CERN - LHC performance reaches new highs

CERN - European Organization for Nuclear Research logo.

July 9, 2016

Image above: The LHC reached three new performance records: unprecedented luminosity, number of proton bunches and beam lifetime. (Photo: Maximilien Brice).

It’s full speed ahead for the Large Hadron Collider (LHC), as it shatters its own records one after the other, achieving record luminosity, record numbers of bunches and a record beam lifespan.

Some 2076 bunches of 120 billion protons are currently circulating in the ring in each direction. At the end of June, beams were maintained in the accelerator for a record 37 consecutive hours! But the main indicator of success for the operators is luminosity, the measurement of the number of potential collisions in a given time period. On 29 June, peak luminosity (the number of potential collisions per second and per surface unit) exceeded 10³⁴cm^-2s^-1. This number may not mean much to most of us, but it made the LHC operators very proud as it corresponds to the ultimate objective defined by those who originally designed this huge machine!

The result is a torrent of data for the experiments. “At present, we are providing an integrated luminosity of 2 inverse femtobarns of data per week,” says Jorg Wenninger, who is in charge of the LHC operations team. The inverse femtobarn  (fb^-1) is the unit of measurement for integrated luminosity, indicating the cumulative number of potential collisions. One inverse femtobarn corresponds to around 80 million million collisions.

Graphic above: This graph shows the integrated luminosity delivered by the LHC to the ATLAS and CMS experiments in 2011, 2012, 2015 and 2016. The integrated luminosity indicates the amount of data delivered to the experiments and is measured in inverse femtobarns. One inverse femtobarn corresponds to around 80 million million collisions. Graphic Credit: CERN.

On Wednesday, the ATLAS and CMS experiments, which take the most data from the LHC, passed the threshold of 10 inverse femtobarns (fb^-1) of integrated luminosity for 2016. The goal for 2016 is to reach 25 fb^-1

These huge volumes of data are causing much excitement in the experiments. Physicists are adding new data to their analyses and actively preparing their results. The next goal will be to present the first results from the 2016 harvest at the ICHEP 2016 conference, which will take place at the start of August in Chicago in the United States.

Note:

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

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

Founded in 1954, the CERN Laboratory sits astride the Franco–Swiss border near Geneva. It was one of Europe’s first joint ventures and now has 21 Member States.

Related links:

ICHEP 2016 conference: https://www.ichep2016.org/

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

ATLAS experiment: http://home.cern/about/experiments/atlas

CMS experiment: http://home.cern/about/experiments/cms

For more information about the European Organization for Nuclear Research (CERN), visit: http://home.web.cern.ch/

Image (mentioned), Graphic (mentioned), Text, Credits: CERN/Corinne Pralavorio.

Best regards, Orbiter.ch

Expedition 48-49 Crew Docks to New Home in Space

ROSCOSMOS - Soyuz MS-01M Mission patch.

July 9, 2016

Image above: The Soyuz MS-01 spacecraft is viewed from the International Space Station as it approaches the Rassvet module docking port. Image Credit: NASA TV

The Soyuz MS-01 spacecraft docked to the International Space Station at 12:06 a.m. EDT Saturday, July 9, 254 statute miles over the South Pacific.

Expedition 48 49 Crew Docks to the Space Station

Aboard the space station, Expedition 48 Commander Jeff Williams of NASA and Flight Engineers Oleg Skripochka and Alexey Ovchinin of Roscosmos will welcome NASA astronaut Kate Rubins, cosmonaut Anatoly Ivanishin of Roscosmos, and astronaut Takuya Onishi of the Japan Aerospace Exploration Agency (JAXA) when the hatches of the two spacecraft are opened at 2:50 a.m.

Hatches Open and Station Crew Grows to Six

NASA astronaut Kate Rubins, cosmonaut Anatoly Ivanishin of Roscosmos, and astronaut Takuya Onishi of the Japan Aerospace Exploration Agency (JAXA) joined their Expedition 48 crew members aboard the International Space Station officially at 2:26 a.m. EDT July 9 when the hatches opened between their Soyuz MS-01 and the space station.

Expedition 48 49 Crew Welcomed to the Space Station

Expedition 48 Commander Jeff Williams of NASA and Flight Engineers Oleg Skripochka and Alexey Ovchinin of Roscosmos welcomed the trio aboard their orbital home.

In the coming months, the crewmates are scheduled to receive multiple cargo resupply flights delivering several tons of food, fuel, supplies and research.

Image above: The new six-member Expedition 48 crew join each other for well wishes and congratulations from family, friends and mission officials. In front, from left, are the new crew members Kate Rubins, Anatoly Ivanishin and Takuya Onishi. In the back row are Flight Engineers Oleg Skripochka and Alexey Ovchinin and Commander Jeff Williams. Image Credit: NASA TV.

SpaceX’s ninth commercial resupply services mission under contract with NASA is scheduled to launch to the space station no earlier than July 18 at 12:45 a.m. Research aboard the Dragon cargo spacecraft will include experiments to test the capabilities for sequencing DNA, understand bone loss, track heart changes in microgravity and regulate temperature aboard spacecraft. The first of two international docking adapters is also headed to station in Dragon’s unpressurized trunk, which will allow commercial spacecraft to dock to the station when transporting astronauts in the near future as part of NASA’s Commercial Crew Program. Williams and Rubins are scheduled to install the adapter during a spacewalk later this summer.

Rubins, Ivanishin and Onishi are scheduled to remain aboard the station until late October. Williams, Skripochka and Ovchinin will return to Earth in September.

To learn more about the International Space Station, visit: https://www.nasa.gov/mission_pages/station/main/index.html

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

Best regards, Orbiter.ch

Russian Cargo Ship Completes Successful Re-docking Test

ROSCOSMOS - Russian Vehicles patch.

July 8, 2016

Image above: The Progress 62 cargo craft is seen moments after undocking and backing away from the Pirs docking compartment. Image Credit: NASA TV.

The Russian ISS Progress 62 cargo ship re-docked to the International Space Station’s Pirs docking compartment on July 1, 2016 at 2:05 a.m. EDT after a short test flight.

The system test included verification of software and a new signal converter incorporated in the upgraded manual docking system for future use in Progress vehicles in the unlikely event the “Kurs” automated rendezvous system encounters a problem.

Russian Docking System Tested Aboard the ISS

Video above: A Russian ISS Progress 62 cargo ship automatically undocked from the International Space Station July 1, moved to a distance of about 600 feet away from the complex, then re-approached and re-docked a short time later under the manual control of Expedition 48 cosmonauts Alexey Ovchinin and Oleg Skripochka of Roscosmos. The cosmonauts were testing an upgraded backup rendezvous system of the spacecraft, which cosmonauts can use to take over the manual control of an approaching unpiloted craft for docking in the unlikely event a problem. Video Credit: NASA TV.

