NASA's Fermi Mission Brings Deeper Focus to Thunderstorm Gamma-rays

NASA - Fermi Gamma-ray Space Telescope logo.

December 15, 2014

Each day, thunderstorms around the world produce about a thousand quick bursts of gamma rays, some of the highest-energy light naturally found on Earth. By merging records of events seen by NASA's Fermi Gamma-ray Space Telescope with data from ground-based radar and lightning detectors, scientists have completed the most detailed analysis to date of the types of thunderstorms involved.

"Remarkably, we have found that any thunderstorm can produce gamma rays, even those that appear to be so weak a meteorologist wouldn't look twice at them," said Themis Chronis, who led the research at the University of Alabama in Huntsville (UAH).

NASA Fermi Helps Scientists Study Gamma-ray Thunderstorms

Video above: New research merging Fermi data with information from ground-based radar and lightning networks shows that terrestrial gamma-ray flashes arise from an unexpected diversity of storms and may be more common than currently thought. Image Credit: NASA's Goddard Space Flight Center.

The outbursts, called terrestrial gamma-ray flashes (TGFs), were discovered in 1992 by NASA's Compton Gamma-Ray Observatory, which operated until 2000. TGFs occur unpredictably and fleetingly, with durations less than a thousandth of a second, and remain poorly understood.

In late 2012, Fermi scientists employed new techniques that effectively upgraded the satellite's Gamma-ray Burst Monitor (GBM), making it 10 times more sensitive to TGFs and allowing it to record weak events that were overlooked before.

"As a result of our enhanced discovery rate, we were able to show that most TGFs also generate strong bursts of radio waves like those produced by lightning," said Michael Briggs, assistant director of the Center for Space Plasma and Aeronomic Research at UAH and a member of the GBM team.

Previously, TGF positions could be roughly estimated based on Fermi's location at the time of the event. The GBM can detect flashes within about 500 miles (800 kilometers), but this is too imprecise to definitively associate a TGF with a specific storm.

Ground-based lightning networks use radio data to pin down strike locations. The discovery of similar signals from TGFs meant that scientists could use the networks to determine which storms produce gamma-ray flashes, opening the door to a deeper understanding of the meteorology powering these extreme events.

Fermi Gamma-ray Space Telescope. Image Credit: NASA

Chronis, Briggs and their colleagues sifted through 2,279 TGFs detected by Fermi's GBM to derive a sample of nearly 900 events accurately located by the Total Lightning Network operated by Earth Networks in Germantown, Maryland, and the World Wide Lightning Location Network, a research collaboration run by the University of Washington in Seattle. These systems can pinpoint the location of lightning discharges -- and the corresponding signals from TGFs -- to within 6 miles (10 km) anywhere on the globe.

From this group, the team identified 24 TGFs that occurred within areas covered by Next Generation Weather Radar (NEXRAD) sites in Florida, Louisiana, Texas, Puerto Rico and Guam. For eight of these storms, the researchers obtained additional information about atmospheric conditions through sensor data collected by the Department of Atmospheric Science at the University of Wyoming in Laramie.

"All told, this study is our best look yet at TGF-producing storms, and it shows convincingly that storm intensity is not the key," said Chronis, who will present the findings Wed., Dec. 17, in an invited talk at the American Geophysical Union meeting in San Francisco. A paper describing the research has been submitted to the Bulletin of the American Meteorological Society.

Scientists suspect that TGFs arise from strong electric fields near the tops of thunderstorms. Updrafts and downdrafts within the storms force rain, snow and ice to collide and acquire electrical charge. Usually, positive charge accumulates in the upper part of the storm and negative charge accumulates below. When the storm's electrical field becomes so strong it breaks down the insulating properties of air, a lightning discharge occurs.

Image above: This photograph, taken in May 2008 as the Fermi Gamma-ray Space Telescope was being readied for launch, highlights the detectors of the spacecraft's Gamma-ray Burst Monitor (GBM). The GBM is an array of 14 crystal detectors designed for transient lower-energy gamma-ray outbursts, such as TGFs. Image Credit: NASA/Jim Grossmann.

