tiny that it doesn't completely cover our host star. Transits of Phobos across the sun have been photographed by several Mars-faring spacecraft.

The origin of Phobos and Deimos is still being debated. Scientists concluded that the two moons were made of the same material as asteroids. This composition and their irregular shapes led some astrophysicists to theorize that the Martian moons came from the asteroid belt.


Animation above: Phobos, the Greek personification of fear, is one of two tiny moons orbiting Mars. Animation Credit: NASA.

However, because of their stable, nearly circular orbits, other scientists doubt that the moons were born as asteroids. Such orbits are rare for captured objects, which tend to move erratically. An atmosphere could have slowed down Phobos and Deimos and settled them into their current orbits, but the Martian atmosphere is too thin to have circularized the orbits. Also, the moons are not as dense as members of the asteroid belt.

Phobos may be a pile of rubble that is held together by a thin crust. It may have formed as dust and rocks encircling Mars were drawn together by gravity. Or, it may have experienced a more violent birth, where a large body smashing into Mars flung pieces skyward, and those pieces were brought together by gravity. Perhaps an existing moon was destroyed, reduced to the rubble that would become Phobos.

Hubble took the images of Phobos orbiting the Red Planet on May 12, 2016, when Mars was 50 million miles from Earth. This was just a few days before the planet passed closer to Earth in its orbit than it had in the past 11 years.

Hubble Space Telescope. Animation Credits: NASA/ESA

The Hubble Space Telescope is a project of international cooperation between NASA and ESA (European Space Agency). NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, Inc., in Washington, D.C.

For images and more information about Hubble, visit:

http://hubblesite.org/
http://www.nasa.gov/hubble
http://www.spacetelescope.org/

Animation (mentioned), Images (mentioned), Video (mentioned), Text, Credits: NASA/Karl Hille/Space Telescope Science Institute/Ann Jenkins/Ray Villard/Zolt Levay.

Greetings, Orbiter.ch

mercredi 19 juillet 2017

In Orbit Today: Improving Longer-Duration Space Travel and Cancer Treatments










ISS - Expedition 52 Mission patch.

July 19, 2017

The Expedition 52 crew embarked on tasks Wednesday to further NASA’s eventual journey to Mars and aid researchers in understanding how to stimulate cancer-fighting drugs to target cancer cells—and cancer cells alone—in the human body.

International Space Station (ISS). Image Credit: NASA

The astronauts lent their opinions to a food questionnaire designed to explore if the current food available in the spaceflight food system would be acceptable for even longer-duration missions, like a Martian sojourn. Their input will help develop strategies to improve futuristic food systems in support of crew health and performance.

Of even greater magnitude to Earthlings approximately 240 miles below the orbiting laboratory is the work being performed with the Efficacy and Metabolism of Azonafide Antibody-Drug Conjugates in Microgravity (ADCs in Microgravity) investigation. The crew retrieved a BioCell Habitat, inoculation kits and ADC samples from a Minus Eighty Degree Celsius Laboratory Freezer for ISS (MELFI), set up hardware inside the Microgravity Science Glovebox (MSG) and inoculated the Multiwall BioCells using syringes. Later, the astronauts will repeat these steps with a second BioCell Habitat, which begins an 11-day experiment stretch. In the zero-g environment of space, cancer cells grow in spheroid structures that closely resemble how they form in the human body. This study may speed up the development of targeted therapies for cancer patients, increasing the effectiveness of chemotherapy treatment and while reducing unwanted side effects.


Image above: This angled image of space station solar arrays frames the Earth scene. Image Credit: NASA.

Expedition 52 is taking out the trash midday tomorrow when Russia’s Progress 66 (66P) uncrewed cargo craft departs the International Space Station for a fiery disposal over the Pacific Ocean. The 66P is loaded with garbage and obsolete gear and will undock from the Pirs docking compartment Thursday at 1:46 p.m. EDT. The Russian resupply ship will orbit Earth for a few more hours before reentering Earth’s atmosphere harmlessly over the Pacific. NASA TV will not be covering the undocking activities.

Related links:

Expedition 52: https://www.nasa.gov/mission_pages/station/expeditions/expedition52/index.html

ADCs in Microgravity: https://www.nasa.gov/mission_pages/station/research/experiments/2347.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/Catherine Williams.

