Bright Spots and Color Differences Revealed on Ceres

NASA - New Horizons Mission logo.

March 22, 2016

Unveiling Ceres

Video above: NASA's Dawn spacecraft has revealed marvelous sights on dwarf planet Ceres during its first year in orbit.

Scientists from NASA's Dawn mission unveiled new images from the spacecraft's lowest orbit at Ceres, including highly-anticipated views of Occator Crater, at the 47th annual Lunar and Planetary Science Conference in The Woodlands, Texas, on Tuesday.

Occator Crater, measuring 57 miles (92 kilometers) across and 2.5 miles (4 kilometers) deep, contains the brightest area on Ceres, the dwarf planet that Dawn has explored since early 2015. The latest images, taken from 240 miles (385 kilometers) above the surface of Ceres, reveal a dome in a smooth-walled pit in the bright center of the crater. Numerous linear features and fractures crisscross the top and flanks of this dome.  Prominent fractures also surround the dome and run through smaller, bright regions found within the crater.

Image above: Occator Crater, measuring 57 miles (92 kilometers) across and 2.5 miles (4 kilometers) deep, contains the brightest area on Ceres. Image Credits: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/PSI.

"Before Dawn began its intensive observations of Ceres last year, Occator Crater looked to be one large bright area. Now, with the latest close views, we can see complex features that provide new mysteries to investigate," said Ralf Jaumann, planetary scientist and Dawn co-investigator at the German Aerospace Center (DLR) in Berlin. "The intricate geometry of the crater interior suggests geologic activity in the recent past, but we will need to complete detailed geologic mapping of the crater in order to test hypotheses for its formation."

Color Differences

The team also released an enhanced color map of the surface of Ceres, highlighting the diversity of surface materials and their relationships to surface morphology. Scientists have been studying the shapes of craters and their distribution with great interest. Ceres does not have as many large impact basins as scientists expected, but the number of smaller craters generally matches their predictions. The blue material highlighted in the color map is related to flows, smooth plains and mountains, which appear to be very young surface features.

Image above: Ceres' Haulani Crater (21 miles, 34 kilometers wide) is shown in these views from the visible and infrared mapping spectrometer (VIR) aboard NASA's Dawn spacecraft. Images Credits: NASA/JPL-Caltech/UCLA/ASI/INAF.

"Although impact processes dominate the surface geology on Ceres, we have identified specific color variations on the surface indicating material alterations that are due to a complex interaction of the impact process and the subsurface composition," Jaumann said. "Additionally, this gives evidence for a subsurface layer enriched in ice and volatiles."

Counting Neutrons

Data relevant to the possibility of subsurface ice is also emerging from Dawn's Gamma Ray and Neutron Detector (GRaND), which began acquiring its primary data set in December. Neutrons and gamma rays produced by cosmic ray interactions with surface materials provide a fingerprint of Ceres’ chemical makeup.  The measurements are sensitive to elemental composition of the topmost yard (meter) of the regolith.

In Dawn's lowest-altitude orbit, the instrument has detected fewer neutrons near the poles of Ceres than at the equator, which indicates increased hydrogen concentration at high latitudes. As hydrogen is a principal constituent of water, water ice could be present close to the surface in polar regions.

Image above: This map shows a portion of the northern hemisphere of Ceres with neutron counting data acquired by the gamma ray and neutron detector (GRaND) instrument aboard NASA's Dawn spacecraft. Image Credits: NASA/JPL-Caltech/UCLA/ASI/INAF.

"Our analyses will test a longstanding prediction that water ice can survive just beneath Ceres' cold, high-latitude surface for billions of years," said Tom Prettyman, the lead for GRaND and Dawn co-investigator at the Planetary Science Institute, Tucson, Arizona.

The Mystery of Haulani Crater

But the subsurface does not have the same composition all over Ceres, according to data from the visible and infrared mapping spectrometer (VIR), a device that looks at how various wavelengths of sunlight are reflected by the surface, allowing scientists to identify minerals.

Haulani Crater in particular is an intriguing example of how diverse Ceres is in terms of its surface material composition. This irregularly-shaped crater, with its striking bright streaks of material, shows a different proportion of surface materials than its surroundings when viewed with the VIR instrument. While the surface of Ceres is mostly made of a mixture of materials containing carbonates and phyllosilicates, their relative proportion varies across the surface.

