mardi 22 août 2017

Cosmic Ray Study Prepped for Installation After Monday Eclipse










ISS - Expedition 52 Mission patch.

August 22, 2017

International Space Station (ISS) Flying Over the Earth. Animation Credit: NASA

Overnight, robotics controllers extracted a new astrophysics experiment from the trunk of the SpaceX Dragon cargo craft. The Canadarm2 will hand off the new astronomy gear to the Japanese robotic arm which will then install it outside the Kibo laboratory module.

Dubbed CREAM, short for Cosmic Ray Energetics and Mass Investigation, it will observe a variety of cosmic rays and measure their charges. The experiment is an extension of what started as high-altitude, long-duration balloon flights over Antarctica. The orbital data is expected to be several orders of magnitude greater than that collected in Earth’s atmosphere.


Image above: The solar eclipse was photographed by Expedition 52 Commander Fyodor Yurchikhin aboard the International Space Station on Monday Aug. 21. Image Credit: NASA.

The six Expedition 52 crew members had a once-in-a-lifetime experience Monday as they witnessed the solar eclipse from space. The orbiting crewmates employed a multitude of cameras to photograph the eclipse. They captured stunning views of the moon’s shadow against the Earth with a high definition camcorder as the eclipse darkened a coast-to-coast swath of the United States.

Related links:

SpaceX Dragon: https://www.nasa.gov/spacex

Cosmic Ray Energetics and Mass Investigation: https://www.nasa.gov/mission_pages/station/research/experiments/1114.html

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

Solar eclipse: https://www.flickr.com/photos/nasa2explore/albums/72157685468419703

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

Greetings, Orbiter.ch

Weekly Recap From the Expedition Lead Scientist, week of August 14, 2017










ISS - Expedition 52 Mission patch.

Aug. 22, 2017

(Highlights: Week of August 14, 2017) - Two tons of science supplies arrived at the International Space Station this week, ahead of a spacewalk by two Russian cosmonauts. The SpaceX Dragon delivery included research seeking to better understand vision impacts of microgravity, a protein implicated in Parkinson’s disease and cosmic rays. Meanwhile, crew members continued work on a variety of investigations aboard the orbiting laboratory.

ESA (European Space Agency) astronaut Paolo Nespoli used light meter hardware for the investigation Testing Solid State Lighting Countermeasures to Improve Circadian Adaptation, Sleep, and Performance During High Fidelity Analog and Flight Studies for the International Space Station (Lighting Effects). This investigation tests a new lighting design using light-emitting diodes to replace the fragile fluorescent lights currently used on the space station. Measurements of various light settings were taken to ensure the LEDs provide enough light to be able to complete science experiments while improving cognitive performance.


Image above: The SpaceX Dragon cargo craft approaches the International Space Station on Aug. 16. The capsule delivered two tons of science investigations. Image Credit: NASA.

LEDs are adjustable for intensity and color -- the blue, white or yellow sections of the light spectrum. Scientists and doctors want to determine if the new lights can improve improve crew sleep cycles and alertness during the day. Besides the potential health benefits, these lights also require less energy to run and are lower in mass, making them a prime candidate for use on future spacecraft. Using the same type of lights on Earth, and subtly adjusting their color temperature during the day may help people be more productive, especially those who work a night shift.

NASA astronaut Peggy Whitson began work on a new investigation on the orbiting laboratory, preparing to culture a rare type of fungus to search for new antibiotics. The Intraterrestrial Fungus (STaARS-iFUNGUS) investigation transports frozen samples of fungal spores to the station, growing them in different nutrient mixtures over different intervals, refreezing the samples before returning them to Earth. The fungus, penicillium chrysogenum, differs from other fungi because it comes from deep in the planet's subsurface and shows potential as a source for new antibacterial compounds.


Image above: NASA astronauts Jack Fischer and Peggy Whitson, along with ESA astronaut Paolo Nespoli, unload two tons of science supplies from the SpaceX Dragon cargo vehicle. Image Credit: NASA.