Best regards, Orbiter.ch

July 14 Solar Flare and a Coronal Mass Ejection












NASA - Solar Dynamics Observatory (SDO) patch.

July 19, 2017


A medium-sized (M2) solar flare and a coronal mass ejection (CME) erupted from the same, large active region of the sun on July 14, 2017. The flare lasted almost two hours, quite a long duration. The coils arcing over this active region are particles spiraling along magnetic field lines, which were reorganizing themselves after the magnetic field was disrupted by the blast. Images were taken in a wavelength of extreme ultraviolet light.

Solar flares are giant explosions on the sun that send energy, light and high speed particles into space. These flares are often associated with solar magnetic storms known as coronal mass ejections (CMEs). While these are the most common solar events, the sun can also emit streams of very fast protons – known as solar energetic particle (SEP) events – and disturbances in the solar wind known as corotating interaction regions (CIRs).

video
Bastille Day Solar Flare and a Coronal Mass Ejection

The Solar Dynamics Observatory is managed by NASA's Goddard Space Flight Center, Greenbelt, Maryland, for NASA's Science Mission Directorate, Washington. Its Atmosphere Imaging Assembly was built by the Lockheed Martin Solar Astrophysics Laboratory (LMSAL), Palo Alto, California.

Solar Dynamics Observatory (SDO): http://www.nasa.gov/mission_pages/sdo/main/index.html

Image, Video, Text, Credits: NASA/Sarah Loff/GSFC/Solar Dynamics Observatory.

Best regards, Orbiter.ch

Goodbye HERA, Hello Sleep: NASA’s HERA XIII Crew Returns Home to Slumber












NASA - HERA XIII Mission patch.

July 19, 2017

After 45 days in NASA’s Human Exploration Research Analog (HERA), the four-man crew can hardly hold their eyes open. This mission was the first of its kind to last 45 days, as well as incorporate sleep reduction for research purposes.

“The sleep deprivation was really difficult,” said, James Titus, HERA crew member. “It really hindered our normalcy. We are used to working and living our lives at a higher level. During this mission the sleep reduction, the no-nap rule and limited caffeine – went hand in hand to really slow us down,” he said.


Image above: Moments after turning the vessel back over to NASA after 45-days inside, the HERA XIII crew is given their mission patch to place on the door. Image Credit: NASA.

HERA is one of several ground-based analogs used by NASA’s Human Research Program (HRP) to research ways to help astronauts move from lower-Earth orbit to deep space explorations. A spaceflight analog is a situation on Earth that produces physical and mental effects on the body similar to those experienced in space. Participants are volunteers that must pass a physical and psychological assessment to qualify.

During this thirteenth HERA mission, crew members went through many of the motions of a real deep space mission without ever actually leaving the Johnson Space Center. This was the fourth in a series of studies, called campaigns, with progressively longer simulated mission lengths. In this campaign, this was the first of four 45-day simulated missions. Previous campaigns studied seven-day, 14-day, and 30-day missions. Longer mission lengths allow for more research studies and more data points relevant to longer duration spaceflight missions.

Several research studies utilize a limited sleep protocol for the four missions of Campaign 4. During Mission 1, crewmembers were allowed to sleep five hours per night, five days per week with a recovery period of two days where they could sleep eight hours each night. No naps and limited caffeine are included in this protocol.

This practice allows researchers to test the use of habitat lighting as a method of combating crewmember fatigue. It also allows for the evaluation of the usability of bio-mathematical models to predict crewmember fatigue. Team cohesion, performance, and interpersonal relationships are also tested under these conditions.


Image above: Flight Analog Program Manager, Lisa Spence, toasts with sparkling grape juice the HERA XIII crew for a successful end to the first 45-day mission. Image Credit: NASA.

Despite the no siesta rule, the crew took their mission tasks seriously. As with past crews, they particularly enjoyed the extravehicular activity (EVA) on an asteroid conducted with virtual reality technology. “It was fun learning to maneuver in three dimensions, and going through the decompression protocol just like a real astronaut would. It was fascinating to me,” said Timothy Evans, HERA crew member.

