vendredi 24 février 2012

Preview of a Forthcoming Supernova











NASA - Hubble Space Telescope patch.

Feb. 24, 2012

Feb. 24, 2012


NASA's Hubble Telescope captured an image of Eta Carinae. This image consists of ultraviolet and visible light images from the High Resolution Channel of Hubble's Advanced Camera for Surveys. The field of view is approximately 30 arcseconds across.

The larger of the two stars in the Eta Carinae system is a huge and unstable star that is nearing the end of its life, and the event that the 19th century astronomers observed was a stellar near-death experience. Scientists call these outbursts supernova impostor events, because they appear similar to supernovae but stop just short of destroying their star.

Although 19th century astronomers did not have telescopes powerful enough to see the 1843 outburst in detail, its effects can be studied today. The huge clouds of matter thrown out a century and a half ago, known as the Homunculus Nebula, have been a regular target for Hubble since its launch in 1990. This image, taken with the Advanced Camera for Surveys High Resolution Channel, is the most detailed yet, and shows how the material from the star was not thrown out in a uniform manner, but forms a huge dumbbell shape.

Eta Carinae is one of the closest stars to Earth that is likely to explode in a supernova in the relatively near future (though in astronomical timescales the "near future" could still be a million years away). When it does, expect an impressive view from Earth, far brighter still than its last outburst: SN 2006gy, the brightest supernova ever observed, came from a star of the same type, though from a galaxy over 200 million light-years away.

NASA Hubble site: http://hubblesite.org/

ESA Hubble site: http://www.spacetelescope.org/

Image, Text, Credit: ESA / NASA.

Greetings, Orbiter.ch

A new generation of meteorological satellites








ESA logo.

24 February 2012

Europe’s next fleet of meteorological satellites is set to debut in 2017, following today’s signing of the development contract. While Meteosat Third Generation will ensure full continuity with the current Meteosat satellite family, it will also introduce significant improvements.

At an event held today at ESA’s headquarters in Paris, the contract between ESA and Thales Alenia Space for developing the new Meteosat Third Generation (MTG) family of satellites was signed.

Following on from Meteosat Second Generation, MTG is a cooperative venture between Eumetsat and ESA, and will ensure continuity of high-resolution meteorological data to beyond 2037.

Meteosat Third Generation

The cooperation on meteorological missions between Eumetsat and ESA is a success story that started with the first Meteosat satellite in 1977 and continues today with Meteosat Second Generation and the polar-orbiting MetOp series.

The new series will comprise six satellites: four MTG-I imaging and two MTG-S sounding satellites.

The first two prototype satellites are scheduled for launch in late 2017 and mid-2019, respectively. Both satellites will be positioned in geostationary orbit above the equator at a longitude between 10ºE and 10ºW.

In addition to the advanced imaging capabilities offered by the Flexible Combined Imager, the satellites will offer an all-new infrared sounding capability and imaging of global lightning that will provide early warning of severe storms.

MTG-S will also carry the Sentinel-4 payload for the Global Monitoring for Environment and Security (GMES) programme. This advanced payload will analyse atmospheric chemistry and identify concentrations of trace gases like ozone and nitrogen dioxide. 

The MTG mission will also provide continued support to global search and rescue monitoring, as well as supporting the Advanced Data Collection System.

MTG-I

At Friday’s event, ESA Director General Jean Jacques Dordain highlighted that Europe can today – and now well into the future – offer state-of-the-art meteorological global monitoring thanks to the 25-year collaboration between ESA and Eumetsat.

Mr Dordain recalled the launch of Meteosat-1 35 years ago, and praised the commitment of ESA, Eumetsat and all industrial partners to continuing the Meteosat legacy.

ESA’s Director of Earth Observation Programmes, Volker Liebig, looked ahead to the significant improvements in performance from the new satellites.

In these difficult economic times, Prof. Liebig stressed, the programme offers many opportunities for European industrial companies to win substantial and high-technology contracts. The MTG contract has an industrial value of over €1.25 billion.

Speeches were also made by Eumetsat Director General Alain Ratier and Thales Alenia Space CEO Reynald Seznec.

The contract between ESA and Thales Alenia Space was signed by Mr. Liebig and Mr Seznec.

Thales Alenia Space leads the industrial consortium that now building the MTG family. Along with being the prime contractor, Thales Alenia Space is responsible for the MTG-I imaging satellite, including the primary payload, the Flexible Combined Imager.

Bremen-based OHB is responsible for the MTG-S satellites and provision of the common satellite platforms, supported by Astrium GmbH as the System Architect.

The state-of-the-art Infrared Sounding Instrument, to be flown on MTG-S, will be developed by Kayser Threde.

Related links:

Thales Alenia Space: http://www.thalesgroup.com/

OHB-System AG: http://www.ohb-system.de/main-company.html

Kayser Threde: http://www.kayser-threde.de/en/

EADS-Astrium: http://www.astrium.eads.net/

Eumetsat: http://www.eumetsat.int/

GMES: http://www.gmes.info/

Images, Text, Credits: ESA / P. Carril.