Keep up with the International Space Station and its research and crews, at: https://www.nasa.gov/mission_pages/station/main/index.html

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

Best regards, Orbiter.ch

NASA Looks at Typhoon Nepartak Over Taiwan in Visible and Infrared Light

NASA - EOS Terra Mission patch / NASA - EOS Aqua Mission logo.

July 8, 2016

Nepartak (NW Pacific Ocean)

NASA's Aqua and Terra satellites provided a visible and infrared view of Typhoon Nepartak before and during its movement over Taiwan.

The MODIS instrument aboard NASA's Aqua satellite read cloud top temperatures in a thermal image of Typhoon Nepartak on July 7 at 17:45 UTC (1:45 p.m. EDT) as it was approaching Taiwan. The infrared temperature data enables scientists to learn where the strongest storms are located within a typhoon. The colder the cloud tops, the higher they are in the troposphere and the stronger the storms. NASA data has shown that cloud tops that are as cold as minus 63 degrees Fahrenheit (minus 53 degrees Celsius) have the ability to generate heavy rainfall. Rainfall totals compiled by Taiwan's Central Weather Bureau confirmed high rainfall totals.

Image above: This is a thermal image of Typhoon Nepartak from the MODIS instrument aboard NASA's Aqua satellite taken on July 7 at 17:45 UTC (1:45 p.m. EDT) as it was approaching Taiwan. Image Credits: NASA Goddard MODIS Rapid Response.

On July 8 at 03:10 UTC (July 7 at 11:10 p.m. EDT) the MODIS instrument aboard NASA's Terra satellite captured a visible image of Typhoon Nepartak that showed the storm over Taiwan.

Taiwan Central Emergency Operations Center reported three deaths and 142 injuries.

At 12 p.m. EDT (1600 UTC) on July 8, 2016, Taiwan's Central Weather Bureau noted several advisories in effect. Torrential Rain Advisory areas include: Nantou County Mountain Area, Chiayi County Mountain Area, Tainan City Mountain Area, Kaohsiung City, Pingtung County, Hengchun Peninsula, Hualien County Mountain Area and Taitung County Mountain Area.

Artist's concept of Terra satellite. Image Credits: NASA/JPL

An Extremely Heavy Rain Advisory remains in effect for the Taichung City Mountain Area, Yunlin County Mountain Area, Chiayi City, Chiayi County, Tainan City, Yilan County Mountain Area, Hualien County, Taitung County, Lanyu and Ludao Islands and Penghu County.

A Heavy Rain Advisory is in effect for the Taipei City Mountain Area, New Taipei City Mountain Area, Taoyuan City Mountain Area, Hsinchu County Mountain Area, Miaoli County Mountain Area, Taichung City, Changhua County, Nantou County, Yunlin County, Yilan County, Kinmen Area and Matsu Area.

Artist's concept of Aqua Satellite. Image Credits: NASA/JPL

At 1500 UTC (11 a.m. EDT) on July 8, 2016 Typhoon Nepartak had maximum sustained winds near 70 knots (80.5 mph/129.6 kph). The center of the storm was located near 23.3 north latitude and 119.7 east longitude, about 146 nautical mile southwest of Taipei, Taiwan. Nepartak was moving slowly across the Taiwan Strait at 4 knots (4.6 mph/7.4 kph) in a northwesterly direction.

Image above: NASA's Terra satellite captured this visible image of Typhoon Nepartak on July 8 at 03:10 UTC (July 7 at 11:10 p.m. EDT) shows Typhoon Nepartak over Taiwan. Image Credits: NASA Goddard MODIS Rapid Response.

The Joint Typhoon Warning Center (JTWC) noted that the central circulation has been decoupled so the system is no longer stacked on top of itself. The strongest thunderstorms and flaring convection is occurring along the southern quadrant of the storm.  JTWC said "Typhoon Nepartak is forecast to continue weakening in the near term due to the decoupled nature of the system, and its close proximity to land."

Taiwan's Central Weather Bureau posted 24 hour accumulated rainfall above 50 mm from weather stations with as of July 7, 2016 as of 23:10 p.m. (7:10 p.m. Taiwan local time):  Hualien County Fuli Township: 551.0 mm; Pingtung County Shizi Township: 487.0 mm; Hualien County Xiulin Township: 486.0 mm; Pingtung County Mudan Township: 477.0 mm; Taitung County Daren Township: 466.0 mm; Hualien County Yuli Township: 459.5 mm; Hualien County Wanrong Township: 457.5 mm; Taitung County Guanshan Township: 446.0 mm; Pingtung County Chunri Township: 444.0 mm; Hualien County Zhuoxi Township: 414.0 mm; Hualien County Fenglin Township: 402.0 mm; Pingtung County Taiwu Township: 400.0 mm; Taitung County Haiduan Township: 382.0 mm; Hualien County Guangfu Township: 378.5 mm; Hualien County Ruisui Township: 377.0 mm; Hualien County Shoufeng Township: 350.5 mm.

For updates from Taiwan's Central Weather Bureau, visit: http://www.cwb.gov.tw.

Nepartak has crossed Taiwan and is now headed for mainland China, where it will dissipate.

Related links:

NASA's Aqua satellite: http://aqua.nasa.gov/

NASA's Terra satellite: http://www.nasa.gov/mission_pages/terra/index.html

Images (mentioned), Text, Credits: NASA's Goddard Space Flight Center/Rob Gutro.

Dawn Maps Ceres Craters Where Ice Can Accumulate

NASA - Dawn Mission patch.

July 8, 2016

Scientists with NASA's Dawn mission have identified permanently shadowed regions on the dwarf planet Ceres. Most of these areas likely have been cold enough to trap water ice for a billion years, suggesting that ice deposits could exist there now.

"The conditions on Ceres are right for accumulating deposits of water ice," said Norbert Schorghofer, a Dawn guest investigator at the University of Hawaii at Manoa. "Ceres has just enough mass to hold on to water molecules, and the permanently shadowed regions we identified are extremely cold -- colder than most that exist on the moon or Mercury."

Permanent Shadows on Ceres

Video above: Permanently shadowed regions capable of accumulating surface ice were identified in the northern hemisphere of Ceres using images taken by NASA’s Dawn mission combined with sophisticated computer modeling of illumination. Video Credits: NASA/JPL-Caltech.

