mardi 5 avril 2016

Opportunity's Devilish View from on High











NASA - Mars Exploration Rover B (MER-B) patch.

April 5, 2016


From its perch high on a ridge, NASA's Mars Exploration Rover Opportunity recorded this image of a Martian dust devil twisting through the valley below. The view looks back at the rover's tracks leading up the north-facing slope of "Knudsen Ridge," which forms part of the southern edge of "Marathon Valley."

Opportunity took the image using its navigation camera (Navcam) on March 31, 2016, during the 4,332nd Martian day, or sol, of the rover's work on Mars.

Dust devils were a common sight for Opportunity's twin rover, Spirit, in its outpost at Gusev Crater. Dust devils have been an uncommon sight for Opportunity though.

Just as on Earth, a dust devil is created by a rising, rotating column of hot air. When the column whirls fast enough, it picks up tiny grains of dust from the ground, making the vortex visible.

During the uphill drive to reach the top of Knudsen Ridge, Opportunity's tilt reached 32 degrees, the steepest ever for any rover on Mars.

NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Exploration Rover Project for NASA's Science Mission Directorate, Washington.

For more information about Opportunity, visit http://www.nasa.gov/rovers and http://marsrovers.jpl.nasa.gov.

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

Greetings, Orbiter.ch

lundi 4 avril 2016

NASA Examines El Niño's Impact on Ocean’s Food Source












NASA's Goddard Space Flight Center logo.

April 4, 2016

El Niño years can have a big impact on the littlest plants in the ocean, and NASA scientists are studying the relationship between the two.

In El Niño years, huge masses of warm water – equivalent to about half of the volume of the Mediterranean Sea – slosh east across the Pacific Ocean towards South America. While this warm water changes storm systems in the atmosphere, it also has an impact below the ocean’s surface. These impacts, which researchers can visualize with satellite data, can ripple up the food chain to fisheries and the livelihoods of fishermen.


Animation above: Strong El Nino events have a big impact on phytoplankton (in green), especially when the warm water pushes far to the east of the Pacific Ocean, as in 1997.
Animation Credits: NASA/Goddard.

El Niño’s mass of warm water puts a lid on the normal currents of cold, deep water that typically rise to the surface along the equator and off the coast of Chile and Peru, said Stephanie Uz, ocean scientist at Goddard Space Flight Center in Greenbelt, Maryland. In a process called upwelling, those cold waters normally bring up the nutrients that feed the tiny organisms, which form the base of the food chain.

"An El Niño basically stops the normal upwelling," Uz said. "There’s a lot of starvation that happens to the marine food web." These tiny plants, called phytoplankton, are fish food – without them, fish populations drop, and the fishing industries that many coastal regions depend on can collapse.

How El Niño Impacts Marine Plant Life

Video above: El Niño years can have a big impact on the littlest plants in the ocean, and NASA scientists are studying the relationship between the two. Ocean color maps, based on a month's worth of satellite data, show El Niño's impact on phytoplankton. Video Credits: NASA's Goddard Scientific Visualization Studio.

With NASA satellite data, and ocean color software called SeaDAS, developed at the Ocean Biology Processing Group at Goddard, Uz has been mapping where these important phytoplankton appear. Orbiting instruments like the Moderate Resolution Imaging Spectrometer on the Aqua satellite, and the Visible Infrared Imaging Radiometer Suite on the Suomi NPP satellite collect data on the color of the ocean. From shades of blue and green, scientists can calculate the amount of green chlorophyll – and therefore the amount of phytoplankton present.

The ocean color maps, based on a month’s worth of satellite data, can show that El Niño impact on phytoplankton. In December 2015, at the peak of the current El Niño event, there was more blue – and less green chlorophyll – in the Pacific Ocean off of Peru and Chile, compared to the previous year. Uz and her colleagues are also watching as the El Niño weakens this spring, to see when and where the phytoplankton reappear as the upwelling cold water brings nutrients back to the region.

"They can pop back up pretty quickly, once they have a source of nutrients," Uz said.

Researchers can also examine the differences in ocean color between two different El Niño events. During the large 1997-1998 El Niño event, the green chlorophyll virtually disappeared from the coast of Chile. This year’s event, while it caused a drop in chlorophyll primarily along the equator, was much less severe for the coastal phytoplankton population. The reason – the warmer-than-normal waters associated with the two El Niño events were centered in different geographical locations. In 1997-1998, the biggest ocean temperature abnormalities were in the eastern Pacific Ocean; this year the focus was in the central ocean. This difference impacts where the phytoplankton can feed on nutrients, and where the fish can feed on phytoplankton.