Cheers, Orbiter.ch

jeudi 23 février 2012

Aiming for an Open Window











NASA logo.

02.23.12

Why does NASA sometimes schedule a rocket launch for the middle of the night, or aim for a liftoff time when weather is notoriously unlikely to cooperate?

The simplicity of the question belies the complexity of the answer. The best time to start a mission is based on a blend of factors: the flight's target and goals, the needs of the spacecraft, the type of rocket, and the desired trajectory, which refers to the path the vehicle and spacecraft must take to successfully start the mission. Not only do these variables influence the preferred launch time -- the ideal time of departure -- but the overall length of the launch window, which can vary from one second to several hours.


Image above: A Delta II arcs across the sky carrying NASA's Suomi NPP spacecraft. Image credit: NASA/Bill Ingalls.

The dynamics change from mission to mission, and determining the launch window is an important part of the overall flight design.

"The interesting thing about our job is each mission is almost completely different from any other mission," said Eric Haddox, the lead flight design engineer in NASA's Launch Services Program (LSP), based at Kennedy Space Center in Florida.

Haddox leads the team of agency and contractor personnel overseeing and integrating the trajectory design efforts of the spacecraft team and launch service contractor for each LSP mission. Once the spacecraft team identifies its needs, a rocket is selected, and the work of hammering out the best launch window and trajectory begins. Ultimately, the launch window and preferred liftoff time are set by the launch service contractor.


Image above: Artist's concept of the Mars Science Laboratory spacecraft approaching the Red Planet. Image credit: NASA/JPL-Caltech.

"We help everybody understand the requirements of the spacecraft and what the capabilities are of the launch vehicle, and try to mesh the two," Haddox explained.

The most significant deciding factors in when to launch are where the spacecraft is headed, and what its solar needs are. Earth-observing spacecraft, for example, may be sent into low-Earth orbit. Some payloads must arrive at a specific point at a precise time, perhaps to rendezvous with another object or join a constellation of satellites already in place. Missions to the moon or a planet involve aiming for a moving object a long distance away.

For example, NASA's Mars Science Laboratory spacecraft began its eight-month journey to the Red Planet on Nov. 26, 2011 with a launch aboard a United Launch Alliance (ULA) Atlas V rocket from Cape Canaveral Air Force Station in Florida. After the initial push from the powerful Atlas V booster, the Centaur upper stage then sent the spacecraft away from Earth on a specific track to place the laboratory, with its car-sized Curiosity rover, inside Mars' Gale Crater on Aug. 6, 2012. Due to the location of Mars relative to Earth, the prime planetary launch opportunity for the Red Planet occurs only once every 26 months.

Additionally, spacecraft often have solar requirements: they may need sunlight to perform the science necessary to meet the mission's objectives, or they may need to avoid the sun's light in order to look deeper into the dark, distant reaches of space.


Image above: As the sun rises at Cape Canaveral Air Force Station, Fla., clouds backdrop the Atlas V set to launch NASA's Juno spacecraft. Image credit: NASA/Kenny Allen.

Such precision was needed for NASA's Suomi National Polar-orbiting Partnership (NPP) spacecraft, which launched Oct. 28, 2011 aboard a ULA Delta II rocket from Vandenberg Air Force Base in California. The Earth-observing satellite circles at an altitude of 512 miles, sweeping from pole to pole 14 times each day as the planet turns on its axis. A very limited launch window was required so that the spacecraft would cross the ascending node at exactly 1:30 p.m. local time and scan Earth's surface twice each day, always at the same local time.

All of these variables influence a flight's trajectory and launch time. A low-Earth mission with specific timing needs must lift off at the right time to slip into the same orbit as its target; a planetary mission typically has to launch when the trajectory will take it away from Earth and out on the correct course.

According to Haddox, aiming for a specific target -- another planet, a rendezvous point, or even a specific location in Earth orbit where the solar conditions will be just right -- is a bit like skeet shooting.

"You've got this object that's going to go flying out into the air and you've got to shoot it," said Haddox. "You have to be able to judge how far away your target is and how fast it's moving, and make sure you reach the same point at the same time."

But Haddox also emphasized that Earth is rotating on its axis while it orbits the sun, making the launch pad a moving platform. With so many moving players, launch windows and trajectories must be carefully choreographed.

Of course, weather or technical problems can interfere with the team's best plans. Launch windows are intended to absorb small delays while still offering plenty of chances to lift off on a given day. However, launching at a time other than the preferred time could reduce the rocket's performance, potentially limiting the payload mass.

"To launch at any time other than that optimal time, you're going to have to alter the trajectory, steer the rocket to get back to that point," Haddox said. "So that's where it becomes a trade of, 'Okay, if my window were a half hour long, how much performance would I need to fly at any time within a half hour? Or, if my window were an hour long, how much performance would I be able to get out of the rocket to fly at any time within that one hour?'"

