What happened while the LHC slept over winter?

CERN - European Organization for Nuclear Research logo.

April 11, 2017

Image above: The winter shutdown of the LHC enabled upgrades and maintenance to take place (Image: Maximilien Brice/CERN).

Since the beginning of December, hundreds of people have been busy underground at CERN, working to make important repairs and to upgrade many facilities, across the whole of CERN’s accelerator chain and experiments.

This year the annual shutdown, called the Extended Year End Technical Stop (EYETS) is particularly long, lasting until May 2017, to allow more work to be carried out than in previous years.

At the beginning of the shutdown, the entire machine was drained of its liquid helium to avoid wasting any of the precious element, while important work was done to the LHC’s cryogenics system.

Image above: The new dipole magnet ready to be installed in sector 1-2. The magnet was finally replaced on Monday, 16 January. (Image: CERN).

After removing the helium, scientists and engineers were also able to check the cooling and ventilation, vacuum, electrical and other systems, to make sure they were running properly.

Next, the technical team have had to replace one of the 1232 magnets in the LHC’s ring. Once the magnet was replaced, the team had to carry out many tests at room temperature, triple-checking the magnet was connected properly with no leaks, or deformation.

Also, the Super Proton Synchrotron (SPS) beam dump needed replacing. Beam dumps are radiation-shielded blocks, deep underground, where scientists can choose to send beams that have become degraded so that they can be safely absorbed.

Image above: Researchers re-designed and produced a new beam dump that would allow the SPS to reach its full performance for the 2017 run (Image: Maximilien Brice/ CERN).

Issues with the SPS dump last year had limited the number of particle bunches that could be injected into the Large Hadron Collider (LHC), so it needed to be replaced. A heroic effort was made to re-design and produce a new beam dump, which was finally installed in March and will allow the SPS to reach its full performance again for the 2017 run.

A large part of the shutdown had been identifying and labelling individual cables and removing unnecessary ones in preparation for the many new cables that will be needed for future upgrades.

Over the past few weeks the helium has been re-injected into the system and is being slowly cooled so that the machine can be handed back to the operations teams. From now, the injectors in the accelerator chain are being reawakened.

Timelapse CMS experiment clip 5

Video above: A timelapse video showing the CMS detector closing, as the experiments are now getting ready for the LHC restart in early May (Video: CMS/ CERN).

The experiments also used this time to maintain and improve their machines, including the replacement of the detector’s pixel tracker, at the heart of the experiment. All the experiments are now doing final checks before the caverns close, in time for the LHC to be able to inject the first beam in early May.

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 22 Member States.

Related links:

LHC’s cryogenics system: http://home.cern/about/engineering/cryogenics-low-temperatures-high-performance

Super Proton Synchrotron (SPS): https://home.cern/about/accelerators/super-proton-synchrotron

For more information about European Organization for Nuclear Research (CERN), Visit: http://home.cern/

Images (mentioned), Video (mentioned), Text, Credits: CERN/Harriet Jarlett.

Best regards, Orbiter.ch

Clinoforms in Melas Chasma

NASA - Mars Reconnaissance Orbiter (MRO) patch.

April 11, 2017

In this image from NASA's Mars Reconnaissance Orbiter, a group of steeply inclined light-toned layers is bounded above and below by unconformities (sudden or irregular changes from one deposit to another) that indicate a "break" where erosion of pre-existing layers was taking place at a higher rate than deposition of new materials.

The layered deposits in Melas Basin may have been deposited during the growth of a delta complex. This depositional sequence likely represents a period where materials were being deposited on the floor of a lake or running river.

This is a stereo pair with http://www.uahirise.org/PSP_007878_1700

The map is projected here at a scale of 25 centimeters (9.8 inches) per pixel. [The original image scale is 28.9 centimeters (11.4 inches) per pixel (with 1 x 1 binning); objects on the order of 87 centimeters (34.2 inches) across are resolved.] North is up.

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 Caltech in Pasadena, California, manages the Mars Reconnaissance Orbiter Project for NASA's Science Mission Directorate, Washington.

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

Image, Text, Credits: NASA/JPL-Caltech/Univ. of Arizona.

