Fermi shows that Tycho's star shines in gamma rays

Fig: Gamma rays detected by Fermi's LAT show that the remnant of Tycho's supernova shines in the highest-energy form of light. This portrait of the shattered star includes gamma rays (magenta), X-rays (yellow, green, and blue), infrared (red) and optical data. Gamma ray, NASA/DOE/Fermi LAT Collaboration; X-ray, NASA/CXC/SAO; Infrared, NASA/JPL-Caltech; Optical, MPIA, Calar Alto, O. Krause et al. and DSS

By NASA's Goddard Space Flight Center, Greenbelt, Maryland

Published: December 16, 2011

In early November 1572, observers on Earth witnessed the appearance of a “new star” in the constellation Cassiopeia, an event now recognized as the brightest naked-eye supernova in more than 400 years. It’s often called “Tycho’s supernova” after the great Danish astronomer Tycho Brahe, who gained renown for his extensive study of the object. Now, years of data collected by NASA’s Fermi Gamma-Ray Space Telescope reveal that the shattered star’s remains shine in high-energy gamma rays.

The detection gives astronomers another clue in understanding the origin of cosmic rays, subatomic particles — mainly protons — that move through space at nearly the speed of light. Exactly where and how these particles attain such incredible energies has been a long-standing mystery because charged particles speeding through the galaxy are easily deflected by interstellar magnetic fields. This makes it impossible to track cosmic rays back to their sources.

“Fortunately, high-energy gamma rays are produced when cosmic rays strike interstellar gas and starlight,” said Francesco Giordano from the University of Bari and the National Institute of Nuclear Physics in Italy. “These gamma rays come to Fermi straight from their sources.”

Better understanding the origins of cosmic rays is one of Fermi’s key goals. Its Large Area Telescope (LAT) scans the entire sky every three hours, gradually building up an ever-deeper view of the gamma-ray sky. Because gamma rays are the most energetic and penetrating form of light, they serve as signposts for the particle acceleration that gives rise to cosmic rays.

“This detection gives us another piece of evidence supporting the notion that supernova remnants can accelerate cosmic rays,” said Stefan Funk from the Kavli Institute for Particle Astrophysics and Cosmology (KIPAC) in Stanford, California.

In 1949, physicist Enrico Fermi — the satellite’s namesake — suggested that the highest-energy cosmic rays were accelerated in the magnetic fields of interstellar gas clouds. In the decades that followed, astronomers showed that supernova remnants might be the galaxy’s best candidate sites for this process.

When a star explodes, it is transformed into a supernova remnant, a rapidly expanding shell of hot gas bounded by the blast’s shock wave. Scientists expect that magnetic fields on either side of the shock front can trap particles between them in what amounts to a subatomic Pingpong game.

“A supernova remnant’s magnetic fields are very weak relative to Earth’s, but they extend across a vast region, ultimately spanning thousands of light-years,” said Melitta Naumann-Godo from Paris Diderot University and the Atomic Energy Commission in Saclay, France. “They have a major influence on the course of charged particles.”

As they shuttle back and forth across the supernova shock, the charged particles gain energy with each traverse. Eventually, they break out of their magnetic confinement, escaping the supernova remnant and freely roaming the galaxy.

The LAT’s ongoing sky survey provides additional evidence favoring this scenario. Many younger remnants, like Tycho’s, tend to produce more high-energy gamma rays than older remnants. “The gamma-ray energies reflect the energies of the accelerated particles that produce them, and we expect more cosmic rays to be accelerated to higher energies in younger objects because the shock waves and their tangled magnetic fields are stronger,” Funk said. By contrast, older remnants with weaker shock waves cannot retain the highest-energy particles, and the LAT does not detect gamma rays with corresponding energies.

The supernova of 1572 was one of the great watersheds in the history of astronomy. The star blazed forth at a time when the starry sky was regarded as a fixed and unchanging part of the universe. Tycho’s candid account of his own discovery of the strange star gives a sense of how radical an event it was.

The supernova first appeared around November 6, but poor weather kept it from Tycho until November 11, when he noticed it during a walk before dinner. “When I had satisfied myself that no star of that kind had ever shone forth before, I was led into such perplexity by the unbelievability of the thing that I began to doubt the faith of my own eyes, and so, turning to the servants who were accompanying me, I asked them whether they too could see a certain extremely bright star. ... They immediately replied with one voice that they saw it completely and that it was extremely bright,” he said.

The supernova remained visible for 15 months and exhibited no movement in the heavens, indicating that it was located far beyond the Sun, Moon, and planets. Modern astronomers estimate that the remnant lies between 9,000 and 11,000 light-years away.

After more than 2.5 years of scanning the sky, LAT data clearly show that an unresolved region of GeV (billion electron volt) gamma-ray emission is associated with the remnant of Tycho’s supernova. (For comparison, the energy of visible light is between about 2 and 3 electron volts.)

“We knew that Tycho’s supernova remnant could be an important find for Fermi because this object has been so extensively studied in other parts of the electromagnetic spectrum,” said Keith Bechtol from SLAC. “We thought it might be one of our best opportunities to identify a spectral signature indicating the presence of cosmic-ray protons.” he said.

The science team’s model of the emission is based on LAT observations along with higher-energy TeV (trillion electron volt) gamma rays mapped by ground-based facilities and radio and X-ray data. The researchers conclude that a process called pion production best explains the emission. First, a proton traveling close to the speed of light strikes a slower-moving proton. This interaction creates an unstable particle — a pion — with only 14 percent of the proton’s mass. In just 10 millionths of a billionth of a second, the pion decays into a pair of gamma rays.

If this interpretation is correct, then somewhere within the remnant protons are being accelerated to near the speed of light, and then interacting with slower particles to produce gamma rays, the most extreme form of light. With such unbelievable goings-on in what’s left of his “unbelievable” star, it’s easy to imagine that Tycho Brahe himself might be pleased.

Astronomers discover two planets that survived their star's expansion

Fig: Two planets that survived the red-giant expansion of their host star. Illustration by Stéphane Charpinet/Institut de Recherche en Astrophysique et Planétologie in Toulouse, France

By Iowa State University, Ames

Published: December 22, 2011

Astronomers have discovered two Earth-sized planets that survived getting caught in the red-giant expansion of their host star.

Steve Kawaler from Iowa State University helped the research team study data from the Kepler space telescope to confirm that tiny variations of light from a star were actually caused by two planets orbiting it. Stéphane Charpinet from the Institut de Recherche en Astrophysique et Planétologie in Toulouse, France, is the leader of the research team.

“This is a snapshot of what our solar system might look like after several billion more years of evolution,” Kawaler said. “This can help us learn about the future of planetary systems and of our own Sun.”

Kawaler said the researchers have studied pulsations of the planets’ host star, KIC 05807616 — an old star just past its red-giant stage — for about two years. While analyzing the data, Charpinet noticed two tiny variations repeated in 5.76- and 8.23-hour intervals.

He asked other astronomers, including Kawaler, to analyze the original Kepler data and a subsequent set of data to see if they also could see the variations.

“We saw them in the same place and the same periodicity,” Kawaler said. “So we knew they were real.”

That led to the next question: “So what are they?”

Kawaler has studied the fastest and slowest rates that stars could pulsate. Using that result, the team could conclude the variations seen by Kepler were too slow to be from the star itself. So the astronomers started testing the idea that the variations were from two planets orbiting the star.

Astronomers believe the variations from the two planets, KOI 55.01 and KOI 55.02, are caused by reflection of the star’s light on the planets and by temperature differences between the hot day-sides and cooler night-sides of the planets.

The astronomers also report the planets are 76 percent and 87 percent the size of Earth. That makes them among the smallest planets detected around a star other than our Sun.

They further report the planets are close to their host star, only 0.6 percent and 0.76 percent the distance between the Sun and Earth. That means conditions on the planets are harsh with temperatures up to 16,000° Fahrenheit (9,000° Celsius).

That’s so close that the host star’s expansion to a red giant would have engulfed the planets, possibly stripping gas giant planets similar to Jupiter down to their dense cores. The planets also could have contributed to the host star’s unusual loss of mass.

The research team said the discovery of the two planets raises many questions about their ability to survive such harsh conditions. It also raises questions about how planets can affect the evolution of their host stars.

A galaxy cluster gets sloshed

Fig: The hot gas in the galaxy cluster Abell 2052 is being sloshed back and forth. The sloshing was set in motion when a small cluster smashed into the larger central one. The large spiral structure on the outside of the image was also caused by that off-center collision. Sloshing of hot gas like this can affect how the giant elliptical galaxy and its supermassive black hole at the center grow.