When the samples are returned to Earth, scientists will examine how they grew and what chemicals they produced. The investigation demonstrates how the microgravity environment on the station can serve as a laboratory and production facility for new life science discoveries. The unique conditions of space allow scientists to search for compounds that can prevent infections on Earth.


Image above: This new lighting system was installed on the International Space Station to test a possible replacement for the fluorescent light bulbs that are currently used. The new light source is a series of solid-state, light-emitting diodes, which use less energy and create less heat. Image Credit: NASA.

NASA astronaut Jack Fischer performed a non-invasive assessment of intracranial pressure for spaceflight and related visual impairment (IPVI). Long-term spaceflight increases pressure in the head, resulting in changes to the shape of crew members' eyes and optic nerves, causing vision changes. JAXA's (Japan Aerospace Exploration Agency) IPVI investigation analyzes blood pressure and blood flow in the brain before and after spaceflight. Using a non-invasive method, scientists hope to detect possible swelling of the optic nerve earlier to prevent eye abnormalities in astronauts. Physicians on Earth currently use invasive procedures to measure intracranial pressure such as a spinal tap – inserting a needle in a person's spine. Results of this investigation can benefit patients who need to be tested for fluid on the brain, cerebral swelling or low intracranial pressure by providing a less-invasive -- yet just as effective -- solution.

video
Space to Ground: Moon Shadow: 08/18/17

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.

Progress was made on other investigations this week, including: At Home In Space, Fine Motor Skills, Rodent Research-5, Cool Flames, MARROW, Meteor, MagVector, Space Headaches, TReK, Neuromapping, Vascular Echo, Habitability, SPRINT, Lung Tissue, Biochem Profile, ISS Ham Radio (ARISS), and LMM Biophysics.

Related links:

Lighting Effects: https://www.nasa.gov/mission_pages/station/research/experiments/2279.html

Crew sleep cycles: https://www.nasa.gov/mission_pages/station/research/catching_zs_microgravity

STaARS-iFUNGUS: https://www.nasa.gov/mission_pages/station/research/experiments/2492.html

IPVI: https://www.nasa.gov/mission_pages/station/research/experiments/1950.html

At Home In Space: https://www.nasa.gov/mission_pages/station/research/experiments/1988.html

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

Rodent Research-5: https://www.nasa.gov/mission_pages/station/research/experiments/2283.html

Cool Flames: https://www.nasa.gov/mission_pages/station/research/experiments/1947.html

MARROW: https://www.nasa.gov/mission_pages/station/research/experiments/1931.html

Meteor: https://www.nasa.gov/mission_pages/station/research/experiments/1323.html

MagVector: https://www.nasa.gov/mission_pages/station/research/experiments/1176.html

Space Headaches: https://www.nasa.gov/mission_pages/station/research/experiments/181.html

TReK: https://www.nasa.gov/mission_pages/station/research/experiments/2111.html

Neuromapping: https://www.nasa.gov/mission_pages/station/research/experiments/1007.html

Vascular Echo: https://www.nasa.gov/mission_pages/station/research/experiments/1921.html

Habitability: https://www.nasa.gov/mission_pages/station/research/experiments/1772.html

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

Lung Tissue: https://www.nasa.gov/mission_pages/station/research/experiments/2399.html

Biochem Profile: https://www.nasa.gov/mission_pages/station/research/experiments/1008.html

ISS Ham Radio (ARISS): http://www.nasa.gov/mission_pages/station/research/experiments/346.html

LMM Biophysics: https://www.nasa.gov/mission_pages/station/research/experiments/1970.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

Saturn-lit Tethys












NASA & ESA - Cassini-Huygens Mission to Saturn & Titan patch.

Aug. 21, 2017


Cassini gazes across the icy rings of Saturn toward the icy moon Tethys, whose night side is illuminated by Saturnshine, or sunlight reflected by the planet.