Greetings, Orbiter.ch

Solar Storms Can Drain Electrical Charge Above Earth

NASA - Solar Dynamics Observatory (SDO) patch.

April 11, 2017

New research on solar storms finds that they not only can cause regions of excessive electrical charge in the upper atmosphere above Earth's poles, they also can do the exact opposite: cause regions that are nearly depleted of electrically charged particles. The finding adds to our knowledge of how solar storms affect Earth and could possibly lead to improved radio communication and navigation systems for the Arctic.

A team of researchers from Denmark, the United States and Canada made the discovery while studying a solar storm that reached Earth on Feb. 19, 2014. The storm was observed to affect the ionosphere in all of Earth's northern latitudes. Its effects on Greenland were documented by a network of global navigation satellite system, or GNSS, stations as well as geomagnetic observatories and other resources. Attila Komjathy of NASA's Jet Propulsion Laboratory, Pasadena, California, developed software to process the GNSS data and helped with the data processing. The results were published in the journal Radio Science.

Solar storms often include an eruption on the sun called a coronal mass ejection, or CME. This is a vast cloud of electrically charged particles hurled into space that disturbs the interplanetary magnetic field in our solar system. When these particles and the magnetic disturbances encounter Earth's magnetic field, they interact in a series of complex physical processes, and trigger perturbations in the Earth’s magnetic field. Those perturbations are called geomagnetic storms. The interactions may cause unstable patches of excess electrons in the ionosphere, an atmospheric region starting about 50 miles (80 kilometers) above Earth's surface that already contains ions and electrons.

Animation above: A solar eruption on Sept. 26, 2014, seen by NASA's Solar Dynamics Observatory. If erupted solar material reaches Earth, it can deplete the electrons in the upper atmosphere in some locations while adding electrons in others, disrupting communications either way. Animation Credit: NASA.

The 2014 geomagnetic storm was a result of two powerful Earth-directed CMEs. The storm initially produced patches of extra electrons in the ionosphere over northern Greenland, as usual. But just south of these patches, the scientists were surprised to find broad areas extending 300 to 600 miles (500 to 1,000 kilometers) where the electrons were "almost vacuumed out," in the words of Per Hoeg of the National Space Research Institute at the Technical University of Denmark, Lyngby. These areas remained depleted of electrons for several days.

The electrons in the ionosphere normally reflect radio waves back to ground level, enabling long-distance radio communications. Both electron depletion and electron increases in this layer can possibly cause radio communications to fail, reduce the accuracy of GPS systems, damage satellites and harm electrical grids.

"We don’t know exactly what causes the depletion," Komjathy said. "One possible explanation is that electrons are recombining with positively charged ions until there are no excess electrons. There could also be redistribution -- electrons being displaced and pushed away from the region, not only horizontally but vertically."

The paper is titled "Multiinstrument observations of a geomagnetic storm and its effects on the Arctic ionosphere: A case study of the 19 February 2014 storm." Lead author Tibor Durgonics is a doctoral student at the Technical University of Denmark. Richard Langley (University of New Brunswick, Canada) provided data sets and interpretation.

JPL is a division of Caltech in Pasadena, California.

Related links:

Earth Research Findings: https://www.nasa.gov/subject/7782/earth-research-findings

Sun: http://www.nasa.gov/sun

NASA Solar Dynamics Observatory (SDO): https://www.nasa.gov/mission_pages/sdo/main/index.html

Animation (mentioned), Text, Credits: NASA's Earth Science News Team, written by Carol Rasmussen/Tony Greicius/JPL/Alan Buis.

Greetings, Orbiter.ch

NASA's MAVEN Reveals Mars Has Metal in its Atmosphere

NASA - Mars Atmosphere and Volatile Evolution (MAVEN) mission logo.

April 10, 2017

Mars has electrically charged metal atoms (ions) high in its atmosphere, according to new results from NASA's MAVEN spacecraft. The metal ions can reveal previously invisible activity in the mysterious electrically charged upper atmosphere (ionosphere) of Mars.