X-ray: NASA/CXC/BU/L.Blanton; Optical: ESO/VLT

By Chandra X-ray Center, Cambridge, Massachusetts

Published: December 14, 2011

Like wine in a glass, vast clouds of hot gas are sloshing back and forth in Abell 2052, a galaxy cluster located about 480 million light-years from Earth. X-ray data (blue) from NASA’s Chandra X-ray Observatory shows the hot gas in this dynamic system, and optical data (gold) from the Very Large Telescope shows the galaxies. The hot X-ray-bright gas has an average temperature of about 30 million degrees.

A huge spiral structure in the hot gas — spanning almost a million light-years across — is seen around the outside of the image, surrounding a giant elliptical galaxy at the center. This spiral was created when a small cluster of galaxies smashed into a larger one that surrounds the central elliptical galaxy.

As the smaller cluster approached, the dense hot gas of the central cluster was attracted to it by gravity. After the smaller cluster passed the cluster core, the direction of motion of the cluster gas reversed, and it traveled back toward the cluster center. The cluster gas moved through the center again and “sloshed” back and forth. The sides of the glass push the wine back to the center, whereas in the cluster the gravitational force of the matter in the clusters pulls it back. The sloshing gas ended up in a spiral pattern because the collision between the two clusters was off-center.

This type of sloshing in Abell 2052 has important physical implications. First, it helps push some of the more dense, cooler gas located in the center of the cluster — where temperatures are only about 10 million degrees — farther away from the core. This helps prevent further cooling of this gas in the core and could limit the amount of new stars being formed in the central galaxy. Sloshing motions like those seen in Abell 2052 also redistribute heavy elements, like iron and oxygen, which are forged in supernova explosions. These elements are used in the future generations of stars and planets and are necessary for life, as we know it.

Chandra’s observation of Abell 2052 was particularly long, lasting more than a week. Such a deep observation was necessary to detect all of the details in this image. Even then, processing to emphasize more-subtle features was necessary to reveal the outer spiral structure.

In addition to the large-scale spiral feature, the deep Chandra observation reveals exquisite detail in the cluster center related to outbursts from the central supermassive black hole. The Chandra data show clear bubbles evacuated by material blasted away from the black hole, which are surrounded by dense, bright, cool rims. As with the sloshing, this activity helps prevent cooling of the gas in the cluster’s core, setting limits on the growth of the giant elliptical galaxy and its supermassive black hole.

Coronal mass ejections (CMEs) could "sandblast" the Moon

Fig: Coronal mass ejection as viewed by the Solar Dynamics Observatory
(June 7, 2011. NASA/SDO)

By NASA's Goddard Space Flight Center, Greenbelt, Maryland

Published: December 12, 2011

Solar storms and associated coronal mass ejections (CMEs) can significantly erode the lunar surface, according to a new set of computer simulations by NASA scientists. In addition to removing a surprisingly large amount of material from the lunar surface, this could be a major method of atmospheric loss for planets like Mars that are unprotected by a global magnetic field.

Rosemary Killen is leading the research from NASA’s Goddard Space Flight Center in Greenbelt, Maryland, as part of the Dynamic Response of the Environment At the Moon (DREAM) team within the NASA Lunar Science Institute.

CMEs are basically an intense gust of the normal solar wind, a diffuse stream of electrically conductive gas called plasma that’s blown outward from the surface of the Sun into space. A strong CME may contain around a billion tons of plasma moving at up to 1 million mph (1.6 million km/h) in a cloud many times the size of Earth.

The Moon has just the barest wisp of an atmosphere, technically called an exosphere because it is so tenuous, which leaves it vulnerable to CME effects. The plasma from CMEs impacts the lunar surface, and atoms from the surface are ejected in a process called “sputtering.”

“We found that when this massive cloud of plasma strikes the Moon, it acts like a sandblaster and easily removes volatile material from the surface,” said William Farrell from NASA’s Goddard Space Flight Center. “The model predicts 100 to 200 tons of lunar material — the equivalent of 10 dump-truck loads — could be stripped off the lunar surface during the typical two-day passage of a CME.”

This is the first time researchers have attempted to predict the effects of a CME on the Moon. “Connecting various models together to mimic conditions during solar storms is a major goal of the DREAM project,” said Farrell.

Plasma is created when energetic events, like intense heat or radiation, remove electrons from the atoms in a gas, turning the atoms into electrically charged particles called ions. The Sun is so hot that the gas is emitted in the form of free ions and electrons called the solar wind plasma. Ejection of atoms from a surface or an atmosphere by plasma ions is called sputtering.

“Sputtering is among the top five processes that create the Moon’s exosphere under normal solar conditions, but our model predicts that during a CME, it becomes the dominant method by far, with up to 50 times the yield of the other methods,” said Killen.

CMEs are effective at removing lunar material not only because they are denser and faster than the normal solar wind, but also because they are enriched in highly charged, heavy ions, according to the team. The typical solar wind is dominated by lightweight hydrogen ions (protons). However, a heavier helium ion with more electrons removed, and hence a greater electric charge, can sputter tens of times more atoms from the lunar surface than a hydrogen ion.

The team used data from satellite observations that revealed this enrichment as input to their model. For example, helium ions make up about 4 percent of the normal solar wind, but observations reveal that during a CME they can increase to over 20 percent. When this enrichment is combined with the increased density and velocity of a CME, the highly charged, heavy ions in CMEs can sputter 50 times more material than protons in the normal solar wind.

“The computer models isolate the contributions from sputtering and other processes,” said Dana Hurley from the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland. “Comparing model predictions through a range of solar wind conditions allows us to predict the conditions when sputtering should dominate over the other processes. Those predictions can later be compared to data during a solar storm.”

The researchers believe that NASA’s Lunar Atmosphere And Dust Environment Explorer (LADEE) — a lunar orbiter mission scheduled to launch in 2013 — will be able to test their predictions. The strong sputtering effect should kick lunar surface atoms to LADEE’s orbital altitude, about 12 to 31 miles (19 to 50 kilometers), so the spacecraft will see them increase in abundance.

“This huge CME sputtering effect will make LADEE almost like a surface mineralogy explorer, not because LADEE is on the surface, but because during solar storms surface atoms are blasted up to LADEE,” said Farrell.

The Moon is not the only heavenly body affected by the dense CME driver gas. Space scientists have long been aware that these solar storms dramatically affect Earth’s magnetic field and are responsible for intense aurorae (the northern and southern lights).

While certain areas of the martian surface are magnetized, Mars does not have a magnetic field that surrounds the entire planet. Therefore, CME gases have a direct path to sputter and erode that planet’s upper atmosphere. In late 2013, NASA will launch the Mars Atmosphere and Volatile Evolution (MAVEN) mission that will orbit the Red Planet to investigate exactly how solar activity, including CMEs, removes the atmosphere.

On exposed small bodies like asteroids, the dense, fast-streaming CME gas should create a sputtered-enhanced exosphere about the object, similar to that expected at the Moon.

Kepler's First Planet Inside Habitable (Outside Solar System)

This diagram compares our own solar system to Kepler-22, a star system containing the first "habitable zone" planet discovered by NASA's Kepler mission. NASA/Ames/JPL-Caltech

By NASA Headquarters, Washington, D.C.

Published: December 5, 2011

NASA’s Kepler mission has confirmed its first planet in the “habitable zone,” the region where liquid water could exist on a planet’s surface. Kepler also has discovered more than 1,000 new planet candidates, nearly doubling its previously known count. Ten of these candidates are near Earth’s size and orbit in the habitable zone of their host star. Candidates require follow-up observations to verify they are actual planets.

The newly confirmed planet, Kepler-22b, is the smallest yet found to orbit in the middle of the habitable zone of a star similar to our Sun. The planet is about 2.4 times the radius of Earth. Scientists don’t yet know if Kepler-22b has a predominantly rocky, gaseous, or liquid composition, but its discovery is a step closer to finding Earth-like planets.

Previous research hinted at the existence of near-Earth-sized planets in habitable zones, but clear confirmation proved elusive. Two other small planets orbiting stars smaller and cooler than our Sun recently were confirmed on the edges of the habitable zone, with orbits more closely resembling those of Venus and Mars.

“This is a major milestone on the road to finding Earth’s twin,” said Douglas Hudgins from NASA Headquarters in Washington, D.C. “Kepler’s results continue to demonstrate the importance of NASA’s science missions, which aim to answer some of the biggest questions about our place in the universe.”

