samedi 11 juin 2016

The future of the Patrouille Suisse in question after a crash in the Netherlands Airshow












Swiss Air Force - Patrouille Suisse patch.

June 11, 2016

This crash in the Netherlands is the first for the Patrouille Suisse in 52 years of existence


Image above: The F-5E Tiger fighter used by the Patrouille Suisse seen from different angles in this image taken during an aerial acrobatics.

The Patrouille Suisse experienced this Thursday, June 9 2016 a first in the Netherlands, where two of its planes were affected, causing the crash of one of them. It was indeed the first accident of its kind in 52 years of existence.

The pilot, very experienced with 1250 hours of flight, was able to eject and only suffers from scratches after landing in a greenhouse with tomatoes. The second fighter, although damaged, was able to rejoins the base and land safely.


Image above: The second F5 was able to land despite the right wing ripped off upon impact, image taken by a spectator of the air show (mentioned in the credits below).

But this accident calls into question the existence of the Patrouille Suisse to politicians, or in any case, air shows. As some politicians claim that such events made unnecessary risk to pilots and spectators.

Swiss F-5 fighter jet crashed near Leeuwarden Air Base in the Netherlands

Other politicians (generally opposite to those mentioned above) admit that these shows involve risk, but they at least allow pilots to show their expertise and equipment.

Aldo Schellenberg, head of the Swiss Air Force, however, recalled at a press conference that the airline presentations have never held above the audience. And it has not remove from service the F5 Tiger, a 40 year old machine.

 Patrouille Suisse in the skies over Toggenburg

There is indeed no sign of mechanical failure, is he justified. And the Patrol will continue to fly in the future on this unit. The shelved aircraft is expected in 2018 at the earliest.

Get well soon to the pilot and long life to the Patrouille Suisse! In hope that our politicians and the Swiss people will soon give you the opportunity to fly in a new aircraft and again thank you for making us dream with your fabulous shows.

One of your biggest fan, Roland Berga, Orbiter.ch Aerospace fonder and owner.

Related articles:

Cracks in the Swiss Air Force F-5E Tiger
http://orbiterchspacenews.blogspot.ch/2015/01/cracks-in-swiss-air-force-f-5e-tiger.html

It is not! The Gripen aircraft will not fly in Switzerland
http://orbiterchspacenews.blogspot.ch/2014/05/it-is-not-gripen-aircraft-will-not-fly.html

New fighter aircraft for the Swiss Air Force, the people will decide on May 18
http://orbiterchspacenews.blogspot.ch/2014/04/new-fighter-aircraft-for-swiss-air.html

The Patrouille Suisse will continue to exist
http://orbiterchspacenews.blogspot.ch/2013/02/the-patrouille-suisse-will-continue-to.html

Patrouille Suisse: a boss flies to the rescue
http://orbiterchspacenews.blogspot.ch/2013/02/patrouille-suisse-boss-flies-to-rescue.html

Swiss Air Force - The Gripen ongoing saga ...
http://orbiterchspacenews.blogspot.ch/2013/02/swiss-air-force-gripen-saga-continues.html

Choice of a new fighter aircraft of the Swiss Air Force: Description and comparison
http://orbiterchspacenews.blogspot.ch/2013/01/choice-of-new-fighter-aircraft-of-swiss.html

Images, Text, Credits: Swiss Air Force/Airlive/Rob Venmans/Twitter/Orbiter.ch Aerospace/Roland Berga.

Best regards, Orbiter.ch

Launch of Worlds Largest Rocket Delta IV Heavy with NROL-37












NRO / ULA - NROL-37 Mission patch.

June 11, 2016

Delta IV rocket launch (illustration image)

A United Launch Alliance (ULA) Delta IV rocket carrying the NROL-37 mission lifted off from Space Launch Complex-37 at 1:51 p.m. EDT.

video
Delta 4 Heavy carrying NROL-37 liftoff, video capture by Carl Atkinson

Rocket/Payload:  A United Launch Alliance Delta IV Heavy will launch the NROL-37 mission for the National Reconnaissance Office (NRO). NROL-37 will be the 32nd Delta IV mission since the vehicle’s inaugural launch in 2002, and the 10th NRO mission to launch on Delta IV.

ULA - NROL-37 Mission poster

Mission Description:

The mission will be launched for the National Reconnaissance Office in support of national defense (USA).

For more information about United Launch Alliance (ULA), visit: http://www.ulalaunch.com/

Images, Video, Text, Credits: ULA/Carl Atkinson/YouTube.

Greetings, Orbiter.ch

Si2 landed in New York City after a flight over the Statue of Liberty











SolarImpulse - Around The World patch.


June 11, 2016


This flight has stood out from the rest - it was short (a relief for the engineers at the Mission Control Center who didn’t lose much sleep) but, more importantly, it included a flight over the Statue of Liberty.

Solar Impulse 2 have now finished the crossing of the United States of America, finally landing at bustling JFK, in New York City. This flight marks the completion of a huge milestone in our journey around the world with Solar Impulse 2. Ending it with the flight over the Statue of Liberty is symbolic for Solar Impulse as the statue serves to welcome travellers to the country. Although Si2 will soon be leaving with Bertrand Piccard to cross the Atlantic Ocean, we wanted to pay tribute to all those who welcomed us in the land of pioneers this past month and a half.

video
Solar Impulse Airplane - Leg 14 - Flight Lehigh Valley to New York

After a flight that lasted just over 5 hours from Lehigh Valley, Pennsylvania to New York City, André Borschberg touched down at JFK at 7:59AM UTC, 9:59AM CET, 3:59AM on June 11th.

“The Statue of Liberty is a symbol of American values: the liberty to be a pioneer, the freedom to explore and invent. It welcomes travellers who arrive in this country, and flying over it was a tribute we paid for the special welcome we received at each destination.” Say André Borschberg.


Unfortunately, we won’t be able to host a public visit of the plane as JFK is a very busy airport. But hopefully you’ll be able to catch a glimpse of Si2 when it takes off for the crossing of the Atlantic.

When will that be? No idea yet. The Monaco Mission Control Center has already started looking for a clear weather window to cross the pond. We’ll be landing somewhere between Ireland and Morocco, destinations include Ireland, France, Portugal, Spain, and Morocco.


