vendredi 9 octobre 2015

New Horizons Picks Up Styx












NASA - New Horizons Mission logo.

Oct. 9, 2015

NASA Spacecraft Observes Pluto’s Smallest Moon

New images from NASA’s New Horizons reveal the size and shape of Pluto’s smallest moon, Styx.

Styx – also the faintest of Pluto’s five moons – was discovered using the Hubble Space Telescope in 2012, when New Horizons was more than two-thirds into its voyage to Pluto. The Styx images downlinked on Oct. 5, 2015, were taken by the Long Range Reconnaissance Imager (LORRI) on July 13, approximately 12.5 hours before New Horizons’ closest approach to Pluto.


Image above: This Long Range Reconnaissance Imager (LORRI) composite image of Pluto’s smallest moon, Styx, was taken July 14, 2015, when the New Horizons spacecraft was 391,000 miles (631,000 kilometers) from the tiny moon. The image reveals a highly-elongated satellite, roughly 4.5 miles [7 kilometers] across in its longest dimension and 3 miles [5 kilometers] in its shortest dimension. For context, the orbits of Pluto’s moons are shown above. Image Credits: NASA/JHUAPL/SwRI.

At that time, the spacecraft was still 391,000 miles (631,000 kilometers) from Styx, making it difficult even for the powerful LORRI camera to see details on such a small moon. “Although it may not look like much, the new composite image of Styx reveals a highly-elongated satellite, roughly 4.5 miles [7 kilometers] across in its longest dimension and 3 miles [5 kilometers] in its shortest dimension,” said New Horizons Project Scientist Hal Weaver, of the Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland.

Styx’s measured brightness, combined with this new size estimate, suggest this tiny moon has a highly reflective, icy surface, similar to what was previously found for two of Pluto’s other small moons, Nix and Hydra.

New Horizons spacecraft on way to deep space. Image Credit: NASA

Using these new images, together with the many measurements of Styx’s brightness taken over several months during New Horizons’ approach to Pluto, the science team hopes to unravel more details about this small moon’s shape and rotational properties. “Ultimately, we hope to learn more about all four of Pluto’s small moons, to understand their similarities and differences, how they formed, and how they evolved,” says New Horizons Principal Investigator Alan Stern, of the Southwest Research Institute, Boulder, Colorado.

The New Horizons spacecraft is currently 3.1 billion miles (5 billion kilometers) from Earth, with all systems healthy and operating normally.

For more information about New Horizons, visit: http://www.nasa.gov/mission_pages/newhorizons/main/index.html

Images (mentioned), Text, Credits: NASA/Lillian Gipson.

Best regards, Orbiter.ch

Hubble Sees an Aging Star Wave Goodbye












NASA - Hubble Space Telescope patch.

Oct. 9, 2015


This planetary nebula is called PK 329-02.2 and is located in the constellation of Norma in the southern sky. It is also sometimes referred to as Menzel 2, or Mz 2, named after the astronomer Donald Menzel who discovered the nebula in 1922.

When stars that are around the mass of the sun reach their final stages of life, they shed their outer layers into space, which appear as glowing clouds of gas called planetary nebulae. The ejection of mass in stellar burnout is irregular and not symmetrical, so that planetary nebulae can have very complex shapes. In the case of Menzel 2 the nebula forms a winding blue cloud that perfectly aligns with two stars at its center. In 1999 astronomers discovered that the star at the upper right is in fact the central star of the nebula, and the star to the lower left is probably a true physical companion of the central star.

For tens of thousands of years the stellar core will be cocooned in spectacular clouds of gas and then, over a period of a few thousand years, the gas will fade away into the depths of the universe. The curving structure of Menzel 2 resembles a last goodbye before the star reaches its final stage of retirement as a white dwarf.

video
Hubble and the sunrise over Earth

The Hubble Space Telescope is a project of international cooperation between NASA and the 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, in Washington.

For more information on the Hubble Space Telescope, visit:

http://www.nasa.gov/hubble

http://hubblesite.org/

http://www.spacetelescope.org/

Image, Video, Credits: ESA/Hubble & NASA, Acknowledgement: Serge Meunier/Text Credits: European Space Agency/NASA/Ashley Morrow.

Greetings, Orbiter.ch

New Horizons Finds Blue Skies and Water Ice on Pluto












NASA - New Horizons Mission logo.

Oct. 9, 2015

The first color images of Pluto’s atmospheric hazes, returned by NASA’s New Horizons spacecraft last week, reveal that the hazes are blue.

“Who would have expected a blue sky in the Kuiper Belt? It’s gorgeous,” said Alan Stern, New Horizons principal investigator from Southwest Research Institute (SwRI), Boulder, Colorado.


Image above: Pluto’s Blue Sky: Pluto’s haze layer shows its blue color in this picture taken by the New Horizons Ralph/Multispectral Visible Imaging Camera (MVIC). The high-altitude haze is thought to be similar in nature to that seen at Saturn’s moon Titan. The source of both hazes likely involves sunlight-initiated chemical reactions of nitrogen and methane, leading to relatively small, soot-like particles (called tholins) that grow as they settle toward the surface. This image was generated by software that combines information from blue, red and near-infrared images to replicate the color a human eye would perceive as closely as possible. Image Credits: NASA/JHUAPL/SwRI.

The haze particles themselves are likely gray or red, but the way they scatter blue light has gotten the attention of the New Horizons science team. “That striking blue tint tells us about the size and composition of the haze particles,” said science team researcher Carly Howett, also of SwRI. “A blue sky often results from scattering of sunlight by very small particles. On Earth, those particles are very tiny nitrogen molecules. On Pluto they appear to be larger — but still relatively small — soot-like particles we call tholins.”

Scientists believe the tholin particles form high in the atmosphere, where ultraviolet sunlight breaks apart and ionizes nitrogen and methane molecules and allows them to react with one another to form more and more complex negatively and positively charged ions. When they recombine, they form very complex macromolecules, a process first found to occur in the upper atmosphere of Saturn’s moon Titan. The more complex molecules continue to combine and grow until they become small particles; volatile gases condense and coat their surfaces with ice frost before they have time to fall through the atmosphere to the surface, where they add to Pluto’s red coloring.

In a second significant finding, New Horizons has detected numerous small, exposed regions of water ice on Pluto. The discovery was made from data collected by the Ralph spectral composition mapper on New Horizons.


Image above: Water Ice on Pluto: Regions with exposed water ice are highlighted in blue in this composite image from New Horizons' Ralph instrument, combining visible imagery from the Multispectral Visible Imaging Camera (MVIC) with infrared spectroscopy from the Linear Etalon Imaging Spectral Array (LEISA). The strongest signatures of water ice occur along Virgil Fossa, just west of Elliot crater on the left side of the inset image, and also in Viking Terra near the top of the frame. A major outcrop also occurs in Baré Montes towards the right of the image, along with numerous much smaller outcrops, mostly associated with impact craters and valleys between mountains. The scene is approximately 280 miles (450 kilometers) across. Note that all surface feature names are informal. Image Credits: NASA/JHUAPL/SwRI.

“Large expanses of Pluto don’t show exposed water ice,” said science team member Jason Cook, of SwRI, “because it’s apparently masked by other, more volatile ices across most of the planet. Understanding why water appears exactly where it does, and not in other places, is a challenge that we are digging into.”