Kepler discovers planets and planet candidates by measuring dips in the brightness of more than 150,000 stars to search for planets that cross in front, or “transit,” the stars. Kepler requires at least three transits to verify a signal as a planet.

“Fortune smiled upon us with the detection of this planet,” said William Borucki from NASA Ames Research Center at Moffett Field, California. “The first transit was captured just three days after we declared the spacecraft operationally ready. We witnessed the defining third transit over the 2010 holiday season.”

The Kepler science team uses ground-based telescopes and the Spitzer Space Telescope to review observations on planet candidates the spacecraft finds. The star field that Kepler observes in the constellations Cygnus and Lyra are only visible from ground-based observatories in spring through early fall. The data from these other observations help determine which candidates can be validated as planets.

Kepler-22b is located 600 light-years away. While the planet is larger than Earth, its orbit of 290 days around a Sun-like star resembles that of our world. The planet’s host star belongs to the same class as our Sun, called G-type, although it is slightly smaller and cooler.

Of the 54 habitable zone planet candidates reported in February 2011, Kepler-22b is the first to be confirmed.

The Kepler team is hosting its inaugural science conference at Ames December 5–9, announcing 1,094 new planet candidate discoveries. Since the last catalog was released in February, the number of planet candidates identified by Kepler has increased by 89 percent, and now totals 2,326. Of these, 207 are approximately Earth-sized, 680 are super-Earth-sized, 1,181 are Neptune-sized, 203 are Jupiter-sized, and 55 are larger than Jupiter.

The findings, based on observations conducted May 2009 to September 2010, show a dramatic increase in the numbers of smaller-sized planet candidates.


Kepler observed many large planets in small orbits early in its mission, which were reflected in the February data release. Having had more time to observe three transits of planets with longer orbital periods, the new data suggest that planets one to four times the size of Earth may be abundant in the galaxy.

The number of Earth-sized and super-Earth-sized candidates has increased by more than 200 and 140 percent since February, respectively.

There are 48 planet candidates in their stars’ habitable zones. While this is a decrease from the 54 reported in February, the Kepler team has applied a stricter definition of what constitutes a habitable zone in the new catalog to account for the warming effect of atmospheres, which would move the zone away from the star out to longer orbital periods.

“The tremendous growth in the number of Earth-size candidates tells us that we’re honing in on the planets that Kepler was designed to detect: those that are not only Earth-size, but also are potentially habitable,” said Natalie Batalha from San Jose State University in California. “The more data we collect, the keener our eye for finding the smallest planets out at longer orbital periods.”

Mars Science Laboratory : The Historic Voyage to Mars

NASA's Mars Science Laboratory spacecraft, sealed inside its payload fairing atop the United Launch Alliance Atlas V rocket, clears the tower at Space Launch Complex 41 on Cape Canaveral Air Force Station in Florida. The mission lifted off at 10:02 a.m. EST November 26, beginning an eight-month interplanetary cruise to Mars.

Photo by NASA/Bill White

Published By : NASA (Goddard & GPL)
Edited By : Engineer Yousuf Ibrahim Khan

Date : 29th November, 2011

NASA began a historic voyage to Mars with the November 26 launch of the Mars Science Laboratory (MSL), which carries a car-sized rover named Curiosity. Liftoff from Cape Canaveral Air Force Station aboard an Atlas V rocket occurred at 10:02 a.m. EST.

Some Key Facts and NASA's Earlier Concerns about MSL:

The MSL mission has four science goals:

1. Determine whether Mars could ever have supported life
2. Study the climate of Mars
3. Study the geology of Mars
4. Plan for a human mission to Mars

To contribute to these goals, MSL has six main scientific objectives:

1. Determine the mineralogical composition of the Martian surface and near-surface geological materials.
2. Attempt to detect chemical building blocks of life (bio-signatures).
3. Interpret the processes that have formed and modified rocks and soils.
4. Assess long-timescale (i.e., 4-billion-year) Martian atmospheric evolution processes.
5. Determine present state, distribution, and cycling of water and carbon dioxide.
6. Characterize the broad spectrum of surface radiation, including galactic radiation, cosmic radiation, solar proton events and secondary neutrons.

Mass of Rover: 1,950 pounds (890 kilograms)
Launch Vehicle:
Atlas V 541 from Cape Canaveral Air Force Station, FL
Arrival at Mars: August 6-20, 2012

The Mars Science Laboratory is designed to enable scientists to determine whether past or present environmental conditions at a selected area on the Red Planet could support microbial life and its preservation in the rock record. Outfitted with six wheels and a sophisticated suite of scientific equipment that includes a large robot arm, a laser, a weather station, and a drill, the Mars Science Laboratory’s jeep-sized rover is named Curiosity. The technology of the rover and its landing system is designed to demonstrate substantial new capabilities and operational techniques that would benefit future NASA missions, from precision landing in a small target zone to extended surface life-times to the transmission of extremely large data volumes back to Earth. Scheduled for launch on an Atlas V rocket, Curiosity will derive its electrical power from a Multi Mission Radioisotope Thermoelectric Generator (MMRTG). Similar to the radioisotope power systems used to safely and successfully power numerous solar system exploration missions from Voyager to Pluto/New Horizons for more than 40 years, the MMRTG will significantly enhance the range and lifetime of the rover. It will also promote greater operability of the rover’s science experiments, which include the first ever plans to drill into Martian rocks for powdered samples to analyze on-site. The MMRTG contains 10.6 pounds (4.8 kilograms) of plutonium dioxide as the source of the steady supply of heat used to produce the onboard electricity and to warm the rover’s systems during the frigid Martian night. As with any NASA mission that relies on a radioisotope power system, the Mars Science Laboratory has undergone a comprehensive multi-agency environmental review, including public meetings and open comment periods, as part of NASA’s compliance with the National Environmental Policy Act. Additionally, the mission will not launch until formal approval is received from the Office of the President. Like previous generations of this type of electrical power generator, the MMRTG is built with several layers of protective material designed to contain its plutonium dioxide fuel in a wide range of potential accidents, verified through impact testing. Each MMRTG carries eight individually shielded general purpose heat source modules (compared to 18 modules in the previous generation). The thickness of the protective graphite material in the center of the modules and between the shells of each module in the MMRTG has been increased by 20 percent over previous modules. Extensive technical analysis of the planned launch of the Mars Science Laboratory, including review of all similar past expendable rocket launches, has been conducted by NASA, the U.S. Department of Energy (which provides the MMRTG), and external experts. This work has determined that the chances of any launch accident are small (3.3 percent), and the chances of an accident of the type that would release plutonium are about ten times smaller. In the event of a launch accident, it is unlikely that any plutonium would be released or that anyone would be exposed to nuclear material. The type of plutonium used in a radioisotope power system is different from the material used in weapons, and cannot explode like a bomb. It is manufactured in a ceramic form that does not become a significant health hazard unless it becomes broken into very fine pieces or vaporized and then inhaled or swallowed. Those people who might be exposed in a Mars Science Laboratory launch accident would receive an average dose of 5-10 millirem, equal to about a week of background radiation. The average American receives 360 millirem of radiation each year from natural sources, such as radon and cosmic rays. NASA, several other federal agencies, the State of Florida and the local governments surrounding Kennedy Space Center are preparing in advance to respond to any launch accident through specific communication procedures, the use of advanced environmental sensors around the launch area, rehearsal of coordinated response to various launch scenarios, and informational briefings to local communities and emergency responders. In the case of a launch accident, related alerts could include precautionary measures such as directions for people to stay indoors for a limited duration.

But Finally it Happened :


Fig : Artist’s concept of Curiosity on Mars

“We are very excited about sending the world’s most advanced scientific laboratory to Mars,” NASA Administrator Charles Bolden said. “MSL will tell us critical things we need to know about Mars, and while it advances science, we’ll be working on the capabilities for a human mission to the Red Planet and to other destinations where we’ve never been.”

The mission will pioneer precision landing technology and a sky-crane touchdown to place Curiosity near the foot of a mountain inside Gale Crater on August 6, 2012. During a nearly two-year prime mission after landing, the rover will investigate whether the region has ever offered conditions favorable for microbial life, including the chemical ingredients for life.


Fig: Full-scale cutaway models of an MMRTG and one of its heat source modules, which produce electricity passively using thermocouples with no moving parts.(The MMRTG is 26 inches [67 centimeters] tall.)

“The launch vehicle has given us a great injection into our trajectory, and we’re on our way to Mars,” said Mars Science Laboratory Project Manager Peter Theisinger of NASA’s Jet Propulsion Laboratory in Pasadena, California. “The spacecraft is in communication, thermally stable, and power positive.”