Likewise, if a spacecraft has to use any of its onboard propellant to make up for any difference in the trajectory, that could impact the entire mission.

"The more propellant they have, the longer they can do maneuvers or adjust things" during the flight, Haddox explained. "It basically equates to how long they can stay in orbit and do their science."

These potential give-and-take situations are carefully considered during flight planning. Mission managers must find a way to balance the sacrifices while maximizing the chance of getting off the ground.

Even when the launch and mission teams have chosen the best launch window, they face an additional challenge from the U.S. Air Force: collision avoidance, also called COLA. The U.S. Air Force's 45th Space Wing controls the Eastern Range surrounding Cape Canaveral Air Force Station in Florida; the 30th Space Wing operates the Western Range, including Vandenberg Air Force Base. The range determines whether any orbiting spacecraft or debris could strike the vehicle during its climb to space, and cut out portions of the launch window that are too risky.

Collision avoidance can get tricky, because even though the trajectory has been carefully planned, real-time factors result in some uncertainty. For example, during the trajectory design process, the team assumes certain propellant temperatures. But if the temperatures are slightly different on launch day, that will affect the propellant, which in turn alters the efficiency of the rocket's engines or solid rocket motors.

"The navigation system on the rocket is going to do what it needs to do to get the spacecraft where it needs to be, but it's not going to be the same trajectory you looked at before," said Haddox. "When you've got things that are moving seven to eight kilometers a second, half a second can result in a big distance."

"So it just makes things a lot harder to predict," he added.

On launch day, Haddox and other members of the flight design team are involved in the countdown. Even in the final hours before liftoff, they continue to fine-tune the trajectory analysis based on real-time data collected from weather balloons, ensuring the safety of the rocket and spacecraft as the window opens for another successful mission.

For more information about NASA, visit: http://www.nasa.gov/

Images (mentioned), Text, Credit; NASA's John F. Kennedy Space Center / Anna Heiney.

Greetings, Orbiter.ch

NASA Satellite Finds Earth's Clouds are Getting Lower












NASA - EOS TERRA Mission patch.

Feb. 23, 2012


This image of clouds over the southern Indian Ocean was acquired on July 23, 2007 by one of the backward (northward)-viewing cameras of the Multi-angle Imaging SpectroRadiometer (MISR) instrument on NASA’s polar-orbiting Terra spacecraft. Image credit: NASA/JPL-Caltech.

Earth's clouds got a little lower -- about one percent on average -- during the first decade of this century, finds a new NASA-funded university study based on NASA satellite data. The results have potential implications for future global climate.

Scientists at the University of Auckland in New Zealand analyzed the first 10 years of global cloud-top height measurements (from March 2000 to February 2010) from the Multi-angle Imaging SpectroRadiometer (MISR) instrument on NASA's Terra spacecraft. The study, published recently in the journal Geophysical Research Letters, revealed an overall trend of decreasing cloud height. Global average cloud height declined by around one percent over the decade, or by around 100 to 130 feet (30 to 40 meters). Most of the reduction was due to fewer clouds occurring at very high altitudes.


Data from NASA's MISR instrument on NASA's Terra spacecraft show that global average cloud height declined by about 1 percent over the decade from 2000 to 2010, or around 100 to 130 feet (30 to 40 meters). Image credit: University of Auckland/NASA JPL-Caltech.

Lead researcher Roger Davies said that while the record is too short to be definitive, it provides a hint that something quite important might be going on. Longer-term monitoring will be required to determine the significance of the observation for global temperatures.

A consistent reduction in cloud height would allow Earth to cool to space more efficiently, reducing the surface temperature of the planet and potentially slowing the effects of global warming. This may represent a "negative feedback" mechanism – a change caused by global warming that works to counteract it. "We don't know exactly what causes the cloud heights to lower," says Davies. "But it must be due to a change in the circulation patterns that give rise to cloud formation at high altitude."

NASA's Terra spacecraft is scheduled to continue gathering data through the remainder of this decade. Scientists will continue to monitor the MISR data closely to see if this trend continues.

For more information, visit: http://www.auckland.ac.nz/uoa/home/news/template/news_item.jsp?cid=466683

 
Patterns that relate changes in cloud-top height with El Niño/ La Niña indicators. Image credit: University of Auckland/NASA JPL-Caltech.

MISR, built and managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., is one of five instruments on NASA's Terra spacecraft, launched in December 1999. The instrument uses nine cameras at different angles to produce a stereo image of clouds around the globe, allowing measurement of their altitude and movement. For more on MISR, visit: http://www-misr.jpl.nasa.gov/ . For more on Terra, visit: http://terra.nasa.gov/

Another NASA mission that studies clouds is NASA's CloudSat, also built by JPL and launched in 2006. CloudSat is the first satellite that uses an advanced radar to "slice" through clouds to see their vertical structure, providing a completely new observational capability from space. CloudSat's primary goal is to furnish data needed to evaluate and improve the way clouds are represented in global models, thereby contributing to better predictions of clouds and thus to their poorly understood role in climate change and the cloud-climate feedback. For information on NASA's CloudSat mission, visit: http://cloudsat.atmos.colostate.edu/ and http://www.nasa.gov/cloudsat

Images (mentioned), Text, Credit: NASA / JPL / Alan Buis.