Image above: This colorized global map of Ceres was created from a clear-filter mosaic. Image Credits: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA.

"False-color images of Haulani show that material excavated by an impact is different than the general surface composition of Ceres. The diversity of materials implies either that there is a mixed layer underneath, or that the impact itself changed the properties of the materials," said Maria Cristina de Sanctis, the VIR instrument lead scientist, based at the National Institute of Astrophysics, Rome.

The Big Picture

Dawn made history last year as the first mission to reach a dwarf planet, and the first to orbit two distinct extraterrestrial targets -- both of them in the main asteroid belt between Mars and Jupiter. The mission conducted extensive observations of Vesta during its 14-month orbit there in 2011-2012.

Image above: This global map shows the surface of Ceres in enhanced color, encompassing infrared wavelengths beyond human visual range. Image Credits: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA.

"We're excited to unveil these beautiful new images, especially Occator, which illustrate the complexity of the processes shaping Ceres' surface. Now that we can see Ceres’ enigmatic bright spots, surface minerals and morphology in high resolution, we're busy working to figure out what processes shaped this unique dwarf planet. By comparing Ceres with Vesta, we'll glean new insights about the early solar system," said Carol Raymond, deputy principal investigator for the Dawn mission, based at NASA's Jet Propulsion Laboratory, Pasadena, California.

Image above: The bright spots of Occator Crater are shown in enhanced color in this view from NASA's Dawn spacecraft. Such views can be used to highlight subtle color differences on Ceres' surface. Image Credits: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/PSI/LPI.

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

http://dawn.jpl.nasa.gov/mission

More information about Dawn is available at the following sites:

http://dawn.jpl.nasa.gov

http://www.nasa.gov/dawn

Images (mentioned), Video (mentioned), Text, Credits: NASA/Martin Perez.

Best regards, Orbiter.ch

NASA’s SDO Sees Circular Outburst

NASA - Solar Dynamics Observatory patch.

March 22, 2016

A round solar prominence burst from the sun on March 13, 2016. Image Credits: NASA/SDO

A round solar prominence burst from the sun on March 13, 2016, shortly after it rotated into the view of NASA’s Solar Dynamics Observatory, or SDO. Much of the solar material did not escape the sun’s gravitational pull, falling back to the solar surface. Prominences – called filaments when seen against the sun’s face instead of over the horizon – are notoriously unstable clouds of solar material suspended above the solar surface by the sun’s complex magnetic forces. They often break apart after a few days.

NASA’s SDO Sees Circular Outburst

Video above: This video was made from images taken every 12 seconds by SDO – the fastest-ever cadence for solar observations from space. This prominence was captured in wavelengths of 304 angstroms, a type of extreme ultraviolet light that is typically invisible to our eyes, but is colorized here in red. Video Credits: NASA/SDO.

For more information about Solar Dynamics Observatory (SDO), visit:
http://www.nasa.gov/mission_pages/sdo/main/index.html

Image (mentioned), Video (mentioned), Text, Credits: NASA’s Goddard Space Flight Center/Steele Hill/Sarah Frazier/Rob Garner.

Greetings, Orbiter.ch

Solar Storms Ignite X-ray "Northern Lights" on Jupiter

NASA - Chandra X-ray Observatory patch.

March 22, 2016

Images Credits: X-ray: NASA/CXC/UCL/W.Dunn et al, Optical: NASA/STScI

Solar storms are triggering X-ray auroras on Jupiter that are about eight times brighter than normal over a large area of the planet and hundreds of times more energetic than Earth’s ‘northern lights,’ according to a new study using data from NASA’s Chandra X-ray Observatory. This result is the first time that Jupiter’s auroras have been studied in X-ray light when a giant solar storm arrived at the planet.

The Sun constantly ejects streams of particles intoes, giant storms, known as coronal mass ejections (CMEs), erupt and the winds become much stronger. These events compress Jupiter’s magnetosphere, the region of space controlled by Jupiter’s magnetic field, shifting its boundary with the solar wind inward by more than a million miles. This new study found that the interaction at the boundary triggers the X-rays in Jupiter’s auroras, which cover an area bigger than the surface of the Earth.

These composite images show Jupiter and its aurora.  The impact of the CME on Jupiter’s aurora was tracked by monitoring the X-rays emitted during two 11-hour observations. The scientists used that data to pinpoint the source of the X-ray activity and identify areas to investigate further at different time points. They plan to find out how the X-rays form by collecting data on Jupiter’s magnetic field, magnetosphere and aurora using Chandra and ESA’s XMM-Newton.