Image above: The #StatueofLiberty welcomes travellers, flying over it now we pay tribute to the special welcome we received here. André Borschberg on Twitter.

Yes, it’s a vast distance, but we’ll keep you posted as soon as we know which country will be our next destination. To be the first to know, here’s where you have to be: http://www.solarimpulse.com/subscribe

For more information about SolarImpulse Around The World, visit: http://www.solarimpulse.com/

Images, Video, Text, Credit: SolarImpulse.

Best regards, Orbiter.ch

vendredi 10 juin 2016

The Jagged Shores of Pluto’s Highlands












NASA - New Horizons Mission logo.

June 10, 2016

 Image Credits: NASA/JHUAPL/SwRI.

This enhanced color view from NASA’s New Horizons spacecraft zooms in on the southeastern portion of Pluto’s great ice plains, where at lower right the plains border rugged, dark highlands informally named Krun Macula. (Krun is the lord of the underworld in the Mandaean religion, and a ‘macula’ is a dark feature on a planetary surface.)

Pluto is believed to get its dark red color from tholins, complex molecules found across much of the surface. Krun Macula rises 1.5 miles (2.5 kilometers) above the surrounding plain – informally named Sputnik Planum – and is scarred by clusters of connected, roughly circular pits that typically reach between 5 and 8 miles (8 and 13 kilometers) across, and up to 1.5 miles (2.5 kilometers) deep.

At the boundary with Sputnik Planum, these pits form deep valleys reaching more than 25 miles (40 kilometers) long, 12.5 miles (20 kilometers) wide and almost 2 miles (3 kilometers) deep – almost twice as deep as the Grand Canyon in Arizona – and have floors covered with nitrogen ice.  New Horizons scientists think these pits may have formed through surface collapse, although what may have prompted such a collapse is a mystery.


Image above: This dramatic image from NASA’s New Horizons spacecraft shows the dark, rugged highlands known as Krun Macula (lower right), which border a section of Pluto’s icy plains. Click on the image and zoom in for maximum detail. Image Credits: NASA/JHUAPL/SwRI.

This scene was created using three separate observations made by New Horizons in July 2015. The right half of the image is composed of 260 feet- (80 meter-) per-pixel data from the Long Range Reconnaissance Imager (LORRI), obtained at 9,850 miles (15,850 kilometers) from Pluto, about 23 minutes before New Horizons’ closest approach.  The left half is composed of 410 feet- (125 meter-) per-pixel LORRI data, obtained about six minutes earlier, with New Horizons 15,470 miles (24,900 kilometers) from Pluto.

These data respectively represent portions of the highest- and second-highest-resolution observations obtained by New Horizons in the Pluto system. The entire scene was then colorized using 2,230 feet- (680 meter-) per-pixel data from New Horizons’ Ralph/Multispectral Visual Imaging Camera (MVIC), obtained at 21,100 miles (33,900 kilometers) from Pluto, about 45 minutes before closest approach.

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

Images, Text, Credits: NASA/JHUAPL/SwRI/Bill Keeter.

Greetings, Orbiter.ch

Hubble Uncovers a Mysterious Hermit











NASA - Hubble Space Telescope patch.

June 10, 2016


The drizzle of stars scattered across this image forms a galaxy known as UGC 4879. UGC 4879 is an irregular dwarf galaxy — as the name suggests, galaxies of this type are a little smaller and messier than their cosmic cousins, lacking the majestic swirl of a spiral or the coherence of an elliptical.

This galaxy is also very isolated. There are about 2.3 million light years between UGC 4879 and its closest neighbor, Leo A, which is about the same distance as that between the Andromeda Galaxy and the Milky Way.

This galaxy’s isolation means that it has not interacted with any surrounding galaxies, making it an ideal laboratory for studying star formation uncomplicated by interactions with other galaxies. Studies of UGC 4879 have revealed a significant amount of star formation in the first 4 billion years after the Big Bang, followed by a strange 9-billion-year lull in star formation that ended 1 billion years ago by a more recent re-ignition. The reason for this behavior, however, remains mysterious, and the solitary galaxy continues to provide ample study material for astronomers looking to understand the complex mysteries of star birth throughout the universe.

For more information about the Hubble Space Telescope, visit:

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

Image, Text, Credits: NASA/ESA/Text Credits: European Space Agency/NASA/Ashley Morrow.

Greetings, Orbiter.ch

ILS Proton Successfully Launches the INTELSAT 31 Satellite













ILS - International Launch Services logo.

June 10, 2016

Proton Launches the INTELSAT 31 Satellite

Intelsat S.A., operator of the world’s first Globalized Network, powered by its leading satellite backbone, and International Launch Services (ILS) announced today that an ILS Proton Breeze M successfully launched the Intelsat 31 satellite from the Baikonur Cosmodrome in Kazakhstan.

The Proton Breeze M launch vehicle, utilizing a 5-burn Breeze M Supersynchronous Transfer Orbit (SSTO) mission design, lifted off from Pad 24 at 13:10 local time (3:10 ET, 07:10 GMT) from the Baikonur Cosmodrome in Kazakhstan, with the Intelsat 31 satellite on board. The first three stages of the Proton used a standard ascent profile to place the orbital unit (Breeze M upper stage and the Intelsat 31 satellite) into a sub-orbital trajectory. From this point in the mission, the Breeze M performed planned mission maneuvers to insert the orbital unit first to a circular parking orbit, then to intermediate and transfer orbits, and finally to a Supersynchronous Transfer Orbit where the Intelsat 31 was separated after a 15-hour, 31-minute mission. SSTO missions provide increased heavy-lift performance over GTO mission designs, allowing ILS’ customers the capability to maximize spacecraft operational lifetime.

video
Launch of Russian Proton-M Rocket carrying Intelsat 31

Built for Intelsat by Space Systems Loral (SSL), Intelsat 31 is a 20-kilowatt class Ku-and C-band satellite. The Ku-band payload, known as DLA-2, is designed to provide redundancy for DIRECTV Latin America’s distribution services in South America and the Caribbean in a reflection of the company’s commitment to providing their subscribers with the highest reliability in the region. The C-band portion enhances Intelsat’s existing C-band service infrastructure serving Latin America.

“A launch is always a culmination of years of hard work and dedication that begin with the design and manufacture of the satellite up to its delivery to orbit. We appreciate all of the teams who worked with us to make this program another success, including ILS and Khrunichev for ensuring a successful launch,” said Executive Vice President and Chief Technology Officer, Thierry Guillemin.