Under the right conditions, the upper part of an intracloud lightning bolt disrupts the storm's electric field in such a way that an avalanche of electrons surges upward at high speed. When these fast-moving electrons are deflected by air molecules, they emit gamma rays and create a TGF.

About 75 percent of lightning stays within the storm, and about 2,000 of these intracloud discharges occur for each TGF Fermi detects.

The new study confirms previous findings indicating that TGFs tend to occur near the highest parts of a thunderstorm, between about 7 and 9 miles (11 to 14 kilometers) high. "We suspect this isn't the full story," explained Briggs. "Lightning often occurs at lower altitudes and TGFs probably do too, but traveling the greater depth of air weakens the gamma rays so much the GBM can't detect them."

Based on current Fermi statistics, scientists estimate that some 1,100 TGFs occur each day, but the number may be much higher if low-altitude flashes are being missed.

While it is too early to draw conclusions, Chronis notes, there are a few hints that gamma-ray flashes may prefer storm areas where updrafts have weakened and the aging storm has become less organized. "Part of our ongoing research is to track these storms with NEXRAD radar to determine if we can relate TGFs to the thunderstorm life cycle," he said.

For more information about Fermi Gamma-ray Space Telescope, visit: http://fermi.gsfc.nasa.gov/ and http://www.nasa.gov/mission_pages/GLAST/main/

Related Links:

Download video in HD formats from NASA Goddard's Scientific Visualization Studio: http://svs.gsfc.nasa.gov/goto?10278

Fermi Improves its Vision for Thunderstorm Gamma-Ray Flashes (12.06.2012): http://orbiterchspacenews.blogspot.ch/2012/12/fermi-improves-its-vision-for.html

NASA's Fermi Catches Thunderstorms Hurling Antimatter into Space (01.10.2011): http://orbiterchspacenews.blogspot.ch/2011/01/nasas-fermi-catches-thunderstorms.html

Images (mentioned), Video (mentioned), Text, Credits: NASA's Goddard Space Flight Center/Francis Reddy.

Greetings, Orbiter.ch

NASA’s MAVEN Mission Identifies Links in Chain Leading to Atmospheric Loss

NASA - MAVEN Mission logo.

December 15, 2014

Early discoveries by NASA’s newest Mars orbiter are starting to reveal key features about the loss of the planet’s atmosphere to space over time.

The findings are among the first returns from NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) mission, which entered its science phase on Nov. 16. The observations reveal a new process by which the solar wind can penetrate deep into a planetary atmosphere. They include the first comprehensive measurements of the composition of Mars’ upper atmosphere and electrically charged ionosphere. The results also offer an unprecedented view of ions as they gain the energy that will lead to their to escape from the atmosphere.

“We are beginning to see the links in a chain that begins with solar-driven processes acting on gas in the upper atmosphere and leads to atmospheric loss,” said Bruce Jakosky, MAVEN principal investigator with the Laboratory for Atmospheric and Space Physics at the University of Colorado, Boulder. “Over the course of the full mission, we’ll be able to fill in this picture and really understand the processes by which the atmosphere changed over time.”

Image above: NASA’s MAVEN mission is observing the upper atmosphere of Mars to help understand climate change on the planet. MAVEN entered its science phase on Nov. 16, 2014. Image Credit: NASA's Goddard Space Flight Center.

On each orbit around Mars, MAVEN dips into the ionosphere – the layer of ions and electrons extending from about 75 to 300 miles above the surface. This layer serves as a kind of shield around the planet, deflecting the solar wind, an intense stream of hot, high-energy particles from the sun.

Scientists have long thought that measurements of the solar wind could be made only before these particles hit the invisible boundary of the ionosphere. MAVEN’s Solar Wind Ion Analyzer, however, has discovered a stream of solar-wind particles that are not deflected but penetrate deep into Mars’ upper atmosphere and ionosphere.

Interactions in the upper atmosphere appear to transform this stream of ions into a neutral form that can penetrate to surprisingly low altitudes. Deep in the ionosphere, the stream emerges, almost Houdini-like, in ion form again. The reappearance of these ions, which retain characteristics of the pristine solar wind, provides a new way to track the properties of the solar wind and may make it easier to link drivers of atmospheric loss directly to activity in the upper atmosphere and ionosphere.