Best regards, Orbiter.ch

The non-LHC experiments in 2012












CERN - European Organization for Nuclear Research logo.

Feb. 23, 2012

There is more to CERN than the Large Hadron Collider (LHC). A thousand or so physicists on site research topics from antimatter to astronomy in the non-LHC experiments.

View inside the chamber used by CLOUD, one of the many non-LHC experiments at CERN. Image: CERN

This year the ALPHA, ASACUSA, and ATRAP experiments will compare the properties of antiatoms with their matter counterparts, and AEgIS will try to measure the gravitational constant g using antihydrogen. The CLOUD experiment seeks to understand the influence of cosmic rays on cloud formation, while ACE is researching the use of antiproton beams in cancer therapy.

ISOLDE continues to produce radioisotopes for over 50 experiments, and the nTOF facility provides neutron beams for research fields from astronomy to radioactivity. The CAST and OSQAR experiments are hot on the tail of "axions" and "chameleons", some of the many hypothetical and exotic particles proposed by theorists to explain the nature of dark matter.

These are just a few of the many non-LHC experiments looking forward to a productive 2012 at CERN.

Find out more:

    Non-LHC experiments: http://public.web.cern.ch/public/en/Research/OtherExp-en.html

    Quantum diaries: The hidden face of CERN: http://www.quantumdiaries.org/2012/02/15/the-hidden-face-of-cern/

Faster than light neutrinos

The results of the experiment Opera that had shaken the scientific world by measuring end of September of neutrinos at a speed faster than light would in fact due to a bad connection, ensures Wednesday the journal "Science" on its website.

"A bad connection between a computer and a GPS is probably the cause of the error," says the American magazine, citing authoritative sources.

Opera experiment

In late September, the Opera experience experts had said he saw neutrinos through the facilities of CERN in Geneva about 6 km / s faster than light.

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 20 Member States.

More information about the CERN, visit: http://public.web.cern.ch/public/Welcome.html

Images, Text, Credit: CERN.

Greetings, Orbiter.ch

mercredi 22 février 2012

NASA'S Spitzer Finds Solid Buckyballs in Space












NASA - SPITZER Space Telescope patch.

Feb. 22, 2012

Astronomers using data from NASA's Spitzer Space Telescope have, for the first time, discovered buckyballs in a solid form in space. Prior to this discovery, the microscopic carbon spheres had been found only in gas form.


NASA's Spitzer Space Telescope has at last found buckyballs in space, as illustrated by this artist's conception showing the carbon balls coming out from the type of object where they were discovered. Image credit: NASA / JPL-Caltech.

Formally named buckminsterfullerene, buckyballs are named after their resemblance to the late architect Buckminster Fuller's geodesic domes. They are made up of 60 carbon molecules arranged into a hollow sphere, like a soccer ball. Their unusual structure makes them ideal candidates for electrical and chemical applications on Earth, including superconducting materials, medicines, water purification and armor.

In the latest discovery, scientists using Spitzer detected tiny specks of matter, or particles, consisting of stacked buckyballs. They found them around a pair of stars called "XX Ophiuchi," 6,500 light-years from Earth.

video

"These buckyballs are stacked together to form a solid, like oranges in a crate," said Nye Evans of Keele University in England, lead author of a paper appearing in the Monthly Notices of the Royal Astronomical Society. "The particles we detected are miniscule, far smaller than the width of a hair, but each one would contain stacks of millions of buckyballs."

Buckyballs were detected definitively in space for the first time by Spitzer in 2010. Spitzer later identified the molecules in a host of different cosmic environments. It even found them in staggering quantities, the equivalent in mass to 15 Earth moons, in a nearby galaxy called the Small Magellanic Cloud.

In all of those cases, the molecules were in the form of gas. The recent discovery of buckyballs particles means that large quantities of these molecules must be present in some stellar environments in order to link up and form solid particles. The research team was able to identify the solid form of buckyballs in the Spitzer data because they emit light in a unique way that differs from the gaseous form.

"This exciting result suggests that buckyballs are even more widespread in space than the earlier Spitzer results showed," said Mike Werner, project scientist for Spitzer at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "They may be an important form of carbon, an essential building block for life, throughout the cosmos."

Buckyballs have been found on Earth in various forms. They form as a gas from burning candles and exist as solids in certain types of rock, such as the mineral shungite found in Russia, and fulgurite, a glassy rock from Colorado that forms when lightning strikes the ground. In a test tube, the solids take on the form of dark, brown "goo."


These data from NASA's Spitzer Space Telescope show the signatures of buckyballs in space. Image credit: NASA / JPL-Caltech / University of Western Ontario.