Permanently shadowed regions do not receive direct sunlight. They are typically located on the crater floor or along a section of the crater wall facing toward the pole. The regions still receive indirect sunlight, but if the temperature stays below about minus 240 degrees Fahrenheit (minus 151 degrees Celsius), the permanently shadowed area is a cold trap -- a good place for water ice to accumulate and remain stable. Cold traps were predicted for Ceres but had not been identified until now.

In this study, Schorghofer and colleagues studied Ceres' northern hemisphere, which was better illuminated than the south. Images from Dawn's cameras were combined to yield the dwarf planet's shape, showing craters, plains and other features in three dimensions. Using this input, a sophisticated computer model developed at NASA's Goddard Space Flight Center, Greenbelt, Maryland, was used to determine which areas receive direct sunlight, how much solar radiation reaches the surface, and how the conditions change over the course of a year on Ceres.

Artist's view of Dawn passing over Ceres. Image Credit: NASA

The researchers found dozens of sizeable permanently shadowed regions across the northern hemisphere. The largest one is inside a 10-mile-wide (16-kilometer) crater located less than 40 miles (65 kilometers) from the north pole.

Taken together, Ceres' permanently shadowed regions occupy about 695 square miles (1,800 square kilometers). This is a small fraction of the landscape -- much less than 1 percent of the surface area of the northern hemisphere.

The team expects the permanently shadowed regions on Ceres to be colder than those on Mercury or the moon. That's because Ceres is quite far from the sun, and the shadowed parts of its craters receive little indirect radiation.

"On Ceres, these regions act as cold traps down to relatively low latitudes," said Erwan Mazarico, a Dawn guest investigator at Goddard. "On the moon and Mercury, only the permanently shadowed regions very close to the poles get cold enough for ice to be stable on the surface."

Permanent Shadows on Ceres. Image Credits: NASA/JPL-Caltech

The situation on Ceres is more similar to that on Mercury than the moon. On Mercury, permanently shadowed regions account for roughly the same fraction of the northern hemisphere. The trapping efficiency -- the ability to accumulate water ice -- is also comparable.

By the team's calculations, about 1 out of every 1,000 water molecules generated on the surface of Ceres will end up in a cold trap during a year on Ceres (1,682 days). That's enough to build up thin but detectable ice deposits over 100,000 years or so.

"While cold traps may provide surface deposits of water ice as have been seen at the moon and Mercury, Ceres may have been formed with a relatively greater reservoir of water," said Chris Russell, principal investigator of the Dawn mission, based at the University of California, Los Angeles. "Some observations indicate Ceres may be a volatile-rich world that is not dependent on current-day external sources."

The findings are available online in the journal Geophysical Research Letters:
http://onlinelibrary.wiley.com/doi/10.1002/2016GL069368/full

Dawn's mission is managed by NASA's Jet Propulsion Laboratory for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital ATK Inc., in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, Max Planck Institute for Solar System Research, Italian Space Agency and Italian National Astrophysical Institute are international partners on the mission team. For a complete list of mission participants, visit: http://dawn.jpl.nasa.gov/mission

More information about Dawn is available at the following sites:

http://dawn.jpl.nasa.gov

http://www.nasa.gov/dawn

Image (mentioned), Video (mentioned), Text, Credits: NASA/Karl Hille/JPL/Elizabeth Landau/Goddard Space Flight Center, written by Elizabeth Zubritsky.

Greetings, Orbiter.ch

Frosty Cold Nights Year-Round on Mars May Stir Dust

NASA - Mars Reconnaissance Orbiter (MRO) patch.

July 8, 2016

Some dusty parts of Mars get as cold at night year-round as the planet's poles do in winter, even regions near the equator in summer, according to new NASA findings based on Mars Reconnaissance Orbiter observations.

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

The surface in these regions becomes so frigid overnight that an extremely thin layer of carbon dioxide frost appears to form. The frost then vaporizes in the morning. Enough dust covers these regions that their heat-holding capacity is low and so the daily temperature swing is large. Daily volatilization of frost crystals that form among the dust grains may help keep the dust fluffy and so sustain this deep overnight chill.

Carbon dioxide is the main ingredient of Mars' atmosphere. The planet also has large reserves of frozen carbon dioxide buried in the polar ice caps. Seasonal buildup and thawing of carbon dioxide frost at high latitudes on Mars have been studied for years and linked to strange phenomena such as geyser-like eruptions and groove-cutting ice sleds.

Here's what's new knowledge: the presence and extent of transient overnight carbon dioxide frosts, even at middle and low latitudes. Infrared-wavelength observations of dust-covered regions by the Mars Climate Sounder instrument on NASA's Mars Reconnaissance Orbiter not only indicate cold-enough nighttime surface temperatures for carbon dioxide frost to form, they also detect a spectrum signature at night consistent with a trace of frost.

"The temperature gets so low, you start freezing the atmosphere onto the surface," said Sylvain Piqueux of NASA's Jet Propulsion Laboratory, Pasadena, California, lead author of a report on these findings published online by the Journal of Geophysical Research: Planets. "Once you reach that temperature, you don't get colder, you just accumulate more frost. So even on the polar caps, the surface temperature isn't any colder than what these lower-latitude regions get to overnight."

Three middle- and low-latitude areas in the Tharsis, Arabia and Elysium regions of Mars have nightly temperatures cold enough for carbon dioxide frost year-round or nearly year-round. Each of the three is bigger than Texas. All three are dust-covered to the extent that surface temperatures change much quicker than in areas with exposed-bedrock surfaces.

Image above: This map shows the frequency of carbon dioxide frost's presence at sunrise on Mars, as a percentage of days year-round. Carbon dioxide ice more often covers the ground at night in some mid-latitude regions than in polar regions, where it is generally absent for much of summer and fall. Image Credits: NASA/JPL-Caltech.

Piqueux said, "These same regions that are coldest at night are the warmest during the day.  It has to do with the nature of the material -- it's so fluffy. Think of when you're at the beach on a  summer afternoon, where you step on the fine grain sand. You almost burn your foot, it's so hot at the surface, but just below the surface it's not as hot, and if you touch a boulder, it doesn't feel as hot. Then it's the opposite at night: The surface of the sand cools off quickly, while the boulder stays warm."

Unlike the polar regions, at lower latitudes the atmosphere is warmer than the ground at night. A critical step in understanding just how cold the ground in these areas gets at night was correcting observations of the planet's surface for slightly warmer atmospheric temperatures. Temperatures are determined from orbit by analyzing the infrared radiation observed at the top of the atmosphere; this includes radiation from both the ground and the atmosphere. The Mars Climate Sounder instrument, by observing both sideways toward the horizon from orbit and downward, can record infrared emissions from a cross-section of the atmosphere, as well as from the planet's surface. Analysis then reveals the true -- colder -- ground temperature.