The Atlas V initially lofted the spacecraft into Earth orbit and then, with a second burst from the vehicle’s upper stage, pushed it out of Earth orbit into a 352-million-mile (567 million kilometers) journey to Mars.

“Our first trajectory correction maneuver will be in about two weeks,” Theisinger said. “We’ll do instrument checkouts in the next several weeks and continue with thorough preparations for the landing on Mars and operations on the surface.”

Curiosity’s ambitious science goals are among the mission’s many differences from earlier Mars rovers. It will use a drill and scoop at the end of its robotic arm to gather soil and powdered samples of rock interiors, then sieve and parcel out these samples into analytical laboratory instruments inside the rover. Curiosity carries 10 science instruments with a total mass 15 times as large as the science- instrument payloads on the Mars rovers Spirit and Opportunity. Some of the tools are the first of their kind on Mars, such as a laser-firing instrument for checking the elemental composition of rocks from a distance and an X-ray diffraction instrument for definitive identification of minerals in powdered samples.


To haul and wield its science payload, Curiosity is twice as long and five times as heavy as Spirit or Opportunity. Because of its 1-ton mass, Curiosity is too heavy to employ airbags to cushion its landing as previous Mars rovers could. Part of the Mars Science Laboratory spacecraft is a rocket-powered descent stage that will lower the rover on tethers as the rocket engines control the speed of descent.

The mission’s landing site offers Curiosity access for driving to layers of the mountain inside Gale Crater. Observations from orbit have identified clay and sulfate minerals in the lower layers, indicating a wet history.


Precision landing maneuvers as the spacecraft flies through the martian atmosphere before opening its parachute make Gale a safe target for the first time. This innovation shrinks the target area to less than one-fourth the size of earlier Mars landing targets. Without it, rough terrain at the edges of Curiosity’s target would make the site unacceptably hazardous.

The innovations for landing a heavier spacecraft with greater precision are steps in technology development for human Mars missions.

In addition, Curiosity carries an instrument for monitoring the natural radiation environment on Mars, important information for designing human Mars missions that protect astronauts’ health.

MSL and Others are on their way :


Fig : This artist's concept shows the MAVEN spacecraft orbiting Mars. NASA/Goddard Space Flight Center

Maybe because it appears as a speck of blood in the sky, the planet Mars was named after the Roman god of war. From the point of view of life as we know it, that’s appropriate. The martian surface is incredibly hostile for life. The Red Planet’s thin atmosphere does little to shield the ground against radiation from the Sun and space. Harsh chemicals, like hydrogen peroxide, permeate the soil. Liquid water, a necessity for life, can’t exist for very long there — any that does not quickly evaporate in the diffuse air will soon freeze out in subzero temperatures common over much of the planet.

It wasn’t always this way. There are signs that in the distant past, billions of years ago, Mars was a much more inviting place. Martian terrain is carved with channels that resemble dry riverbeds. Spacecraft sent to orbit Mars have identified patches of minerals that form only in the presence of liquid water. It appears that in its youth, Mars was a place that could have harbored life with a thicker atmosphere warm enough for rain that formed lakes or even seas.

Two new NASA missions, one that will roam the surface and another that will orbit the planet and dip briefly into its upper atmosphere, will try to discover what transformed Mars. “The ultimate driver for these missions is the question, ‘Did Mars ever have life?’” said Paul Mahaffy of NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “Did microbial life ever originate on Mars, and what happened to it as the planet changed? Did it just go extinct, or did it go underground where it would be protected from space radiation and temperatures might be warm enough for liquid water?”

The Mars Science Laboratory (MSL) mission features Curiosity, the largest and most advanced rover ever sent to the Red Planet. The Curiosity rover bristles with multiple cameras and instruments, including Goddard’s Sample Analysis at Mars (SAM) instrument suite. By looking for evidence of water, carbon, and other important building blocks of life in the martian soil and atmosphere, SAM will help discover whether Mars ever had the potential to support life. Scheduled to launch in late November or December 2011 (first window of opportunity being November 26), Curiosity will be delivered to Gale Crater, a 96-mile-wide (154 kilometers) crater that contains a record of environmental changes in its sedimentary rock, in August 2012.

The Mars Atmosphere and Volatile EvolutioN (MAVEN) mission, scheduled to launch in late 2013, will orbit Mars and is devoted to understanding the Red Planet’s upper atmosphere. It will help determine what caused the martian atmosphere — and water — to be lost to space, making the climate increasingly inhospitable for life.

“Both MAVEN and Curiosity/SAM will determine the history of the martian climate and atmosphere using multiple approaches,” said Bruce Jakosky from the University of Colorado in Boulder. “Measurements of isotope ratios are an approach shared by both missions.”

Isotopes are heavier versions of an element. For example, deuterium is a heavy version of hydrogen. Normally, two atoms of hydrogen join to an oxygen atom to make a water molecule, but sometimes the heavy (and rare) deuterium takes a hydrogen atom’s place.

When water gets lofted into Mars’ upper atmosphere, solar radiation can break it apart into hydrogen (or deuterium) and oxygen. Hydrogen escapes faster because it is lighter than deuterium. Since the lighter version escapes more often, over time the martian atmosphere has less and less hydrogen compared to the amount of deuterium remaining. The martian atmosphere therefore becomes richer and richer in deuterium.

The MAVEN team will measure the amount of deuterium compared to the amount of hydrogen in Mars’ upper atmosphere, which is the planet’s present-day deuterium to hydrogen (D/H) ratio. They will compare it to the ratio Mars had when it was young — the early D/H ratio. The early ratio can be measured from the D/H ratio in ancient martian minerals and estimated from observations of the D/H ratio in comets and asteroids, which are believed to be pristine “fossil” remnants of our solar system’s formation.

Comparing the present and early D/H ratios will allow the team to calculate how much hydrogen — and, therefore, water — has been lost over Mars’ lifetime. MAVEN will also determine how much martian atmosphere has been lost over time by measuring the isotope ratios of other elements in the high atmosphere, such as nitrogen, oxygen, carbon, and noble gases like argon.

MAVEN is expected to reach Mars in 2014. By then, SAM on board the Curiosity rover will have made similar measurements from Gale Crater, which will help guide the interpretation of MAVEN’s upper atmosphere measurements.

Measuring isotopes in the atmosphere will reveal its present state. To find out what the martian atmosphere was like in the past, scientists will use what they discover with MAVEN about the various ways the atmosphere is being removed. With that data, they will build computer simulations to estimate the condition of the Red Planet’s atmosphere billions of years ago.

Scientists estimate Gale Crater may have formed more than three billion years ago. Curiosity will grind up Gale Crater minerals and deliver them to SAM so the isotope ratios can be measured, giving a glimpse of the martian atmosphere from long ago, perhaps when it could have supported life. “SAM’s inputs from the surface of past martian history will help the MAVEN team work backwards to discover how the martian atmosphere evolved,” said Joseph Grebowsky from NASA’s Goddard Space Flight Center.

“For example, MAVEN will focus primarily on how solar activity erodes the martian atmosphere,” said Mahaffy. Things like the solar wind, a tenuous stream of electrically conducting gas blown from the surface of the Sun, explosions in the Sun’s atmosphere called solar flares, and eruptions of solar material called coronal mass ejections can all strip away the upper atmosphere of Mars in various ways. “If we figure out how much atmosphere is removed by changes in solar activity, we can extrapolate back to estimate what the isotope ratios should have been billions of years ago. However, if the measurements of the ancient ratios from SAM don’t match up, this suggests that we may have to look at other ways the atmosphere could have been lost, such as giant impacts from asteroids,” said Mahaffy. Some scientists believe giant impacts could have blasted significant amounts of the martian atmosphere into space.

Also, Curiosity will carry a weather station, which will help the MAVEN team understand how changes in the upper atmosphere are related to changes at the surface. “For example, if the rover detects a dust storm, it may have an effect higher up because of the winds and the gravity waves — the bobbing up and down of a parcel of air — it sets up,” said Grebowsky.

“Curiosity will focus on geology and minerals to determine if the environment on Mars in the distant past had the potential to support life,” said Mahaffy. “It will be digging in the dirt trying to understand the habitability issue in a place where water may have flowed, where there could have been a lake. Habitability is also the basic theme of MAVEN — it will be trying to understand from the top down how the atmosphere evolved over time and how it was lost, which ties back to how clement it was early on.”