A curious aspect of the detection is that the areas showing the most obvious water ice spectral signatures correspond to areas that are bright red in recently released color images. “I’m surprised that this water ice is so red,” says Silvia Protopapa, a science team member from the University of Maryland, College Park. “We don’t yet understand the relationship between water ice and the reddish tholin colorants on Pluto's surface.”

The New Horizons spacecraft is currently 3.1 billion miles (5 billion kilometers) from Earth, with all systems healthy and operating normally.

New Horizons is part of NASA’s New Frontiers Program, managed by the agency’s Marshall Space Flight Center in Huntsville, Alabama.  APL designed, built, and operates the New Horizons spacecraft and manages the mission for NASA’s Science Mission Directorate. SwRI leads the science mission, payload operations, and encounter science planning.

Related articles:

New Horizons Team Finds Haze, Flowing Ice on Pluto:
http://orbiterchspacenews.blogspot.ch/2015/07/new-horizons-team-finds-haze-flowing.html

Perplexing Pluto: New ‘Snakeskin’ Image and More from New Horizons:
http://orbiterchspacenews.blogspot.ch/2015/09/perplexing-pluto-new-snakeskin-image.html

For more information about New Horizons mission, visit: http://www.nasa.gov/mission_pages/newhorizons/main/index.html

Images (mentioned), Text, Credits: NASA/Lillian Gipson.

Cheers, Orbiter.ch

AAUSAT5 CubeSat starts its space mission















ISS - International Space Station logo / AAUSAT5 CubeSat logo.

9 October 2015

According to radio transmissions received by radio amateurs around the world, AAUSAT5 is alive and kicking! The student-built AAUSAT5 CubeSat was deployed from the International Space Station (ISS) on 5 October at 16:05 CET, together with ESA’s  technology demonstration CubeSat GomX-3. Both CubeSats have now started their mission in space.

The AAUSAT5 team has decoded the telemetry data received and have confirmed the good conditions of the satellite, including battery voltage and temperature.

AAUSAT5 deployment

CubeSats, small satellites having the size of a cube 10x10x10 (or multiples of it), are gaining increasing popularity in the space sector. They can be used as a cheaper and faster way – with respect to conventional satellites of bigger size and higher cost - to demonstrate the use of miniaturised technology in space for a number of applications. These include the new radio technology to be demonstrated by GomX-3, eventually aimed at supporting the identification of the positioning of civilian aircraft and measuring telecommunication satellite signal quality, and that of AAUSAT5, tracking ships at open sea using the Automatic Identification System (AIS).

video
ESA CubeSats deployed from the ISS

CubeSats are also an excellent way for university students to gain experience in the full life-cycle of a space project – from design to launch and operations – before they start their space professions. Since 2012 the ESA Education Office supports students across Europe in the development of CubeSats through the Fly Your Satellite! programme. ESA mentors the students of the selected CubeSat teams, facilitates the transfer of know-how from professional specialists to the students, offers access to test facilities, sponsors the students in the international travel needed for their CubeSat project, and provides launch opportunities. With AAUSAT5, ESA’s Education Office is inaugurating a new branch of the initiative: Fly Your Satellite from the ISS!

AAUSAT5 and GomX-3 are the first ESA CubeSat projects to be launched from the ISS.

For further information on ESA’s Fly Your Satellite! Programme contact:

Piero Galeone, ESA Head of Tertiary Education Unit
Email: Piero.galeone@esa.int

You can hear a radio signal recording from AAUSAT5 on Soundcloud:
https://soundcloud.com/esaops/2015-10-05-19-40-utc-pass-cut

More information:

Fly Your Satellite from the ISS programme: http://www.esa.int/Education/CubeSats_-_Fly_Your_Satellite/Fly_Your_Satellite_from_the_ISS_programme

AAUSAT5 CubeSat: http://www.esa.int/Education/CubeSats_-_Fly_Your_Satellite/AAUSAT5_CubeSat

AAUSAT5 mission: http://www.esa.int/Education/CubeSats_-_Fly_Your_Satellite/AAUSAT5_mission

Meet the team: AAUSAT5: http://www.esa.int/Education/CubeSats_-_Fly_Your_Satellite/Meet_the_team_AAUSAT5

Delivery to Houston: http://www.esa.int/Education/Student_satellite_wins_green_light_for_Station_deployment

Launch to the ISS: http://www.esa.int/Education/Student_satellite_soon_to_take_off_to_International_Space_Station

AAUSAT5 - Main/Home Page: http://www.space.aau.dk/aausat5/

Images, Text, Credits: ESA/NASA.

Greetings, Orbiter.ch

jeudi 8 octobre 2015

Banking X-ray Data For The Future












NASA - Chandra X-ray Observatory patch.

Oct. 8, 2015

Archives, in their many forms, save information from today that people will want to access and study in the future. This is a critical function of all archives, but it is especially important when it comes to storing data from today's modern telescopes.

NASA's Chandra X-ray Observatory. Image Credits: NASA/CXC

NASA's Chandra X-ray Observatory has collected data for over sixteen years on thousands of different objects throughout the Universe. Once the data is processed, all of the data goes into an archive and is available to the public.

To celebrate American Archive Month, we are releasing a collection of new images from the Chandra archive.

By combining data from different observation dates, new perspectives of cosmic objects can be created. With archives like those from Chandra and other major observatories, such vistas will be available for future exploration.


The objects in this year's archive release (above), from left to right, are:

Top row:
W44: Also known as G34.7-0.4, W44 is an expanding supernova remnant that is interacting with dense interstellar material that surrounds it. X-rays from Chandra (blue) show that hot gas fills the shell of the supernova remnant as it moves outward. Infrared observations from the Spitzer Space Telescope reveal the shell of the supernova remnant (green) as well as the molecular cloud (red) into which the supernova remnant is moving and the stars in the field of view. Image credits: X-ray: NASA/CXC/Univ. of Georgia/R.Shelton & NASA/CXC/GSFC/R.Petre; Infrared: NASA/JPL-Caltech

SN 1987A: First seen in 1987, this supernova (dubbed SN 1987A) was the brightest supernova and nearest one to Earth in the last century. In a supernova explosion, a massive star runs out of fuel then collapses onto their core, flinging the outer layers of the star into space. By combining X-ray data from Chandra (blue) with optical data from the Hubble Space Telescope (appearing orange and red), astronomers can observe the evolution of the expanding shell of hot gas generated by the explosion and watch as a shock wave from the blast heats gas that once surrounded the doomed star. The two bright stars near SN 1987A are not associated with the supernova. Image credits: X-ray: NASA/CXC/PUS/E.Helder et al; Optical: NASA/STScI

Kesteven 79: Like SN 1987A, this object, known as Kesteven 79, is the remnant of a supernova explosion, but one that went off thousands of years ago. When massive stars run out of fuel, their cores collapse, generating a shock wave that flings the outer layers of the star into space. An expanding shell of debris and the surviving dense central core are often heated to millions of degrees, and give off X-rays. In this image of Kesteven 79, X-rays detected by Chandra (red, green, and blue) have been combined with an optical image from the Digitized Sky Survey of the field of view that reveals the stars (appearing as white). Image credits: X-ray: NASA/CXC/SAO/F.Seward et al, Optical: DSS