Tethys was on the far side of Saturn with respect to Cassini here; an observer looking upward from the moon's surface toward Cassini would see Saturn's illuminated disk filling the sky.

Tethys was brightened by a factor of two in this image to increase its visibility. A sliver of the moon's sunlit northern hemisphere is seen at top. A bright wedge of Saturn's sunlit side is seen at lower left.

This view looks toward the sunlit side of the rings from about 10 degrees above the ring plane. The image was taken in visible light with the Cassini spacecraft wide-angle camera on May 13, 2017.

The view was acquired at a distance of approximately 750,000 miles (1.2 million kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 140 degrees. Image scale is 43 miles (70 kilometers) per pixel on Saturn. The distance to Tethys was about 930,000 miles (1.5 million kilometers). The image scale on Tethys is about 56 miles (90 kilometers) per pixel.

Cassini Grand Finale

The Cassini mission is a cooperative project of NASA, ESA (the European Space Agency) and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colorado.

For more information about the Cassini-Huygens mission visit https://saturn.jpl.nasa.gov and http://www.nasa.gov/cassini . The Cassini imaging team homepage is at http://ciclops.org and ESA's website: http://www.esa.int/Our_Activities/Space_Science/Cassini-Huygens

Image, Animation, Text, Credits: Credit: NASA/Tony Greicius/ESA/JPL-Caltech/Space Science Institute.

Best regards, Orbiter.ch

Hubble's Twisted Galaxy












NASA - Hubble Space Telescope patch.

Aug. 22, 2017


Gravity governs the movements of the cosmos. It draws flocks of galaxies together to form small groups and more massive galaxy clusters, and brings duos so close that they begin to tug at one another. This latter scenario can have extreme consequences, with members of interacting pairs of galaxies often being dramatically distorted, torn apart, or driven to smash into one another, abandoning their former identities and merging to form a single accumulation of gas, dust and stars.

The subject of this NASA/ESA Hubble Space Telescope image, IC 1727, is currently interacting with its near neighbor, NGC 672 (which is just out of frame). The pair’s interactions have triggered peculiar and intriguing phenomena within both objects — most noticeably in IC 1727. The galaxy’s structure is visibly twisted and asymmetric, and its bright nucleus has been dragged off-center.

In interacting galaxies such as these, astronomers often see signs of intense star formation (in episodic flurries known as starbursts) and spot newly-formed star clusters. They are thought to be caused by gravity churning, redistributing and compacting the gas and dust. In fact, astronomers have analyzed the star formation within IC 1727 and NGC 672 and discovered something interesting — observations show that simultaneous bursts of star formation occurred in both galaxies some 20 to 30 and 450 to 750 million years ago. The most likely explanation for this is that the galaxies are indeed an interacting pair, approaching each other every so often and swirling up gas and dust as they pass close by.

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, Text, Credits: NASA/Sara Blumberg/Hubble/ESA.

Greetings, Orbiter.ch

The moving Martian bow shock












ESA - Mars Express Mission patch.

22 August 2017

As the energetic particles of the solar wind speed across interplanetary space, their motion is modified by objects in their path. A study, based on data from ESA's Mars Express orbiter, has thrown new light on a surprising interaction between the planet Mars and supersonic particles in the solar wind.

The moving Martian bow shock. Credit: ESA/ATG medialab

Scientists have long been aware that a feature known as a bow shock forms upstream of a planet – rather like the bow of a ship, where the water is slowed and then diverted around the obstacle.

The bow shock marks a fairly sharp boundary where the solar wind slows suddenly as it begins to plough into a planet's magnetosphere or outer atmosphere.

In the case of Mars, which does not generate a global magnetic field and has a thin atmosphere, the main obstacle to the solar wind is the ionosphere – a region of electrically charged particles in its upper atmosphere.

Furthermore, the relatively small size, mass and gravity of Mars enable the formation of an extended exosphere – the outermost layer of the atmosphere, where gaseous atoms and molecules escape into space and interact directly with the solar wind.