The same instrument also provides readings at multiple infrared wavelengths, yielding results consistent with the presence of microscopic-scale carbon dioxide frost crystals forming a layer no thicker than a few sheets of paper.

"If at night you form little frost crystals between the grains of dust on the surface, pushing the grains apart, then the frost crystal becomes a little puff of air in the morning, that might be helping to maintain the fluffiness of the surface," Piqueux said. "You prevent the cementation of grains, the locking together of grains into a more consolidated surface. It's a self-maintaining process: Where you keep the soil fluffy, you maintain the conditions to form frost at night."

"A cycle of carbon dioxide frost that happens every night could be related to other active processes on Mars," said Rich Zurek, JPL's chief Mars scientist. "This agitation of the soil would affect surface physical properties and could have implications for erosive processes and for the exchange of water vapor between the atmosphere and surface."

Many streaks on Martian slopes appear to be slides of dry material, with no liquid involved. The lubrication effect of carbon dioxide frost thawing directly into gas has been linked to such slides where winter frost thaws in spring. Daily frost cycles may have similar effects.

Another type of slope activity on Mars is called recurring slope lineae (RSL). These appear as dark streaks advancing downhill in a warm season, then fade away, then re-appear the next warm season. Hydrated salt has been confirmed at some of these sites, and they are considered the strongest evidence for the possible presence of liquid water on the surface of modern Mars. "Although RSL appear to start on steep, rocky slopes, the realization that overnight carbon dioxide frosts occur even during warm seasons adds another factor to be considered in RSL activity," Zurek said.

The science instruments on NASA's Mars Reconnaissance Orbiter have been examining Mars since 2006. JPL, a division of Caltech in Pasadena, manages the mission for NASA's Science Mission Directorate in Washington and built the Mars Climate Sounder. Lockheed Martin Space Systems of Denver built the orbiter and supports its operations.

Martian Morse Code

This image of dark dunes on Mars was taken on Feb. 6, 2016, at 15:16 local Mars time by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter. These dunes are influenced by local topography. The shape and orientation of dunes can usually tell us about wind direction, but in this image, the dune-forms are very complex, so it’s difficult to know the wind direction.

However, a circular depression (probably an old and infilled impact crater) has limited the amount of sand available for dune formation and influenced local winds. As a result, the dunes here form distinct dots and dashes. The “dashes” are linear dunes formed by bi-directional winds, which are not traveling parallel to the dune. Instead, the combined effect of winds from two directions at right angles to the dunes, funnels material into a linear shape. The smaller “dots” (called “barchanoid dunes”) occur where there is some interruption to the process forming those linear dunes. This process is not well understood at present and is one motivation for HiRISE to image this area.

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. Image Credit: NASA/JPL/University of Arizona/Caption: HiRISE Targeting Specialists.

Related link:

High Resolution Imaging Science Experiment (HiRISE) camera: http://www.uahirise.org/ESP_044675_2580

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

Images (mentioned), Text, Credits: NASA/Tony Greicius/JPL/Guy Webster/Sarah Loff.

Greetings, Orbiter.ch

A Surprising Planet with Three Suns

ESO - European Southern Observatory logo.

7 July 2016

Artist’s impression of planet in the HD 131399 system

A team of astronomers have used the SPHERE instrument on ESO’s Very Large Telescope to image the first planet ever found in a wide orbit inside a triple-star system. The orbit of such a planet had been expected to be unstable, probably resulting in the planet being quickly ejected from the system. But somehow this one survives. This unexpected observation suggests that such systems may actually be more common than previously thought. The results will be published online in the journal Science on 7 July 2016.

Artist’s impression of planet in the HD 131399 system

Luke Skywalker's home planet, Tatooine, in the Star Wars saga, was a strange world with two suns in the sky, but astronomers have now found a planet in an even more exotic system, where an observer would either experience constant daylight or enjoy triple sunrises and sunsets each day, depending on the seasons, which last longer than human lifetimes.

The orbits of the planet and stars in the HD 131399 system

This world has been discovered by a team of astronomers led by the University of Arizona, USA, using direct imaging at ESO’s Very Large Telescope (VLT) in Chile. The planet, HD 131399Ab [1], is unlike any other known world — its orbit around the brightest of the three stars is by far the widest known within a multi-star system. Such orbits are often unstable, because of the complex and changing gravitational attraction from the other two stars in the system, and planets in stable orbits were thought to be very unlikely.

Located about 320 light-years from Earth in the constellation of Centaurus (The Centaur), HD 131399Ab is about 16 million years old, making it also one of the youngest exoplanets discovered to date, and one of very few directly imaged planets. With a temperature of around 580 degrees Celsius and an estimated mass of four Jupiter masses, it is also one of the coldest and least massive directly-imaged exoplanets.

SPHERE observations of the planet HD 131399Ab

"HD 131399Ab is one of the few exoplanets that have been directly imaged, and it's the first one in such an interesting dynamical configuration," said Daniel Apai, from the University of Arizona, USA, and one of the co-authors of the new paper.

"For about half of the planet’s orbit, which lasts 550 Earth-years, three stars are visible in the sky; the fainter two are always much closer together, and change in apparent separation from the brightest star throughout the year," adds Kevin Wagner, the paper's first author and discoverer of HD 131399Ab [2].

The sky around the triple-star system HD 131399

Kevin Wagner, who is a PhD student at the University of Arizona, identified the planet among hundreds of candidate planets and led the follow-up observations to verify its nature.

The planet also marks the first discovery of an exoplanet made with the SPHERE instrument on the VLT. SPHERE is sensitive to infrared light, allowing it to detect the heat signatures of young planets, along with sophisticated features correcting for atmospheric disturbances and blocking out the otherwise blinding light of their host stars.

The triple star HD 131399 in the constellation of Centaurus (The Centaur)

Although repeated and long-term observations will be needed to precisely determine the planet's trajectory among its host stars, observations and simulations seem to suggest the following scenario: the brightest star is estimated to be eighty percent more massive than the Sun and dubbed HD 131399A, which itself is orbited by the less massive stars, B and C, at about 300 au (one au, or astronomical unit, equals the average distance between the Earth and the Sun). All the while, B and C twirl around each other like a spinning dumbbell, separated by a distance roughly equal to that between the Sun and Saturn (10 au).