"When you have an East Pacific El Niño, like 1997-1998, it has a much bigger impact on the fisheries off of South America," Uz said.  But Central Pacific El Niño events, like this year’s, still have an impact on ocean ecosystems, just with a shift in location. Researchers are noting reduced food available along the food chain around the Galapagos Islands, for example. And there has been a drop in phytoplankton off the coast of South America, just not as dramatically as before.


Images aboves: Differences in December phytoplankton abundances are visualized for three years: during the strong East Pacific El Nino of 1997 (using SeaWiFS satellite data), during a normal year in 2013 (using data from MODIS on the Aqua satellite), and during the strong Central Pacific El Nino of 2015 (MODIS/Aqua). Images Credits: Uz/NASA Goddard.

Scientists have more tools on hand to study this El Niño, and can study more elements of the event, Uz said. They’re putting these tools to use to ask questions not just about ocean ecology, but about the carbon cycle as well.

"We know how important phytoplankton are for the marine food web, and we’re trying to understand their role as a carbon pump," Uz said. The carbon pump refers to one of the ways the Earth system removes carbon dioxide from the atmosphere. When phytoplankton die, their carbon-based bodies sink to the ocean floor, where they can remain for millions of years. El Niño is a naturally occurring disruption to the typical ocean currents, she said – so it’s important to understand the phenomenon to better attribute what occurs naturally, and what occurs due to human-caused disruptions to the system.

Other scientists at Goddard are investigating ways to forecast the ebbs and flows of nutrients using the center’s supercomputers, incorporating data like winds, sea surface temperatures, air pressures and more.

"It’s like weather forecasts, but for bionutrients and phytoplankton in the ocean," said Cecile Rousseaux, an ocean modeler with Goddard’s Global Modeling and Assimilation Office. The forecasts could help fisheries managers estimate how good the catch could be in a particular year, she said, since fish populations depend on phytoplankton populations. The 1997-1998 El Niño led to a major collapse in the anchovy fishery off of Chile, which caused economic hardships for fishermen along the coast.

So far, Rousseaux said, the phytoplankton forecast models haven’t shown any collapses for the 2015-2016 El Niño, possibly because the warm water isn’t reaching as far east in the Pacific this time around. The forecast of phytoplankton populations effort is a relatively new effort, she said, so it’s too soon to make definite forecasts. But the data so far, from the modeling group and others, show conditions returning to a more normal state this spring.

The next step for the model, she said, is to try to determine which individual species of phytoplankton will bloom where, based on nutrient amounts, temperatures and other factors – using satellites and other tools to determine which kind of microscopic plant is where.

"We rely on satellite data, but this will go one step further and give us even more information," Rousseaux said.

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

Images (mentioned), Video (mentioned), Text, Credits: NASA's Goddard Space Flight Center/Kate Ramsayer/Karl Hille.

Greetings, Orbiter.ch

Saturn Askew












NASA - Cassini Mission to Saturn patch.

April 4, 2016


As a convention for public release, Cassini images of Saturn are generally oriented so that Saturn appears north up, but the spacecraft views the planet and its expansive rings from all sorts of angles. Here, a half-lit Saturn sits askew as tiny Dione (698 miles or 1,123 kilometers across) looks on from lower left. And the terminator, which separates night from day on Saturn, is also askew, owing to the planet’s approach to northern summer solstice. As a result, the planet’s northern pole is in sunlight all throughout Saturn’s day, much as it would be on Earth during northern summer.

This view looks toward the sunlit side of the rings from about 7 degrees above the ring plane. The image was taken with the Cassini spacecraft wide-angle camera on Feb. 19, 2016 using a spectral filter that preferentially admits wavelengths of near-infrared light centered at 752 nanometers. North on Saturn is up and rotated 20 degrees to the right.

The view was obtained at a distance of approximately 1.2 million miles (1.9 million kilometers) from Saturn. Image scale is 68 miles (110 kilometers) per pixel.

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

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

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

Greetings, Orbiter.ch

Pushing the Envelope








Blue Origin logo.

April 4, 2016

Pushing the Envelope (flight 3)

Video above: New Shepard flew again on April 2, 2016 reaching an apogee of 339,178 feet or 103 kilometers. It was the third flight with the same hardware. We pushed the envelope on this flight, restarting the engine for the propulsive landing only 3,600 feet above the ground, requiring the BE-3 engine to start fast and ramp to high thrust fast. Video Credit: Blue Origin.