Not only are the HERA crews isolated from the outside world, they must unplug during their mission. “It was really a little bit disorienting,” said Mark Settles, HERA crew member. “You get in this mode of addressing electronic communications on a daily basis. It was like stepping back 20 years by having a reduced level of constant input of demands on your time from electronic communication.”

This was a rather competitive group. One of their tasks was to use the robotic arm to grab a transport vehicle while dealing with sleep deprivation. They had 12 chances to do so and were given a score on their efforts. “The score was very important to all of us. We’d strive to get better. The ROBoT [Robotic On-Board Trainer] and cognition had a level of inter-competiveness with us,” said John Kennard, HERA crew member.

HERA Graphic Illustration. Image Credit: NASA

When asked their favorite thing to do while on the mission, there was a consensus: Sleep. They also enjoyed playing board games and watching movies together while not working on mission tasks. Upon splashdown at the end of the simulated mission, they planned to call their families and grab some greasy, salty fast food. But soon afterward, they all planned on catching some Zs!

Mission 2 of Campaign 4 will begin on Aug. 5. The Test Subject Screening group is accepting curriculum vitaes (CV) for healthy, non-smoking volunteers, ages 30 to 55 for future missions. Volunteers will be compensated and must pass a physical and psychological assessment to qualify. Volunteers wishing to become test subjects should e-mail their CV to jsc-hera@mail.nasa.gov (US citizen).

NASA's Human Research Program (HRP) is dedicated to discovering the best methods and technologies to support safe, productive human space travel. HRP enables space exploration by reducing the risks to human health and performance using ground research facilities, the International Space Station and analog environments. This leads to the development and delivery of a program focused on: human health, performance and habitability standards; countermeasures and risk-mitigation solutions; and advanced habitability and medical-support technologies. HRP supports innovative, scientific human research by funding more than 300 research grants to respected universities, hospitals and NASA centers to over 200 researchers in more than 30 states.

Related links:

NASA's Human Research Program (HRP): http://www.nasa.gov/hrp

HERA: http://www.nasa.gov/analogs/hera

Johnson Space Center (JSC): https://www.nasa.gov/centers/johnson/home/index.html

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

Images (mentioned), Text, Credits: NASA/Timothy Gushanas/Monica Edwards/Laurie Abadie.

Greetings, Orbiter.ch

NASA’s New Horizons Team Strikes Gold in Argentina












NASA - New Horizons Mission logo.

July 19, 2017

Preparations for the July 17, 2017, observations in Argentina. Image Credit: NASA

A primitive solar system object that’s more four billion miles (6.5 billion kilometers) away passed in front of a distant star as seen from Earth. Just before midnight Eastern Time Sunday (12:50 a.m. local time July 17), several telescopes deployed by the New Horizons team in a remote part of Argentina were in precisely the right place at the right time to catch its fleeting shadow — an event that’s known as an occultation.

In a matter of seconds, NASA’s New Horizons team captured new data on its elusive target, an ancient Kuiper Belt object known as 2014 MU69. Weary but excited team members succeeded in detecting the spacecraft’s next destination, in what’s being called the most ambitious and challenging ground occultation observation campaign in history.

“So far we have five confirmed occultations,” said Marc Buie of the Southwest Research Institute (SwRI) in Boulder, Colorado, holding up five fingers as New Horizons scientists pored over the exhilarating initial data. Buie led a team of more than 60 observers who battled high winds and cold to set up a “picket fence” of 24 mobile telescopes in a remote region of Chubut and Santa Cruz, Argentina. Their goal: to spot the shadow of the mysterious Kuiper Belt object (KBO) where New Horizons will fly by on New Year’s Day 2019 – to better understand its size, shape, orbit and the environment around it. Before these observations, only the Hubble Space Telescope successfully detected MU69, and even it had not been able to determine MU69’s size or shape.



Animation above: Now you see it, now you don’t: NASA’s New Horizons team trained mobile telescopes on an unnamed star (center) from rural Argentina on July 17, 2017. A Kuiper Belt object 4.1 billion miles from Earth -- known as 2014 MU69 -- briefly blocked the light from the background star, in what’s called an occultation. The time difference between frames is 200 milliseconds, or 0.2 seconds. This data helps scientists to better measure the shape, size and environment around the object; the New Horizons spacecraft will fly by this ancient relic of solar system formation on Jan. 1, 2019. Animation Credits: NASA/JHUAPL/SwRI.