Bottom row:
MS 0735.6+7421: The galaxy cluster MS 0735.6+7421 is home to one of the most powerful eruptions ever observed. X-rays detected by Chandra (blue) show the hot gas that comprises much of the mass of this enormous object. Within the Chandra data, holes, or cavities, can be seen. These cavities were created by an outburst from a supermassive black hole at the center of the cluster, which ejected the enormous jets detected in radio waves (pink) detected the Very Large Array. These data have been combined with optical data from Hubble of galaxies in the cluster and stars in the field of view (orange). Image credits: X-ray: NASA/CXC/Univ. of Waterloo/A.Vantyghem et al; Optical: NASA/STScI; Radio: NRAO/VLA

3C295: The vast cloud of 50-million-degree gas that pervades the galaxy cluster 3C295 is only visible with an X-ray telescope like Chandra. This composite image shows the superheated gas, detected by Chandra (pink), which has a mass equal to that of a thousand galaxies. Hubble's optical data (yellow) reveal some of the individual galaxies in the cluster. Galaxy clusters like 3C295 also contain large amounts of dark matter, which holds the hot gas and galaxies together. The total mass of the dark matter needed is typically five times as great as the gas and galaxies combined. Image credits: X-ray: NASA/CXC/Cambridge/S.Allen et al; Optical: NASA/STScI

Guitar Nebula: The pulsar B2224+65 is moving through space very rapidly. Because of its high speed, the pulsar is creating a bow shock in its wake. This structure is known as the Guitar Nebula and the likeness of the musical instrument can be seen in the optical data (blue) of this composite image taken by Hubble and the Palomar Observatory. X-ray data from Chandra (pink) reveal a long jet that is coincident with the location of the pulsar at the tip of the "guitar," but is not aligned with its direction of motion. Astronomers will continue to study this system to determine the nature of this X-ray jet. Image credits: X-ray: NASA/CXC/UMass/S.Johnson et al, Optical: NASA/STScI & Palomar Observatory 5-m Hale Telescope

Read More from NASA's Chandra X-ray Observatory: http://chandra.harvard.edu/photo/2015/archives/

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

Images (mentioned), Text, Credits: NASA/Lee Mohon.

Best regards, Orbiter.ch

ULA Successfully Launches Payload for the NRO


















ULA - Atlas V / NROL-55 Mission poster.


Oct. 8, 2015

United Launch Alliance Successfully Launches Payload for the National Reconnaissance Office

Atlas V Rocket also Delivers 13 CubeSats to Orbit

A United Launch Alliance (ULA) Atlas V rocket carrying a payload for the National Reconnaissance Office (NRO) and 13 CubeSats lifted off from Space Launch Complex-3 Oct. 8 at 5:49 a.m. PDT. Designated NROL-55, the mission is in support of national defense. This is ULA’s 10th launch in 2015 and the 101st successful launch since the company was formed in December 2006.

Atlas V rocket carrying NROL-55 & CubeSats launch

“Congratulations on today’s successful launch of NROL-55! ULA is honored to have collaborated with the NRO Office of Space Launch and the Air Force on the integration and launch of the NROL-55 spacecraft to orbit with our Atlas V vehicle,” said Jim Sponnick, ULA vice president, Atlas and Delta Programs. “Launches like this only happen with exceptional teamwork by an extremely talented team and a one-launch-at-a-time focus on mission success.”    

The Atlas V rocket also delivered 13 Government Rideshare Advanced Concepts Experiment (GRACE) CubeSats to orbit. The nine NRO-sponsored CubeSats and four NASA-sponsored CubeSats were mounted to the Aft-Bulkhead Carrier located on the back end of the Centaur upper stage.

“The GRACE CubeSats will perform missions demonstrating tracking technologies, software-defined radio communications and will also conduct other measurements and experiments,” said Sponnick. “We are happy that ULA could play a part in bringing these nano-satellites to orbit along with the NRO payload through a cost-effective rideshare.”

video
Atlas V NROL-55 Launch Highlights

The 13 CubeSats were developed by Aerospace Corporation, the Army’s Space and Missile Defense Center, Tyvak, SRI International, the University of Alaska-Fairbanks, Salish Kootenai College, AMSAT and the Jet Propulsion Laboratory. Weighing 1-5 kilograms, they are developed, launched and controlled at a fraction of the cost of a typical operating satellite.

The NRO payload and GRACE CubeSats were launched aboard an Atlas V Evolved Expendable Launch Vehicle (EELV) 401 configuration vehicle, which includes a 4-meter-diameter payload fairing. The Atlas booster for this mission was powered by the RD AMROSS RD-180 engine and the Centaur upper stage was powered by the Aerojet Rocketdyne RL10C-1 engine.

A CubeSat (Illustration)

ULA's next launch is the Atlas V Global Positioning System (GPS) IIF-11 satellite for the U.S. Air Force, scheduled for Oct. 30 from Space Launch Complex-41 from Cape Canaveral Air Force Station, Florida.

The EELV program was established by the U.S. Air Force to provide assured access to space for Department of Defense and other government payloads. The commercially developed EELV program supports the full range of government mission requirements, while delivering on schedule and providing significant cost savings over the heritage launch systems.

With more than a century of combined heritage, United Launch Alliance is the nation’s most experienced and reliable launch service provider. ULA has successfully delivered more than 100 satellites to orbit that provide critical capabilities for troops in the field, aid meteorologists in tracking severe weather, enable personal device-based GPS navigation and unlock the mysteries of our solar system.

For more information on ULA, visit the ULA website at http://www.ulalaunch.com. Join the conversation at http://www.facebook.com/ulalaunch, http://twitter.com/ulalaunch and http://instagram.com/ulalaunch.

Images, Video, Text, Credits: United Launch Alliance (ULA)/Wikimedia.

Greetings, Orbiter.ch

NASA's Curiosity Rover Team Confirms Ancient Lakes on Mars












NASA - Mars Science Laboratory (MSL) patch.

Oct. 8, 2015

A new study from the team behind NASA's Mars Science Laboratory/Curiosity has confirmed that Mars was once, billions of years ago, capable of storing water in lakes over an extended period of time.

Using data from the Curiosity rover, the team has determined that, long ago, water helped deposit sediment into Gale Crater, where the rover landed more than three years ago. The sediment deposited as layers that formed the foundation for Mount Sharp, the mountain found in the middle of the crater today.


Image above: A view from the "Kimberley" formation on Mars taken by NASA's Curiosity rover. The strata in the foreground dip towards the base of Mount Sharp, indicating flow of water toward a basin that existed before the larger bulk of the mountain formed. Image Credits: NASA/JPL-Caltech/MSSS.

"Observations from the rover suggest that a series of long-lived streams and lakes existed at some point between about 3.8 to 3.3 billion years ago, delivering sediment that slowly built up the lower layers of Mount Sharp," said Ashwin Vasavada, Mars Science Laboratory project scientist at NASA's Jet Propulsion Laboratory in Pasadena, California, and co-author of the new Science article to be published Friday, Oct. 9.

The findings build upon previous work that suggested there were ancient lakes on Mars, and add to the unfolding story of a wet Mars, both past and present. Last month, NASA scientists confirmed current water flows on Mars.

"What we thought we knew about water on Mars is constantly being put to the test,” said Michael Meyer, lead scientist for NASA’s Mars Exploration Program at NASA Headquarters in Washington. "It’s clear that the Mars of billions of years ago more closely resembled Earth than it does today. Our challenge is to figure out how this more clement Mars was even possible, and what happened to that wetter Mars." 