For further information about these missions, contact:
David Lavery
Science Mission Directorate
NASA Headquarters
Washington, DC 20546
(202) 358-4684
david.lavery@hq.nasa.gov

Top Ranked Research Universities

The following ranking is based on research activities (Theories, Discoveries) conducted by the universities through out the last five years (2006-2011) in the field of space and astronomy :

Published By : Yousuf Ibrahim Khan
Date: November 23, 2011

1. University of Arizona
2. Harvard University
3. University of California,Berkeley
4. California Institute of Technology
5. University of California, Santa Cruz
6. University of Colorado, Boulder
7. University of Texas, Austin
8. Johns Hopkins University
9. University of Washington, Seattle
10. University of Michigan, Ann Arbor
11. Penn State University, University Park
12. University of Chicago
12. University of Maryland, College Park
13. Massachusetts Institute of Technology
14. University of Illinois, Urbana-Champaign
15. Cornell University
16. Yale University
17. University of Wisconsin-Madison
18. Arizona State University
19. University of Hawaii (Honolulu & Manoa)

In search of Gravity Waves

LISA Pathfinder about to enter the space environment vacuum test. Credit: Astrium, United Kingdom

By ESA, Noordwijk, Netherlands

Published: November 15, 2011

Sensors destined for the European Space Agency’s (ESA) LISA Pathfinder mission in 2014 have far exceeded expectations, paving the way for a mission to detect one of the most elusive forces permeating through space — gravity waves.

The Optical Metrology Subsystem underwent its first full tests under space-like temperature and vacuum conditions using an almost complete version of the spacecraft.

The results exceeded the precision required to detect the enigmatic ripples in the fabric of space and time predicted by Albert Einstein — and did it by two to three times.

In space, the LISA Pathfinder will measure the distance between two free-floating gold-platinum cubes using lasers. In the ground tests currently being performed by the team in Ottobrunn, Germany, separate mirrors replace these cubes.

In addition to measuring the distance between the cubes, it also measures their angles with respect to the laser beams — and the tests show an accuracy of 10 trillionths of a degree.

“This is equivalent to the angle subtended by an astronaut’s footprint on the Moon!” said Paul McNamara from ESA.

Under perfect conditions in space, the free-floating cubes would be expected to exactly copy each other’s motions.

However, according to Einstein’s general theory of relativity, if a gravitational wave were to pass through space, possibly caused by an event as catastrophic as the collision of two black holes, then a minuscule distortion in the fabric of space itself would be detectable.

The accuracy required to detect such a subtle change is phenomenal — around a hundredth the size of an atom — a picometer.

The requirement set for the instrument was around 6 picometers, measured over 1,000 seconds, which the team initially bettered in 2010.

During the latest testing, a staggering 2-picometer accuracy was obtained, far exceeding the best performance for an instrument of this type.

“The whole team has worked extremely hard to make this measurement possible,” said McNamara. “When LISA Pathfinder is launched, and we’re in the quiet environment of space some 1.5 billion kilometers [930 million miles] from Earth, we expect that performance will be even better.”

The instrument team from Astrium GmbH, the Albert Einstein Institute, and ESA are testing the Optical Metrology Subsystem during LISA Pathfinder’s thermal vacuum tests in Ottobrunn by spacecraft prime contractor Astrium in the United Kingdom.

LISA Pathfinder is expected to be launched in mid-2014 to demonstrate the technologies and endurance in space for a New Gravitational wave Observatory mission, one of the candidates for ESA’s next flagship mission planned for a launch early in the next decade, aiming to find this final piece in Einstein’s cosmic puzzle.

Hubble directly observes the disk around a Black Hole

This picture shows a quasar that has been gravitationally lensed by a galaxy in the foreground, which can be seen as a faint shape around the two bright images of the quasar. Credit: NASA/ESA/J.A. Muñoz (University of Valencia)

By Hubble ESA, Garching, Germany

Published : November 4, 2011

An international team of astronomers has used a new technique to study the bright disk of matter surrounding a faraway black hole. Using the NASA/ESA Hubble Space Telescope, combined with the gravitational lensing effect of stars in a distant galaxy, the team measured the disk’s size and studied the colors and, hence, the temperatures of different parts of the disk. These observations show a level of precision equivalent to spotting individual grains of sand on the surface of the Moon.

While black holes themselves are invisible, the forces they unleash cause some of the brightest phenomena in the universe. Quasars — short for quasi-stellar objects — are glowing disks of matter that orbit supermassive black holes, heating up and emitting extremely bright radiation as they do so.

“A quasar accretion disk has a typical size of a few light-days, or around 62 billion miles (100 billion kilometers) across, but they lie billions of light-years away,” said Jose Muñoz from the University of Valencia, Spain. “This means their apparent size, when viewed from Earth, is so small that we will probably never have a telescope powerful enough to see their structure directly.”

Until now, the minute size of quasars has meant that most of our knowledge of their inner structure has been based on theoretical extrapolations, rather than direct observations.

The team, therefore, used an innovative method to study the quasar.
They used the stars in an intervening galaxy as a scanning microscope to probe features in the quasar’s disk that would otherwise be far too small to see. As these stars move across the light from the quasar, gravitational effects amplify the light from different parts of the quasar, giving detailed color information for a line that crosses through the accretion disk.

The team observed a group of distant quasars that are gravitationally lensed by the chance alignment of other galaxies in the foreground, producing several images of the quasar.

They spotted subtle differences in color between the images as well as changes in color over the time the observations were carried out. The properties of dust in the intervening galaxies cause part of these color differences. The light coming from each one of the lensed images has followed a different path through the galaxy, so the various colors encapsulate information about the material within the galaxy. Measuring the way and extent to which the dust within the galaxies blocks light at such distances is an important result in the study.

For one of the quasars they studied, though, there were clear signs that stars in the intervening galaxy were passing through the path of light from the quasar. Just as the gravitational effect, due to the whole intervening galaxy, can bend and amplify the quasar’s light, so can that of the stars within the intervening galaxy subtly bend and amplify the light from different parts of the accretion disk as they pass through the path of the quasar’s light.

By recording the variation in color, the team was able to reconstruct the color profile across the accretion disk. This is important because the temperature of an accretion disk increases the closer it is to the black hole, and the colors emitted by the hot matter get bluer the hotter they are. This allowed the team to measure the diameter of the disk of hot matter and plot how hot it is at different distances from the center.

They found that the disk is approximately 60-190 billion miles (100-300 billion km) across. While this measurement shows large uncertainties, it is still a remarkably accurate measurement for a small object at such a great distance, and the method holds great potential for increased accuracy in the future.

“This result is very relevant because it implies we are now able to obtain observational data on the structure of these systems, rather than relying on theory alone,” said Muñoz. “Quasars’ physical properties are not yet well understood. This new ability to obtain observational measurements is therefore opening a new window to help understand the nature of these objects.”

Youngest Millisecond Pulsar Discovered

In three years, NASA's Fermi has detected more than 100 gamma-ray pulsars, but something new has appeared. Among a type of pulsar with ages typically numbering a billion years or more, Fermi has found one that appears to have been born only millions of years ago.

Credit: NASA's Goddard Space Flight Center

By Max Planck Institute for Radio Astronomy, Bonn, Germany, Max Planck Society, Munich, Germany

Published : November 3, 2011

Paulo Freire from the Max Planck Institute for Radio Astronomy (MPIfR) in Bonn and his collaborators have discovered the first gamma-ray pulsar in a globular cluster using the Large Area Telescope onboard the Fermi Gamma-ray Space Telescope. The pulsar, labeled J1823-3021A, is located in the globular cluster NGC 6624 in Sagittarius, not far from the direction to the galactic center. At a distance of approximately 27,000 light-years, it is also the most distant pulsar ever detected in gamma rays. Its extreme gamma-ray luminosity implies that it is the youngest millisecond pulsar discovered to date and that its magnetic field is much larger than previously predicted by pulsar recycling theories. It suggests the existence of a whole new population of such extreme objects forming at the same rate as the more normal millisecond pulsars.

When the cores of massive stars run out of nuclear fuel, they collapse catastrophically, a phenomenon known as a supernova. This spectacular event marks the birth of a neutron star: a ball of neutrons, a single giant atomic nucleus with a radius of about 6-10 miles (10-16 kilometers) and about half a million times the Earth's mass. A pulsar is a rapidly rotating neutron star for which we can detect pulsations (normally at radio, but now also at gamma-ray wavelengths), modulated by the rotation of the object — like a lighthouse. Ordinary pulsars have rotation periods between 16 milliseconds and 8 seconds. Even faster rotating are the so-called millisecond pulsars (MSPs), which can have rotation periods as fast as 1.4 milliseconds — corresponding to 43,000 rotations per minute. They are thought to have been spun up by accretion of matter from a companion star, a theory that is supported by the observation that roughly 80 percent of MSPs are found in binary systems.