Intelsat 31 satellite

ILS President Kirk Pysher said, “Our partnership with Intelsat spans 18 years with 12 of their satellites launched to date by Proton with the launch of Intelsat 31. We look forward to extending our partnership further with more launches over the coming years under our Multi Launch Agreement with Intelsat. Each and every team member should be commended for their contributions to the success of the Intelsat 31 mission.”

The Proton Breeze M vehicle is built by Khrunichev State Research and Space Production Center (Khrunichev) of Moscow, one of the pillars of the aerospace industry and majority owner of ILS. Proton has a heritage of 412 missions since its maiden flight in 1965. This was the third Proton launch this year and the 12th for Intelsat on ILS Proton.

About ILS and Khrunichev:

ILS provides launch services for global satellite operators and offers a complete array of services and support, from contract signing through mission management and on-orbit delivery. ILS has exclusive rights to market the Proton and Angara vehicles to commercial satellite operators worldwide and is a U.S. company headquartered in Reston, VA., near Washington, D.C. To date, ILS has launched 93 commercial missions. For more information, visit http://www.ilslaunch.com.

Khrunichev, which holds the majority interest in ILS, is one of the cornerstones of the Russian space industry. Khrunichev manufactures the Proton system and the Angara family of vehicles. The Proton vehicle launches from facilities at the Baikonur Cosmodrome in Kazakhstan, and has a heritage of more than 410 missions since 1965. Khrunichev includes, among its branches, a number of key manufacturers of launch vehicle and spacecraft components in Moscow and in other cities of the Russian Federation. For more information, visit http://www.khrunichev.com.

About Intelsat:

Intelsat S.A. (NYSE: I) operates the world’s first Globalized Network, delivering high-quality, cost-effective video and broadband services anywhere in the world. Intelsat’s Globalized Network combines the world’s largest satellite backbone with terrestrial infrastructure and managed services to enable customers to drive revenue and reach through a new generation of network services. Thousands of organizations serving billions of people worldwide rely on the Intelsat Globalized Network to provide ubiquitous broadband connectivity, multi-format video broadcasting, secure satellite communications and seamless mobility services. The end result is an entirely new world, one that allows us to envision the impossible, connect without boundaries, and transform the ways in which we live. For more information, visit http://www.intelsat.com.

Images, Video, Text, Credits: International Launch Services (ILS)/ROSCOSMOS/Günter Space Page/Orbiter.ch Aerospace.

Best regards, Orbiter.ch

jeudi 9 juin 2016

NASA Mars Orbiters Reveal Seasonal Dust Storm Pattern












NASA - Mars Reconnaissance Orbiter (MRO) logo.

June 9, 2016

Fast Facts:

- A pattern of three large regional dust storms occurs with similar timing most Martian years.

- The seasonal pattern was detected from dust storms' effects on atmospheric temperatures, monitored by NASA orbiters since 1997.

- Improving the ability to predict large-scale, potentially hazardous dust storms on Mars would have safety benefits for planning robotic and human missions


Image above: This graphic presents Martian atmospheric temperature data as curtains over an image of Mars taken during a regional dust storm. The temperature profiles extend from the surface to about 50 miles up. Temperatures are color coded, from minus 243 degrees Fahrenheit (purple) to minus 9 F (red). Image credits: NASA/JPL-Caltech.

After decades of research to discern seasonal patterns in Martian dust storms from images showing the dust, but the clearest pattern appears to be captured by measuring the temperature of the Red Planet's atmosphere.

For six recent Martian years, temperature records from NASA Mars orbiters reveal a pattern of three types of large regional dust storms occurring in sequence at about the same times each year during the southern hemisphere spring and summer. Each Martian year lasts about two Earth years.

"When we look at the temperature structure instead of the visible dust, we finally see some regularity in the large dust storms," said David Kass of NASA's Jet Propulsion Laboratory, Pasadena, California. He is the instrument scientist for the Mars Climate Sounder on NASA's Mars Reconnaissance Orbiter and lead author of a report about these findings posted this week by the journal Geophysical Research Letters.

"Recognizing a pattern in the occurrence of regional dust storms is a step toward understanding the fundamental atmospheric properties controlling them," he said. "We still have much to learn, but this gives us a valuable opening."

Dust lofted by Martian winds links directly to atmospheric temperature: The dust absorbs sunlight, so the sun heats dusty air more than clear air. In some cases, this can be dramatic, with a difference of more than 63 Fahrenheit degrees (35 Celsius degrees) between dusty air and clear air. This heating also affects the global wind distribution, which can produce downward motion that warms the air outside the dust-heated regions. Thus, temperature observations capture both direct and indirect effects of the dust storms on the atmosphere.

 Mars Reconnaissance Orbiter (MRO). Image credits: NASA/JPL-Caltech

Improving the ability to predict large-scale, potentially hazardous dust storms on Mars would have safety benefits for planning robotic and human missions to the planet's surface. Also, by recognizing patterns and categories of dust storms, researchers make progress toward understanding how seasonal local events affect global weather in a typical Mars year.

NASA has been operating orbiters at Mars continuously since 1997. The Mars Climate Sounder on Mars Reconnaissance Orbiter, which reached Mars in 2006, and the Thermal Emission Spectrometer on Mars Global Surveyor, which studied Mars from 1997 to 2006, have used infrared observations to assess atmospheric temperature. Kass and co-authors analyzed temperature data representative of a broad layer centered about 16 miles (25 kilometers) above the Martian surface. That's high enough to be more affected by regional storms than by local storms.

Most Martian dust storms are localized, smaller than about 1,200 miles (about 2,000 kilometers) across and dissipating within a few days. Some become regional, affecting up to a third of the planet and persisting up to three weeks. A few encircle Mars, covering the southern hemisphere but not the whole planet. Twice since 1997, global dust storms have fully enshrouded Mars. The behavior of large regional dust storms in Martian years that include global dust storms is currently unclear, and years with a global storm were not included in the new analysis.

Three large regional storms, dubbed types A, B and C, all appeared in each of the six Martian years investigated.