Before Curiosity landed on Mars in 2012, scientists proposed that Gale Crater had filled with layers of sediments. Some hypotheses were "dry," suggesting that sediment accumulated from wind-blown dust and sand. Others focused on the possibility that sediment layers were deposited in ancient lakes.

The latest results from Curiosity indicate that these wetter scenarios were correct for the lower portions of Mount Sharp. Based on the new analysis, the filling of at least the bottom layers of the mountain occurred mostly by ancient rivers and lakes over a period of less than 500 million years.


Image above: An image taken at the "Hidden Valley" site, en-route to Mount Sharp, by NASA's Curiosity rover. A variety of mudstone strata in the area indicate a lakebed deposit, with river- and stream-related deposits nearby.
Image Credits: NASA/JPL-Caltech/MSSS.

"During the traverse of Gale, we have noticed patterns in the geology where we saw evidence of ancient fast-moving streams with coarser gravel, as well as places where streams appear to have emptied out into bodies of standing water," Vasavada said. "The prediction was that we should start seeing water-deposited, fine-grained rocks closer to Mount Sharp. Now that we've arrived, we're seeing finely laminated mudstones in abundance that look like lake deposits."

The mudstone indicates the presence of bodies of standing water in the form of lakes that remained for long periods of time, possibly repeatedly expanding and contracting during hundreds to millions of years. These lakes deposited the sediment that eventually formed the lower portion of the mountain. 

"Paradoxically, where there is a mountain today there was once a basin, and it was sometimes filled with water," said John Grotzinger, the former project scientist for Mars Science Laboratory at the California Institute of Technology in Pasadena, and lead author of the new report. "We see evidence of about 250 feet (75 meters) of sedimentary fill, and based on mapping data from NASA's Mars Reconnaissance Orbiter and images from Curiosity's camera, it appears that the water-transported sedimentary deposition could have extended at least 500 to 650 feet (150 to 200) meters above the crater floor."

Furthermore, the total thickness of sedimentary deposits in Gale Crater that indicate interaction with water could extend higher still, perhaps up to one-half mile (800 meters) above the crater floor.

Above 800 meters, Mount Sharp shows no evidence of hydrated strata, and that is the bulk of what forms Mount Sharp. Grotzinger suggests that perhaps this later segment of the crater's history may have been dominated by dry, wind-driven deposits, as was once imagined for the lower part explored by Curiosity.

Mars Science Laboratory (MSL) or Curiosity rover. Image Credits: NASA/J PL-Caltech

A lingering question surrounds the original source of the water that carried sediment into the crater. For flowing water to have existed on the surface, Mars must have had a thicker atmosphere and warmer climate than has been theorized for the ancient era when Gale Crater experienced the intense geological activity. However, current models of this paleoclimate have, literally, come up dry.

At least some of the water may have been supplied to the lakes by snowfall and rain in the highlands of the Gale Crater rim. Some have made the argument that there was an ocean in the plains north of the crater, but that does not explain how the water managed to exist as a liquid for extended periods of time on the surface.

"We have tended to think of Mars as being simple," Grotzinger mused. "We once thought of the Earth as being simple too. But the more you look into it, questions come up because you're beginning to fathom the real complexity of what we see on Mars. This is a good time to go back to reevaluate all our assumptions. Something is missing somewhere."

More information about Mars Science Laboratory is online at: http://www.nasa.gov/msl

NASA's Mars Science Laboratory Project is using Curiosity to assess ancient habitable environments and major changes in Martian environmental conditions. NASA's Jet Propulsion Laboratory, a division of Caltech, built the rover and manages the project for NASA's Science Mission Directorate in Washington.

Based on a Caltech news release written by Rod Pyle.

Images /mentioned), Text (mentioned), Credits: NASA/JPL/Whitney Clavin.

Greetings, Orbiter.ch

Astronaut brains as beacons for researchers












ISS - International Space Station logo.

8 October 2015

How astronauts adapt to the stresses of living in space is helping researchers to pinpoint the causes of common disorders on Earth.

Upside down or right way up?

From the brain’s point of view, living in space is very stressful. The signals from an astronaut’s body in space go haywire as they float in weightlessness. The inner ear reports that it is falling, but the eyes show that nothing is moving.

As fluid shifts to the head, the brain usually interprets this extra pressure as a sign it is upside down – but in space there is no up or down. The body clock might signal that it is tired after a day’s work on the International Space Station, but astronauts experience 16 sunrises and sunsets every 24 hours.

Spacewalks can be extra stressful

Despite all these conflicting signals the brain adapts and within a few days astronauts float through their home in space as if born there.

The amazing ability of our brains to adapt to new experiences is what makes us survive and thrive, but brains also seem to benefit from the past. Experienced astronauts need less time to readapt to weightlessness than rookies, even if the missions are years apart.

Searching connections

Researchers at the University of Antwerpen, Liege and Leuven in Belgium have devised the ‘Brain-DTI’ study to learn more about how astronauts’ brains adapt to spaceflight.

Before and after their flights, up to 16 astronauts will be put in an advanced MRI scanner. The images show the brain’s neural networks and how the connections change after the astronauts’ experiences in space.

MRI scanner

The research has far to go but it is already revealing some areas of the brain that are involved in adapting to new experiences based on conflicting signals from the body – and pointing to areas of interest for people on Earth.

Research for people closer to Earth

Several common disorders found on the ground arise from the brain not adapting to signals from the body correctly. A type of vertigo, for example, can develop when the brain does not adapt to conflicting signals from the inner ear, much like when an astronaut is in space.

Medical researchers now have a starting point to look for problem areas in the complex brain structure in people who suffer from such disorders.

Principle investigator Professor Floris Wuyts explains: “The research on astronauts is an ethical way to look at people’s brains before and after a stressful incident.

“Ideally, we would have brain scans of people when they were healthy and after they started suffering from a disorder, because then we can see where the changes have taken place. But such an ideal situation does not exist, and neither can we give subjects a traumatic experience on purpose, of course.”

Neural networks shown in MRI scan

For the first time a controlled study using advanced MRI methods is showing researchers where to look in the brain’s complex neural network to target areas for further study and cures.

Floris concludes: “The scans from the astronauts are like lighthouses, illuminating points where problems can be in patients on Earth.”

The Brain-DTI study should finish collecting data in 2018 but the first paper, including also data from recent ESA parabolic flight campaigns, has already been published: http://rd.springer.com/article/10.1007%2Fs00429-015-1054-3

Related links:

University of Antwerpen: http://www.uantwerp.be/aurea

University of Liege: http://www.ulg.ac.be/cms/c_5000/en/home

University of Leuven: http://www.kuleuven.be/english

International Space Station Benefits for Humanity: http://www.esa.int/Our_Activities/Human_Spaceflight/International_Space_Station_Benefits_for_Humanity

European space laboratory Columbus: http://www.esa.int/Our_Activities/Human_Spaceflight/Columbus

Experiment archive: http://eea.spaceflight.esa.int/

Images, Text, Credits: ESA/NASA/DLR/University of Antwerpen.

Greetings, Orbiter.ch

mercredi 7 octobre 2015

China launches Long March 2D carrying Jilin-1 mission












CASC - China Aerospace Science and Technology Corporation logo.