Image above: The reusable New Shepard space vehicle ascends through clear skies to an apogee of 339,138 feet (flight 2). Image Credit: Blue Origin.

Related articles:

Blue Origin Makes Historic Rocket Landing:
http://orbiterchspacenews.blogspot.ch/2015/11/blue-origin-makes-historic-rocket.html

Blue Origin - Launch. Land. Repeat.:
http://orbiterchspacenews.blogspot.ch/2016/01/blue-origin-launch-land-repeat.html

For more information about Blue Origin, visit: https://www.blueorigin.com/

Image (mentioned), Video (mentioned), Text, Credit: Blue Origin.

Greetings, Orbiter.ch

samedi 2 avril 2016

Russian Cargo Ship Arrives, SpaceX Dragon Due Next Sunday











ROSCOSMOS - Russian Vehicles patch.

April 2, 2016

Russian Supply Spacecraft Arrives Safely to the ISS

The Progress 63 cargo spacecraft docked successfully to the rear port of the Zvezda Service Module on the International Space Station at 1:58 p.m. EDT. The Kurs automated docking system enabled a smooth rendezvous as the cargo resupply craft and the International Space Station flew about 250 miles above Astana, the capital of Kazakhstan.


Archive image: Progress 62P Cargo Craft Approaching the Station. Image Credit: NASA.

Progress 63 arrived with more than three tons of food, fuel and supplies for the space station crew, after its launch Thursday from the Baikonur Cosmodrome in Kazakhstan.


Image above: Saturday’s arrival of the Progress 63 spacecraft marks five spacecraft parked at the International Space Station. Image Credit: NASA TV.

The docking of the Progress 63 vehicle marked the second cargo ship in as many weeks to arrive at the station. Up next is the scheduled launch of the SpaceX Dragon cargo resupply vehicle on April 8 from the Cape Canaveral Air Force Station, Florida. The Dragon’s arrival at the complex on April 10 will be the third resupply vehicle for the station in three weeks, resulting in some 12 tons of cargo for the station’s residents from Progress, Dragon and the Orbital ATK Cygnus ship, which arrived at the station on March 26.

For more information about the space station, visit: http://www.nasa.gov/station.

Images, Video, Text, Credits: NASA/NASA TV/Mark Garcia.

Best regards, Orbiter.ch

Rosetta - Comet Watch 27 March












ESA - Rosetta Mission patch.

April 2, 2016

This week's CometWatch is an image taken on the outward leg of the excursion, on 27 March, when the spacecraft was 329 km from the nucleus.


Image above: Enhanced NAVCAM image of Comet 67P/C-G taken on 27 March 2016, 329 km from the comet nucleus. The scale is 28 m/pixel and the image measures 28.7 km across. Image Credits: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0.

In February and March, Rosetta spent several weeks at very close distances from the comet nucleus, which overfilled the field of view of the NAVCAM, providing us with striking views of the surface. During the current excursion, instead, we can enjoy again a view of the full nucleus and the environment around it.

In this CometWatch image, the small comet lobe is on the left and the large one on the right. The image was taken at a very large phase angle of about 159 degrees, meaning that the comet lies between the spacecraft and the Sun, and that all three are very close to being on the same line.

In this configuration, the nucleus appears backlit, with only a few portions of the illuminated surface visible from this view – in the upper and upper right part of the nucleus.

Thanks to the combination of a long, four-second exposure, no attenuation filter and a low-gain setting on the analogue signal processor of NAVCAM (a setting that is used to image bright targets), the image reveals the bright environment of the comet, displaying beautiful outflows of activity streaming away from the nucleus in various directions.


Image above: The original NAVCAM image. Image Credits: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0.

It is interesting to note hints of the shadow cast by the nucleus on the coma below it, as well as a number of background stars sprinkled across the image.

Today, Rosetta is moving back below 600 km from the nucleus, having been at 1000 km on 30 March. The spacecraft will come back to about 200 km early next week and carry out a zero phase flyby on 9 April at around 30 km altitude.