Image above: This graphic shows Martian atmospheric temperature data related to seasonal patterns in occurrence of large regional dust storms. The data shown here were collected by the Mars Climate Sounder instrument on NASA's Mars Reconnaissance Orbiter over the course of one-half of a Martian year, during 2012 and 2013. Image credits: NASA/JPL-Caltech.

Multiple small storms form sequentially near Mars' north pole in the northern autumn, similar to Earth's cold-season arctic storms that swing one after another across North America.

"On Mars, some of these break off and head farther south along favored tracks," Kass said. "If they cross into the southern hemisphere, where it is mid-spring, they get warmer and can explode into the much larger Type A dust storms."

Southern hemisphere spring and summer on modern-day Mars are much warmer than northern spring and summer, because the eccentricity of Mars' orbit puts the planet closest to the sun near the end of southern spring. Southern spring and summer have long been recognized as the dustiest part of the Martian year and the season of global dust storms, even though the more detailed pattern documented in the new report had not been previously described.

When a Type A storm from the north moves into southern-hemisphere spring, the sunlight on the dust warms the atmosphere. That energy boosts the speed of winds. The stronger winds lift more dust, further expanding the area and vertical reach of the storm.

In contrast, the Type B storm starts close to the south pole shortly before the beginning of southern summer. Its origin may be from winds generated at the edge of the retreating south-polar carbon dioxide ice cap. Multiple storms may contribute to a regional haze.

The Type C storm starts after the B storm ends. It originates in the north during northern winter (southern summer) and moves to the southern hemisphere like the Type A storm. From one year to another, the C storm varies more in strength, in terms of peak temperature and duration, than the A and B storms do.

The longevity of NASA's Mars Reconnaissance Orbiter has helped enable studies such as this of seasonal patterns on Mars. JPL provided the Mars Climate Sounder instrument and manages the mission for NASA's Science Mission Directorate. Arizona State University, Tempe, provided the Thermal Emission Spectrometer for Mars Global Surveyor. Lockheed Martin Space Systems, Denver, built both orbiters.

Related link:

Mars Reconnaissance Orbiter report on the journal Geophysical Research Letters: http://onlinelibrary.wiley.com/doi/10.1002/2016GL068978/full

For more information about Mars Reconnaissance Orbiter (MRO), visit: http://mars.nasa.gov/mro/

Images (mentioned), Text, Credits: NASA/JPL/Guy Webster.


Greetings, Orbiter.ch

mercredi 8 juin 2016

BEAM Closed as Crew Packs Spaceships for Departure












ISS - Expedition 47 Mission patch.

June 8, 2016

BEAM’s hatches have been closed completing crew operations for the month. Meanwhile, a pair of spaceships is also being packed for departure this month.

After three days of operations inside BEAM, the Bigelow Expandable Activity Module has been outfitted with sensors and other hardware. The next crew entry into the Bigelow Expandable Activity Module is targeted for August for more checks. BEAM will be attached to the International Space Station for two years of performance and durability tests.


Image above: Astronaut Jeff Williams works inside the BEAM before closing its hatches. Image Credit: NASA TV.

Orbital ATK’s Cygnus space freighter is due to be released from the Tranquility module June 14 having arrived March 26. The Canadarm2 will grapple and release Cygnus into space where it will remain in orbit for tests until June 22. Three Expedition 47 crew members are counting down to their departure June 18. They are packing the Soyuz TMA-19M spacecraft that will return them to Earth after 186 days in space.

Today’s science activities included collecting air and breath samples for a bone marrow study. The crew also explored how astronauts adapt to detailed tasks requiring high concentration and also measured how lack of sleep in space affects cognitive performance.

Related links:

Bigelow Expandable Activity Module: http://www.nasa.gov/beam

Bone marrow study: http://www.nasa.gov/mission_pages/station/research/experiments/1931.html

Orbital ATK: http://www.nasa.gov/orbital

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

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

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

Greetings, Orbiter.ch

Cloudy Days on Exoplanets May Hide Atmospheric Water











NASA - Hubble Space Telescope patch.

June 8, 2016


Image above: Hot Jupiters, exoplanets around the same size as Jupiter that orbit very closely to their stars, often have cloud or haze layers in their atmospheres. This may prevent space telescopes from detecting atmospheric water that lies beneath the clouds, according to a study in the Astrophysical Journal. Image Credits: NASA/JPL-Caltech.

Water is a hot topic in the study of exoplanets, including "hot Jupiters," whose masses are similar to that of Jupiter, but which are much closer to their parent star than Jupiter is to the sun. They can reach a scorching 2,000 degrees Fahrenheit (1,100 degrees Celsius), meaning any water they host would take the form of water vapor.

Astronomers have found many hot Jupiters with water in their atmospheres, but others appear to have none. Scientists at NASA's Jet Propulsion Laboratory, Pasadena, California, wanted to find out what the atmospheres of these giant worlds have in common.

Researchers focused on a collection of hot Jupiters studied by NASA's Hubble Space Telescope. They found that the atmospheres of about half of the planets were blocked by clouds or haze.

"The motivation of our study was to see what these planets would be like if they were grouped together, and to see whether they share any atmospheric properties," said Aishwarya Iyer, a JPL intern and master's degree candidate at California State University, Northridge, who led the study. 

The new study, published in the June 1 issue of the Astrophysical Journal, suggests that clouds or haze layers could be preventing a substantial amount of atmospheric water from being detected by space telescopes. The clouds themselves are likely not made of water, as the planets in this sample are too hot for water-based clouds.

"Clouds or haze seem to be on almost every planet we studied," Iyer said. "You have to be careful to take clouds or haze into account, or else you could underestimate the amount of water in an exoplanet's atmosphere by a factor of two."

In the study, scientists looked at a set of 19 hot Jupiters previously observed by Hubble. The telescope's Wide Field Camera 3 had detected water vapor in the atmospheres of 10 of these planets, and no water on the other nine. But that information was spread across more than a dozen studies. The methods of analyzing and interpretation varied because the studies were conducted separately. There had not been one overarching analysis of all these planets.

To compare the planets and look for patterns, the JPL team had to standardize the data: Researchers combined the datasets for all 19 hot Jupiters to create an average overall light spectrum for the group of planets. They then compared these data to models of clear, cloud-free atmospheres and those with various cloud thicknesses.

The scientists determined that, for almost every planet they studied, haze or clouds were blocking half of the atmosphere, on average.