"The window Spitzer provides into the infrared universe has revealed beautiful structure on a cosmic scale," said Bill Danchi, Spitzer program scientist at NASA Headquarters in Washington. "In yet another surprise discovery from the mission, we're lucky enough to see elegant structure at one of the smallest scales, teaching us about the internal architecture of existence."

NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif., manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate in Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA.

For information about previous Spitzer discoveries of buckyballs, visit: http://www.nasa.gov/mission_pages/spitzer/news/spitzer20100722.html and http://www.nasa.gov/mission_pages/spitzer/news/spitzer20101027.html

For more information about Spitzer, visit: http://www.nasa.gov/spitzer

Images (mentioned), Video, Text, Credit: NASA / J.D. Harrington / JPL / Alan Buis.

Greetings, Orbiter.ch

mardi 21 février 2012

NASA's Chandra Finds Fastest Wind from Stellar-Mass Black Hole











NASA - Chandra X-ray Observatory patch.

Feb. 21, 2012


Image above: Artist impression of binary system containing stellar-mass black hole IGR J17091. (NASA/CXC/M.Weiss).

Astronomers using NASA's Chandra X-ray Observatory have clocked the fastest wind yet discovered blowing off a disk around a stellar-mass black hole. This result has important implications for understanding how this type of black hole behaves.

The record-breaking wind is moving about 20 million mph, or about 3 percent of the speed of light. This is nearly 10 times faster than had ever been seen from a stellar-mass black hole.

Stellar-mass black holes are born when extremely massive stars collapse. They typically weigh between five and 10 times the mass of the sun. The stellar-mass black hole powering this super wind is known as IGR J17091-3624, or IGR J17091 for short.

"This is like the cosmic equivalent of winds from a category five hurricane," said Ashley King from the University of Michigan, lead author of the study published in the Feb. 20 issue of The Astrophysical Journal Letters. "We weren't expecting to see such powerful winds from a black hole like this."

The wind speed in IGR J17091 matches some of the fastest winds generated by supermassive black holes, objects millions or billions of times more massive.

"It's a surprise this small black hole is able to muster the wind speeds we typically only see in the giant black holes," said co-author Jon M. Miller, also from the University of Michigan. "In other words, this black hole is performing well above its weight class."

Another unanticipated finding is that the wind, which comes from a disk of gas surrounding the black hole, may be carrying away more material than the black hole is capturing.

"Contrary to the popular perception of black holes pulling in all of the material that gets close, we estimate up to 95 percent of the matter in the disk around IGR J17091 is expelled by the wind," King said.

Unlike winds from hurricanes on Earth, the wind from IGR J17091 is blowing in many different directions. This pattern also distinguishes it from a jet, where material flows in highly focused beams perpendicular to the disk, often at nearly the speed of light.

Simultaneous observations made with the National Radio Astronomy Observatory's Expanded Very Large Array showed a radio jet from the black hole was not present when the ultra-fast wind was seen, although a radio jet is seen at other times. This agrees with observations of other stellar-mass black holes, providing further evidence the production of winds can stifle jets.

Chandra X-ray Observatory

The high speed for the wind was estimated from a spectrum made by Chandra in 2011. Ions emit and absorb distinct features in spectra, which allow scientists to monitor them and their behavior. A Chandra spectrum of iron ions made two months earlier showed no evidence of the high-speed wind, meaning the wind likely turns on and off over time.

Astronomers believe that magnetic fields in the disks of black holes are responsible for producing both winds and jets. The geometry of the magnetic fields and rate at which material falls towards the black hole must influence whether jets or winds are produced.

IGR J17091 is a binary system in which a sun-like star orbits the black hole. It is found in the bulge of the Milky Way galaxy, about 28,000 light years away from Earth.

NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra's science and flight operations from Cambridge, Mass.

For more information about Chandra, visit: http://www.nasa.gov/chandra

For an additional interactive image, podcast and video on the finding, visit: http://chandra.si.edu

Image, Text, Credits: Illustration: NASA / CXC / M.Weiss.

Best regards, Orbiter.ch

Hubble Reveals a New Class of Extrasolar Planet












ESA - Hubble Space Telescope logo.

21 February 2012


Observations by the NASA/ESA Hubble Space Telescope have come up with a new class of planet, a waterworld enshrouded by a thick, steamy atmosphere. It’s smaller than Uranus but larger than Earth.

An international team of astronomers led by Zachory Berta of the Harvard-Smithsonian Center for Astrophysics (CfA) made the observations of the planet GJ 1214b.

“GJ 1214b is like no planet we know of,” Berta said. “A huge fraction of its mass is made up of water.”

The ground-based MEarth Project, led by CfA’s David Charbonneau, discovered GJ 1214b in 2009. This super-Earth is about 2.7 times Earth’s diameter and weighs almost seven times as much. It orbits a red-dwarf star every 38 hours at a distance of 2 million kilometres, giving it an estimated temperature of 230 degrees Celsius.