In this scenario, planet HD 131399Ab travels around the star A in an orbit with a radius of about 80 au, about twice as large as Pluto’s in the Solar System, and brings the planet to about one third of the separation between star A and the B/C star pair. The authors point out that a range of orbital scenarios is possible, and the verdict on the long-term stability of the system will have to wait for planned follow-up observations that will better constrain the planet’s orbit.

SPHERE observations of the planet HD 131399Ab

"If the planet was further away from the most massive star in the system, it would be kicked out of the system," Apai explained. "Our computer simulations have shown that this type of orbit can be stable, but if you change things around just a little bit, it can become unstable very quickly."

Artist’s impression of planet orbiting in the HD 131399 system

Planets in multi-star systems are of special interest to astronomers and planetary scientists because they provide an example of how the mechanism of planetary formation functions in these more extreme scenarios. While multi-star systems seem exotic to us in our orbit around our solitary star, multi-star systems are in fact just as common as single stars.

Zooming in on the HD 131399 triple-star system

"It is not clear how this planet ended up on its wide orbit in this extreme system, and we can't say yet what this means for our broader understanding of the types of planetary systems, but it shows that there is more variety out there than many would have deemed possible," concludes Kevin Wagner. "What we do know is that planets in multi-star systems have been studied far less often, but are potentially just as numerous as planets in single-star systems."

Notes:

[1] The three components of the triple star are named HD 131399A, HD 131399B and HD 131399C respectively, in decreasing order of brightness. The planet orbits the brightest star and hence is named HD 131399Ab.

[2] For much of the planet’s year the stars would appear close together in the sky, giving it a familiar night-side and day-side with a unique triple sunset and sunrise each day. As the planet moves along its orbit the stars grow further apart each day, until they reach a point where the setting of one coincides with the rising of the other — at which point the planet is in near-constant daytime for about one-quarter of its orbit, or roughly 140 Earth-years.

More information:

This research was presented in a paper entitled “Direct Imaging Discovery of a Jovian Exoplanet Within a Triple Star System”, by K. Wagner et al., to appear online in the journal Science on 7 July 2016.

The team is composed of Kevin Wagner (Steward Observatory, The University of Arizona, Tucson, Arizona, USA), Dániel Apai (Steward Observatory and Lunar and Planetary Laboratory, The University of Arizona, Tucson, Arizona, USA), Markus Kasper (ESO, Garching, Germany), Kaitlin Kratter (Steward Observatory, The University of Arizona, Tucson, Arizona, USA), Melissa McClure (ESO, Garching, Germany), Massimo Robberto (Space Telescope Science Institute, Baltimore, Maryland, USA) and Jean-Luc Beuzit (Université Grenoble Alpes, Institut de Planétologie et d’Astrophysique de Grenoble, Grenoble, France; Centre National de la Recherche Scientifique, Institut de Planétologie et d’Astrophysique de Grenoble, Grenoble, France).

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 article:

Newly-Discovered Planet Has 3 Suns
http://orbiterchspacenews.blogspot.ch/2016/07/newly-discovered-planet-has-3-suns.html

Links:

Photos of the VLT: http://www.eso.org/public/images/archive/category/paranal/

ESO’s Very Large Telescope (VLT): http://www.eso.org/vlt

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

Images, Text, Credits: ESO/L. Calçada/M. Kornmesser/K. Wagner et al./Digitized Sky Survey 2/IAU and Sky & Telescope/Videos: ESO/L. Calçada/M. Kornmesser/Digitized Sky Survey 2/N. Risinger (skysurvey.org)/Music: Johan B. Monell.

Greetings, Orbiter.ch

Setting a satellite to catch a satellite

ESA - Clean Space logo.

8 July 2016

 e.Deorbit closing on target satellite

The target is set: a large derelict satellite currently silently tumbling its way through low orbit. If all goes to plan, in 2023 it will vanish – and efforts against space debris will have made a giant leap forward.

That is the vision underpinning e.Deorbit, intended as the world’s first mission to remove a large piece of space junk – if it is given the initial go-ahead by Europe’s space ministers at the Agency’s Ministerial Council in December.

e.Deorbit mission profile

The basic idea is simple: set a satellite to catch a satellite. e.Deorbit will rendezvous with, grapple and hard-capture the drifting satellite, then push the pair down to burn up harmlessly in the atmosphere.

More than 75% of trackable space debris whizzes around in Earth’s heavily trafficked low orbits, below 2000 km altitude. Even if all launches stopped tomorrow, the level of debris would go on rising, driven by continuing collisions.

The only way to stabilise debris levels over the long run will be to remove entire large items.

ESA's active debris removal mission: e.Deorbit

“While the concept is straightforward, the implementation is not – e.Deorbit will be like nothing ESA has ever attempted before,” explains Robin Biesbroek, ESA’s study manager.

“The chaser satellite requires extremely sophisticated guidance, navigation and control to synchronise motion and then capture its target, guided in turn by advanced image processing, blending inputs from optical and multispectral cameras as well as ‘laser radar’ lidar to derive a precise, reliable sense of the target and its motion.

“In addition, e.Deorbit needs a reliable method of capturing its target. We are now looking at a net, harpoon or gripper as well as advanced robotics to secure the two satellites together.

Grappling derelict satellite

“Finally, the satellite also requires a very high level of autonomy, because continuous realtime control from the ground will not be practical, especially during the crucial capture phase.”

ESA’s Clean Space initative, focused on safeguarding the terrestrial and orbital environments, has supported e.Deorbit development so far.

“Industry is eager to participate,” says Luisa Innocenti, heading Clean Space. “The mission should be a spectacular showcase for the capabilities of Europe’s space businesses.

Transporting netted satellite

“The industry consensus is that a new class of ‘space tugs’ will arise to offer various services such as in-orbit servicing or refuelling.

“The technologies such spacecraft will require overlap with those being developed for e.Deorbit – so it will be the first of the space tugs, demonstrating its performance with an unprecedented achievement.

Clean Space: Netting a satellite

“After this Ministerial, we propose to finalise the design and realistically test key technologies – including weightless net testing on a suborbital rocket – to be ready to build after final approval from the next Ministerial, for a planned launch in April 2023.”

About Clean Space:

What is Clean Space?: http://www.esa.int/Our_Activities/Space_Engineering/Clean_Space/What_is_Clean_Space

Why is it needed?: http://www.esa.int/Our_Activities/Space_Engineering/Clean_Space/Why_is_it_needed

What are its objectives?: http://www.esa.int/Our_Activities/Space_Engineering/Clean_Space/What_are_its_objectives

Q & A on Clean Space: http://www.esa.int/Our_Activities/Space_Engineering/Clean_Space/Q_A_on_Clean_Space

Images, Graphic, Videos, Credits: ESA/Airbus Defence and Space.