Image above: This artist concept shows the MAVEN spacecraft and the limb of Mars. Image Credits: NASA's Goddard Space Flight Center.

"MAVEN has made the first direct detection of the permanent presence of metal ions in the ionosphere of a planet other than Earth," said Joseph Grebowsky of NASA's Goddard Space Flight Center in Greenbelt, Maryland. "Because metallic ions have long lifetimes and are transported far from their region of origin by neutral winds and electric fields, they can be used to infer motion in the ionosphere, similar to the way we use a lofted leaf to reveal which way the wind is blowing." Grebowsky is lead author of a paper on this research appearing April 10 in Geophysical Research Letters.

MAVEN (Mars Atmosphere and Volatile Evolution Mission) is exploring the Martian upper atmosphere to understand how the planet lost most of its air, transforming from a world that could have supported life billions of years ago into a cold desert planet today. Understanding ionospheric activity is shedding light on how the Martian atmosphere is being lost to space, according to the team.

The metal comes from a constant rain of tiny meteoroids onto the Red Planet. When a high-speed meteoroid hits the Martian atmosphere, it vaporizes. Metal atoms in the vapor trail get some of their electrons torn away by other charged atoms and molecules in the ionosphere, transforming the metal atoms into electrically charged ions.

MAVEN has detected iron, magnesium, and sodium ions in the upper atmosphere of Mars over the last two years using its Neutral Gas and Ion Mass Spectrometer instrument, giving the team confidence that the metal ions are a permanent feature. "We detected metal ions associated with the close passage of Comet Siding Spring in 2014, but that was a unique event and it didn't tell us about the long-term presence of the ions," said Grebowsky.

The interplanetary dust that causes the meteor showers is common throughout our solar system, so it's likely that all solar system planets and moons with substantial atmospheres have metal ions, according to the team.

Sounding rockets, radar and satellite measurements have detected metal ion layers high in the atmosphere above Earth. There's also been indirect evidence for metal ions above other planets in our solar system. When spacecraft are exploring these worlds from orbit, sometimes their radio signals pass through the planet's atmosphere on the way to Earth, and sometimes portions of the signal have been blocked. This has been interpreted as interference from electrons in the ionosphere, some of which are thought to be associated with metal ions. However, long-term direct detection of the metal ions by MAVEN is the first conclusive evidence that these ions exist on another planet and that they are a permanent feature there.

The team found that the metal ions behaved differently on Mars than on Earth. Earth is surrounded by a global magnetic field generated in its interior, and this magnetic field together with ionospheric winds forces the metal ions into layers. However, Mars has only local magnetic fields fossilized in certain regions of its crust, and the team only saw the layers near these areas. "Elsewhere, the metal ion distributions are totally unlike those observed at Earth," said Grebowsky.

The research has other applications as well. For example it is unclear if the metal ions can affect the formation or behavior of high-altitude clouds. Also, detailed understanding of the meteoritic ions in the totally different Earth and Mars environments will be useful for better predicting consequences of interplanetary dust impacts in other yet-unexplored solar system atmospheres. "Observing metal ions on another planet gives us something to compare and contrast with Earth to understand the ionosphere and atmospheric chemistry better," said Grebowsky.

The research was funded by the MAVEN mission. MAVEN's principal investigator is based at the University of Colorado's Laboratory for Atmospheric and Space Physics, Boulder. The university provided two science instruments and leads science operations, as well as education and public outreach, for the mission. NASA Goddard manages the MAVEN project and provided two science instruments for the mission. The University of California at Berkeley's Space Sciences Laboratory also provided four science instruments for the mission. Lockheed Martin built the spacecraft and is responsible for mission operations. NASA's Jet Propulsion Laboratory in Pasadena, California, provides navigation and Deep Space Network support, as well as the Electra telecommunications relay hardware and operations.

Related link:

Geophysical Research Letters: http://onlinelibrary.wiley.com/doi/10.1002/2017GL072635/abstract

MAVEN (Mars Atmosphere and Volatile Evolution): https://www.nasa.gov/mission_pages/maven/main/index.html

Image (mentioned), Text, Credits: NASA Goddard Space Flight Center/Bill Steigerwald/Nancy Jones.