Observations made by numerous spacecraft over many decades have shown that variations in the ionosphere and exosphere play a role in changes in the location of the bow shock boundary.

As expected, the distance of the Martian bow shock from the planet increases as the dynamic pressure of the solar wind decreases. This is rather like a weakening of the bow wave ahead of a ship as the water's flow slows down.

On the other hand, increases in the distance of the Martian bow shock coincide with increases in the amount of incoming solar radiation at extreme ultraviolet (EUV) wavelengths. Consequently, the rate at which ions and electrons are produced from atoms and molecules in the upper atmosphere increases. This results in increased thermal pressure within the ionosphere, enabling it to better counteract the incoming solar wind flow.

At the same time, newly created ions within the extended exosphere are picked up and accelerated by the electromagnetic fields carried by the solar wind. The result is a slowdown in the solar wind and a shift in the position of the bow shock.

Another possible factor in influencing the bow shock's location is the orbit of Mars. The planet's distance from the Sun is much more elliptical than that of Earth, ranging from 206 million km to 249 million km – a 20% difference.

Mars in orbit – aphelion and perihelion. Credit: ESA/ATG medialab

A team of European scientists has investigated how and why the bow shock's location varies during the Martian year. In a paper published online in the 21 November 2016 issue of the Journal of Geophysical Research: Space Physics, the team has analysed more than five Martian years of measurements from the Mars Express Analyser of Space Plasma and EneRgetic Atoms (ASPERA-3) Electron Spectrometer (ELS) to identify 11 861 bow shock crossings. This is the first analysis of the bow shock to be based on data obtained over such a prolonged period and during all Martian seasons.

video
ESA Science & Technology Mars bow shock crossings with Mars Express

Video above: Mars bow shock crossings with Mars Express. Click here for details and large versions of the video. Video Credit: B.E. Hall, University of Leicester.

As Mars Express crosses the Martian bow shock the ELS instrument typically registers a sudden increase in flux of electrons across a wide range of energies (typically up to a few hundred eV).

The scientists discovered that, on average, the bow shock is closer to Mars near aphelion (the planet's furthest point from the Sun), and further away from Mars near perihelion (the planet's closest point to the Sun). The bow shock's average distance from Mars, when measured from above the terminator (the day-night boundary) reaches a minimum of 8102 km around aphelion, while its maximum distance of 8984 km occurs around perihelion. This is an overall variation of approximately 11% during each Martian orbit.

The moving Martian bow shock. Credit: ESA/ATG medialab

The team also verified previous findings that the bow shock in the southern hemisphere is, on average, located farther away from Mars than in the northern hemisphere. However, this hemispherical asymmetry is small (a total distance variation of 2.4%), and the same annual variations in the bow shock occur irrespective of the hemisphere.

Solar wind density (and, therefore, dynamic pressure), the strength of the interplanetary magnetic field, and solar irradiation, are all expected to reduce with distance from the Sun. Since these parameters impact the bow shock location in different ways, the team wanted to find out which is the dominant factor throughout the Martian year.

Their somewhat surprising discovery was that the bow shock's location is more sensitive to variations in the solar EUV output than to solar wind dynamic pressure variations.

This may be largely due to the well recognised impact of EUV on the density and thermal pressure of the ionosphere, and the expansion of the exosphere (see above). These processes create buffers against the solar wind.

However, the variations in bow shock distance also correlate with annual changes in the amount of dust in the Martian atmosphere. The Martian dust storm season occurs around perihelion, when the planet is warmer and receives more solar radiation.

"Dust storms have been previously shown to interact with the upper atmosphere and ionosphere of Mars, so there may be an indirect coupling between the dust storms and bow shock location," said Benjamin Hall, lead author of the paper, who was until recently at the University of Leicester, and is currently a researcher at Lancaster University, UK.