MAVEN’s Neutral Gas and Ion Mass Spectrometer is exploring the nature of the reservoir from which gases are escaping by conducting the first comprehensive analysis of the composition of the upper atmosphere and ionosphere. These studies will help researchers make connections between the lower atmosphere, which controls climate, and the upper atmosphere, where the loss is occurring.

The instrument has measured the abundances of many gases in ion and neutral forms, revealing well-defined structure in the upper atmosphere and ionosphere, in contrast to the lower atmosphere, where gases are well-mixed. The variations in these abundances over time will provide new insights into the physics and chemistry of this region and have already provided evidence of significant upper-atmospheric “weather” that has not been measured in detail before.

New insight into how gases leave the atmosphere is being provided by the spacecraft’s Suprathermal and Thermal Ion Composition (STATIC) instrument. Within hours after being turned on at Mars, STATIC detected the “polar plume” of ions escaping from Mars. This measurement is important in determining the rate of atmospheric loss.

As the satellite dips down into the atmosphere, STATIC identifies the cold ionosphere at closest approach and subsequently measures the heating of this charged gas to escape velocities as MAVEN rises in altitude. The energized ions ultimately break free of the planet’s gravity as they move along a plume that extends behind Mars.

The MAVEN spacecraft and its instruments have the full technical capability proposed in 2007 and are on track to carry out the primary science mission. The MAVEN team delivered the spacecraft to Mars on schedule, launching on the very day in 2013 projected by the team 5 years earlier. MAVEN was also delivered well under the confirmed budget established by NASA in 2010.

The team’s success can be attributed to a focused science mission that matched the available funding and diligent management of resources. There were also minimal changes in requirements on the hardware or science capabilities that could have driven costs. It also reflects good coordination between the principal investigator; the project management at NASA’s Goddard Space Flight Center; the Mars Program Office at NASA’s Jet Propulsion Laboratory in Pasadena, California; and the Mars Exploration Program at NASA Headquarters.

The entire project team contributed to MAVEN’s success to date, including the management team, the spacecraft and science-instrument institutions, and the launch-services provider.

“The MAVEN spacecraft and its instruments are fully operational and well on their way to carrying out the primary science mission,” said Jim Green, director of NASA’s Planetary Science Division at NASA Headquarters in Washington. “The management team’s outstanding work enabled the project to be delivered on schedule and under budget.”

MAVEN’s principal investigator is based at the University of Colorado’s Laboratory for Atmospheric and Space Physics in Boulder, and NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the mission.

For more information about NASA’s MAVEN mission, visit: http://www.nasa.gov/maven

Image (mentioned), Text, Credits: NASA's Goddard Space Flight Center/Nancy Neal-Jones/Elizabeth Zubritsky.

Greetings, Orbiter.ch

CryoSat extends its reach on the Arctic

ESA - Cryosat 2 Mission logo.

15 December 2014

CryoSat has delivered this year’s map of autumn sea-ice thickness in the Arctic, revealing a small decrease in ice volume. In a new phase for ESA’s ice mission, the measurements can now also be used to help vessels navigate through the north coastal waters of Alaska, for example.

Measurements made during October and November show that the volume of Arctic sea ice now stands at about 10 200 cubic km – a small drop compared to last year’s 10 900 cubic km.

The volume is the second-highest since measurements began in 2010, and the five-year average is relatively stable. This, however, does not necessarily indicate a turn in the long-term downward trend.

Five years ice-thickness change

“We must to take care when computing long-term trends as this CryoSat assessment is short when compared to other climate records,” said Prof. Andrew Shepherd from University College London and the University of Leeds.

“For reliable predictions, we should try other approaches, like considering what is forcing the changes, incorporating the CryoSat data into predictive models based on solid physics, or simply waiting until more measurements have been collected.”

CryoSat was designed to measure sea-ice thickness across the entire Arctic Ocean, enabling scientists to monitor accurately the overall change in volume.