“It was the most historic occultation on the face of the Earth,” said Jim Green, NASA’s director of planetary science in a congratulatory call to the team. “You pulled it off and you made it happen.”

The first MU69 occultation campaign scientist to see the telltale signature of MU69 was Amanda Zangari, a New Horizons co-investigator from SwRI, who said, “We nailed it spectacularly.”

The New Horizons team enjoyed strong support from Argentinian scientists, government officials, and locals, who went above and beyond to ensure mission success. “I’ve been calling the people who helped us, our ‘twelfth player,’” Buie said. “The Comodoro Rivadavia community came together and did some amazing things for us.” A major national highway was closed for two hours to keep car headlights away. Street lights were turned off to ensure absolute darkness. People like the Intendente or Mayor of the Comodoro parked trucks as wind breaks. Said Buie, “The local people were a major team player.”



Image above: Marc Buie, New Horizons occultation campaign lead, holds up five fingers to represent the number of mobile telescopes in Argentina initially thought to have detected the fleeting shadow of 2014 MU69. The New Horizons spacecraft will fly by the ancient Kuiper Belt object on Jan. 1, 2019. Image Credits: NASA/JHUAPL/SwRI/Adriana Ocampo.

“Planning for this complex astronomical deployment started just a few months ago and although the odds seem daunting -- like finding a needle in a haystack -- the team succeeded, thanks to the help of institutions like CONAE (Argentina's National Commission on Space Activities), and all the goodwill of the Argentinian people. This is another example of how space exploration brings out the best in us,” said New Horizons Program Executive Adriana Ocampo.

This was the third of three ambitious occultation observations for New Horizons, and all contributed to the success of the campaign. On June 3, teams in both Argentina and South Africa attempted to observe MU69. On July 10, researchers using NASA’s Stratospheric Observatory for Infrared Astronomy, or SOFIA, studied the environment around MU69 while flying over the Pacific Ocean from Christchurch, New Zealand.

When New Horizons flies by it, MU69 will be the most distant object ever explored by a spacecraft, over a billion miles farther from our sun than Pluto. This ancient Kuiper Belt object is not well understood, because it is faint (likely 14-25 miles or 22-40 kilometers across) and so far away. To study this distant object from Earth, the New Horizons team used Hubble Space Telescope and Gaia satellite data to calculate where MU69 would cast a shadow on Earth’s surface. Both satellites were crucial to the occultation campaign.



Image above: New Horizons Co-Investigator Amanda Zangari was the first occultation campaign scientist to see the telltale signature of MU69 while analyzing data from July 17, saying, “We nailed it spectacularly.” Image Credits: NASA/JHUAPL/SwRI/Adriana Ocampo.

It will take weeks for scientists to analyze the many datasets from the multi-faceted campaign. This advance observation is a critical step in flyby planning before the New Horizons spacecraft arrives at MU69 on Jan. 1, 2019.

“This effort, spanning six months, three spacecraft, 24 portable ground-based telescopes, and NASA’s SOFIA airborne observatory was the most challenging stellar occultation in the history of astronomy, but we did it!” said Alan Stern, New Horizons principal investigator from SwRI. “We spied the shape and size of 2014 MU69 for the first time, a Kuiper Belt scientific treasure we will explore just over 17 months from now. Thanks to this success we can now plan the upcoming flyby with much more confidence.”

To see a video of preparations for the July 17 observations in Argentina: https://t.co/nzyOzbPVh3

Related links:


NASA New Horizons website: http://www.nasa.gov/newhorizons

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

Gaia satellite: http://sci.esa.int/gaia/

KBO Chasers: http://pluto.jhuapl.edu/Mission/KBO-Chasers.php

Animation (mentioned), Images (mentioned), Text, Credits: NASA/Tricia Talbert.


Greetings, Orbiter.ch

mardi 18 juillet 2017

HIE-ISOLDE: Nuclear physics gets further energy boost












CERN - European Organization for Nuclear Research logo.

July 18, 2017


Image above: This is the Miniball germanium array, which is using the first HIE-ISOLDE beams for the experiments described below (Image: Julien Ordan /CERN).