In 2010, CfA scientist Jacob Bean and colleagues reported that they had measured the atmosphere of GJ 1214b, finding it likely that it was composed mainly of water. However, their observations could also be explained by the presence of a planet-enshrouding haze in GJ 1214b’s atmosphere.

Berta and his co-authors, who include Derek Homeier of ENS Lyon, France, used Hubble’s Wide Field Camera 3 (WFC3) to study GJ 1214b when it crossed in front of its host star. During such a transit, the star’s light is filtered through the planet’s atmosphere, giving clues to the mix of gases.

“We’re using Hubble to measure the infrared colour of sunset on this world,” Berta explained.

Hazes are more transparent to infrared light than to visible light, so the Hubble observations help to tell the difference between a steamy and a hazy atmosphere.

They found the spectrum of GJ 1214b to be featureless over a wide range of wavelengths, or colours. The atmospheric model most consistent with the Hubble data is a dense atmosphere of water vapour.

“The Hubble measurements really tip the balance in favour of a steamy atmosphere,” Berta said.

Since the planet’s mass and size are known, astronomers can calculate the density, of only about 2 grams per cubic centimetre. Water has a density of 1 gram per cubic centimetre, while Earth’s average density is 5.5 grams per cubic centimetre. This suggests that GJ 1214b has much more water than Earth does, and much less rock.

As a result, the internal structure of GJ 1214b would be extraordinarily different from that of our world.

“The high temperatures and high pressures would form exotic materials like ‘hot ice’ or ‘superfluid water’, substances that are completely alien to our everyday experience,” Berta said.

Theorists expect that GJ 1214b formed further out from its star, where water ice was plentiful, and migrated inward early in the system’s history. In the process, it would have passed through the star’s habitable zone, where surface temperatures would be similar to Earth’s. How long it lingered there is unknown.

Hubble in orbit

GJ 1214b is located in the constellation of Ophiuchus (The Serpent Bearer), and just 40 light-years from Earth. Therefore, it’s a prime candidate for study by the NASA/ESA/CSA James Webb Space Telescope, planned for launch later this decade.

A paper reporting these results has been accepted for publication in the Astrophysical Journal and is available online.

Notes:

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

The international team of astronomers in this study consists of Z. K. Berta (Harvard-Smithsonian Center for Astronomy, USA), D. Charbonneau (Harvard-Smithsonian Center for Astronomy, USA), J.-M. Desert (Harvard-Smithsonian Center for Astronomy, USA), E. M.-R. Kempton (University of California, Santa Cruz, USA), P. R. McCullough (Space Telescope Science Institute, USA and Smithsonian Astronomical Observatory, USA), C. J. Burke (SETI Institute/NASA Ames Research Center), J. J. Fortney (University of California, Santa Cruz, USA), J. Irwin (Harvard-Smithsonian Center for Astronomy, USA), P. Nutzman (University of California, Santa Cruz, USA), D.  Homeier (CRAL Lyon/ENS Lyon, France and Georg-August University of Göttingen, Germany)

The calibration of the WFC3 slitless spectroscopy modes was undertaken by the Space Telescope European Co-ordinating Facility as part of ESA's contribution to the Hubble Space Telescope project.

Links:

    Research paper: http://www.spacetelescope.org/static/archives/releases/science_papers/heic1204.pdf

    NASA release: http://hubblesite.org/news/2012/13

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

Images, Credit: NASA / ESA / D. Aguilar (Harvard-Smithsonian Center for Astrophysics) / Text: Zachory Berta / Harvard-Smithsonian Center for Astrophysics / Derek Homeier / Centre de Recherche Astrophysique de Lyon and Georg-August University of Göttingen / Oli Usher / Hubble-ESA / David Aguilar / Christine Pulliam / Harvard-Smithsonian Center for Astrophysics Cambridge, USA.

Greetings, Orbiter.ch

LHC to run at 4 TeV per beam in 2012












CERN - European Organization for Nuclear Research logo.

Feb. 21, 2012

CERN was announced (Geneva, 13 February 2012) that the LHC will run with a beam energy of 4 TeV this year, 0.5 TeV higher than in 2010 and 2011. This decision was taken by CERN management following the annual performance workshop held in Chamonix last week and a report delivered today by the external CERN Machine Advisory Committee (CMAC). It is accompanied by a strategy to optimise LHC running to deliver the maximum possible amount of data in 2012 before the LHC goes into a long shutdown to prepare for higher energy running. The data target for 2012 is 15 inverse femtobarns for ATLAS and CMS, three times higher than in 2011. Bunch spacing in the LHC will remain at 50 nanoseconds.

LHC - CERN

“When we started operating the LHC for physics in 2010, we chose the lowest safe beam energy consistent with the physics we wanted to do,” said CERN’s Director for Accelerators and Technology, Steve Myers. “Two good years of operational experience with beam and many additional measurements made during 2011 give us the confidence to safely move up a notch, and thereby extend the physics reach of the experiments before we go into the LHC’s first long shutdown.”