MSPs possess extraordinary long-term rotational stability, which is in some cases similar to those of the best atomic clocks on Earth. They are basically giant flywheels in space where nothing disturbs their rotation. They are being used to test Einstein's general theory of relativity, search for gravitational waves, and study the properties of the super-dense matter at their center.

"We have discovered more than 100 of these objects in globular clusters with radio telescopes," said Freire. "Thanks to the sensitivity of the Large Area Telescope on the Fermi satellite, we have been able, for the first time, to see one of them in gamma rays."

Globular clusters are ancient swarms of hundreds of thousands of stars bound together by their mutual gravity. They produce many binary systems of the kind that lead to the formation of millisecond pulsars. One of these clusters is NGC 6624 in Sagittarius. At a distance of about 27,000 light-years, it is in the proximity of the galactic center. A total of six pulsars have been discovered in this globular cluster to date, three of these to be announced soon. The first pulsar found in NGC 6624 was J1823-3021A. With a rotation period of 5.44 milliseconds (11,000 rotations/minute), it is the most luminous radio pulsar found in a globular cluster to date. It has been timed since its discovery in 1990 with several large radio telescopes, in particular with the Lovell Telescope of the University of Manchester/England and with the radio telescope at Nançay/France.

"To our surprise, we found the pulsar to be extremely bright in gamma rays, as well," said Damien Parent from the Center for Earth Observing and Space Research. "Millisecond pulsars were not supposed to be that bright. This implies an unexpectedly high magnetic field for such a fast pulsar."

"This challenges our current theories for the formation of such objects," saud Michael Kramer from MPIfR. "We are currently investigating a number of possibilities. Nature might even be forming millisecond pulsars in a way we have not anticipated."

"Whichever way these anomalous pulsars are formed, one thing appears to be clear," said Freire. "At least in globular clusters, they are so young that they are probably forming at rates comparable to the large known population of normal millisecond pulsars."

Dwarf Galaxies could uncover the nature of Dark Matter

The circled cluster of stars is the dwarf galaxy Andromeda 29, which University of Michigan astronomers have discovered. The bright star within the circle is a foreground star within our own Milky Way galaxy. This image was obtained with the Gemini Multi-Object Spectrograph at the Gemini North Telescope in Hawaii. Credit: Gemini Observstory/AURA/Eric Bell

By University of Michigan, Ann Arbor

Published : November 7, 2011

In work that could help advance astronomers' understanding of dark matter, University of Michigan researchers have discovered two additional dwarf galaxies that appear to be satellites of Andromeda, the closest spiral galaxy to Earth.

Eric Bell and Colin Slater found Andromeda XXVIII and XXIX. They did it by using a tested star-counting technique on the newest data from the Sloan Digital Sky Survey, which has mapped more than a third of the night sky. They also used follow-up data from the Gemini North Telescope in Hawaii.

At 1.7 million light-years from Andromeda, these are two of the furthest satellite galaxies ever detected. Invisible to the naked eye, the galaxies are 100,000 times fainter than Andromeda and are barely visible even through large telescopes.

These astronomers set out looking for dwarf galaxies around Andromeda to help them understand how matter relates to dark matter, an invisible substance that doesn't emit or reflect light, but is believed to make up most of the universe's mass. Astronomers believe it exists because they can detect its gravitational effects on visible matter. With its gravity, dark matter is believed to be responsible for organizing visible matter into galaxies.

"These faint, dwarf, relatively nearby galaxies are a real battleground in trying to understand how dark matter acts at small scales," Bell said. "The stakes are high."

The prevailing hypothesis is that visible galaxies are all nestled in beds of dark matter, and each bed of dark matter has a galaxy in it.
For a given volume of universe, the predictions match observations of large galaxies.

"But it seems to break down when we get to smaller galaxies," Slater said. "The models predict far more dark matter halos than we observe galaxies. We don't know if it's because we're not seeing all of the galaxies or because our predictions are wrong."

"The exciting answer," Bell said, "would be that there just aren't that many dark matter halos. This is part of the grand effort to test that paradigm."

Next NASA Mission :The Nuclear Spectroscopic Telescope Array

Figure: NuSTAR (Credit: California Institute of Technology)

The NuSTAR mission will deploy the first focusing telescopes to image the sky in the high energy X-ray (6 - 79 keV) region of the electromagnetic spectrum. Our view of the universe in this spectral window has been limited because previous orbiting telescopes have not employed true focusing optics, but rather have used coded apertures that have intrinsically high backgrounds and limited sensitivity.

During a two-year primary mission phase, NuSTAR will map selected regions of the sky in order to:

(1) take a census of collapsed stars and black holes of different sizes by surveying regions surrounding the center of own Milky Way Galaxy and performing deep observations of the extragalactic sky;

(2) map recently-synthesized material in young supernova remnants to understand how stars explode and how elements are created; and

(3) understand what powers relativistic jets of particles from the most extreme active galaxies hosting supermassive black holes.

In addition to its core science program, NuSTAR will offer opportunities for a broad range of science investigations, ranging from probing cosmic ray origins to studying the extreme physics around collapsed stars to mapping microflares on the surface of the Sun. NuSTAR will also respond to targets of opportunity including supernovae and gamma-ray bursts.

The NuSTAR instrument consists of two co-aligned grazing incidence telescopes with specially coated optics and newly developed detectors that extend sensitivity to higher energies as compared to previous missions such as Chandra and XMM. After launching into orbit on a small rocket, the NuSTAR telescope extends to achieve a 10-meter focal length. The observatory will provide a combination of sensitivity, spatial, and spectral resolution factors of 10 to 100 improved over previous missions that have operated at these X-ray energies.



Figure: NuSTAR focal plane motherboard with one of the four CdZnTe detectors installed. NuSTAR will have two such units, providing for a total of two 4K high energy X-ray cameras.

NuSTAR has two detector units, each at the focus of one of the two co-aligned NuSTAR optics units. The optical units observe the same area of sky, and the two images are combined on the ground. The focal planes are each comprised of four 32×32 pixel Cadmium-Zinc-Tellurium (CdZnTe, or CZT) detectors manufactured by eV Products. CZT detectors are state-of-the-art room temperature semiconductors that are very efficient at turning high energy photons into electrons. The electrons are then digitally recorded using custom Application Specific Integrated Circuits (ASICs) designed by the NuSTAR Caltech Focal Plane Team.

A NASA Small Explorer (SMEX) mission, NuSTAR is currently in Phase C/D and is scheduled to launch into low-Earth equatorial orbit in February 2012.

Faster than Light Experiment : OPERA

CERN Neutrinos to Gran Sasso Underground Structures

Credit : CERN

Published : 3rd October, 2011

The Oscillation Project with Emulsion-tRacking Apparatus (OPERA) is an experiment to test the phenomenon of neutrino oscillations. It exploits CERN Neutrinos to Gran Sasso (CNGS), a high-intensity and high-energy beam of muon neutrinos produced at the CERN Super Proton Synchrotron in Geneva and pointing to the Laboratori Nazionali del Gran Sasso (LNGS) underground laboratory, 733 km (455 mi) away at Gran Sasso in central Italy (Abruzzo region). OPERA is located in Hall C of LNGS and is aimed at detecting for the first time the appearance of tau neutrinos from the oscillation of muon neutrinos during their 3 millisecond travel from Geneva to Gran Sasso. Tau particles resulting from the interaction of tau neutrinos will be observed in "bricks" of photographic emulsion films interleaved with lead plates. The apparatus contains about 150,000 bricks, for a total mass of 1300 tons, and is complemented by electronic detectors (trackers and spectrometers) and ancillary infrastructure. Its construction was completed in spring 2008 and the experiment is currently collecting data.

On 31 May 2010, OPERA researchers announced the observation of a first tau neutrino candidate event in a muon neutrino beam. In September 2011, CERN and OPERA announced that time of flight measurements made by their collaboration had indicated muon neutrinos traveling at faster than lightspeed. While acknowledging that such a measurement would be a major discovery if correct, many physicists,and the OPERA team itself, have expressed skepticism that OPERA's measurements are sufficiently free of error. Experimental groups such as the MINOS Experiment at Fermilab and the T2K experiment are planning to attempt to replicate the result, while others in the physics community search for any experimental errors which might account for it.