Meanwhile, 984 new NAVCAM images were released yesterday, covering the weeks between 16 December 2015 and 9 February 2016. You can browse through them via the NAVCAM Image Browser tool: http://imagearchives.esac.esa.int/index.php?/category/59

Related links:

Where is Rosetta?: http://sci.esa.int/where_is_rosetta/

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

Rosetta overview: http://www.esa.int/Our_Activities/Space_Science/Rosetta_overview

Rosetta in depth: http://sci.esa.int/rosetta

Rosetta at Astrium: http://www.astrium.eads.net/en/programme/rosetta-1go.html

Rosetta at DLR: http://www.dlr.de/dlr/en/desktopdefault.aspx/tabid-10394/

Ground-based comet observation campaign: http://www.rosetta-campaign.net/home

Rosetta factsheet: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Rosetta_factsheet

Frequently asked questions: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Frequently_asked_questions

Images (mentioned), Text, Credits: ESA/Rosetta Blog, Caudia.

Greetings, Orbiter.ch

vendredi 1 avril 2016

CERN - In Theory: Why are theoreticians filled with wanderlust?












CERN - European Organization for Nuclear Research logo.

April 1, 2016


Image above: Nanie Perrin (pictured) and her colleagues in the Theory Secretariat are the first port of call for those embarking on a stay in the Theory department. (Image: Sophia Bennett/ CERN).

A large tin holding dozens of keys sits in the office of the Theory Secretariat. Each one unlocks a stay on a Theory corridor. Nanie Perrin hands them out, and collects them back, in a constant game of musical chairs - or rather, musical offices. On the Secretariat's board (the only whiteboard in the corridor), departures are listed in red, arrivals in green.

One theoretician going away for a fortnight leaves his office to another, and so on. Several dozen new brains pass through the Secretariat's door each month, arriving for visits that last a day, a month or several years. They come to attend seminars and workshops, to begin contracts as post-doctoral students, fellows and staff members (although this is rarer), or simply to hold discussions with their colleagues.

The Secretariat is their haven, a place for information, lost property and lost theoreticians. The assistants, Nanie Perrin, Michelle Connor and Jeanne Rostant, help them to organise their meetings and seminars. Behind the scenes, Elena Gianolio provides IT support. Everything is arranged so that the theoreticians can focus exclusively on thinking, problem-solving, calculations, and writing.

"We have around 800 visitors a year," explains Nanie Perrin. "There are more during the summer, because many theoreticians have teaching jobs at universities and come to work at CERN during their holidays."

Travel is an integral part of a theoretician's life, racking up kilometres and time differences. 'I make about two intercontinental trips a year, plus six or so within Europe,' explains Wolfgang Lerche, a theoretician at CERN. 'Last year, I spent 300 hours on aeroplanes and travelled around 200,000 kilometres,' says his colleague Michelangelo Mangano.


Image above: The Secretariat have the keys, the information and the computers needed to ensure that the theoreticians can focus exclusively – well, almost - on their work. (Image: sophia Bennett/ CERN).

Experienced theoreticians travel primarily to give lessons and presentations, to attend conferences and to sit on thesis juries and boards.

In an age when MOOCs, Skype and video-conferences are everywhere, travelling to speak to students may seem as old-fashioned as writing on a blackboard in chalk. However, all theoreticians agree that actually meeting people is indispensable for their work.

"Skype is used more and more for collaborative work. But nothing can beat a meeting in person. If you meet a collaborator, you can talk for 10 hours in a row or more. There is no way you can do this electronically," says Michelangelo Mangano.

"It's human interaction that produces the spark. Exchanging ideas is essential in a discipline like ours, which is constantly evolving. Projects are often born out of impromptu discussions. We attend conferences not only to present our own work but also to develop new projects. Conferences are project incubators!" explains Christophe Grojean, a theoretician at the DESY laboratory and a former resident of CERN's Theory corridor.

"You have to be in the same room for ideas to sparkle," says Slava Rychkov, a theoretician at CERN. "The Simons Foundation, which funds a collaborative programme in mathematical and physical sciences, requires 25% of its budget to be spent on organising face-to-face meetings and conferences."


Image above: Michelangelo Mangano takes a break in his office. Behind him, a wall covered in his 'ultra-trailer' race numbers. Three or four times a year, he takes part in these extreme mountain races of 100 kilometres or more, sometimes with drops and climbs of 10,000 metres. It is the long plane journeys and the determination to master interminable calculations that have prepared him for these races, he explains. 'Running for hours with only myself for company doesn't bother me. I trained for it during all those flights when I was younger, spending as many as nine hours completely idle, with nothing to look at but the seat in front of me. We didn't have laptops or films to watch then.' (Image: Maximillien Brice/ CERN).

Gian Giudice, the head of CERN's Theory department, has established a daily meeting in the Theory corridor's small meeting room. During the afternoon coffee break, discussions thrive. It's a way of encouraging the scientists to tear themselves away from their solitary calculations and spend time with their colleagues. Working in theory is something of a paradox, at once solitary and collaborative, fostering both solidarity and competition.