A paper describing these results appeared in the MarchCL), Graziella Branduardi-Raymont (UCL), Ronald Elsner (NASA’s Marshall Space Flight Center), Marissa Vogt (Boston University), Laurent Lamy (University of Paris Diderot), Peter Ford (Massachusetts Institute of Technology), Andrew Coates (UCL), Randall Gladstone (Southwest Research Institute), Caitriona Jackman (University of Southampton), Jonathan Nichols (University of Leicester), Jonathan Rae (UCL), Ali Varsani (UCL), Tomoki Kimura (JAXA), Kenneth Hansen (University of Michigan), and Jamie Jasinski (UCL).

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

Read More from NASA's Chandra X-ray Observatory: http://chandra.si.edu/photo/2016/jupiter/

For more Chandra images, multimedia and related materials, visit: http://www.nasa.gov/chandra

ESA’s XMM-Newton: http://sci.esa.int/xmm-newton/

Images (mentioned), Text, Credits: NASA/Jennifer Harbaugh/Marshall Space Flight Center/Molly Porter/Chandra X-ray Center/Megan Watzke.

Greetings, Orbiter.ch

Caught For The First Time: The Early Flash Of An Exploding Star

NASA - Kepler Space Telescope patch.

March 21, 2016

The brilliant flash of an exploding star’s shockwave—what astronomers call the “shock breakout”—has been captured for the first time in the optical wavelength or visible light by NASA's planet-hunter, the Kepler space telescope.

An international science team led by Peter Garnavich, an astrophysics professor at the University of Notre Dame in Indiana, analyzed light captured by Kepler every 30 minutes over a three-year period from 500 distant galaxies, searching some 50 trillion stars. They were hunting for signs of massive stellar death explosions known as supernovae.

In 2011, two of these massive stars, called red supergiants, exploded while in Kepler’s view. The first behemoth, KSN 2011a, is nearly 300 times the size of our sun and a mere 700 million light years from Earth. The second, KSN 2011d, is roughly 500 times the size of our sun and around 1.2 billion light years away.

“To put their size into perspective, Earth's orbit about our sun would fit comfortably within these colossal stars,” said Garnavich.

Image above: The diagram illustrates the brightness of a supernova event relative to the sun as it unfolds. For the first time, a supernova shockwave has been observed in the optical wavelength or visible light as it reaches the surface of the star. This early flash of light is called a shock breakout. The explosive death of this star, called KSN 2011d, as it reaches its maximum brightness takes 14 days. The shock breakout itself lasts only about 20 minutes, so catching the flash of energy is an investigative milestone for astronomers. The unceasing gaze of NASA's Kepler space telescope allowed astronomers to see, at last, this early moment as the star blows itself to bits. Supernovae like these — known as Type II — begin when the internal furnace of a star runs out of nuclear fuel causing its core to collapse as gravity takes over. This type of star is called a red supergiant star and it is 20,000 times brighter than our sun. As the supergiant star goes supernova, the energy traveling from the core reaches the surfaces with a burst of light that is 130,000,000 times brighter than the sun. The star continues to explode and grow reaching maximum brightness that is about 1,000,000,000 times brighter than the sun. Image Credits: NASA Ames/W. Stenzel.

Whether it’s a plane crash, car wreck or supernova, capturing images of sudden, catastrophic events is extremely difficult but tremendously helpful in understanding root cause. Just as widespread deployment of mobile cameras has made forensic videos more common, the steady gaze of Kepler allowed astronomers to see, at last, a supernova shockwave as it reached the surface of a star. The shock breakout itself lasts only about 20 minutes, so catching the flash of energy is an investigative milestone for astronomers.

“In order to see something that happens on timescales of minutes, like a shock breakout, you want to have a camera continuously monitoring the sky,” said Garnavich. “You don’t know when a supernova is going to go off, and Kepler's vigilance allowed us to be a witness as the explosion began.”

Supernovae like these — known as Type II — begin when the internal furnace of a star runs out of nuclear fuel causing its core to collapse as gravity takes over.

The two supernovae matched up well with mathematical models of Type II explosions reinforcing existing theories. But they also revealed what could turn out to be an unexpected variety in the individual details of these cataclysmic stellar events.