"However, we do not draw any further conclusions on how the dust storms could directly impact the location of the Martian bow shock and leave such an investigation to a future study.

Mars Express. Image Credit: ESA

"It seems likely that no single mechanism can explain our observations, but rather a combined effect of all of them. At this point none of them can be excluded.

"Future investigations of links between atmospheric dust loading and the Martian upper atmosphere are needed, involving joint investigations by ESA's Mars Express and Trace Gas Orbiter, and NASA's MAVEN mission. Early data from MAVEN seem to confirm the trends that we discovered."

"Similar investigations were made by the ASPERA instrument that was flown on board the Venus Express orbiter, enabling us to compare physical processes and conditions at two very different planets that both have weak magnetic fields," said Dmitri Titov, ESA's Mars Express Project Scientist.

"This demonstrates the value of using the same instrumentation to explore different worlds."

Background information:

The results described in this article are published in "Annual variations in the Martian bow shock location as observed by the Mars Express mission," by B.E.S. Hall et al., Journal of Geophysical Research: Space Physics, 121, 2016; doi: 10.1002/2016JA023316
https://dx.doi.org/10.1002/2016JA023316

Related links:

ESA's Mars Express: http://sci.esa.int/mars-express

Trace Gas Orbiter: http://exploration.esa.int/mars/46475-trace-gas-orbiter/

NASA's MAVEN: https://www.nasa.gov/mission_pages/maven/main/index.html

Venus Express orbiter: http://sci.esa.int/venus-express

Images (mentioned), Video (mentioned), Text, Credits: ESA/Dmitri Titov/Space & Planetary Physics Group Department of Physics/Benjamin Hall.

Greetings, Orbiter.ch

Solar spectacular seen from Earth and space








ESA - European Space Agency patch.

22 August 2017

Total eclipse

While ground-based observers experienced the awe-inspiring view of a total solar eclipse yesterday, astronauts aboard the International Space Station, and our Sun-watching satellites, enjoyed unique perspectives of this spectacular sight from space.

Thanks to a quirk of our cosmos, the Moon’s average distance from Earth is just right for it to appear as the same size in the sky as the significantly larger Sun: the Sun’s diameter is 400 times wider than the Moon’s, but it is also 400 times farther away.

Moon's shadow on Earth

When the two align such that the Moon slides directly between Earth and the Sun, it appears to cover our star completely, temporarily blocking out its light and creating a total solar eclipse for those along the narrow path cast by the Moon’s shadow.

Yesterday, 21 August, observers situated along a 115 km-wide swath stretching from Oregon to South Carolina in the US were under this path of totality. The eclipse shadow took about 1.5 hours to cross the continent, with the peak totality lasting for about 2 minutes 40 seconds.

Total eclipse

A team of astronomers from ESA imaged the eclipse from the US and captured phenomena such as beads of light shining through gaps in the lunar terrain, and the glittering ‘diamond ring’ effect as the last and first slither of sunlight glints through immediately before and after totality.

They also imaged the Sun’s extended atmosphere, the corona, which is visible to the naked eye only during totality when the rest of the Sun’s light is blocked out.

Partial eclipse from Kourou

Astronomers at ESA’s Spaceport in Kourou, French Guiana, enjoyed a partial eclipse after totality had finished in North America. On the north-eastern coast of South America, it was one of the last places to observe the eclipse before it ended worldwide.

Lucky observers in the westernmost parts of Europe also captured a few moments of the partial eclipse at sunset, including astronomers observing from ESA's European Space Astronomy Centre near Madrid, in Spain.

Meanwhile, from their unique vantage point about 400 km above Earth, astronauts aboard the International Space Station, including ESA’s Paolo Nespoli, viewed partial eclipses and the Moon’s fuzzy shadow on the surface of the planet. The space station traversed across the path of totality three times on its 90 minute-long orbits around the Earth.

Proba-2 partial eclipse

Also orbiting Earth 14.5 times a day in its 800 km altitude polar orbit is ESA’s Proba-2 satellite, which was predicted to see the Moon pass four times through its field-of-view, with three partial eclipses.