October 7, 2015


Image above: A Long March 2D rocket carrying the Jilin-1 satellites lifts off from the Jiuquan Satellite Launch Center in northwest China. Image Credits: Xinhua/Zhao Peng.

China launched four satellites to provide photographs to commercial clients while helping with harvest assessment, geological disaster prevention and resource surveys. The launch of the Jilin-1 mission took place at 04:13 UTC on Wednesday, using a Long March-2D launch vehicle from the 603 Launch Pad at the Jiuquan Satellite Launch Center’s LC43.

video
China launches commercial remote-sensing satellites

The Jilin-1 mission was developed on the China’s Jilin Province and is the country’s first self-developed remote sensing satellite for commercial use. Jilin-1 consists of four satellites, one for high-definition images, one for testing new space technology and another two for video.

Data will be provided to commercial clients to help them forecast and mitigate geological disasters, as well as shorten the time scale for the exploration of natural resources. The satellites were developed by the Chang Guang Satellite Technology Co., Ltd under the Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences.

Hight Resolution Video Camera on satellite. Image Credit: CASC

Jilin-1 is a 420 kg high-definition optical satellite with a 0.72 m resolution pan-chromatic camera and 4 m resolution multi-spectral camera. It is equipped with three deployable solar panels for power generation that will be stored in internal batteries. The satellite will operate on a 656 km sun synchronous orbit.

Jilin-1 satellite. Image Credit: CASC

The first phase will see the launch of the first four Jilin-1 satellites. Between 2016 and 2019 there are plans to have 16 satellites in orbit, completing a remote sensing network that will cover the entire globe and will be capable of a three to four hours update in the data provided. From 2020, the plans point to a 60 satellite orbital constellation capable of a 30 minutes update in the data provided.

From 2030 the Jilin constellation will have 138 satellites in orbit, forming a all-day, all-weather, full spectrum acquisition segment data and a capability of observing any global arbitrary point with a 10 minutes revisit capability, providing the world’s highest spatial resolution and time resolution space information products.

For more information about China Aerospace Science and Technology Corporation (CASC), visit: http://english.spacechina.com/n16421/index.html

Images (mentioned), Video, Text, Credits: CASC/China.org.cn/CNTV/Orbiter.ch Aerospace.

Greetings, Orbiter.ch

All Along the Fractures












NASA - Mars Reconnaissance Orbiter (MRO) patch.

Oct. 7, 2015


The High Resolution Imaging Science Experiment (HiRISE) camera aboard NASA's Mars Reconnaissance Orbiter often takes images of Martian sand dunes to study the mobile soils. These images provide information about erosion and movement of surface material, about wind and weather patterns, even about the soil grains and grain sizes. However, looking past the dunes, these images also reveal the nature of the substrate beneath.

Within the spaces between the dunes, a resistant and highly fractured surface is revealed. The fractured ground is resistant to erosion by the wind, and suggests the material is bedrock that is now shattered by a history of bending stresses or temperature changes, such as cooling, for example.

Alternately, the surface may be a sedimentary layer that was once wet and shrunk and fractured as it dried, like gigantic mud cracks. In either case, the relative small and indistinct fractures have trapped the dark dune sand marching overhead. Now the fractures have become quite distinct, allowing us to examine the orientation and spacing of the fractures to learn more about the processes that formed them.

This view is one image product from HiRISE observation (http://www.uahirise.org/ESP_042223_1890), taken July 30, 2015, at 2:33 p.m. local Mars time, 8.719 degrees north latitude, 67.347 degrees east longitude.

Mars Reconnaissance Orbiter. Image Credit: NASA/JPL-Caltech

HiRISE is one of six instruments on the Mars Reconnaissance Orbiter. The University of Arizona, Tucson, operates HiRISE, which was built by Ball Aerospace & Technologies Corp., Boulder, Colorado. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter Project for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, built the orbiter and collaborates with JPL to operate it.

For more information about Mars Reconnaissance Orbiter (MRO), visit: http://www.nasa.gov/mission_pages/MRO/main/index.html

Images, Text, Credits: NASA/JPL-Caltech/University of Arizona/Caption: Mike Mellon/Sarah Loff.

Greetings, Orbiter.ch

Mysterious Ripples Found Racing Through Planet-forming Disc












ESA - Hubble Space Telescope logo.


7 October 2015

Unique structures spotted around nearby star

Hubble and VLT images of the disc around AU Microscopii

Using images from the NASA/ESA Hubble Space Telescope and ESO’s Very Large Telescope, astronomers have discovered never-before-seen structures within a dusty disc surrounding a nearby star. The fast-moving wave-like features in the disc of the star AU Microscopii are unlike anything ever observed, or even predicted, before now. The origin and nature of these features present a new mystery for astronomers to explore. The results are published in the journal Nature on 8 October 2015.

AU Microscopii, or AU Mic for short, is a young, nearby star surrounded by a large disc of dust [1]. Studies of such debris discs can provide valuable clues about how planets, which form from these discs, are created.

Ground-based view of the sky around the nearby star AU Microscopii

Astronomers have been searching AU Mic’s disc for any signs of clumpy or warped features, as such signs might give away the location of possible planets. And in 2014 they used the  powerful high-contrast imaging capabilities of ESO’s newly installed SPHERE instrument, mounted on the Very Large Telescope for their search — and discovered something very unusual.

“Our observations have shown something unexpected,” explains Anthony Boccaletti of the Observatoire de Paris, France, lead author on the paper. “The images from SPHERE show a set of unexplained features in the disc which have an arch-like, or wave-like, structure, unlike anything that has ever been observed before.”

video
Zoom on AU Mic

Five wave-like arches at different distances from the star show up in the new images, reminiscent of ripples in water. After spotting the features in the SPHERE data the team turned to earlier images of the disc taken by the NASA/ESA Hubble Space Telescope in 2010 and 2011 to see whether the features were also visible in these [2]. They were not only able to identify the features on the earlier Hubble images — but they also discovered that they had changed over time. It turns out that these ripples are moving — and very fast!

“We reprocessed images from the Hubble data and ended up with enough information to track the movement of these strange features over a four-year period,” explains team member Christian Thalmann (ETH Zürich, Switzerland). “By doing this, we found that the arches are racing away from the star at speeds of up to about 40 000 kilometres/hour!”

The features further away from the star seem to be moving faster than those closer to it. At least three of the features are moving so fast that they could well be escaping from the gravitational attraction of the star. Such high speeds rule out the possibility that these are conventional disc features caused by objects — like planets — disturbing material in the disc while orbiting the star. There must have been something else involved to speed up the ripples and make them move so quickly, meaning that they are a sign of something truly unusual [3].

video
Mysterious ripples moving through the disc of AU Microscopii

“Everything about this find was pretty surprising!” comments co-author Carol Grady of Eureka Scientific, USA. “And because nothing like this has been observed or predicted in theory we can only hypothesise when it comes to what we are seeing and how it came about.”

The team cannot say for sure what caused these mysterious ripples around the star. But they have considered and ruled out a series of phenomena as explanations, including the collision of two massive and rare asteroid-like objects releasing large quantities of dust, and spiral waves triggered by instabilities in the system’s gravity.

But other ideas that they have considered look more promising.

“One explanation for the strange structure links them to the star’s flares. AU Mic is a star with high flaring activity — it often lets off huge and sudden bursts of energy from on or near its surface,” explains co-author Glenn Schneider of Steward Observatory, USA. “One of these flares could perhaps have triggered something on one of the planets — if there are planets — like a violent stripping of material which could now be propagating through the disc, propelled by the flare’s force.”