While experimental physics brings scientists together around great instruments, such as the LHC and its experiments, theoretical physics requires only blackboards, chalk, computers and, of course, brains. And since scientific talent is rare but evenly distributed around the world, this small community is scattered and its members are obliged to travel constantly.

The geographical dispersion of the community is also a great asset. Firstly, it means that institutes develop their own specialities. For example, thanks to its closeness to the experiments, CERN is the kingdom of phenomenology. Phenomenology forms a bridge between the theoretical models and experimental physics. Phenomenologists will propose quantities that are measurable by the experiments, starting from the theoretical models, or, the other way round, reveal theoretical models starting from observations.


Image above: The Theory corridor welcomes hundreds of visitors each year, all of whom must be provided with offices. The strips of white paper stuck to this door act as name plates. There's no need to reprint them each time: when someone moves into the office, their name is slipped into the space provided, and when they leave, it is removed and stuck back on the door. (Image: Sophia Bennett/CERN).

Furthermore, different cultures inspire different ways of thinking. "We often underestimate how great an effect culture has on scientific thought," says Christophe Grojean. "Equations may be universal, but the way we understand them and combine them with other results is very personal."

While experienced physicists travel to spread their knowledge, young ones go from country to country to take up post-doctoral and temporary contracts. It takes them several years to get a permanent job. Their CVs make for dizzying reading.

"It's impossible to get a permanent job without working at several different institutes first," says Camille Bonvin, a fellow in CERN's Theory department. "I've worked at four institutes so far, and I'm going to another one in June. The job I’ll be taking up isn't permanent, so it's highly likely that I'll move again afterwards."

This lack of job security discourages many young graduates, who often end up leaving the field. Some go on to work in computing or finance, where their analytical abilities are highly valued.

"One famous, if atypical, example is Yuri Milner, who left particle physics for the financial world. He is now a billionaire and a science philanthropist. As he himself quipped: 'That I quit was a net gain for physics'" – Slava Rychov.

The instability of the first years is, however, seen as an essential part of the training. "In my opinion, it's very beneficial. Working at different institutes enables you to explore different environments and widen your fields of research and your interests," adds Camille Bonvin.

"All theoreticians have to go through it," says Gian Giudice. "It's essential, because moving is an enriching experience. You can’t spend all of your life in the same place and expect to make breakthroughs."


Image above: Camille Bonvin (back right), a fellow in CERN's Theory department, in her office, surrounded by other young theoreticians. Young theoreticians travel around from contract to contract before finding a permanent job. (Image: Sophia Bennett/ CERN).

"It's hard to judge young people right after their PhD. They have to get out from under the wing of their advisor, show independence and produce important results, then they are ready for a tenured job," explains Slava Rychkov.

The constant movement enables young physicists to build up a network of colleagues and, sometimes, to find a new direction for their research.

A life spent travelling from country to country may sound exhilarating, but combining it with a family life is difficult. Yet, it is precisely between the ages of 25 and 35 that theoreticians are busy proving themselves, constantly travelling from one institute to another.

"A certain talent is needed to juggle both science and personal life," says Slava Rychkov.

But many theoreticians manage to do just that. Their children grow up in several countries. "It's complicated sometimes, but it's beneficial for the whole family," explains Christophe Grojean, who has three children with another theoretician. Camille Bonvin, a young mother, hopes to succeed in this herself: "My thesis supervisor has a wonderful career and three fantastic children. She's a great example that proves that it’s possible."

The next article in the In Theory series will look at the differences between experimentalists and theorists, how they compete and how they collaborate . Read the previous articles here:

CERN - In Theory: Are theoreticians just football fanatics?
http://orbiterchspacenews.blogspot.ch/2016/03/cern-in-theory-are-theoreticians-just.html

CERN - In theory: Welcome to the Theory corridor:
http://orbiterchspacenews.blogspot.ch/2016/02/cern-in-theory-welcome-to-theory.html

CERN - In Theory: why bother with theoretical physics?:
http://orbiterchspacenews.blogspot.ch/2016/03/cern-in-theory-why-bother-with.html

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.

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

CERN's "Group of Theoretical Studies": http://home.cern/cern-people/opinion/2014/10/theory-cern-turns-62

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

Images (mentioned), Text, Credits: CERN/Corinne Pralavorio/Harriet Kim Jarlett.

Best regards, Orbiter.ch