Best regards, Orbiter.ch

Juno - Team Begins Powering up Science Instruments

NASA - JUNO Mission logo.

July 8, 2016

Mission Status Report

Image above: Artist's concept of NASA's Juno spacecraft crossing the orbits of Jupiter. Image Credits: NASA/JPL-Caltech.

The engineers and scientists working on NASA’s Juno mission have been busying themselves, getting their newly arrived Jupiter orbiter ready for operations around the largest planetary inhabitant in the solar system. Juno successfully entered Jupiter's orbit during a 35-minute engine burn on Monday, July 4. Confirmation that the burn had completed was received on Earth at 8:53 pm. PDT (11:53 p.m. EDT) that evening.

As planned, the spacecraft returned to high-rate communications on July 5 and powered up five of its science instruments on July 6. Per the mission plan, the remaining science instruments will be powered up before the end of the month. Juno’s science instruments had been turned off in the days leading up to Jupiter orbit insertion.

The Juno team has scheduled a short trajectory correction maneuver on July 13 to refine the orbit around Jupiter.

Animation of Juno 14-day orbits starting in late 2016. Credits: NASA/JPL-Caltech

"Prior to launch five years ago we planned a date and time for the Jupiter orbit insertion burn and the team nailed it,” said Rick Nybakken, project manager for Juno from NASA's Jet Propulsion Laboratory in Pasadena, California. "We are in our planned 53.4 day orbit. Now we are focusing on preparing for our fourth and final main engine burn, which will put us in our 14-day science orbit on October 19.”

The next time Juno’s orbit carries it close by the planet will be on Aug. 27. The flyby is expected to provide some preliminary science data.

“We had to turn all our beautiful instruments off to help ensure a successful Jupiter orbit insertion on July 4,” said Scott Bolton, Juno principal investigator from the Southwest Research Institute in San Antonio. “But next time around we will have our eyes and ears open. You can expect us to release some information about our findings around September 1.”

Juno Approach Movie of Jupiter and the Galilean Moons

Video above: NASA's Juno spacecraft captured a unique time-lapse movie of the Galilean satellites in motion about Jupiter. The movie begins on June 12th with Juno 10 million miles from Jupiter, and ends on June 29th, 3 million miles distant. Video Credits: NASA/JPL-Caltech.

The Juno spacecraft launched on Aug. 5, 2011, from Cape Canaveral, Florida.

JPL manages the Juno mission for the principal investigator, Scott Bolton, of Southwest Research Institute in San Antonio. Juno is part of NASA's New Frontiers Program, which is managed at NASA's Marshall Space Flight Center in Huntsville, Alabama, for NASA's Science Mission Directorate. Lockheed Martin Space Systems, Denver, built the spacecraft. Caltech in Pasadena manages JPL for NASA.

More information on the Juno mission is available at: http://www.nasa.gov/juno

The public can follow the mission on Facebook and Twitter at:

http://www.facebook.com/NASAJuno

http://www.twitter.com/NASAJuno

Image (mentioned), Animation (mentioned), Video (mentioned), Text, Credits: NASA/Dwayne Brown / Laurie Cantillo/JPL/DC Agle/Tony Greicius.

Greetings, Orbiter.ch

Mars Canyons Study Adds Clues about Possible Water

NASA - Mars Reconnaissance Orbiter (MRO) logo.

July 7, 2016

Puzzles persist about possible water at seasonally dark streaks on Martian slopes, according to a new study of thousands of such features in the Red Planet's largest canyon system.

Image above: Blue dots on this map indicate sites of recurring slope lineae (RSL) in part of the Valles Marineris canyon network on Mars. RSL are seasonal dark streaks that may be indicators of liquid water. The area mapped here has the highest density of known RSL on Mars. Image Credits: NASA/JPL-Caltech/Univ. of Arizona.

The study published today investigated thousands of these warm-season features in the Valles Marineris region near Mars' equator. Some of the sites displaying the seasonal flows are canyon ridges and isolated peaks, ground shapes that make it hard to explain the streaks as resulting from underground water directly reaching the surface. It is highly unlikey that shallow ground ice would be present as a source for seasonal melting, given the warm temperatures in the equatorial canyons.

Water pulled from the atmosphere by salts, or mechanisms with no flowing water involved, remain possible explanations for the features at these sites.

What are RSL?

These features are called recurring slope lineae, or RSL, a mouthful chosen to describe them without implying how they form. Since their discovery in 2011, Martian RSL have become one of the hottest topics in planetary exploration, the strongest evidence for any liquid water on the surface of modern Mars, even if transient. They appear as dark lines extending downslope during a warm season, then fading away during colder parts of the year, then repeating the progression in a following year. Water, in the form of hydrated salts, was confirmed at some RSL sites last year, including in Valles Marineris.

Research results published today present many findings from detailed observation of 41 RSL sites in central and eastern portions of Valles Marineris, the largest canyon system in the solar system. Each site is defined as the size of a single image from the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter: about 3.4 miles by 8 miles (5.4 by 12 kilometers). The number of individual lineae (flows) in each site ranges from a few to more than 1,000.

Densest Population of RSL

"There are so many of them, it's hard to keep track," said Matthew Chojnacki of the University of Arizona's Lunar and Planetary Laboratory, Tucson, and lead author of today's report in the Journal of Geophysical Research: Planets. "The occurrence of recurring slope lineae in these canyons is much more widespread than previously recognized. As far as we can tell, this is the densest population of them on the planet, so if they are indeed associated with contemporary aqueous activity, that makes this canyon system an even more interesting area than it is just from the spectacular geology alone."

Image above: The white arrows indicate locations in this scene where numerous seasonal dark streaks, called "recurring slope lineae," have been identified in the Coprates Montes area of Mars' Valles Marineris by repeated observations from orbit. Image Credits: NASA/JPL-Caltech/Univ. of Arizona.

The possibility of liquid water at or near the surface of Mars carries major ramifications for investigating whether life exists on Mars, since all known life relies on liquid water. Either liquid or frozen water near the surface could become an important resource for humans on Mars. Fresh crater impacts and other data have revealed water ice close to the surface at many locations in middle and high latitudes of Mars. If RSL are indicators of water, they extend possible water-access sites to low latitudes.

If water is involved in forming RSL, what is the mechanism? Seeking an answer, Chojnacki and five co-authors examined the geological context of canyonland RSL sites and also calculated how much water would need to be present if the streaks are due to liquid water seeping through a thin surface layer to darken the ground.