While the amount of ice normally fluctuates depending on the season, longer-term satellite records show a constant downward trend in ice extent during all seasons, in particular in summer, with a minimum occurring in the autumn of 2012.

CryoSat

Establishing whether the ice volume is following a similar trend is one of CryoSat’s key mission objectives.

A team of UK researchers at the Centre for Polar Observation and Modelling are presenting their findings this week at the American Geophysical Union’s autumn meeting in San Francisco, California.

“October is interesting because it is the first month we get data directly following the sea-ice minimum in September, so that’s where we see the largest interannual variability in our volume estimates,” said the Centre’s Rachel Tilling, who is working on the CryoSat measurements as part of her PhD studies.

Launched in 2010, CryoSat has long surpassed its planned three-year life. At the mission’s recent mid-term review, it was further extended until February 2017.

Ice thickness for operational applications

Tommaso Parrinello, ESA’s CryoSat Mission Manager, said, “CryoSat has already achieved outstanding results, both within its original mission objectives and for unexpected applications.

“Looking ahead, we are working hard to prototype new operational capabilities so that the measurements can be used for routine assessments in climate science and for services affected by Arctic sea ice.”

To test this, scientists have produced an assessment of sea-ice thickness north of Alaska and eastern Russia with data acquired over the last month. Products like this could prove useful for maritime services, such as shipping and exploration.

Related links:

Introducing CryoSat: http://www.esa.int/Our_Activities/Observing_the_Earth/CryoSat/Introducing_CryoSat

Access CryoSat data: https://earth.esa.int/web/guest/missions/esa-operational-eo-missions/cryosat

University College London: http://www.ucl.ac.uk/

University of Leeds: http://www.leeds.ac.uk/

Centre for Polar Observation and Modelling: http://www.cpom.org/index.html

AGU Fall Meeting 2014: http://fallmeeting.agu.org/2014/

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

Best regards, Orbiter.ch

ILS Proton Successfully Launches the Yamal-401 Satellite Marking the 400th Proton Mission

ILS - Yamal-401 launch mission poster.


December 15, 2014

International Launch Services (ILS), a leader in providing mission integration and launch services to the global commercial satellite industry, successfully launched the Yamal-401 satellite into geosynchronous orbit today on an ILS Proton for JSC Gazprom Space Systems (Gazprom) of Moscow.  This was the landmark 400th mission for the Proton launch vehicle since its first flight in 1965.

The ILS Proton Breeze M vehicle launched from Pad 24 at the Baikonur Cosmodrome at 6:16 a.m. today local time (00:16 GMT and 7:16 p.m. EST on December 14).  The first three stages of the Proton vehicle used a standard ascent profile to place the orbital unit (Breeze M upper stage and the Yamal-401 satellite) into a sub-orbital trajectory.

Full View of 400th Proton-M Launch with Yamal-401

Utilizing a 4-burn Breeze M flight design, the Breeze M performed its planned mission maneuvers to advance the orbital unit first to a circular parking orbit, then to an intermediate orbit, followed by a transfer orbit, and finally to a geosynchronous orbit where the satellite was successfully separated from the Breeze M.

The satellite, weighing nearly 3 metric tons, was built by JSC ISS Reshetnev on the Express 2000-A platform.  In collaboration with JSC ISS Reshetnev, Thales Alenia Space was responsible for the repeater, antennas, parts of the satellite platform, and support to the customer for satellite AIT in Siberia and Baïkonur.

At an orbital location of 90° East longitude, the Yamal 401 communications satellite will provide services to users in Russia and CIS countries. The total capacity of the Yamal 401 satellite will amount to 53 physical transponders or 88 equivalent (36 MHz) transponders, which will compose one fixed beam in C band and two fixed beams in Ku band. JSC Gazprom Space Systems has ensured the development of the ground infrastructure to control and operate the satellite.

Yamal-401 communications satellite

Phil Slack, president of ILS commented, “We thank Gazprom for the opportunity to launch this important satellite and to help expand their business with the launch of Yamal 401, the second launch for Gazprom by ILS. We are grateful for the mission teams of Gazprom, ILS, Khrunichev, ISS Reshetnev and Thales Alenia Space for their dedication to mission success throughout the entire campaign.”