For the first time in 2017, the HIE- ISOLDE linear accelerator began sending beams to an experiment, marking the start of ISOLDE’s high-energy physics programme for this year.

The HIE-ISOLDE (High-Intensity and Energy upgrade of ISOLDE) project incorporates a new linear accelerator (Linac) into CERN’s ISOLDE facility (which stands for the Isotope mass Separator On-Line). ISOLDE is a unique nuclear research facility, which produces radioactive nuclei (ones with too many, or too few, neutrons) that physicists use to research a range of topics, from studying the properties of atomic nuclei to biomedical research and to astrophysics.

Although ISOLDE has been running since April, when the accelerator chain at CERN woke up from its technical stop over winter, HIE-ISOLDE had to wait until now as new components, specifically a new cryomodule, needed to be installed, calibrated, aligned and tested.

Each cryomodule contains five superconducting cavities used to accelerate the beam to higher energies. With a third module installed, HIE-ISOLDE is able to accelerate the nuclei up to an average energy of 7.5 MeV per nucleon, compared with the 5.5 MeV per nucleon reached in 2016.

This higher energy also allows physicists to study the properties of heavier isotopes – ones with a mass up to 200, with a study of 206 planned later this year, compared to last year when the heaviest beam was 142. From 2018, the HIE-ISOLDE Linac will contain four of these cryomodules and be able to reach up to 10 MeV per nucleon.

“Each isotope we study is unique, so each experiment either studies a different isotope or a different property of that isotope. The HIE-ISOLDE linac gives us the ability to tailor make a beam for each experiment’s energy and mass needs,” explains Liam Gaffney, who runs the Miniball station where many of HIE-ISOLDE’s experiments are connected.

The HIE-ISOLDE beams will be available until the end of November, with thirteen experiments hoping to use the facility during that time – more than double the number that took data last year. The first experiment, which begins today, will study the electromagnetic interactions between colliding nuclei of the radioactive isotope Selenium 72 and a platinum target. With this reaction they can measure whether or not the nuclei is more like a squashed disc or stretched out, like a rugby ball; or some quantum mechanical mixture of both shapes.

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 link:

Miniball station: http://isolde.web.cern.ch/experiments/miniball

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

Image (mentioned), Text, Credits: CERN/Harriet Jarlett.

Best regards, Orbiter.ch

Five Ways ISS National Lab Enables Commercial Research












ISS - International Space Station patch.

July 18, 2017

A growing number of commercial partners use the International Space Station National Lab. With that growth, we will see more discoveries in fundamental and applied research that could improve life on the ground.


Image above: NASA astronaut Tim Kopra sets up hardware for the Burning and Suppression of Solids – Milliken (BASS-M) investigation, which will test flame-retardant clothing against microgravity conditions. Results from the investigation will impact how flame-retardant textiles will be used on Earth and in space. Image Credit: NASA.

Since 2011, when NASA engaged the Center for the Advancement of Science in Space (CASIS) to manage the ISS National Lab, CASIS has partnered with academic researchers, other government organizations, startups and major commercial companies to take advantage of the unique microgravity lab. Today, more than 50 percent of the CASIS flight manifest represents commercial research.


Image above: NASA astronaut Kate Rubins after the installation of the Global AIS on Space Station (GLASS) investigation hardware. This investigation uses a space-based AIS receiver system on ISS to acquire and disseminate ship information. Image Credit: NASA.

Here’s a look at five ways the ISS National Lab is enabling new opportunities for commercial research in space:

1. Supporting commercial life sciences research: One of the main areas of focus for NASA in the early origins of the space station program was life sciences, and it is still a major priority for the agency today. Studying the effects of microgravity on astronauts provides insight into human physiology, and how it evolves or erodes in space. CASIS took this knowledge and began robust outreach to the pharmaceutical community, which could now take advantage of the microgravity environment on the ISS National Lab to develop and enhance therapies for patients on Earth. Companies such as Merck, Eli Lilly & Company, and Novartis have sent several payloads to the station, including investigations aimed at studying diseases such as osteoporosis, and examining ways to enhance drug tablets for increased potency to help patients on Earth. These companies are trailblazers for many other life science companies who are looking at how the ISS National Lab to advance their research aims.