Many of the sites where RSL were previously identified are on inner walls of impact craters. At that type of site, a conceivable explanation could be that an extensive underground layer holding water was punctured by the crater-forming impact long ago and still feeds warm-season flows. No such underground layer fits the ridge or peak shapes at several of the RSL sites in the new study.

Salt Connection

Another possible mechanism previously proposed for RSL is that some types of salts so strongly pull water vapor out of the Martian atmosphere that liquid brine forms at the ground surface. The new study bolsters the link between RSL and salts. Some sites bear bright, persistent streaks near the dark, seasonal ones. The bright streaks might result from salt left behind after evaporation of brine.

"There are problems with the mechanism of pulling water from the atmosphere, too," Chojnacki said. If it is seeping water that darkens RSL, the amount of liquid water required each year to form the streaks in the studied portion of Valles Marineris would total about 10 to 40 Olympic-size swimming pools (about 30,000 to 100,000 cubic meters), the researchers estimate. The amount of water vapor in the atmosphere above the whole Valles Marineris region is larger than that, but researchers have not identified a process efficient enough at extracting water from the atmosphere to get that much onto the surface.

Artist's view of Mars Reconnaissance Orbiter (MRO). Image Credits: NASA/JPL-Caltech

"There do seem to be more ways atmosphere and surface interact in the canyons than in blander topography, such as clouds trailing out of the canyons and low-lying haze in the canyons." he said. "Perhaps the atmosphere-surface interactions in this region are associated with the high abundance of recurring slope lineae. We can't rule that out, but a mechanism to make the connection is far from clear."

An RSL-forming mechanism with very limited flowing water may also be possible. Based on an Earth resident's experience, it's easy to see a resemblance to wet ground extending from seeping water, but Mars is foreign, even when it looks familiar. Water-free processes do produce other flow features on Mars. RSL's formation mechanism might be entirely dry, or perhaps a hybrid "damp" model requiring much less water than suggested by flowing-water mechanisms.

Three-Dimensional Changes

Another factor added by the new study is that RSL not only darken the surface, but are also associated with material moving downslope. The new study documents slumping and other three-dimensional changes at some RSL sites, occurring seasonally in tandem with the streaks.

Other studies of RSL, including laboratory experiments simulating them on Earth, are in progress. The report published today offers this interim conclusion: "Collectively, results provide additional support for the notion that significant amounts of near-surface water can be found on Mars today and suggest that a widespread mechanism, possibly related to the atmosphere, is recharging RSL sources."

The University of Arizona, Tucson, operates HiRISE, which was built by Ball Aerospace & Technologies Corp. of Boulder, Colorado. NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, 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 (mentioned), Text, Credits: NASA/Dwayne Brown/Laurie Cantillo/Tony Greicius/JPL/Guy Webster.

Best regards, Orbiter.ch

Newly-Discovered Planet Has 3 Suns

NASA - Goddard Space Flight Center logo.

July 7, 2016

If you thought Luke Skywalker's home planet, Tatooine, was a strange world with its two suns in the sky, imagine this: a planet with either constant daylight or triple sunrises and sunsets each day depending on the seasons (which last longer than human lifetimes).

Such a world has been discovered by a team of astronomers led by the University of Arizona using direct imaging. The planet, HD 131399Ab, is unlike any other known world – one with, by far, the widest known orbit within a multi-star system. The discovery will be published in an early online edition of the journal Science on July 7.

Artist's impression of planet orbiting in the HD 131399 system

Video above: This artists impression shows the orbit of the planet in the triple-star system HD 131399. Two of the stars are close together and the third, brighter component is orbited by a gas giant planet named HD 131399Ab. Video Credits: video courtesy European Southern Observatory/L. Calçada/M. Kornmesser.

Located about 340 light years from Earth in the constellation Centaurus, HD 131399Ab is believed to be about 16 million years old, making it one of the youngest exoplanets discovered to date. With a temperature of 850 kelvins (about 1,070 F or 580 C) and weighing in at an estimated four Jupiter masses, it is also one of the coldest and least massive directly-imaged exoplanets.

"HD 131399Ab is one of the few exoplanets that have been directly imaged, and it's the first one in such an interesting dynamical configuration," said Daniel Apai, an assistant professor of Astronomy and Planetary Sciences at the University of Arizona. He is the principal investigator of one of NASA’s teams in the Nexus for Exoplanet System Science (NExSS), which is an interdisciplinary network dedicated to the search for life on planets outside our solar system.

"For about half of the planet’s orbit, which lasts 550 Earth-years, three stars are visible in the sky, the fainter two always much closer together, and changing in apparent separation from the brightest star throughout the year," said Kevin Wagner, a doctoral student in Apai's research group and the paper's first author, who discovered HD 131399Ab. "For much of the planet’s year the stars appear close together, giving it a familiar night-side and day-side with a unique triple-sunset and sunrise each day. As the planet orbits and the stars grow farther apart each day, they reach a point where the setting of one coincides with the rising of the other – at which point the planet is in near-constant daytime for about one-quarter of its orbit, or roughly 140 Earth-years."

The planet marks the first discovery of an exoplanet made with SPHERE, which stands for the Spectro-Polarimetric High-Contrast Exoplanet Research Instrument. It is installed on the Very Large Telescope operated by the European Southern Observatory on Cerro Paranal in the Atacama Desert of northern Chile, and dedicated to finding planets around other stars. SPHERE is sensitive to infrared light, making it capable of detecting the heat signatures of young planets, along with sophisticated features correcting for atmospheric disturbances and blocking out the otherwise blinding light of their host stars.

Although repeated and long-term observations will be needed to precisely determine the planet's trajectory among its host stars, observations and simulations seem to suggest the following scenario: At the center of the system lies a star estimated to be 80 percent more massive than the sun and dubbed HD 131399A, which itself is orbited by the two remaining stars, B and C, at about 300 AU (one AU, or astronomical unit, equals the average distance between Earth and the sun). All the while, B and C twirl around each other like a spinning dumbbell, separated by a distance roughly equal to that between our sun and Saturn.

In this scenario, planet HD 131399Ab travels around the central star, A, in an orbit about twice as large as Pluto’s if compared to our solar system, and brings the planet to about one-third of the separation of the stars themselves. The authors point out that a range of orbital scenarios is possible, and the verdict on long-term stability of the system will have to wait for planned follow-up observations that will better constrain the planet's orbit.

"If the planet was further away from the most massive star in the system, it would be kicked out of the system," Apai explained. "Our computer simulations showed that this type of orbit can be stable, but if you change things around just a little bit, it can become unstable very quickly."