"In some of these planets, you can see water peeking its head up above the clouds or haze, and there could still be more water below," Iyer said.

Scientists do not yet know the nature of these clouds or hazes, including what they are they made of.

"Clouds or haze being on almost all these planets is pretty surprising," said Robert Zellem, a postdoctoral fellow at JPL and co-author of the study.

The implications of this result agree with findings published in the Dec. 14, 2015, issue of the journal Nature. The Nature study used data from NASA's Hubble and Spitzer Space Telescopes to suggest that clouds or haze could be hiding undetected water in hot Jupiters. This new study uses exoplanet data from a single instrument on Hubble to uniformly characterize a larger group of hot Jupiters, and is the first to quantify how much of the atmosphere would be shielded as a result of clouds or haze.

video
Hubble and the sunrise over Earth

The new research could have implications for follow-up studies with future space observatories, such as NASA's James Webb Space Telescope. Exoplanets with thick cloud covers blocking the detection of water and other substances may be less desirable targets for more extensive study.

These results are also important for figuring out how planets form, scientists say.

"Did these planets form in their current positions or migrate toward their host stars from farther out? Understanding the abundances of molecules such as water helps us answer those questions," Zellem said.

"This paper is an exciting step forward for the study of exoplanets and comparing their properties," said Mark Swain, study co-author and group supervisor for the exoplanet discovery and science group at JPL.

Michael Line of the University of California, Santa Cruz, also contributed to the study. Other co-authors from JPL included Gael Roudier, Graca Rocha and John Livingston.

For more information about the Hubble Space Telescope, visit:

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

Related link:

James Webb Space Telescope: http://www.jwst.nasa.gov/

Image (mentioned), Text, Credits: NASA/Tony Greicius/JPL/Elizabeth Landau/Video: European Space Agency (ESA).

Greetings, Orbiter.ch

Black Hole Fed by Cold Intergalactic Deluge












ESO - European Southern Observatory logo.

8 June 2016

Artist’s impression of cold intergalactic rain

An international team of astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) has witnessed a cosmic weather event that has never been seen before — a cluster of towering intergalactic gas clouds raining in on the supermassive black hole at the centre of a huge galaxy one billion light-years from Earth. The results will appear in the journal Nature on 9 June 2016.

The new ALMA observation is the first direct evidence that cold dense clouds can coalesce out of hot intergalactic gas and plunge into the heart of a galaxy to feed its central supermassive black hole. It also reshapes astronomers’ views on how supermassive black holes feed, in a process known as accretion.

Previously, astronomers believed that, in the largest galaxies, supermassive black holes fed on a slow and steady diet of hot ionised gas from the galaxy’s halo. The new ALMA observations show that, when the intergalactic weather conditions are right, black holes can also gorge on a clumpy, chaotic downpour of giant clouds of very cold molecular gas.

Artist’s impression of cold intergalactic rain

“Although it has been a major theoretical prediction in recent years, this is one of the first unambiguous pieces of observational evidence for a chaotic, cold rain feeding a supermassive black hole,” said Grant Tremblay, an astronomer with Yale University in New Haven, Connecticut, USA, former ESO Fellow, and lead author on the new paper. “It’s exciting to think we might actually be observing this galaxy-spanning rainstorm feeding a black hole whose mass is about 300 million times that of the Sun.”

Tremblay and his team used ALMA to peer into an unusually bright cluster of about 50 galaxies, collectively known as Abell 2597. At its core is a massive elliptical galaxy, descriptively named the Abell 2597 Brightest Cluster Galaxy. Suffusing the space between these galaxies is a diffuse atmosphere of hot ionised gas, which was previously observed with NASA’s Chandra X-ray Observatory.

"This very, very hot gas can quickly cool, condense, and precipitate in much the same way that warm, humid air in Earth's atmosphere can spawn rain clouds and precipitation," Tremblay said. "The newly condensed clouds then rain in on the galaxy, fueling star formation and feeding its supermassive black hole."

Composite image of Abell 2597 Brightest Cluster Galaxy

Near the centre of this galaxy the researchers discovered just this scenario: three massive clumps of cold gas are careening toward the supermassive black hole in the galaxy’s core at about a million kilometres per hour. Each cloud contains as much material as a million Suns and is tens of light-years across.

Normally, objects on that scale would be difficult to distinguish at these cosmic distances, even with ALMA’s amazing resolution. They were revealed, however, by the billion-light-year-long “shadows” they cast toward Earth [1].

Additional data from the National Science Foundation’s Very Long Baseline Array indicate that the gas clouds observed by ALMA are only about 300 light-years from the central black hole, essentially teetering on the edge of being devoured, in astronomical terms.

video
Artist’s impression of cold intergalactic rain

While ALMA was only able to detect three clouds of cold gas near the black hole, the astronomers speculate that there may be thousands like them in the vicinity, setting up the black hole for a continuing downpour that could fuel its activity for a long time.

The astronomers now plan to use ALMA to search for these "rainstorms" in other galaxies in order to determine whether such cosmic weather is as common as current theory suggests it might be.

Notes:

[1] The shadows are formed when the in-falling opaque gas clouds block out a portion of the bright background millimetre-wavelength light emitted by electrons spiraIling around magnetic fields very near the central supermassive black hole.

More information:

This research was presented in a paper entitled “Cold, clumpy accretion onto an active supermassive black hole”, by Grant R. Tremblay et al., to appear in the journal Nature on 9 June 2016.