The LHC’s excellent performance in 2010 and 2011 has brought tantalising hints of new physics, notably narrowing the range of masses available to the Higgs particle to a window of just 16 GeV. Within this window, both the ATLAS and CMS experiments have seen hints that a Higgs might exist in the mass range 124-126 GeV. However, to turn those hints into a discovery, or to rule out the Standard Model Higgs particle altogether, requires one more year’s worth of data. The LHC is scheduled to enter a long technical stop at the end of this year to prepare for running at its full design energy of around 7 TeV per beam.

video
CERN News - LHC to run at 4 TeV per beam in 2012

“By the time the LHC goes into its first long stop at the end of this year, we will either know that a Higgs particle exists or have ruled out the existence of a Standard Model Higgs,” said CERN’s Research Director, Sergio Bertolucci. “Either would be a major advance in our exploration of nature, bringing us closer to understanding how the fundamental particles acquire their mass, and marking the beginning of a new chapter in particle physics."

The schedule announced today foresees beams back in the LHC next month, and running through to November. There will then be a long technical stop of around 20 months, with the LHC restarting close to its full design energy late in 2014 and operating for physics at the new high energy in early 2015.

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 20 Member States.

More information:

    CERN video news: http://cdsweb.cern.ch/record/1423359

    ATLAS: http://atlas.ch/

    CMS: http://cms.web.cern.ch/

    LHCb: http://lhcb-public.web.cern.ch/lhcb-public/

    ALICE: http://aliceinfo.cern.ch/Public/Welcome.html

Follow CERN at:

    http://www.cern.ch
    http://twitter.com/cern/
    http://www.youtube.com/user/CERNTV
    http://www.quantumdiaries.org/

Image, Video, Text, Credit: CERN.

Cheers, Orbiter.ch

lundi 20 février 2012

NASA Spacecraft Reveals Recent Geological Activity on the Moon












NASA - Lunar Reconnaissance Orbiter (LRO) patch.

02.20.12

New images from NASA's Lunar Reconnaissance Orbiter (LRO) spacecraft show the moon's crust is being stretched, forming minute valleys in a few small areas on the lunar surface. Scientists propose this geologic activity occurred less than 50 million years ago, which is considered recent compared to the moon's age of more than 4.5 billion years.

A team of researchers analyzing high-resolution images obtained by the Lunar Reconnaissance Orbiter Camera (LROC) show small, narrow trenches typically much longer than they are wide. This indicates the lunar crust is being pulled apart at these locations. These linear valleys, known as graben, form when the moon's crust stretches, breaks and drops down along two bounding faults. A handful of these graben systems have been found across the lunar surface.

video

Video above: Dr. Thomas Watters discusses the lunar graben and what they reveal about how the moon evolved. (Credit: NASA's Goddard Space Flight Center, Dan Gallagher).

"We think the moon is in a general state of global contraction because of cooling of a still hot interior," said Thomas Watters of the Center for Earth and Planetary Studies at the Smithsonian's National Air and Space Museum in Washington, and lead author of a paper on this research appearing in the March issue of the journal Nature Geoscience. "The graben tell us forces acting to shrink the moon were overcome in places by forces acting to pull it apart. This means the contractional forces shrinking the moon cannot be large, or the small graben might never form."

The weak contraction suggests that the moon, unlike the terrestrial planets, did not completely melt in the very early stages of its evolution. Rather, observations support an alternative view that only the moon's exterior initially melted forming an ocean of molten rock.


This shows the largest of the newly detected graben found in highlands of the lunar farside. The broadest graben is about 500 meters (1,640 feet) wide and topography derived from Lunar Reconnaissance Orbiter Camera (LROC) Narrow Angle Camera (NAC) stereo images indicates they are almost 20 meters (almost 66 feet) deep. (Credit: NASA/Goddard/Arizona State University/Smithsonian Institution).

In August 2010, the team used LROC images to identify physical signs of contraction on the lunar surface, in the form of lobe-shaped cliffs known as lobate scarps. The scarps are evidence the moon shrank globally in the geologically recent past and might still be shrinking today. The team saw these scarps widely distributed across the moon and concluded it was shrinking as the interior slowly cooled.

Based on the size of the scarps, it is estimated that the distance between the moon's center and its surface shank by approximately 300 feet. The graben were an unexpected discovery and the images provide contradictory evidence that the regions of the lunar crust are also being pulled apart.

"This pulling apart tells us the moon is still active," said Richard Vondrak, LRO Project Scientist at NASA's Goddard Space Flight Center in Greenbelt, Md. "LRO gives us a detailed look at that process."


Graben are troughs formed when the lunar crust was stretched and pulled apart. This stretching causes the near-surface materials to break along two parallel normal faults, the terrain in between the twin faults drops down forming a valley. (Credit: Arizona State University/Smithsonian Institution).

As the LRO mission progresses and coverage increases, scientists will have a better picture of how common these young graben are and what other types of tectonic features are nearby. The graben systems the team finds may help scientists refine the state of stress in the lunar crust.