Image above: This artist's impression shows a view of the triple-star system HD 131399 from close to the giant planet orbiting in the system. The planet is known as HD 131399Ab and appears at the lower-left of the picture. Image Credits: image courtesy European Southern Observatory/L. Calçada.

Planets in multi-star systems are of special interest to astronomers and planetary scientists because they provide an example of how planet formation functions in these extreme scenarios. While multi-star systems seem exotic to us in our orbit around our solitary star – multi-star systems are in fact just as common as single stars.

"It is not clear how this planet ended up on its wide orbit in this extreme system, and we can't say yet what this means for our broader understanding of the types of planetary systems out there, but it shows there is more variety out there than many would have deemed possible," Wagner said. "What we do know is that planets in multi-star systems are much less explored, and potentially just as numerous as planets in single-star systems."

“This is the kind of discovery that helps us place our own solar system in the context of the diversity of worlds beyond it, by finding systems that are much different from our own,” says Mary Voytek, senior scientist for astrobiology and program manager of the NExSS network at NASA Headquarters in Washington. “By combining these results with research on the formation of habitable worlds, we will have a better understanding of the systems in which habitable worlds might form. NExSS will ensure such connections are made, within and beyond our NExSS teams.”

NExSS is a NASA-led research coordination network dedicated to the study of planetary habitability by bringing together researchers from different fields. NExSS aims to build an international community of interdisciplinary researchers, including those supported by other agencies, dedicated to exoplanet research through NASA investments. This network will explore the diversity of exoplanets and to learn how their history, geology and climate interact to create the conditions for life. NExSS investigators also strive to put planets into an architectural context – as solar systems built over the eons through dynamical processes and sculpted by stars. Based on our understanding of our own solar system and habitable planet Earth, researchers in the network aim to identify where habitable niches are most likely to occur, which planets are most likely to be habitable. NExSS will accelerate the discovery and characterization of other potentially life-bearing worlds in the galaxy.

The co-authors on the paper are Markus Kasper and Melissa McClure of the European Southern Observatory in Garching, Germany; Kaitlin Kratter at the UA's Steward Observatory; Massimo Roberto at the Space Telescope Science Institute in Baltimore; and Jean-Luc Beuzit with the University of Grenoble Alpes and the National Center of Scientific Research, both in Grenoble, France.

Related Links:

NASA's exoplanets website: http://www.nasa.gov/exoplanets

Feature: "NASA's NExSS Coalition to Lead Search for Life on Distant Worlds": http://www.nasa.gov/feature/nasa-s-nexss-coalition-to-lead-search-for-life-on-distant-worlds

NExSS website: https://nexss.info/

"Many Worlds" blog: http://manyworlds.space/

Goddard Space Flight Center: https://www.nasa.gov/centers/goddard/home/index.html

Image (mentioned), Video (mentioned), Text, Credits: NASA/Felicia Chou/Rob Garner.

Greetings, Orbiter.ch

Powerful processes at work

ESA - Hubble Space Telescope logo.

7 July 2016

The Crab Nebula as never seen before

Moving heart of the Crab Nebula

This new NASA/ESA Hubble Space Telescope image reveals the beating heart of one of the most visually appealing, and most studied, supernova remnants known — the Crab Nebula. At the centre of this nebula the spinning core of a deceased star breathes life into the gas that surrounds it.

The Crab Nebula, which lies 6500 light-years away in the constellation of Taurus (The Bull), is the result of a supernova — a colossal explosion that was the dying act of a massive star. During this explosion most of the material that made up the star was blown into space at immense speeds, forming an expanding cloud of gas known as a supernova remnant.

This extraordinary view of the nebula is one that has never been seen before. Unlike many popular images of this well-known object, which highlight the spectacular filaments in the outer regions, this image shows just the inner part of the nebula and combines three separate high-resolution images — each represented in a different colour — taken around ten years apart.

Digitized Sky Survey 2 image of the Crab Nebula (ground-based image)

At the very centre of the Crab Nebula lies what remains of the innermost core of the original star, now a strange and exotic object known as a neutron star. Made entirely of subatomic particles called neutrons, a neutron star has about the same mass as the Sun, but compressed into a sphere only a few tens of kilometres across. A typical neutron star spins incredibly fast and the one at the centre of the Crab Nebula is no exception, rotating approximately 30 times per second.

The region around a neutron star is a showcase for extreme physical processes and considerable violence. The rapid motion of the material nearest to the star is revealed by the subtle rainbow of colours in this time-lapse image, the rainbow effect being due to the movement of material over the time between one image and another.

Zooming in on the Crab Nebula

Hubble’s sharp eye also captures the intricate details of the ionised gas, shown in red in this image, that forms a swirling medley of cavities and filaments. Inside this shell of ionised gas a ghostly blue glow surrounds the spinning neutron star. This glow is radiation given off by electrons spiralling in the powerful magnetic field around the star at nearly the speed of light [1].

The supernova explosion from which the Crab Nebula was born was one of the first to be recorded in human history [2]. This has made the Crab Nebula an invaluable object for the study of supernova remnants and has enabled astronomers to probe the lives and deaths of stars as never before.

A fulldome study of the Crab Nebula

Notes:

[1] The star’s intense magnetic field is channelling infalling gas and dust to the star’s poles where it is ejected at immense speeds. Two symmetric jets of material are beamed out from the poles, sweeping out into space as the star rotates. Rather like a lighthouse beam, the jets periodically point towards Earth and present astronomers with a blinking — or pulsing — source of light in the sky. Accordingly, these objects are known as pulsars.

[2] The story began in the year 1054 CE, when a new star became visible in the night sky. The new star was the brightest object in the night sky, second only to the Moon. At the time, Chinese and Japanese astronomers recorded the event, and monitored the new star as it gradually faded in brightness until, after several years, it became invisible to the naked eye.

More information:

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

Links:

Images of Hubble: http://www.spacetelescope.org/images/archive/category/spacecraft/

Peering into the heart of the Crab Nebula: https://www.spacetelescope.org/images/opo0015a/

Crab Nebula in different Wavelengths: https://www.spacetelescope.org/videos/astro_b/

Link to hubblesite release: http://hubblesite.org/newscenter/archive/releases/2016/26/

Images, Text, Credits: NASA/ESA Hubble and Digitized Sky Survey 2. Acknowledgements: Davide De Martin (ESA/Hubble)/Videos: ESA/Hubble, Digitized Sky Survey, Nick Risinger (skysurvey.org)/Music: Johan Monell/NASA, ESA and Allison Loll/Jeff Hester (Arizona State University). Acknowledgement: Davide De Martin (ESA/Hubble).

Best regards, Orbiter.ch