The team is composed of Grant R. Tremblay (Yale University, New Haven, Connecticut, USA; ESO, Garching, Germany), J. B. Raymond Oonk (ASTRON, Netherlands Institute for Radio Astronomy, Dwingeloo, the Netherlands; Leiden Observatory, Leiden University, Leiden, the Netherlands), Françoise Combes (LERMA, Observatoire de Paris, PSL Research University, College de France, CNRS, Sorbonne University, Paris, France), Philippe Salomé (LERMA, Observatoire de Paris, PSL Research University, College de France, CNRS, Sorbonne University, Paris, France), Christopher O’Dea (University of Manitoba, Winnipeg, Canada; Rochester Institute of Technology, Rochester, New York, USA), Stefi A. Baum (University of Manitoba, Winnipeg, Canada; Rochester Institute of Technology, Rochester, New York, USA), G. Mark Voit (Michigan State University, East Lansing, Michigan, USA), Megan Donahue (Michigan State University, East Lansing, Michigan, USA), Brian R. McNamara (Waterloo University, Waterloo, Ontario, Canada), Timothy A. Davis (Cardiff University, Cardiff, United Kingdom; ESO, Garching, Germany), Michael A. McDonald (Kavli Institute for Astrophysics & Space Research, MIT, Cambridge, Massachusetts, USA), Alastair C. Edge (Durham University, Durham, United Kingdom), Tracy E. Clarke (Naval Research Laboratory Remote Sensing Division, Washington DC, USA), Roberto Galván-Madrid (Instituto de Radioastronomía y Astrofísica, UNAM, Morelia, Michoacan, Mexico; ESO, Garching, Germany), Malcolm N. Bremer (University of Bristol, Bristol, United Kingdom), Louise O. V. Edwards (Yale University, New Haven, Connecticut, USA), Andrew C. Fabian (Institute of Astronomy, Cambridge University, Cambridge, United Kingdom), Stephen Hamer (LERMA, Observatoire de Paris, PSL Research University, College de France, CNRS, Sorbonne University, Paris, France) , Yuan Li (University of Michigan, Ann Arbor, Michigan, USA ), Anaëlle Maury (Laboratoire AIMParis-Saclay, CEA/DSM/Irfu CNRS, University Paris Diderot, CE-Saclay, Gif-sur-Yvette, France), Helen Russell (Institute of Astronomy, Cambridge University, Cambridge, United Kingdom), Alice C. Quillen (University of Rochester, Rochester, New York, USA), C. Megan Urry (Yale University, New Haven, Connecticut, USA), Jeremy S. Sanders (Max-Planck-Institut für extraterrestrische Physik, Garching bei München, Germany), and Michael Wise (ASTRON, Netherlands Institute for Radio Astronomy, Dwingeloo, the Netherlands).

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of ESO, the U.S. National Science Foundation (NSF) and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI).

ALMA construction and operations are led by ESO on behalf of its Member States; by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America; and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 16 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is a major partner in ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre European Extremely Large Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

Related links:

Supermassive black holes: https://en.wikipedia.org/wiki/Supermassive_black_hole

NASA’s Chandra X-ray Observatory: https://www.nasa.gov/mission_pages/chandra/main/

National Science Foundation’s Very Long Baseline Array: https://science.nrao.edu/facilities/vlba

Links:

Research paper: http://www.eso.org/public/archives/releases/sciencepapers/eso1618/eso1618a.pdf

Photos of ALMA: http://www.eso.org/public/images/archive/search/?adv=&subject_name=Atacama%20Large%20Millimeter/submillimeter%20Array

Images, Text, Credits: ESO/NRAO/AUI/NSF; Dana Berry/SkyWorks; ALMA (ESO/NAOJ/NRAO)/B. Saxton (NRAO/AUI/NSF)/G. Tremblay et al./NASA/ESA Hubble/ALMA (ESO/NAOJ/NRAO)/Video Credits: NRAO/AUI/NSF; Dana Berry/SkyWorks; ALMA (ESO/NAOJ/NRAO). Music: Johan B. Monell.

Best regards, Orbiter.ch

mardi 7 juin 2016

BEAM Sensors Installed as Station Prepares for Crew Swap












ISS - Expedition 47 Mission patch.

June 7, 2016

The hatch to BEAM was opened up again today for the second day of outfitting the expandable module to determine its habitability and durability. BEAM, or the Bigelow Expandable Activity Module, is set to demonstrate the overall performance and capability of expandable habitats for the next two years. The crew is predicted to enter BEAM between 12 and 14 times during its stay.

Three Expedition 46-47 crew members are winding down a six-month mission at the International Space Station. Commander Tim Kopra, veteran cosmonaut Yuri Malenchenko and first-time British astronaut Tim Peake are packing their Soyuz TMA-19M spacecraft before they undock June 18 for the 3.5 hour ride back to Earth.


Image above: Astronaut Jeff Williams works inside the Bigelow Expandable Activity Module. Image Credit: NASA TV.

The station will raise its orbit Wednesday morning to support the undocking as well as the arrival of the next crew on July 9. New Expedition 48-49 crew members Anatoly Ivanishin, Kate Rubins and Takuya Onishi will launch July 7 aboard a new Soyuz MS-01 spacecraft for a two-day trip to their new home in space.

Inside the space station, the astronauts explored how future crews will communicate and perform as they travel farther out in space. Saliva samples were collected and stowed so scientists can analyze them to understand how microgravity affects a crew member’s immune system. The crew also photographed Earth’s landmarks and studied the vibrations the station experiences during vehicle dockings, spacewalks and crew exercise.

Related links:

Bigelow Expandable Activity Module: http://www.nasa.gov/beam

Expedition 46-47 crew: http://www.nasa.gov/mission_pages/station/expeditions/expedition47/index.html

Expedition 48-49 crew: http://www.nasa.gov/mission_pages/station/expeditions/expedition48/index.html

Vibrations the station experiences: http://www.nasa.gov/mission_pages/station/research/experiments/477.html

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

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

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

Greetings, Orbiter.ch

Frosted Dunes on Mars












NASA - Mars Reconnaissance Orbiter (MRO) patch.

June 7, 2016


Sand dunes cover much of this terrain, which has large boulders lying on flat areas between the dunes. It is late winter in the southern hemisphere of Mars, and these dunes are just getting enough sunlight to start defrosting their seasonal cover of carbon dioxide. Spots form where pressurized carbon dioxide gas escapes to the surface.

This image was taken on March 27, 2016, at 15:31 local Mars time by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter. The University of Arizona, Tucson, operates HiRISE, which was built by Ball Aerospace & Technologies Corp., Boulder, Colo. 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.

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

Image, Text, Credits: NASA/JPL/University of Arizona/Caption: Alfred McEwen/Sarah Loff.

Greetings, Orbiter.ch

LISA Pathfinder exceeds expectations












ESA - LISA Pathfinder Mission patch.

7 June 2016

ESA’s LISA Pathfinder mission has demonstrated the technology needed to build a space-based gravitational wave observatory.

Results from only two months of science operations show that the two cubes at the heart of the spacecraft are falling freely through space under the influence of gravity alone, unperturbed by other external forces, to a precision more than five times better than originally required.