2. Enabling commercial investigations in material and physical sciences: Over the past few years, CASIS and the ISS National Lab also have seen a major push toward material and physical sciences research by companies interested in enhancing their products for consumers. Examples range from Proctor and Gamble’s investigation aimed at increasing the longevity of daily household products, to Milliken’s flame-retardant textile investigation to improve protective clothing for individuals in harm’s way, and companies looking to enhance materials for household appliances. Additionally, CASIS has been working with a variety of companies to improve remote sensing capabilities in order to better monitor our oceans, predict harmful algal blooms, and ultimately, to better understand our planet from a vantage point roughly 250 miles above Earth.

3. Supporting startup companies interested in microgravity research: CASIS has funded a variety of investigations with small startup companies (in particular through seed funding and grant funding from partnerships and funded solicitations) to leverage the ISS National Lab for both research and test-validation model experiments. CASIS and The Boeing Company recently partnered with MassChallenge, the largest startup accelerator in the world, to fund three startup companies to conduct microgravity research.

4. Enabling validation of low-Earth orbit business models: The ISS National Lab helps validate low-Earth orbit business models. Companies such as NanoRacks, Space Tango, Made In Space, Techshot, and Controlled Dynamics either have been funded by CASIS or manifested to send hardware instruments to the ISS National Lab that the research community can use, and that open new channels for inquiry. This has allowed the companies that operate these facilities to validate their business model with the space station while also building for the future beyond station.

5. Demonstrating the commercial value of space-based research: NASA has been a key partner in working with CASIS to demonstrate to American businesses the value of conducting research in space. Through outreach events such as NASA’s Destination Station, where representatives from the International Space Station Program Science Office and CASIS select cities with several major companies and meet with the companies to discuss how they could benefit from space-based research. Over the past few years, this outreach mechanism has proven a terrific example of building awareness on the benefits of microgravity research.

Benefits for Humanity: Space is Our Business

Related links:

Center for the Advancement of Science in Space (CASIS): http://www.iss-casis.org/

Remote sensing capabilities: http://www.nasa.gov/mission_pages/station/research/experiments/1915.html

Monitor our oceans: http://www.iss-casis.org/NewsEvents/OnStation/tabid/113/ArticleID/198/ArtMID/570/PgrID/570/PageID/2/Looking-into-the-Eye-of-a-Hurricane.aspx

MassChallenge: http://www.iss-casis.org/NewsEvents/PressReleases/tabid/111/ArticleID/57/ArtMID/586/CASIS-and-MassChallenge-Announce-Partnership-to-Send-Entrepreneurial-Research-to-the-ISS.aspx

NanoRacks: http://www.nasa.gov/mission_pages/station/research/experiments/829.html

Space Tango: http://www.spacetango.com/

Made In Space: http://www.nasa.gov/centers/ames/researchpark/partners/space/made-in-space/

Techshot: http://techshot.com/

Controlled Dynamics: http://controlled-dynamics.com/

Destination Station: https://www.nasa.gov/mission_pages/station/news/destination_station/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), Video, Text, Credits: NASA/Kristine Rainey/JSC/Jenny Howard.

Best regards, Orbiter.ch

Gamma-ray Telescopes Reveal a High-energy Trap in Our Galaxy's Center











NASA - Fermi Gamma-ray Space Telescope logo.

July 18, 2017

A combined analysis of data from NASA's Fermi Gamma-ray Space Telescope and the High Energy Stereoscopic System (H.E.S.S.), a ground-based observatory in Namibia, suggests the center of our Milky Way contains a "trap" that concentrates some of the highest-energy cosmic rays, among the fastest particles in the galaxy.


Image above: An illustration of NASA's Fermi Gamma-ray Space Telescope orbiting Earth. Image Credits: NASA's Goddard Space Flight Center Conceptual Image Lab.

"Our results suggest that most of the cosmic rays populating the innermost region of our galaxy, and especially the most energetic ones, are produced in active regions beyond the galactic center and later slowed there through interactions with gas clouds," said lead author Daniele Gaggero at the University of Amsterdam. "Those interactions produce much of the gamma-ray emission observed by Fermi and H.E.S.S." 

Cosmic rays are high-energy particles moving through space at almost the speed of light. About 90 percent are protons, with electrons and the nuclei of various atoms making up the rest. In their journey across the galaxy, these electrically charged particles are affected by magnetic fields, which alter their paths and make it impossible to know where they originated.