Artist's view of the explosive death star KSN 2011d. Image Credits: NASA/Ames/STScI

While both explosions delivered a similar energetic punch, no shock breakout was seen in the smaller of the supergiants. Scientists think that is likely due to the smaller star being surrounded by gas, perhaps enough to mask the shockwave when it reached the star's surface.

“That is the puzzle of these results,” said Garnavich. “You look at two supernovae and see two different things. That’s maximum diversity.”

Understanding the physics of these violent events allows scientists to better understand how the seeds of chemical complexity and life itself have been scattered in space and time in our Milky Way galaxy

"All heavy elements in the universe come from supernova explosions. For example, all the silver, nickel, and copper in the earth and even in our bodies came from the explosive death throes of stars," said Steve Howell, project scientist for NASA's Kepler and K2 missions at NASA’s Ames Research Center in California's Silicon Valley. "Life exists because of supernovae."

Garnavich is part of a research team known as the Kepler Extragalactic Survey or KEGS. The team is nearly finished mining data from Kepler’s primary mission, which ended in 2013 with the failure of reaction wheels that helped keep the spacecraft steady. However, with the reboot of the Kepler spacecraft as NASA's K2 mission, the team is now combing through more data hunting for supernova events in even more galaxies far, far away.

Caught for the First Time: The Early Flash of an Exploding Star

Video above: The brilliant flash of an exploding star’s shockwave—what astronomers call the “shock breakout” -- is illustrated in this video animation. The cartoon video begins with a view of a red supergiant star that is 500 hundred times bigger and 20,000 brighter than our sun. When the star’s internal furnace can no longer sustain nuclear fusion its core to collapses under gravity. A shockwave from the implosion rushes upward through the star’s layers. The shockwave initially breaks through the star’s visible surface as a series of finger-like plasma jets. Only 20 minute later the full fury of the shockwave reaches the surface and the doomed star blasts apart as a supernova explosion. This animation is based on photometric observations made by NASA’s Kepler space telescope. By closely monitoring the star KSN 2011d, located 1.2 billion light-years away, Kepler caught the onset of the early flash and subsequent explosion. Video Credits: Credit: NASA Ames, STScI/G. Bacon.

"While Kepler cracked the door open on observing the development of these spectacular events, K2 will push it wide open observing dozens more supernovae," said Tom Barclay, senior research scientist and director of the Kepler and K2 guest observer office at Ames. "These results are a tantalizing preamble to what's to come from K2!"

In addition to Notre Dame, the KEGS team also includes researchers from the University of Maryland in College Park; the Australian National University in Canberra, Australia; the Space Telescope Science Institute in Baltimore, Maryland; and the University of California, Berkeley.

The research paper reporting this discovery has been accepted for publication in the Astrophysical Journal.

Ames manages the Kepler and K2 missions for NASA’s Science Mission Directorate. NASA's Jet Propulsion Laboratory in Pasadena, California, managed Kepler mission development. Ball Aerospace & Technologies Corporation operates the flight system with support from the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder.

Authored by H. Pat Brennan/JPL and Michele Johnson/Ames.

Related links:

Kepler space telescope: http://www.nasa.gov/kepler

NASA's K2 mission: http://www.nasa.gov/feature/ames/nasas-k2-mission-the-kepler-space-telescopes-second-chance-to-shine

Research paper: http://arxiv.org/abs/1603.05657

Images (mentioned), Video (mentioned), Text, Credits: NASA/Michele Johnson/Ames Research Center/Michele Johnson.

Best regards, Orbiter.ch

New Gravity Map Gives Best View Yet Inside Mars

NASA - Mars Global Surveyor (MGS) patch / NASA- Mars Reconnaissance Orbiter (MRO) patch / NASA - Mars Odyssey (ODY) patch.

March 21, 2016

A new map of Mars' gravity made with three NASA spacecraft is the most detailed to date, providing a revealing glimpse into the hidden interior of the Red Planet.

"Gravity maps allow us to see inside a planet, just as a doctor uses an X-ray to see inside a patient," said Antonio Genova of the Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts. "The new gravity map will be helpful for future Mars exploration, because better knowledge of the planet's gravity anomalies helps mission controllers insert spacecraft more precisely into orbit about Mars. Furthermore, the improved resolution of our gravity map will help us understand the still-mysterious formation of specific regions of the planet." Genova, who is affiliated with MIT but is located at NASA's Goddard Space Flight Center in Greenbelt, Maryland, is the lead author of a paper on this research published online March 5 in the journal Icarus.