LISA Pathfinder in space

In a paper published today in Physical Review Letters, the LISA Pathfinder team show that the test masses are almost motionless with respect to each other, with a relative acceleration lower than 1 part in ten millionths of a billionth of Earth’s gravity.

The demonstration of the mission’s key technologies opens the door to the development of a large space observatory capable of detecting gravitational waves emanating from a wide range of exotic objects in the Universe.

Hypothesised by Albert Einstein a century ago, gravitational waves are oscillations in the fabric of spacetime, moving at the speed of light and caused by the acceleration of massive objects.

They can be generated, for example, by supernovas, neutron star binaries spiralling around each other, and pairs of merging black holes.

Even from these powerful objects, however, the fluctuations in spacetime are tiny by the time they arrive at Earth – smaller than 1 part in 100 billion billion.

LISA Pathfinder performance

Sophisticated technologies are needed to register such minuscule changes, and gravitational waves were directly detected for the first time only in September 2015 by the ground-based Laser Interferometer Gravitational-Wave Observatory (LIGO).

This experiment saw the characteristic signal of two black holes, each with some 30 times the mass of the Sun, spiralling towards one another in the final 0.3 seconds before they coalesced to form a single, more massive object.

The signals seen by LIGO have a frequency of around 100 Hz, but gravitational waves span a much broader spectrum. In particular, lower-frequency oscillations are produced by even more exotic events such as the mergers of supermassive black holes.

With masses of millions to billions of times that of the Sun, these giant black holes sit at the centres of massive galaxies. When two galaxies collide, these black holes eventually coalesce, releasing vast amounts of energy in the form of gravitational waves throughout the merger process, and peaking in the last few minutes.

To detect these events and fully exploit the new field of gravitational astronomy, it is crucial to open access to gravitational waves at low frequencies between 0.1 mHz and 1 Hz.

This requires measuring tiny fluctuations in distance between objects placed millions of kilometres apart, something that can only be achieved in space, where an observatory would also be free of the seismic, thermal and terrestrial gravity noises that limit ground-based detectors.

LISA Pathfinder was designed to demonstrate key technologies needed to build such an observatory.

A crucial aspect is placing two test masses in freefall, monitoring their relative positions as they move under the effect of gravity alone. Even in space this is very difficult, as several forces, including the solar wind and pressure from sunlight, continually disturb the cubes and the spacecraft.

video
Inside LISA Pathfinder, with narration

Thus, in LISA Pathfinder, a pair of identical, 2 kg, 46 mm gold–platinum cubes, 38 cm apart, fly, surrounded, but untouched, by a spacecraft whose job is to shield them from external influences, adjusting its position constantly to avoid hitting them.

“LISA Pathfinder’s test masses are now still with respect to each other to an astonishing degree, ” says Alvaro Giménez, ESA’s Director of Science.

“This is the level of control needed to enable the observation of low-frequency gravitational waves with a future space observatory.”

LISA Pathfinder was launched on 3 December 2015, reaching its operational orbit roughly 1.5 million km from Earth towards the Sun in late January 2016.

The mission started operations on 1 March, with scientists performing a series of experiments on the test masses to measure and control all of the different aspects at play, and determine how still the masses really are.

“The measurements have exceeded our most optimistic expectations,” says Paul McNamara, LISA Pathfinder Project Scientist.

Test masses inside LISA Pathfinder payload

“We reached the level of precision originally required for LISA Pathfinder within the first day, and so we spent the following weeks improving the results a factor of five.”

These extraordinary results show that the control achieved over the test masses is essentially at the level required to implement a gravitational wave observatory in space.

“Not only do we see the test masses as almost motionless, but we have identified, with unprecedented precision, most of the remaining tiny forces disturbing them,” explains Stefano Vitale of University of Trento and INFN, Italy, Principal Investigator of the LISA Technology Package, the mission’s core payload.

The first two months of data show that, in the frequency range between 60 mHz and 1 Hz, LISA Pathfinder's precision is only limited by the sensing noise of the laser measurement system used to monitor the position and orientation of the cubes.

“The performance of the laser instrument has already surpassed the level of precision required by a future gravitational-wave observatory by a factor of more than 100,” says Martin Hewitson, LISA Pathfinder Senior Scientist from Max Planck Institute for Gravitational Physics and Leibniz Universität Hannover, Germany.

At lower frequencies of 1–60 mHz, control over the cubes is limited by gas molecules bouncing off them – a small number remain in the surrounding vacuum. This effect was seen reducing as more molecules were vented into space, and is expected to improve in the following months.

LISA Technology Package

“We have observed the performance steadily improving, day by day, since the start of the mission,” says William Weber, LISA Pathfinder Senior Scientist from University of Trento, Italy.

At even lower frequencies, below 1 mHz, the scientists measured a small centrifugal force acting on the cubes, from a combination of the shape of LISA Pathfinder’s orbit and to the effect of the noise in the signal of the startrackers used to orient it.

While this force slightly disturbs the cubes’ motion in LISA Pathfinder, it would not be an issue for a future space observatory, in which each test mass would be housed in its own spacecraft, and linked to the others over millions of kilometres via lasers.

“At the precision reached by LISA Pathfinder, a full-scale gravitational wave observatory in space would be able to detect fluctuations caused by the mergers of supermassive black holes in galaxies anywhere in the Universe,” says Karsten Danzmann, director at the Max Planck Institute for Gravitational Physics, director of the Institute for Gravitational Physics of Leibniz Universität Hannover, Germany, and Co-Principal Investigator of the LISA Technology Package.

Today’s results demonstrate that LISA Pathfinder has proven the key technologies and paved the way for such an observatory, as the third ‘Large-class’ (L3) mission in ESA’s Cosmic Vision programme.

Notes for Editors:

“Sub-femto-g free-fall for space-borne gravitational wave detectors: LISA Pathfinder results,” is published in Physical Review Letters:
http://link.aps.org/doi/10.1103/PhysRevLett.116.231101

The results were presented today during a media briefing at ESA’s European Space Astronomy Centre in Villanueva de la Cañada, Madrid, Spain.

There will be an Ask Me Anything session on Reddit on 7 June at 14:00 CEST (12:00 GMT).

LISA Pathfinder is an ESA mission with important contributions from its member states and NASA.