"It was a big surprise when I spotted graben in the far side highlands," said co-author Mark Robinson of the School of Earth and Space Exploration at Arizona State University, principal investigator of LROC. "I immediately targeted the area for high-resolution stereo images so we could create a three-dimensional view of the graben. It's exciting when you discover something totally unexpected and only about half the lunar surface has been imaged in high resolution. There is much more of the moon to be explored."

The research was funded by the LRO mission, currently under NASA's Science Mission Directorate at NASA Headquarters in Washington. LRO is managed by NASA's Goddard Space Flight Center in Greenbelt, Md.

For more information about LRO Mission, visit: http://www.nasa.gov/mission_pages/LRO/main/index.html and http://lro.gsfc.nasa.gov/

Images (mentioned), Video (mentioned), Text, Credit: NASA / Dwayne Brown.

Greetings, Orbiter.ch

The experiment "RIM-PAMELA" continues











Roscosmos patch.


02/20/2012

Since 2006, the spacecraft (SC) "Resource DK1", developed and manufactured in accordance with the Federal Space Program of Russia commissioned by the Federal Space Agency, holds a joint Russian-Italian experiment "RIM-PAMELA."

The experiment was conducted in order to space research aimed at finding and studying antimatter (antiprotons, positrons), nuclear and electronic components in the primary cosmic radiation. Carrying out the experiment, the scientists plan will help to solve some fundamental problems in cosmology (the origin of the universe).

With the help of a magnetic spectrometer, "PAMELA", designed and created by scientists from Russia and Italy, and continue to be made precise measurements of charged particles and antiparticles in cosmic radiation. To date, obtained and published several scientific world-class results.

Scientific instrumentation of  "PAMELA"

An increase with increasing energy flux ratio of high-energy cosmic positrons to electrons, which required a substantial revision of ideas about the generation and propagation of such particles in the Galaxy (Nature v.458., P.607-609, 2009).

Interpretation of experimental results devoted nearly a thousand scientific papers in various scientific journals. The most interesting and important from the standpoint of the fundamental problems of the nature of dark matter, is to explain the annihilation and decay of dark matter particles. In practice this is the first experimental result on the problem of the existence of dark matter particles.

The growth of the flux ratio of positrons to electrons in the literature is called "anomalous PAMELA" and included the American Physical Society in the list of 10 outstanding world of physical results for 2008, along with the launch of the LHC in Geneva.

For the first time measured the flux of cosmic antiprotons in the energy range from fifty to two hundred thousand million electron-volts, which allowed, in particular, to analyze the different theoretical models of the nature and properties of dark matter particles (Physical Review Letter v.105., R.121101, 2010) .

As a result of measuring the energy spectra of protons and helium nuclei in cosmic rays was first shown that the energy spectra of protons and helium nuclei are different due to different mechanisms of particle acceleration and, therefore, the advantage of flow of helium nuclei at extremely high energies (Science v.332 № 6025, p. 69-72, 2011).

The experiment is also open to the near-Earth space are captured by the geomagnetic field of high-energy antiprotons, formed by the collapse of albedo antineutrons. This result has as a fundamental value that is associated with the theory of Earth's radiation belt, as well as practical importance to create the model Earth's radiation belt (Astrophysical Journal Letters v. 737, p. 1-19, 2011).

The results of experimental studies "RIM-PAMELA" repeatedly reported at scientific conferences and published in Russian scientific journals, particularly in the scientific journal "Proceedings of the Academy of Sciences", "Bulletin of the Academy of Sciences," "Letters to the Journal of Experimental and Theoretical Physics", "Uspekhi Fizicheskikh Science ", etc.

"Resurs-DK"

If you continue to experiment, "RIM-PAMELA" on board "Resurs DK1" supposed to detect solar flares during the growth of the solar activity cycle, the 24th, in order to study particle acceleration in the Sun and solar terrestrial relations, as well as to measure the energy spectra of light and streams medium nuclei in the galactic cosmic radiation.

23 and January 27 scientific instruments: a magnetic spectrometer, "PAMELA", and a scintillation spectrometer, "Arina", mounted on the spacecraft "Resurs DK1", recorded solar proton events from the most powerful solar flares.

January 23 at 03:59 UT (about 8:00 am Moscow time) observed the eruption of a large sunspot in 1402, accompanied by a solar flare class M9. Shortly thereafter, protons with energies of several hundred MeV were registered devices "Pamela" and "Arina" orbit on Earth.

January 27 at 18:37 UT the same active region on the sun caused a more powerful flash unit class X2. The active region was at that moment at the edge of the sun and therefore the shock wave was not directed toward the Earth. However, increased flows of high-energy particles detected on the satellite "Resurs DK1" was several times stronger.

We are currently processing the data to obtain information about the composition and energy spectra of solar particles, these unique events.

Original text in Russian: http://www.federalspace.ru/main.php?id=2&nid=18705

Images, Text, Credit: Press Service of the Russian Space Agency (Roscosmos PAO) / Translation: Orbiter.ch.

Best regards, Orbiter.ch