Greetings, Orbiter.ch

Plateaus Up Close

NASA - Cassini Mission to Saturn patch.

April 10, 2017

Saturn’s C ring isn’t uniformly bright. Instead, about a dozen regions of the ring stand out as noticeably brighter than the rest of the ring, while about half a dozen regions are devoid of ring material. Scientists call the bright regions “plateaus” and the devoid regions “gaps.”

Scientists have determined that the plateaus are relatively bright because they have higher particle density and reflect more light, but researchers haven’t solved the trickier puzzle of how the plateaus are created and maintained.

This view looks toward the sunlit side of the rings from about 62 degrees above the ring plane. The image was taken Jan. 9, 2017 in green light with the Cassini spacecraft’s narrow-angle camera.

Cassini obtained the image while approximately 194,000 miles (312,000 kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 67 degrees. Image scale is 1.2 miles (2 kilometers) per pixel.

The Cassini mission is a cooperative project of NASA, ESA (the European Space Agency) and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colorado.

For more information about the Cassini-Huygens mission visit https://saturn.jpl.nasa.gov and http://www.nasa.gov/cassini . The Cassini imaging team homepage is at http://ciclops.org and ESA's website http://www.esa.int/Our_Activities/Space_Science/Cassini-Huygens

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

Greetings, Orbiter.ch

Hubble Spots Auroras on Uranus

NASA - Hubble Space Telescope patch.

April 10, 2017



This is a composite image of Uranus by Voyager 2 and two different observations made by Hubble — one for the ring and one for the auroras.

Ever since Voyager 2 beamed home spectacular images of the planets in the 1980s, planet-lovers have been hooked on auroras on other planets. Auroras are caused by streams of charged particles like electrons that come from various origins such as solar winds, the planetary ionosphere, and moon volcanism. They become caught in powerful magnetic fields and are channeled into the upper atmosphere, where their interactions with gas particles, such as oxygen or nitrogen, set off spectacular bursts of light.

The auroras on Jupiter and Saturn are well-studied, but not much is known about the auroras of the giant ice planet Uranus. In 2011, the NASA/ESA Hubble Space Telescope became the first Earth-based telescope to snap an image of the auroras on Uranus. In 2012 and 2014 a team led by an astronomer from Paris Observatory took a second look at the auroras using the ultraviolet capabilities of the Space Telescope Imaging Spectrograph (STIS) installed on Hubble.

They tracked the interplanetary shocks caused by two powerful bursts of solar wind traveling from the sun to Uranus, then used Hubble to capture their effect on Uranus’ auroras — and found themselves observing the most intense auroras ever seen on the planet. By watching the auroras over time, they collected the first direct evidence that these powerful shimmering regions rotate with the planet. They also re-discovered Uranus’ long-lost magnetic poles, which were lost shortly after their discovery by Voyager 2 in 1986 due to uncertainties in measurements and the featureless planet surface.

 Hubble Space Telescope

For images and more information about Hubble, visit:

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

Images, Animation,  Credits: ESA/Hubble & NASA, L. Lamy/Observatoire de Paris/Text credits: European Space Agency/NASA/Karl Hille.

Greetings, Orbiter.ch

South Polar Spiral

NASA - Mars Reconnaissance Orbiter (MRO) patch.

April 7, 2017

This hill in the South Polar layered deposits has influenced the erosion of the icy layers as seen by by NASA's Mars Reconnaissance Orbiter. The hill protects the layers from erosion, so the pattern of erosion to the sides of the hill forms a beautiful spiral pattern.

The map is projected here at a scale of 50 centimeters (19.7 inches) per pixel. [The original image scale is 49.7 centimeters (19.6 inches) per pixel (with 2 x 2 binning); objects on the order of 149 centimeters (58.6 inches) across are resolved.] North is up.

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 Caltech in Pasadena, California, manages the Mars Reconnaissance Orbiter Project for NASA's Science Mission Directorate, Washington.

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

Image, Text,  Credits: NASA/Tony Greicius/JPL-Caltech/Univ. of Arizona.

Greetings, Orbiter.ch