The LISA Technology Package payload has been delivered by several national funding agencies and ESA, in particular: Italy (ASI); Germany (DLR); the United Kingdom (UKSA); France (CNES); Spain (CDTI); Switzerland (SSO); and the Netherlands (SRON). LISA Pathfinder also carries the Disturbance Reduction System payload, provided by NASA-JPL.

Science operations involving the full LISA Technology Package will last until late June, followed by three months of operations with the Disturbance Reduction System.

Related links:

Reddit: http://reddit.com/r/iAmA

About LISA Pathfinder mission: http://sci.esa.int/lisa-pathfinder/

More about...
LISA Pathfinder factsheet: http://www.esa.int/Our_Activities/Space_Science/LISA_Pathfinder_factsheet

Images, Video, Text, Credits: ESA/C.Carreau/Spacecraft: ESA/ATG medialab; data: ESA/LISA Pathfinder Collaboration.

Best regards, Orbiter.ch

lundi 6 juin 2016

BEAM Opens Up For Checks












ISS - Expedition 47 Mission patch.

June 6, 2016

The Bigelow Expandable Activity Module’s (BEAM) hatch was opened up for the first time today. Astronaut Jeff Williams entered BEAM and checked sensors, installed air ducts and reported back to Earth that it was in pristine condition. After Williams completed the BEAM checks he exited and closed the hatch for the day.

The crew will enter BEAM a couple of more times through Wednesday to check sensors and gear. BEAM will stay attached to the International Space Station for two years of tests of its durability.


Image above: Astronaut Jeff Williams works inside the Bigelow Expandable Activity Module. Image Credit: NASA TV.

The rest of the Expedition 47 crew moved right along with human research studies benefiting astronauts in space and people on Earth. British astronaut Tim Peake explored how astronauts adapt to tasks requiring high concentration and detailed procedures. Williams later collected biological samples for stowage and analysis for the Multi-Omics experiment that is studying the immune system.

Commander Tim Peake and Flight Engineer Yuri Malenchenko are packing their Soyuz TMA-19M spacecraft and getting ready for a June 18 departure. Peake will join the duo for the ride home after living in space for six months.

Related links:

Bigelow Expandable Activity Module’s (BEAM): http://www.nasa.gov/beam

Multi-Omics experiment: http://www.nasa.gov/mission_pages/station/research/experiments/1949.html

How astronauts adapt to tasks: http://www.nasa.gov/mission_pages/station/research/experiments/1767.html

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

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

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

Greetings, Orbiter.ch

Rings Interrupted












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

June 6, 2016


Distant Titan, its northern hemisphere drenched in the sunlight of late spring, hangs above Saturn's rings.  What might at first glance look like a gap between the rings and the planet is actually Saturn’s shadow.  During most of Saturn's long year, the projection of the planet's shadow extends well beyond the edge of the A ring.  But, with summer solstice fast approaching, the Sun is now higher in Saturn's sky and most of Saturn's A ring is completely shadow-free.

This view looks toward the sunlit side of the rings from about 3 degrees above the ring plane. The image was taken in red light with NASA's Cassini spacecraft wide-angle camera on Jan. 26, 2016.

The view was obtained at a distance of approximately 1.8 million miles (2.9 million kilometers) from Titan and at a Sun-Titan-spacecraft, or phase, angle of 84 degrees. Image scale on Titan is 109 miles (176 kilometers) per pixel.

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 http://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, Text, Credits: NASA/JPL-Caltech/Space Science Institute/Tony Greicius.

Greetings, Orbiter.ch

Mysterious microwaves












ESA - Planck Mission patch.

June 6, 2016

A mysterious ring of microwaves

Fifty years ago, astronomers discovered a mystery. They called it Loop I. Today, we still have not fully resolved the mystery of how this giant celestial structure formed but we do now have the best image of it, thanks to ESA’s Planck satellite.

Loop I is a nearly circular formation that covers one third of the sky. In reality, it is probably a spherical ‘bubble’ that stretches to more than 100º across, making it wider than 200 full Moons. Its absolute size, however, is extremely uncertain because astronomers do not know how close it is to us: estimates to the centre of the bubble vary from 400 light-years to 25 000 light-years.

What they do know is that the structure shows up in many different wavelengths, from radio waves to gamma rays. Planck sees Loop I in microwaves. This image’s colours reflect the polarisation – the direction in which the microwaves are oscillating.

Our eyes are not sensitive to this information in the visible light, where we perceive only the intensity and colour. Planck, however, can detect all three of these characteristics in the microwaves it targets.

The microwaves detected by Planck are emitted by electrons that are being accelerated by the Galaxy’s magnetic field.

Loop I is most visible in the sky’s northern hemisphere. Astronomers refer to this portion as the north polar spur. It can be seen in this image as the yellow arc. This fades to purple and can be traced into the southern hemisphere, completing the circle. The blue band spanning the image horizontally is the Galactic Plane.

The most popular interpretation places Loop I close to us. If this is correct, it could be related to the ‘Scorpius–Centaurus OB Association’, a region of high-mass star formation that has been active for over 10 million years. Loop I could well be a supernova remnant, a giant bubble hollowed out by the explosion of stars in the OB association.

The stars responsible for Loop I have long since dispersed, so what we see is the ‘smoke’ rather than the ‘fire’ of the explosions.

ESA’s Planck satellite

High-mass stars burn their nuclear fuel so quickly that they live only a few million years before exploding. As these titanic supernovas bloom, their blast waves carve bubbles in the surrounding gas. This compresses the Galaxy’s magnetic field into the bubble ‘walls’, making it stronger and more efficient at accelerating the electrons to produce the observed radiation.

Loop I could well be the combined super-bubble from a number of such cataclysms. As the electrons lose energy and diffuse into the wider Galaxy, so Loop I will eventually fade and disappear. This is likely to take a few million years.

If the loop is more distant, then it could conceivably be the result of an outburst from around the black hole at the centre of the Galaxy.

(A version of the image showing the position of Loop I is available here: http://sci.esa.int/planck/57907-x/. The colour represents the direction of polarisation, while the brightness of the colour measures the intensity of polarisation.)

Related link:

ESA’s Planck satellite: http://sci.esa.int/planck/

Images, Text, Credits: ESA and the Planck Collaboration.

Greetings, Orbiter.ch