This was the 86th ILS Proton mission overall and the 2nd ILS Proton launch of 2014. The Proton Breeze M vehicle is developed and built by Khrunichev State Research and Production Space Center of Moscow, the majority shareholder in ILS.

For more information about International Launch System (ILS), visit: http://www.ilslaunch.com/

Images, Video, Text, Credits: ILS / ROSCOSMOS.

Greetings, Orbiter.ch

Magnetic paint

ESA - Planck Mission patch.

December 15, 2014

The magnetic field along the Galactic plane

While the pastel tones and fine texture of this image may bring to mind brush strokes on an artist’s canvas, they are in fact a visualisation of data from ESA’s Planck satellite. The image portrays the interaction between interstellar dust in the Milky Way and the structure of our Galaxy’s magnetic field.

Between 2009 and 2013, Planck scanned the sky to detect the most ancient light in the history of the Universe – the cosmic microwave background. It also detected significant foreground emission from diffuse material in our Galaxy which, although a nuisance for cosmological studies, is extremely important for studying the birth of stars and other phenomena in the Milky Way.

Among the foreground sources at the wavelengths probed by Planck is cosmic dust, a minor but crucial component of the interstellar medium that pervades the Galaxy. Mainly gas, it is the raw material for stars to form.

Interstellar clouds of gas and dust are also threaded by the Galaxy’s magnetic field, and dust grains tend to align their longest axis at right angles to the direction of the field. As a result, the light emitted by dust grains is partly ‘polarised’ – it vibrates in a preferred direction – and, as such, could be caught by the polarisation-sensitive detectors on Planck.

Scientists in the Planck collaboration are using the polarised emission of interstellar dust to reconstruct the Galaxy’s magnetic field and study its role in the build-up of structure in the Milky Way, leading to star formation.

In this image, the colour scale represents the total intensity of dust emission, revealing the structure of interstellar clouds in the Milky Way. The texture is based on measurements of the direction of the polarised light emitted by the dust, which in turn indicates the orientation of the magnetic field.

Planck spacecraft

This image shows the intricate link between the magnetic field and the structure of the interstellar medium along the plane of the Milky Way. In particular, the arrangement of the magnetic field is more ordered along the Galactic plane, where it follows the spiral structure of the Milky Way. Small clouds are seen just above and below the plane, where the magnetic field structure becomes less regular.

From these and other similar observations, Planck scientists found that filamentary interstellar clouds are preferentially aligned with the direction of the ambient magnetic field, highlighting the strong role played by magnetism in galaxy evolution.

The emission from dust is computed from a combination of Planck observations at 353, 545 and 857 GHz, whereas the direction of the magnetic field is based on Planck polarisation data at 353 GHz.

For more information about Planck mission, visit: http://www.esa.int/Our_Activities/Space_Science/Planck

Images, Text, Credits: ESA/Planck Collaboration. Acknowledgment: M.-A. Miville-Deschênes, CNRS – Institut d’Astrophysique Spatiale, Université Paris-XI, Orsay, France.

Cheers, Orbiter.ch

CERN’s Large Hadron Collider gears up for run 2

CERN - European Organization for Nuclear Research logo.

December 14, 2014

CERN (Friday 12, 2014) announced at the 174th session of the CERN Council that the Large Hadron Collider (LHC) is gearing up for its second three-year run. The LHC is the largest and most powerful particle accelerator in the world and the whole 27-kilometre superconducting machine is now almost cooled to its nominal operating temperature of 1.9 degrees above absolute zero. All teams are at work to get the LHC back online and the CERN Control Centre is in full swing to carry out all the requested tests before circulating proton beams again in March 2015. Run 2 of the LHC follows a 2-year technical stop that prepared the machine for running at almost double the energy of the LHC’s first run.

“With this new energy level, the LHC will open new horizons for physics and for future discoveries,” says CERN Director-General Rolf Heuer. “I’m looking forward to seeing what nature has in store for us”.

Image above: The Large Hadron Collider is preparing for running at higher energy in 2015 (Image: Maximilen Brice/CERN).