“It is very satisfying that SPHERE has proved to be very capable at studying discs like this in its first year of operation,” adds Jean-Luc Beuzit, who is both a co-author of the new study and also led the development of SPHERE itself.

The team plans to continue to observe the AU Mic system with SPHERE and other facilities, including ALMA, to try to understand what is happening. But, for now, these curious features remain an unsolved mystery.

Notes:

[1] AU Microscopii lies just 32 light-years away from Earth. The disc essentially comprises asteroids that have collided with such vigour that they have been ground to dust.

[2] The data were gathered by Hubble’s Space Telescope Imaging Spectrograph (STIS).

[3] The edge-on view of the disc complicates the interpretation of its three-dimensional structure.

Hubblecast 88: Mysterious Ripples Found Racing Through Planet-forming Disc:
http://www.spacetelescope.org/videos/heic1521a/

Notes for editors:

The Hubble Space Telescope is a project of international cooperation between ESA and NASA.

More information:

This research was presented in a paper entitled “Fast-Moving Structures in the Debris Disk Around AU Microscopii”, to appear in the journal Nature on 8 October 2015.

The international team of astronomers in this study consists of Anthony Boccaletti (Observatoire de Paris, CNRS, France), Christian Thalmann (ETH Zürich, Switzerland), Anne-Marie Lagrange (Université Grenoble Alpes, France; CNRS, IPAG, France), Markus Jansons (Stockholm University, Sweden; Max-Planck-Institut für Astronomie, Germany), Jean-Charles Augereau (Université Grenoble Alpes, France; CNRS, IPAG, France), Glenn Schneider (University of Arizona Tucson, USA), Julien Milli (ESO, Chile; CNRS, IPAG, France), Carol Grady (Eureka Scientific, USA), John Debes (STScI, USA), Maud Langlois (CNRS/ENS-L, France), David Mouillet (Université Grenoble Alpes, France; CNRS, IPAG, France), Thomas Henning (Max-Planck-Institut für Astronomie, Germany), Carsten Dominik (University of Amsterdam, Netherlands), Anne-Lise Maire (INAF–Osservatorio Astronomico di Padova, Italy), Jean-Luc Beuzit (Université Grenoble Alpes, France; CNRS, IPAG, France), Joe Carson (College of Charleston, USA), Kjetil Dohlen (CNRS, LAM, France), Markus Feldt (Max-Planck-Institut für Astronomie, Germany), Thierry Fusco (ONERA, France; CNRS, LAM, France), Christian Ginski (Sterrewacht Leiden, Netherlands), Julien H. Girard (ESO, Chile; CNRS, IPAG, France), Dean Hines (STScI, USA), Markus Kasper (ESO, Germany; CNRS, IPAG, France), Dimitri Mawet (ESO, Chile), Francois Ménard (Universidad de Chile, Chile), Michael Meyer (ETH Zürich, Switzerland), Claire Moutou (CNRS, LAM, France), Johan Olofsson (Max-Planck-Institut für Astronomie, Germany), Timothy Rodigas (Carnegie Institution of Washington, USA), Jean-Francois Sauvage (ONERA, France; CNRS, LAM, France), Joshua Schlieder (NASA Ames Research Center, USA; Max-Planck-Institut für Astronomie, Germany), Hans Martin Schmid (ETH Zürich, Switzerland), Massimo Turatto (INAF–Osservatorio Astronomico di Padova, Italy), Stephane Udry (Observatoire de Genève, Switzerland), Farrokh Vakili (Université de Nice-Sophia Antipolis, France), Arthur Vigan (CNRS, LAM, France; ESO, Chile), Zahed Wahhaj (ESO, Chile; CNRS, LAM, France) and John Wisniewski (University of Oklahoma, USA).

Links:

Release on NASA Hubblesite: http://www.spacetelescope.org/news/heic1521/hubblesite.org/newscenter/archive/releases/2015/36/

Relaese on ESO website: http://www.eso.org/public/news/eso1538/

Related links:

SPHERE instrument: http://www.eso.org/public/teles-instr/vlt/vlt-instr/sphere/

Very Large Telescope (VLT): http://www.eso.org/public/teles-instr/vlt/

Image credit: ESO, NASA & ESA/Digitized Sky Survey 2/Videos: ESO, ESA & NASA/Digitized Sky Survey 2/N. Risinger (skysurvey.org)/Music: Johan Monell.

Best regards, Orbiter.ch

Exoplanet Anniversary: From Zero to Thousands in 20 Years












NASA - Kepler Space Telescope Mission patch.

October 7, 2015


Image above: This year we celebrate the discovery of 51 Pegasi b in October, 1995. This giant planet is about half the size of Jupiter and orbits its star in about four days. '51 Peg' helped launch a whole new field of exploration. Image credits: NASA/JPL-Caltech.

October 6 marks the 20th anniversary of the first discovery of a planet orbiting a sun-like, or "normal," star beyond our solar system. The planet, called 51 Pegasi b, belongs to a class of planets now known as exoplanets. Since that momentous discovery, thousands more exoplanets have been found in our galaxy.

Kepler Space Telescope. Image Credit: NASA

For details about planned public events to mark the occasion, and other related stories and graphics, visit: http://planetquest.jpl.nasa.gov/page/20-years

As of today, there are more than 1,800 confirmed exoplanets. More than 1,000 of these were discovered by NASA's Kepler mission, breaking wide open the field of exoplanet science. Kepler has even identified some planets with Earth-like traits, such as Kepler-452b, a near-Earth-size planet found in the habitable zone of a sun-like star. The habitable zone is the region around a star where temperatures are just right for one of life's essential ingredients -- water -- to pool on a planet's surface.

NASA's funny Exoplanet Travel Posters: http://planetquest.jpl.nasa.gov/exoplanettravelbureau

PSO J318.5-22 - Where the Nightlife Never Ends

 
Poster above: Discovered in October 2013 using direct imaging, PSO J318.5-22 belongs to a special class of planets called rogue, or free-floating, planets. Wandering alone in the galaxy, they do not orbit a parent star. Not much is known about how these planets come to exist, but scientists theorize that they may be either failed stars or planets ejected from very young systems after an encounter with another planet. These rogue planets glow faintly from the heat of their formation. Once they cool down, they will be dancing in the dark. Poster Credits: NASA/JPL.

Experience the Gravity of a Super Earth

 
Poster above: Twice as big in volume as the Earth, HD 40307g straddles the line between "Super-Earth" and "mini-Neptune" and scientists aren't sure if it has a rocky surface or one that's buried beneath thick layers of gas and ice. One thing is certain though: at eight time the Earth's mass, its gravitational pull is much, much stronger. Poster Credits: NASA/JPL.

Relax on Kepler-16b - Where your shadow always has company 


Poster above: Like Luke Skywalker's planet "Tatooine" in Star Wars, Kepler-16b orbits a pair of stars. Depicted here as a terrestrial planet, Kepler-16b might also be a gas giant like Saturn. Prospects for life on this unusual world aren't good, as it has a temperature similar to that of dry ice. But the discovery indicates that the movie's iconic double-sunset is anything but science fiction. Poster Credits: NASA/JPL.