Mars Gravity Map

Video above: Scientists have used small fluctuations in the orbits of three NASA spacecraft to map the gravity field of Mars. Video Credits: NASA/GSFC/Scientific Visualization Studio.

The improved resolution of the new gravity map suggests a new explanation for how some features formed across the boundary that divides the relatively smooth northern lowlands from heavily cratered southern highlands. Also, the team confirmed that Mars has a liquid outer core of molten rock by analyzing tides in the Martian crust and mantle caused by the gravitational pull of the sun and the two moons of Mars. Finally, by observing how Mars' gravity changed over 11 years – the period of an entire cycle of solar activity -- the team inferred the massive amount of carbon dioxide that freezes out of the atmosphere onto a Martian polar ice cap when it experiences winter. They also observed how that mass moves between the south pole and the north pole with the change of season in each hemisphere.

Image above: A map of Martian gravity looking down on the North Pole (center). White and red are areas of higher gravity; blue indicates areas of lower gravity. Image Credits: MIT/UMBC-CRESST/GSFC.

The map was derived using Doppler and range tracking data collected by NASA's Deep Space Network from three NASA spacecraft in orbit around Mars: Mars Global Surveyor (MGS), Mars Odyssey (ODY), and the Mars Reconnaissance Orbiter (MRO). Like all planets, Mars is lumpy, which causes the gravitational pull felt by spacecraft in orbit around it to change. For example, the pull will be a bit stronger over a mountain, and slightly weaker over a canyon.

Slight differences in Mars' gravity changed the trajectory of the NASA spacecraft orbiting the planet, which altered the signal being sent from the spacecraft to the Deep Space Network. These small fluctuations in the orbital data were used to build a map of the Martian gravity field.

Image above: A map of Martian gravity looking down at the South Pole (center). White and red are areas of higher gravity; blue indicates areas of lower gravity. Image Credits: MIT/UMBC-CRESST/GSFC.

The gravity field was recovered using about 16 years of data that were continuously collected in orbit around Mars. However, orbital changes from uneven gravity are tiny, and other forces that can perturb the motion of the spacecraft had to be carefully accounted for, such as the force of sunlight on the spacecraft's solar panels and drag from the Red Planet's thin upper atmosphere. It took two years of analysis and computer modeling to remove the motion not caused by gravity.

"With this new map, we've been able to see gravity anomalies as small as about 100 kilometers (about 62 miles) across, and we've determined the crustal thickness of Mars with a resolution of around 120 kilometers (almost 75 miles)," said Genova. "The better resolution of the new map helps interpret how the crust of the planet changed over Mars' history in many regions."

For example, an area of lower gravity between Acidalia Planitia and Tempe Terra was interpreted before as a system of buried channels that delivered water and sediments from Mars' southern highlands into the northern lowlands billions of years ago when the Martian climate was wetter than it is today. The new map reveals that this low gravity anomaly is definitely larger and follows the boundary between the highlands and the lowlands. This system of gravity troughs is unlikely to be only due to buried channels because in places the region is elevated above the surrounding plains. The new gravity map shows that some of these features run perpendicular to the local topography slope, against what would have been the natural downhill flow of water.

Imager above: A Martian gravity map showing the Tharsis volcanoes and surrounding flexure. The white areas in the center are higher-gravity regions produced by the massive Tharsis volcanoes, and the surrounding blue areas are lower-gravity regions that may be cracks in the crust (lithosphere). Image Credits: MIT/UMBC-CRESST/GSFC.

An alternative explanation is that this anomaly may be a consequence of a flexure or bending of the lithosphere -- the strong, outermost layer of the planet -- due to the formation of the Tharsis region. Tharsis is a volcanic plateau on Mars thousands of miles across with the largest volcanoes in the solar system. As the Tharsis volcanoes grew, the surrounding lithosphere buckled under their immense weight.

The new gravity field also allowed the team to confirm indications from previous gravity solutions that Mars has a liquid outer core of molten rock. The new gravity solution improved the measurement of the Martian tides, which will be used by geophysicists to improve the model of Mars' interior.