For the first time on 9 December 2014, the magnets of one sector of the LHC, one eighth of the ring, were successfully powered to the level needed for beams to reach 6.5 TeV, the operating energy for run 2. The goal for 2015 will be to run with two proton beams in order to produce 13 TeV collisions, an energy never achieved by any accelerator in the past.

“After the huge amount of work done over the last two years, the LHC is almost like a new machine,” said CERN’s Director for Accelerators and Technology Frédérick Bordry. “Restarting this extraordinary accelerator is far from routine. Nevertheless, I’m confident that we will be on schedule to provide collisions to the LHC experiments by May 2015”.

ALICE, ATLAS, CMS and LHCb, the four large experiments of the LHC, are also undergoing major preparatory work for run 2, after the long shutdown during which important programmes for maintenance and improvements were achieved. They will now enter their final commissioning phase.

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.

Related links:

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

ALICE: http://home.web.cern.ch/about/experiments/alice

ATLAS: http://home.web.cern.ch/about/experiments/atlas

CMS: http://home.web.cern.ch/about/experiments/cms

LHCb: http://home.web.cern.ch/about/experiments/lhcb

Image, Text, Credits: CERN/Cian O'Luanaigh.

Cheers, Orbiter.ch

The signal of dark matter could have been detected

Ecole Polytechnique Fédérale de Lausanne (EPFL) logo.

December 14, 2014

The signal of a dark matter particle could have been detected. EPFL researchers have identified an atypical photon emission in X-rays from celestial objects. If this discovery is confirmed, "a new era" would open in astronomy, said Thursday the High School.

The researchers analyzed the X-rays emitted by two celestial bodies: the Perseus cluster of galaxies and the Andromeda galaxy. They have thus noticed an error that put their flea in the ear, although the possibility of errors can not be completely excluded.

Image above: Chandra X-ray Observatory observations of the central regions of the Perseus galaxy cluster. Image is 284 arcsec across. RA 03h 19m 47.60s Dec +41° 30' 37.00" in Perseus. Observation dates: 13 pointings between August 8, 2002 and October 20, 2004. Color code: Energy (Red 0.3-1.2 keV, Green 1.2-2 keV, Blue 2-7 keV). Instrument: ACIS. Image Credits: NASA/CXC/IoA/A.Fabian et al.

The signal is manifested by a low emission and non-typical photon can not be traced to any known material. In addition, "the distribution of the signal within the galaxy corresponds exactly to that in which we expect to find dark matter, more concentrated and intense in the center of the objects, weaker and diffuse around the edges," said Oleg Ruchayskiy, one of the researchers quoted in the release.

Image above: Andromeda galaxy (M31) seen by Hubble Space Telescope. Image Credits: NASA/ESA.

To test the hypothesis, "we then conducted surveys within our galaxy, the Milky Way, and made the same observations," adds his colleague Alexey Boyarsky. The discovery of the two employees of the Physics Laboratory particles and cosmology (CFPA) at EPFL in Lausanne will be published Monday in "Physical Review Letters".

80% of the universe

The detected signal is due to the emission of a photon resulting from the destruction of a hypothetical particle, for example a sterile neutrino. If these developments continue, "a new era" opens for astronomy, according to Oleg Ruchayskiy. Thanks to new tools, researchers should be able to understand what dark matter is made.

For the record, physicists are faced with a mystery when studying the dynamics of celestial bodies. Their equations do not take if they are based only on visible matter. The observables do not explain the rotation of objects and gravitational forces.

Image above: The 3D distribution of dark matter obtained from a large numerical simulation and Hubble observations, dark matter it would be at least 80% of the universe. Image Credits: NASA/ESA.

Faced with this lack of understanding, physicists have deduced the existence of invisible matter that does not interact with light, but gravity acts on the set. They called dark matter and think it would be at least 80% of the universe.

For more information about Ecole Polytechnique Fédérale de Lausanne (EPFL), visit: http://www.epfl.ch/index.en.html

Images (mentioned), Text, Credits: ATS / Orbiter.ch Aerospace.

Greetings, Orbiter.ch