OPERA needs an intense and energetic beam of muon neutrinos traveling a distance of hundreds of kilometers to detect the appearance of oscillated tau neutrinos. A beam of this type is generated by collisions of accelerated protons with a graphite target after focusing the particles produced (pions and kaons in particular) in the desired direction. The products of their decays, muons and neutrinos, continue to travel in generally the same direction as the parent particle. Muon neutrinos produced in this way at CERN pass through the Earth's crust reaching OPERA after a 730 km journey.

OPERA is located in Hall C of the Gran Sasso underground labs. Construction started in 2003, and the apparatus was completed in summer 2008. The taus resulting from the interaction of tau neutrinos will be observed in "bricks" of photographic films (nuclear emulsion) interleaved with lead sheets. Each brick has an approximate weight of 8.3 kg and the two OPERA supermodules contain about 150,000 bricks arranged into parallel walls and interleaved with plastic scintillator counters. Each supermodule is followed by a magnetic spectrometer for momentum and charge identification of penetrating particles. During the data collection, a neutrino interaction is tagged in real time by the scintillators and the spectrometers, which also provide the location of the bricks where the neutrino interaction occurred. These bricks are extracted from the walls asynchronously with respect to the beam to allow for film development, scanning and for the topological and kinematic search of tau decays.

NASA Space Telescopes Reveal Secrets of Supermassive Black Hole

This image of the distant active galaxy Markarian 509 was taken in April 2007 with the Hubble Space Telescope's Wide Field Camera 2.

Credit: NASA, ESA, G. Kriss (STScI), and J. de Plaa (SRON Netherlands Institute for Space Research); Acknowledgment: B. Peterson (Ohio State University)

Published: 29th September, 2011

A fleet of spacecraft including NASA's Hubble Space Telescope has uncovered unprecedented details in the surroundings of a supermassive black hole. Observations reveal huge bullets of gas being driven away from the gravitational monster and a corona of very hot gas hovering above the disk of matter that is falling into the black hole.A team led by Jelle Kaastra of SRON Netherlands Institute for Space Research made use of data from ESA's XMM-Newton and INTEGRAL spacecraft (which study X-rays and gamma rays, respectively), the Hubble Space Telescope (for ultraviolet observations with the COS instrument), and NASA's Chandra (X-ray) Observatory and Swift (gamma-ray) satellites.

The black hole that the team chose to study lies at the heart of the galaxy Markarian 509 (Mrk 509), nearly 500 million light-years away. This black hole is colossal, containing 300 million times the mass of the Sun, and is growing more massive every day as it continues to feed on surrounding matter, which glows brightly as it forms a rotating disk around the black hole. Mrk 509 was chosen because it is known to vary in brightness, which indicates that the flow of matter is turbulent.

The above image of Mrk 509 was taken in April 2007 with Hubble's Wide Field Planetary Camera 2. But using a large number of telescopes that are sensitive to different wavelengths of light gave astronomers unprecedented coverage running from the infrared, through the visible, ultraviolet, X-rays, and into the gamma-ray band.The study is presented in a series of seven papers in the journal Astronomy and Astrophysics, with more expected to be published in coming months.

A method to detect the collision of stars with an elusive type of black hole

Princeton and New York University researchers have simulated the effect of a primordial black hole passing through a star. Primordial black holes are among the objects hypothesized to make up dark matter — the invisible substance thought to constitute much of the universe — and astronomers could use the researchers' model to finally observe the elusive black holes. This image illustrates the resulting vibration waves as a primordial black hole (white dots) passes through the center of a star. The different colors correspond to the density of the primordial black hole and strength of the vibration.

Credit: Tim Sandstrom

By Princeton University, Princeton, New Jersey

Published: September 22, 2011

Scientists looking to capture evidence of dark matter — the invisible substance thought to constitute much of the universe — may find a helpful tool in the recent work of researchers from Princeton University in New Jersey and New York University (NYU).

The team unveiled a ready-made method for detecting the collision of stars with an elusive type of black hole, which is on the short list of objects believed to make up dark matter. Such a discovery could serve as observable proof of dark matter and provide a much deeper understanding of the universe’s inner workings.

Researchers Shravan Hanasoge from Princeton and Michael Kesden from NYU simulated the visible result of a primordial black hole passing through a star. Theoretical remnants of the Big Bang, primordial black holes possess the properties of dark matter and are one of various cosmic objects thought to be the source of the mysterious substance, but they have yet to be observed.

If primordial black holes are the source of dark matter, the sheer number of stars in the Milky Way galaxy — roughly 100 billion — makes an encounter inevitable. Unlike larger black holes, a primordial black hole would not “swallow” the star, but instead cause noticeable vibrations on the star’s surface as it passes through.

Thus, as the number of telescopes and satellites probing distant stars in the Milky Way increases, so do the chances to observe a primordial black hole as it slides harmlessly through one of the galaxy’s billions of stars, Hanasoge said. The computer model developed by Hanasoge and Kesden can be used with these current solar-observation techniques to offer a more precise method for detecting primordial black holes than existing tools.

“If astronomers were just looking at the Sun, the chances of observing a primordial black hole are not likely, but people are now looking at thousands of stars,” Hanasoge said.

“There’s a larger question of what constitutes dark matter, and, if a primordial black hole were found, it would fit all the parameters — they have mass and force so they directly influence other objects in the universe, and they don’t interact with light. Identifying one would have profound implications for our understanding of the early universe and dark matter.”

Although dark matter has not been observed directly, galaxies are thought to reside in extended dark-matter halos based on documented gravitational effects of these halos on galaxies’ visible stars and gas. Like other proposed dark-matter candidates, primordial black holes are difficult to detect because they neither emit nor absorb light, stealthily traversing the universe with only subtle gravitational effects on nearby objects.

Because primordial black holes are heavier than other dark-matter candidates, however, their interaction with stars would be detectable by existing and future stellar observatories, Kesden said. When crossing paths with a star, a primordial black hole’s gravity would squeeze the star, and then, once the black hole passed through, cause the star’s surface to ripple as it snaps back into place.

“If you imagine poking a water balloon and watching the water ripple inside, that’s similar to how a star’s surface appears,” Kesden said.

“By looking at how a star’s surface moves, you can figure out what’s going on inside. If a black hole goes through, you can see the surface vibrate.”

Eyeing the Sun’s surface for hints of dark matter
Kesden and Hanasoge used the Sun as a model to calculate the effect of a primordial black hole on a star’s surface. Kesden, whose research includes black holes and dark matter, calculated the masses of a primordial black hole as well as the likely trajectory of the object through the Sun. Hanasoge, who studies seismology in the Sun, Earth, and stars, worked out the black hole’s vibrational effect on the Sun’s surface.

NASA’s Tim Sandstrom created video simulations of the researchers’ calculations using the Pleiades supercomputer at the Ames Research Center in California. One clip shows the vibrations of the Sun’s surface as a primordial black hole — represented by a white trail — passing through its interior. A second movie portrays the result of a black hole grazing the Sun’s surface.

Marc Kamionkowski from Johns Hopkins University in Baltimore, Maryland, said that the work serves as a toolkit for detecting primordial black holes, because Hanasoge and Kesden have provided a thorough and accurate method that takes advantage of existing solar observations.

“It’s been known that as a primordial black hole went by a star, it would have an effect, but this is the first time we have calculations that are numerically precise,” Kamionkowski said. “This is a clever idea that takes advantage of observations and measurements already made by solar physics. It’s like someone calling you to say there might be a million dollars under your front doormat. If it turns out to not be true, it cost you nothing to look. In this case, there might be dark matter in the data sets astronomers already have, so why not look?”

One significant aspect of Kesden and Hanasoge’s technique, Kamionkowski said, is that it narrows a significant gap in the mass that can be detected by existing methods of trolling for primordial black holes.

The search for primordial black holes has thus far been limited to masses too small to include a black hole, or so large that “those black holes would have disrupted galaxies in heinous ways we would have noticed,” Kamionkowski said. “Primordial black holes have been somewhat neglected, and I think that’s because there has not been a single, well-motivated idea of how to find them within the range in which they could likely exist.”

The current mass range in which primordial black holes could be observed was set based on previous direct observations of Hawking radiation — the emissions from black holes as they evaporate into gamma rays — as well as the bending of light around large stellar objects, Kesden said. The difference in mass between those phenomena, however, is enormous even in astronomical terms. Hawking radiation can only be observed if the evaporating black hole’s mass is less than 100 quadrillion grams. On the other end, an object must be larger than 100 septillion (24 zeroes) grams for light to visibly bend around it. The search for primordial black holes covered a swath of mass that spans a factor of 1 billion, Kesden said — similar to searching for an unknown object with a weight somewhere between that of a penny and a mining dump truck.