Changes in Martian gravity over time have been previously measured using the MGS and ODY missions to monitor the polar ice caps. For the first time, the team used MRO data to continue monitoring their mass. The team has determined that when one hemisphere experiences winter, approximately 3 trillion to 4 trillion tons of carbon dioxide freezes out of the atmosphere onto the northern and southern polar caps, respectively. This is about 12 to 16 percent of the mass of the entire Martian atmosphere. NASA's Viking missions first observed this massive seasonal precipitation of carbon dioxide. The new observation confirms numerical predictions from the Mars Global Reference Atmospheric Model – 2010: http://spacescience.arc.nasa.gov/story/mars-global-reference-atmospheric-model-mars-gram

The research was funded by grants from NASA's Mars Reconnaissance Orbiter mission and NASA's Mars Data Analysis Program.

Related links:

NASA's Deep Space Network: http://deepspace.jpl.nasa.gov/

Mars Global Surveyor (MGS): http://marsprogram.jpl.nasa.gov/mgs/

Mars Odyssey (ODY): http://mars.nasa.gov/odyssey/

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

Images (mentioned), Video (mentioned), Text, Credits: NASA Goddard Space Flight Center/Bill Steigerwald.

Greetings, Orbiter.ch

Helorus in Half-light

NASA - Cassini International logo.

March 21, 2016

Cassini captures a crater duo on Saturn's moon Dione that is superimposed on older, linear features. The upper of the pair, named Italus, is overprinted on a grouping of ancient troughs called Petelia Fossae. The lower crater, Caieta, sits atop a feature named Helorus Fossa.

Scientists are confident that Helorus and features like it are very old, both because there are many old craters on top of it and because of the way that material has apparently filled in the shallow valley, giving its edges a softer appearance. Fossae on Dione (698 miles or 1,123 kilometers across) like Helorus are believed to be tectonic features, formed when the area between tectonic faults drops down into trough-like structures.

This view is centered on terrain at 22 degrees south latitude, 73 degrees west longitude. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Sept. 30, 2015.

The view was obtained at a distance of approximately 25,000 miles (41,000 kilometers) from Dione and at a Sun-Dione-spacecraft, or phase, angle of 64 degrees. Image scale is 804 feet (245 meters) per pixel.

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/Martin Perez.

Greetings, Orbiter.ch

CERN - In Theory: Are theoreticians just football fanatics?

CERN - European Organization for Nuclear Research logo.

20 Mar 2016



Image above: Within theoretical physics there are several different theories. Researchers often dedicate their lives to understand one of these theories fully. (Image: Sophia Bennett/CERN).

Listening to a theoretician talk about their field can be a bit like listening to a football fan talking about the team they support.

Whether they fell in love with string theory because of the excitement of something new, like a World Cup win, or doggedly pursued supersymmetry despite several losses, theoreticians will stand by their field while they're working on it, rarely moving into other theories.

This almost obsessive pursuit of one field means, like a supporter who can reel off the goal scorer for every game, theoreticians focus on knowing the ins and outs of their own field.

“The level of complexity of the different branches of theoretical physics is such that nobody can be an expert in everything,” says Gian Giudice, the head of the theory department, who works on particle physics and cosmology.

Image above: Gian Giudice is the head of CERN's Theory Department. He believes that the way science develops often follows paths that are much less logical and rational than most people think. Only at the end of the process a clear picture emerges and then, in retrospect, everything looks simple and straightforward. (Image: Sophia Bennett/CERN).

This can be crucial for them to understand how new developments fit in with the field’s history, who the big players are and how it might influence their own work.

"Our ideas constantly evolve as we are confronted with new theoretical developments and new experimental results. That's why theoretical physicists rarely spend all their careers working on the same subject, but always thrive to break new ground," Giudice explains.

My team’s better than your team

The same factors that influence the football team you choose to support, such as where you live, or who’s the most successful, also play a huge part in influencing why theoreticians might follow their field.

“Just as I moved to Princeton, in the US, the superstring theory exploded. I’d just moved, so it was natural to work on it, as everyone in Princeton was doing it,” says Michelangelo Mangano on how he was first led into string theory.

Image above: “If a new idea comes up suddenly a large cluster of people start working on that and you see every day there’s a new paper coming out on that subject. Within two days everyone who has an interest has read the paper. And then you can start a new collaboration, or a fight in case you disagree.” – Michaelangelo Mangano (Image: Maximillien Brice/ CERN).

It was similar for Wolfgang Lerche, who became a theoretical physicist at a similar time to Mangano.