But astronomers can learn about these cosmic rays when they interact with matter and emit gamma rays, the highest-energy form of light.


Image above: The five telescopes of the High Energy Stereoscopic System (H.E.S.S.), located in Namibia, capture faint flashes that occur when ultrahigh-energy gamma rays are absorbed in the upper atmosphere. A new study of the galactic center combines high-energy observations from H.E.S.S. with lower-energy data from NASA's Fermi Gamma-ray Space Telescope to show that some of the speediest particles become trapped there. Image Credits: H.E.S.S., MPIK/Christian Foehr.

In March 2016, scientists with the H.E.S.S. Collaboration reported gamma-ray evidence of the extreme activity in the galactic center. The team found a diffuse glow of gamma rays reaching nearly 50 trillion electron volts (TeV). That's some 50 times greater than the gamma-ray energies observed by Fermi's Large Area Telescope (LAT). To put these numbers in perspective, the energy of visible light ranges from about 2 to 3 electron volts.

The Fermi spacecraft detects gamma rays when they enter the LAT. On the ground, H.E.S.S. detects the emission when the atmosphere absorbs gamma rays, which triggers a cascade of particles resulting in a flash of blue light.   

In a new analysis, published July 17 in the journal Physical Review Letters, an international team of scientists combined low-energy LAT data with high-energy H.E.S.S. observations. The result was a continuous gamma-ray spectrum describing the galactic center emission across a thousandfold span of energy.

"Once we subtracted bright point sources, we found good agreement between the LAT and H.E.S.S. data, which was somewhat surprising due to the different energy windows and observing techniques used," said co-author Marco Taoso at the Institute of Theoretical Physics in Madrid and Italy's National Institute of Nuclear Physics (INFN) in Turin.

This agreement indicates that the same population of cosmic rays — mostly protons — found throughout the rest of the galaxy is responsible for gamma rays observed from the galactic center. But the highest-energy share of these particles, those reaching 1,000 TeV, move through the region less efficiently than they do everywhere else in the galaxy. This results in a gamma-ray glow extending to the highest energies H.E.S.S. observed.

"The most energetic cosmic rays spend more time in the central part of the galaxy than previously thought, so they make a stronger impression in gamma rays," said co-author Alfredo Urbano at the European Organization for Nuclear Research (CERN) in Geneva and INFN Trieste.

This effect is not included in conventional models of how cosmic rays move through the galaxy. But the researchers show that simulations incorporating this change display even better agreement with Fermi data.

"The same breakneck particle collisions responsible for producing these gamma rays should also produce neutrinos, the fastest, lightest and least understood fundamental particles," said co-author Antonio Marinelli of INFN Pisa. Neutrinos travel straight to us from their sources because they barely interact with other matter and because they carry no electrical charge, so magnetic fields don't sway them.

"Experiments like IceCube in Antarctica are detecting high-energy neutrinos from beyond our solar system, but pinpointing their sources is much more difficult," said Regina Caputo, a Fermi team member at NASA's Goddard Space Flight Center in Greenbelt, Maryland, who was not involved in the study. "The findings from Fermi and H.E.S.S. suggest the galactic center could be detected as a strong neutrino source in the near future, and that's very exciting."

The Fermi mission is an astrophysics and particle physics partnership, developed by NASA in collaboration with the U.S. Department of Energy, along with important contributions from academic institutions and partners in France, Germany, Italy, Japan, Sweden and the United States. The H.E.S.S. Collaboration includes scientists from Germany, France, the United Kingdom, Poland, the Czech Republic, Ireland, Armenia, South Africa and Namibia.

Related link:

High Energy Stereoscopic System (H.E.S.S.): https://www.mpi-hd.mpg.de/hfm/HESS/

Physical Review Letters: https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.119.031101

Experiments like IceCube in Antarctica: https://www.nasa.gov/feature/goddard/2016/nasas-fermi-telescope-helps-link-cosmic-neutrino-to-blazar-blast

For more information about NASA's Fermi, visit: https://www.nasa.gov/fermi

Images (mentioned), Text, Credits: NASA/Rob Garner/Goddard Space Flight Center, by Francis Reddy.

Greetings, Orbiter.ch