Further away, some 1.5 million kilometres from Earth towards the Sun, the ESA/NASA Solar and Heliospheric Observatory, SOHO, captured views of the Sun’s activity and extended coma.

For SOHO, eclipses are business as usual: it permanently blocks out the light from the Sun’s disc in order to see fine details in the corona and features in the Sun’s extended atmosphere.

Eclipse context

These space-based images provide useful context for the ground-based astronomers, offering wide views of the corona and the Sun’s activity at the time of the eclipse, and at a range of wavelengths. This helps to link the features seen at a range of scales, giving an insight into the Sun’s dynamic activity.

More information and images from the various observing campaigns are available at the following links:

ESA’s ground-based observing team in Casper, Wyoming: http://cesar.esa.int/index.php?Section=Total_Eclipse_2017

ESA Proba-2 satellite images: http://proba2.oma.be/eclipse-August-2017

ESA/NASA SOHO images: https://umbra.nascom.nasa.gov/lasco/observations/status/eclipse/20170821/eclipse2017_images.html

More about the observations from the ISS: http://orbiterchspacenews.blogspot.ch/2017/08/the-eclipse-2017-from-international.html

ESA's European Space Astronomy Centre: http://www.esa.int/About_Us/ESAC

ESA’s Spaceport in Kourou: http://www.esa.int/Our_Activities/Space_Transportation/Europe_s_Spaceport/Europe_s_Spaceport2

Did you see the eclipse? Do share your images and eclipse experiences with us via https://twitter.com/esascience on Twitter.

Images, Text, Credits: ESA/M.P. Ayucar, CC BY-SA 3.0 IGO/NASA/Cédric Laffay (2017)/Royal Observatory Belgium/SOHO (ESA & NASA); Proba-2: ESA.

Best regards, Orbiter.ch

lundi 21 août 2017

The Eclipse 2017 from International Space Station










ISS - Expedition 52 Mission patch.

Aug. 22, 2017

The Eclipse 2017 from Space

Image above: iss052e055885 (Aug. 21, 2017) -- Aboard the International Space Station, NASA Flight Engineer Randy Bresnik took still images of the eclipse as seen from the unique vantage of the Expedition 52 crew. Witnessing the eclipse from orbit with Bresnik were NASA’s Jack Fischer and Peggy Whitson, ESA (European Space Agency’s) Paolo Nespoli, and Roscosmos’ Commander Fyodor Yurchikhin and Sergey Ryazanskiy. The space station crossed the path of the eclipse three times as it orbited above the continental United States at an altitude of 250 miles. Image Credit: NASA.

The Eclipse 2017 Umbra Viewed from Space

Image above: iss052e056122 (Aug. 21, 2017) -- As millions of people across the United States experienced a total eclipse as the umbra, or moon’s shadow passed over them, only six people witnessed the umbra from space. Viewing the eclipse from orbit were NASA’s Randy Bresnik, Jack Fischer and Peggy Whitson, ESA (European Space Agency’s) Paolo Nespoli, and Roscosmos’ Commander Fyodor Yurchikhin and Sergey Ryazanskiy. The space station crossed the path of the eclipse three times as it orbited above the continental United States at an altitude of 250 miles. Image Credit: NASA.

The Eclipse 2017 Umbra Viewed from Space
 
 Image above: iss052e056222 (Aug. 21, 2017). Image Credit: NASA.

The Eclipse 2017 Umbra Viewed from Space

Image above: iss052e056225 (Aug. 21, 2017). Image Credit: NASA.

The Eclipse 2017 Umbra Viewed from Space

Image above: iss052e056245 (Aug. 21, 2017). Image Credit: NASA.

Related links:

Eclipses and Transits: http://www.nasa.gov/topics/solarsystem/features/eclipse/index.html

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

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

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

Best regards, Orbiter.ch