“I became a fellow at CERN the year string theory became the big topic.  We fellows were sitting together, trying to get into the field, the lecture theatre was packed, and there was so much excitement. We all thought this was it, that we’ll have solved everything within months, at most a year or so. But it didn’t happen that way,“ he explains.

Giudice agrees that new fashionable theories definitely influence which field most young theoreticians pursue.

“Yes, fashions influence people on the choice of the subject they work on. But the excitement about a subject persists only if important conceptual advancement follows. If not, fashions fade away. Other people prefer to pursue paths that are orthogonal to fashions. Most of the time they hit a dead end, but sometimes they are the ones that make the breakthroughs.” — Gian Giudice.

But Bryan Lynn – a professor at Case Western Reserve University, USA, who left academia for a career on Wall Street and in London's City before returning to teach theoretical physics – believes that mentors, PhD supervisors and professors have more influence on molding young physicists and encouraging them to pursue certain fields and theories. He experienced pressure from his supervisor not to study model building, despite writing what he describes as a ‘beautiful research paper’.

“The paper had some model building in it. So I went to my supervisor and asked him about it. He said 'why are you working on this rubbish?' Then he basically tore my paper up and threw it away.”

Image above: "On one end of the spectrum are people who speculate to come up with models, and this can take extreme proportions that start bordering on being a bit crackpot,” laughs Slava Rychkov (right) being interviewed for this article series by Harriet Jarlett (Image: Sophia Bennett/CERN).

Inevitably, with so many opposing fields in such a competitive science many theoreticians look down on other theories as being less likely to be proved right.

“On one end of the spectrum are people who speculate to come up with models, and this can take extreme proportions that start bordering on being a bit crackpot,” laughs Slava Rychkov, a theoretician at CERN. “Then there are the people who dedicate their lives to technically very challenging computations to get very high precision predictions.”

“The great thing about science is that eventually you get to know the answer, either there is a Higgs Boson or there isn’t, you know which theory is best. But before you reach that moment of closure you’re going to have these tribes – some people call them schools of thought – that compete against each other,” explains John Ellis of Kings College, London, who has worked at CERN since 1973.

This rivalry means that young theorists often feel like they would be looked down on for pursuing one field over another, especially if it’s not fashionable.

Image above: John Ellis, who has worked at CERN since 1973, work is in the field of Supersymmetry (SUSY). (Image: Sophia Bennett/ CERN).

Scoring goals

“There’s a race to publish, especially in this field, as people are judged by the number and weight of their research publications,” Lerche says. “Having a really good idea, or better several of them, is a key factor to landing a permanent position at some point”

This competitive nature, where early career researchers try to beat each other to their goal, whether it’s to publish their science or to put their name to a new theory, is not unique to theoretical physics. But in a subject like this where groups are small and isolated, it can feel personal.

Image above: “There’s a race to publish, especially in this field, as people are judged by the number and weight of their research publications,” Wolfgang Lerche, pictured here, says. (Image: Sophia Bennett/ CERN).

“You do see some early career researchers immediately projected into the limelight and contributing on an equal footing to more senior people. It’s more likely in a branch of string theory or fundamental theories because there’s an evolution happening now, there’s lots of new techniques emerging for them to put their stamp on,” explains Mangano.

While for some success comes early on in their career, for others they have to dedicate their lives to the challenge of unraveling a theory.

“I admire some of the theoreticians, like those working on lattice field theory, they stuck at it for forty years before they discovered something, like Darwin.”

“Darwin looked at his backyard his whole life measuring dirt. He measured it, the dirt! And discovered almost at the end of his life that earthworms make the soil, they didn't know that before, That's science, this cumulatively fanatical look at nature, that’s science.” describes Lynn.

The next article in the In Theory series, to be published next week, will be on how theoretician’s end up with so many stamps in their passports. Read the previous articles:

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.

Related links:

Supersymmetry: http://home.cern/about/physics/supersymmetry

Cosmology: https://www.ted.com/talks/gian_giudice_why_our_universe_might_exist_on_a_knife_edge?language=en

Higgs boson: http://home.cern/topics/higgs-boson

Gravitational waves: http://home.cern/about/updates/2016/02/cern-congratulates-discoverers-gravitational-waves

Standard model: http://home.cern/about/physics/standard-model

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/Harriet Jarlett.

Best regards, Orbiter.ch