He and Hanasoge suggest a technique to give that range a much-needed trim and established more specific parameters for spotting a primordial black hole. The pair found through their simulations that a primordial black hole larger than 1 sextillion (21 zeroes) grams — roughly the mass of an asteroid — would produce a noticeable effect on a star’s surface.

“Now that we know primordial black holes can produce detectable vibrations in stars, we could try to look at a larger sample of stars than just our own Sun,” Kesden said.

“The Milky Way has 100 billion stars, so about 10,000 detectable events should be happening every year in our galaxy if we just knew where to look.”

A huge doughnut-shaped cloud of water vapor created by Enceladus

Water vapor and ice erupt from Saturn's moon Enceladus, the source of a newly discovered doughnut-shaped cloud around Saturn.

Credit: NASA/JPL/Space Science Institute

Published: September 22, 2011

Chalk up one more feat for Saturn's intriguing moon Enceladus. The small, dynamic moon spews out dramatic plumes of water vapor and ice — first seen by NASA's Cassini spacecraft in 2005. It possesses simple organic particles and may house liquid water beneath its surface. Its geyser-like jets create a gigantic halo of ice, dust, and gas around Enceladus that helps feed Saturn's E ring. Now, thanks again to those icy jets, Enceladus is the only moon in our solar system known to substantially influence the chemical composition of its parent planet.

In June, the European Space Agency (ESA) announced that its Herschel Space Observatory, which has important NASA contributions, had found a huge doughnut-shaped cloud, or torus, of water vapor created by Enceladus encircling Saturn. The torus is more than 373,000 miles (600,000 kilometers) across and about 37,000 miles (60,000 km) thick. It appears to be the source of water in Saturn's upper atmosphere.

Though it is enormous, the cloud had not been seen before because water vapor is transparent at most visible wavelengths of light, but Herschel could see the cloud with its infrared detectors. "Herschel is providing dramatic new information about everything from planets in our own solar system to galaxies billions of light-years away," said Paul Goldsmith from NASA's Jet Propulsion Laboratory in Pasadena, California.

The discovery of the torus around Saturn did not come as a complete surprise. NASA's Voyager and Hubble missions had given scientists hints of the existence of water-bearing clouds around Saturn. Then in 1997, ESA’s Infrared Space Observatory confirmed the presence of water in Saturn's upper atmosphere. NASA's Submillimeter Wave Astronomy Satellite also observed water emission from Saturn at far-infrared wavelengths in 1999.

While a small amount of gaseous water is locked in the warm, lower layers of Saturn's atmosphere, it can't rise to the colder, higher levels. To get to the upper atmosphere, water molecules must be entering Saturn's atmosphere from somewhere in space. But from where and how? Those were mysteries until now.

Build the model, and the data will come
The answer came by combining Herschel's observations of the giant cloud of water vapor created by Enceladus' plumes with computer models that researchers had already been developing to describe the behavior of water molecules in clouds around Saturn.

One of these researchers is Tim Cassidy from the University of Colorado, Boulder. "What's amazing is that the model, which is one iteration in a long line of cloud models, was built without knowledge of the observation,” said Cassidy. “Those of us in this small modeling community were using data from Cassini, Voyager, and the Hubble telescope, along with established physics. We weren't expecting such detailed 'images' of the torus, and the match between model and data was a wonderful surprise."

The results show that, though most of the water in the torus is lost to space, some of the water molecules fall and freeze on Saturn's rings, while a small amount — about 3 to 5 percent — gets through the rings to Saturn's atmosphere. This is just enough to account for the water that has been observed there.

Herschel's measurements combined with the cloud models also provided new information about the rate at which water vapor is erupting out of the dark fractures known as "tiger stripes" on Enceladus' southern polar region. Previous measurements by the Ultraviolet Imaging Spectrograph (UVIS) instrument aboard the Cassini spacecraft showed that the moon is ejecting about 440 pounds (200 kilograms) of water vapor every second.

"With the Herschel measurements of the torus from 2009 and 2010 and our cloud model, we were able to calculate a source rate for water vapor coming from Enceladus," said Cassidy. "It agrees very closely with the UVIS finding, which used a completely different method."

"We can see the water leaving Enceladus, and we can detect the end product — atomic oxygen — in the Saturn system," said Cassini UVIS science team member Candy Hansen from the Planetary Science Institute in Tucson, Arizona. "It's very nice with Herschel to track where it goes in the meantime."

While a small fraction of the water molecules inside the torus end up in Saturn's atmosphere, most are broken down into separate atoms of hydrogen and oxygen. "When water hangs out in the torus, it is subject to the processes that dissociate water molecules, first to hydrogen and hydroxide, and then the hydroxide dissociates into hydrogen and atomic oxygen," said Hansen. “This oxygen is dispersed through the Saturn system. Cassini discovered atomic oxygen on its approach to Saturn before it went into orbit insertion. At the time, no one knew where it was coming from. Now we do."

"The profound effect this little moon Enceladus has on Saturn and its environment is astonishing," said Hansen.

Total Eclipse: Dark of the Moon

The December 21, 2010, lunar eclipse dazzled viewers across North America. This image is a two-exposure combination taken in Mead, Colorado, by attaching a digital camera to a 4-inch telescope.
Photo by Richard McCoy

by Michael E. Bakich
Published: June 6, 2011

Don't get scared. This title is not from Hollywood Movies. The first lunar eclipse of 2011 occurs June 15. The timing and the placement of the Moon in its orbit does not favor the Western Hemisphere, however.

Skywatchers can see the entire event from the eastern half of Africa, the Middle East, central Asia, and western Australia. At mid-eclipse, the Moon will lie near the zenith for observers situated in Réunion or Mauritius in the Indian Ocean.

Observers throughout Europe will miss the early stages of the eclipse because they occur before moonrise. But except for northern Scotland and northern Scandinavia, Europeans with clear skies will see totality (when the Moon lies completely within Earth’s umbra).

Likewise, eastern Asia, eastern Australia, and New Zealand will miss the last stages of eclipse because they occur after moonset, but, like those in Europe, most inhabitants will see the total phase. Observers in eastern Brazil, Uruguay, and Argentina also will witness totality. Unfortunately, none of the eclipse will be visible from North America.

A lunar eclipse occurs when the Moon in its orbit passes into Earth’s shadow. Because the Sun isn’t a point of light, the shadow has two parts — the inner, darker umbra and the outer, lighter penumbra. If the entire Moon enters the umbra, the eclipse is total. If the umbra hides only part of our satellite, the eclipse is partial.

This eclipse’s umbral phase begins at 18h22m56s UT (2:22:56 p.m. EDT). As the Moon dips deeper into our planet’s shadow during the next hour or so, darkness gradually overtakes the brilliant orb.

Earth’s shadow takes almost exactly 1 hour to envelop the Moon. Totality begins at 19h22m30s UT (3:22:30 p.m. EDT).

The Moon won’t disappear from view, however. Some sunlight passing through Earth’s atmosphere falls on the lunar surface. The cleaner our atmosphere is, the “lighter” the eclipse will be. “Dark” eclipses generally occur after large volcanic eruptions when the atmosphere contains more dust.

What color will the Moon turn at mideclipse? During previous total eclipses, the Moon has appeared brown, orange, crimson, and brick red. Lunar eclipses exhibit a range of shades because sunlight passing through Earth’s atmosphere during totality becomes scattered and reddened. It’s this dim glow that fills Earth’s shadow and lights the eclipsed Moon. The sky certainly will grow darker, allowing the bright summer stars surrounding our nearest celestial neighbor to spring back to prominence.

Totality lasts 100 minutes, which is rather long. The last eclipse to exceed this duration was in July 2000. During totality, the Moon’s southern edge may appear slightly darker than its northern side. This disparity occurs because the Moon’s southern limb lies a bit closer to the center of Earth’s shadow. After totality ends at 21h02m42s UT (5:02:42 p.m. EDT), it takes the Moon another 60 minutes to leave Earth’s umbra.

Astronomy magazine Contributing Editor Ray Shubinski describes the upcoming eclipse as a missed opportunity: “It’s too bad that nobody in North America will see the eclipse. Luckily, we don’t have all that long to wait until the next one.”

The eclipse to which Shubinski refers will occur December 10. But it won’t be perfect, either. For North Americans, that eclipse will still be in progress as the Moon sets. The farther west you live, however, the larger fraction of the eclipse you will see before moonset. The entire event will be visible for inhabitants of Asia and Australia under clear skies.