Kepler-186 f - Where the Grass is Always Redder

 
Poster above: Kepler-186f is the first Earth-size planet discovered in the potentially 'habitable zone' around another star, where liquid water could exist on the planet's surface. Its star is much cooler and redder than our Sun. If plant life does exist on a planet like Kepler-186f, its photosynthesis could have been influenced by the star's red-wavelength photons, making for a color palette that's very different than the greens on Earth. This discovery was made by Kepler, NASA's planet hunting telescope. Poster Credits: NASA/JPL.

NASA's Ames Research Center, Moffett Field, California, manages the Kepler and K2 missions for NASA's Science Mission Directorate. NASA's Jet Propulsion Laboratory in Pasadena, California, managed Kepler mission development. Ball Aerospace & Technologies Corporation operates the flight system with support from the Laboratory for Atmospheric and Space Physics at the University of Colorado Boulder.

For more information about the Kepler mission, visit: http://www.nasa.gov/kepler

A related feature story about other potentially habitable planets is online at: http://www.jpl.nasa.gov/news/news.php?feature=4666

Images (mentioned), Posters (mentioned), Text, Credits: NASA/JPL/Whitney Clavin.

Best regards, Orbiter.ch

mardi 6 octobre 2015

ISS - Weekly Recap From the Expedition Lead Scientist












ISS - Expedition 45 Mission patch.

Oct. 6, 2015

Even though he won't return to Earth until the spring, NASA astronaut Scott Kelly prepared for the winter season in orbit by getting a flu shot this week on the International Space Station.

Kelly self-administered an influenza vaccine as part of NASA’s Twins Study, a compilation of multiple investigations that take advantage of a unique opportunity to study identical twin astronauts Scott and Mark Kelly, while Scott spends a year in space on the orbiting laboratory and Mark remains on Earth. Mark was injected with the same vaccine. Blood was drawn before and after the injections to compare how their systems respond to the inoculation.


Image above: NASA astronaut Scott Kelly gives himself a flu shot for an ongoing study on the human immune system. The vaccination is part of NASA's Twins Study, a compilation of multiple investigations that take advantage of a unique opportunity to study identical twin astronauts Scott and Mark Kelly, while Scott spends a year aboard the International Space Station and Mark remains on Earth. Image Credit: NASA.

Understanding exactly which parts of the immune system are altered during spaceflight will help scientists know how to ensure that crew members maintain a healthy immune system during long flights, and stay protected against infections from Earth when visitors arrive at the space station. The data also could be used to help develop new treatments and preventative measures for immune dysfunction and related health issues on Earth. A better understanding of how the immune system is activated or suppressed may help in treating a range of auto-immune diseases such as arthritis and diabetes, and in treating the natural decline of the immune system as people age.

Kelly concluded the latest run of the RaDI-N2 Neutron Field Study (RaDI-N2) investigation by recovering eight detectors in predetermined locations throughout the space station and turning them over to the Russian crew to stow for a return flight later in the year. The Canadian Space Agency's bubble spectrometers measure neutron radiation levels while ignoring all other radiation. This investigation will better characterize the station neutron environment, define the risk posed to crew members’ health and provide the data necessary to develop advanced protective measures for future spaceflight. Because neutrons carry no electrical charge, they have greater potential to penetrate the body and damage tissue. RaDI-N2 will help doctors better understand the connections between neutron radiation, DNA damage and mutation rates and can be applied to other radiation health issues on Earth.

International Space Station (ISS). Image Credit: NASA

NASA astronaut Kjell Lindgren adjusted the video feed and prepared the power supply for the ESA (European Space Agency) Magnetic Flux Experiment (MAGVECTOR) investigation. A ground team officially powered on the unit for its fifth science run. The MAGVECTOR investigation studies the interaction between a moving magnetic field and an electrical conductor.

Earth's magnetic field is constantly flowing around us. Aside from protecting us from solar winds, it also makes a compass work and birds find their destination when migrating. This same force can interact and interfere with equipment and experiments on the space station. Using extremely sensitive magnetic sensors placed around and above an electrical conductor, MAGVECTOR will help scientists gain insight into how the field influences conductors. The results will help protect future station experiments and electric equipment, and could offer insights into how magnetic fields influence electrical conductors -- the backbone of current technology.


Image above: JAXA astronaut Kimiya Yui (left) and NASA astronaut Kjell Lindgren work on removing items from a storage rack located inside the International Space Station's Destiny laboratory. The pair are making room for new communications hardware that will be used for future visiting vehicles arriving at the space station, including the new U.S. commercial crew vehicles currently in development. Image Credit: NASA.

Lindgren and JAXA (Japan Aerospace Exploration Agency) astronaut Kimiya Yui completed their flight day 60 Ocular Health exams. Altered vision is one of the numerous risks posed to crews living in space. Crew members' bodies change in a variety of ways during spaceflight, and some experience impaired vision. The Ocular Health investigation gathers data on crew members' visual health during and after long-duration space station missions. Ultrasound scans and tests monitor microgravity-induced visual impairment, as well as changes believed to arise from elevated intracranial pressure, to characterize how living in microgravity can affect the visual, vascular and central nervous systems. The investigation also measures how long it takes for crew members to return to normal after they return to Earth.

video
How the Human Body’s Immune System Responds in Microgravity

Video above: Many factors alter the human body’s immune system during spaceflight. This video explains what those factors are and how scientists are working to understand exactly what parts of the immune system are altered. Video Credit: NASA.

Ocular Health provides insight into structural changes that can occur in the eyes and nervous system, which could be relevant for patients on Earth suffering from a wide range of ocular diseases, such as glaucoma. It also provides data that could be used to help patients suffering from brain diseases, such as hydrocephalus and high blood pressure in the brain.

Other human research investigations continued this week, including Biochemical Profile, Cardio Ox, Cognition, Interactions, Journals, Microbiome, Space Headaches, and Sprint (links bellow).

Related links:

NASA’s Twins Study: https://www.nasa.gov/twins-study

RaDI-N2 Neutron Field Study (RaDI-N2): http://www.nasa.gov/mission_pages/station/research/experiments/898.html

Magnetic Flux Experiment (MAGVECTOR): http://www.nasa.gov/mission_pages/station/research/experiments/1176.html

Ocular Health exams: http://www.nasa.gov/mission_pages/station/research/experiments/204.html

Biochemical Profile: http://www.nasa.gov/mission_pages/station/research/experiments/1008.html

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

Cognition: http://www.nasa.gov/mission_pages/station/research/experiments/1256.html

Interactions: http://www.nasa.gov/mission_pages/station/research/experiments/175.html

Microbiome: http://www.nasa.gov/mission_pages/station/research/experiments/1010.html

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

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

International Space Station (ISS), the space laboratory: http://www.nasa.gov/mission_pages/station/research/index.html

Canadian Space Agency (ASC-CSA): http://www.asc-csa.gc.ca/eng/

European Space Agency (ESA): http://www.esa.int/ESA

Japan Aerospace Exploration Agency (JAXA): http://global.jaxa.jp/

For more information about the current crew and the International Space Station, visit: http://www.nasa.gov/station.

Images (mentioned), Video (mentioned), Text, Credits: NASA/John Love, Lead Increment Scientist/Expeditions 45 & 46/Kristine Rainey.

Greetings, Orbiter.ch

lundi 5 octobre 2015

Pluto’s Small Moons Nix and Hydra












NASA - New Horizons Mission logo.

October 5, 2015

Today’s post is written by Simon Porter, a New Horizons postdoctoral researcher at the Southwest Research Institute in Boulder, Colorado. Simon’s work focuses on the small satellites of Pluto.

Artist's impression of New Horizons arrival at Pluto. Image Credit: NASA

This week’s beautiful Charon images remind us that Pluto is not just one body (link bellow the article); it’s a whole system of worlds.

Pluto and its largest moon Charon dance around each other, making circles around their common center of mass, which lies in an empty space between them. Around the dancing couple are four small moons. In order of increasing distance, their names are Styx (just beyond Charon), then Nix, Kerberos and Hydra. These tiny moons also orbit around the system’s center of mass. The orbits line up like a miniature solar system, except with a binary system at the center, similar to the planetary system around the star Kepler 47. All four of the small moons are less than about 30 miles (50 kilometers) in their longest dimension. Each has a lumpy shape because, unlike Pluto and Charon, they aren’t big enough for gravity to squish them into a ball.

Nix and Hydra were discovered in 2005, shortly before New Horizons launched in 2006, and their initials were a subtle nod to the New Horizons mission that started the search for them, just as the P and L in Pluto are a subtle nod to astronomer Percival Lowell, who began the search for Pluto.


Image above: The orbits of Pluto and its moons Charon, Styx, Nix, Kerberos and Hydra are illustrated around their common center of mass. Image Credit: SwRI/S. Porter.

Styx and Kerberos weren’t discovered until 2011 and 2012, well after the New Horizons spacecraft was on its way to Pluto. Although the mission’s observing plans were pretty well set by then, the New Horizons science team anticipated that new discoveries from other facilities might be made during the long cruise to Pluto and had left room for a handful of “TBD” observations, which became the only ones specifically devoted to Kerberos and Styx. That’s why New Horizons took many more pictures of Nix and Hydra than of Styx and Kerberos.

Nix is the second-largest of Pluto’s small moons and was the closest to New Horizons during the flyby, so we got better imaging of it than any of the other small moons. So far, we’ve been able to download close-up pictures of Nix taken at three different times by the Long Range Reconnaissance Imager (LORRI) high-resolution camera, but the best image is still on the spacecraft’s digital recorders waiting to come to Earth.

From looking at Nix as point of light with the Hubble Space Telescope and with New Horizons on approach, we knew that Nix’s brightness regularly changed over time, and therefore it was probably elongated. However, the first image (on the left) really surprised us, because Nix appeared to be round—not at all elongated.

Mark Showalter – who discovered Styx and Kerberos — pointed out that we were probably just looking down the long axis, and that the next images would look more “potato-ish.” Sure enough, the next image showed Nix looking far more elongated, but with one great surprise in it: a big crater! Nix isn’t very large, and there is a very fine line between an impact that will make a crater that big and one that will break Nix apart. So either Nix was very lucky in surviving that collision, or it’s a fragment of an older moon that was somehow destroyed.


Images above: Pluto’s moon Nix is viewed at three different times during the New Horizons July 2015 flyby. Images Credits: NASA/JHUAPL/SwRI.

The last Nix image we have so far was taken right after the spacecraft passed Pluto and started to look back on its crescent. Because Nix has no atmosphere, it isn’t as spectacular as the images looking back at Pluto, but measuring the brightness of that little crescent of light can help tell us about what the surface of Nix is made of, and whether its surface is smooth or covered in boulders.

What we do know about the big crater on Nix is that it appears to be a different color than the rest of the moon. The color image below was taken by New Horizons’ Ralph-Multispectral Visible Imaging Camera (MVIC) three minutes before the LORRI picture; MVIC has one-fourth of LORRI’s resolution, but it can see in four colors: blue, red, near-infrared, and methane. In this image, the RGB colors are mapped to near-IR, red and blue, just like the enhanced-color images of Pluto and Charon. While most of Nix is a neutral white, the crater and its ejecta blanket (the material thrown out by the crater) appear to be a much redder material. Craters excavate material from below and throw it on the surface. This tells us that under its white surface, Nix is probably made of much darker material. We don’t actually know what either the dark or the light material is, nor will we be able to tell until we download the Nix data from the Ralph-Linear Etalon Imaging Spectral Array (LEISA) composition mapping spectrometer.


Images above: Pluto’s moon Nix is shown in high-resolution black-and-white and lower resolution color. Images Credits: NASA/JHUAPL/SwRI.

New Horizons also imaged Hydra and has sent some of these images to Earth. Below is the best LORRI image of Hydra taken by New Horizons. Unfortunately, Hydra was on the opposite side of Pluto from New Horizons at closest approach, so the images of Hydra are from farther away and therefore are at lower resolution than the Nix images we have. Because Hydra’s orbit was still somewhat uncertain, the mission planners designed this observation to be a mosaic of six slightly-overlapping shots. As it turns out, we hit the jackpot and Hydra fell right at the intersection of four of those six shots, meaning we got two full and two half-views of Hydra for the price of one!

The composite of these images shows that Hydra has a much more complicated shape than Nix and looks a bit like a much bigger version of comet 67P/Churyumov-Gerasimenko, which is currently being orbited by the Rosetta spacecraft. As some have proposed for 67P, it is possible that Hydra is the result of a low-speed collision of two older moons. We haven’t yet had a chance to download the LORRI images of Styx and Kerberos, but they are coming soon, and will be of similar resolution to this image of Hydra.


Image above: Pluto’s moon Hydra as seen from NASA’s New Horizons spacecraft, July 14, 2015. Image Credits: NASA/JHUAPL/SwRI.

Finally, I want to tell you how I processed these images of Nix and Hydra. I created them in Python with AstroPy to read the images and translate from pixels to on-sky coordinates, and Scikit-Image to process and sharpen the images. LORRI’s pixels are smaller than the resolution limit of the imager, which makes the images appear a little bit blurry. But since the optics of LORRI are very stable, we can use a process called “deconvolution” to back out what the image would have been if the camera were perfectly sampled. This makes the images sharper, but also adds “noise.” We can minimize the noise by taking several deconvolved images and finding the median value at each pixel location; this keeps the real detail while throwing out much of the deconvolution noise. Both Astropy and Scikit-Image are free and open sources, and make astronomical image processing fun (and a bit addicting) for anyone with a basic knowledge of Python.


Image above: Simon Porter. Image Credits: Isaac Smith/SwRI.

New Horizons is part of NASA’s New Frontiers Program, managed by the agency’s Marshall Space Flight Center in Huntsville, Alabama.  APL designed, built, and operates the New Horizons spacecraft and manages the mission for NASA’s Science Mission Directorate. SwRI leads the science mission, payload operations, and encounter science planning.

Related article:

Pluto’s Big Moon Charon Reveals a Colorful and Violent History:
http://orbiterchspacenews.blogspot.ch/2015/10/plutos-big-moon-charon-reveals-colorful.html

Related links:

Kepler 47: http://www.nasa.gov/mission_pages/kepler/news/kepler-47.html

AstroPy: http://www.astropy.org/

Scikit-Image: http://scikit-image.org/

For more information and images, visit http://www.nasa.gov/newhorizons and http://pluto.jhuapl.edu.

Images (mentioned), Text, Credits: NASA/Simon Porter.

Greetings, Orbiter.ch