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Thursday, October 31, 2013

Scientists Discover the First Earth-size Rocky Planet


This illustration compares Earth with the newly confirmed scorched world of Kepler-78b. Kepler-78b is about 20 percent larger than Earth and is 70% more massive. Kepler-78b whizzes around its host star every 8.5 hours, making it a blazing inferno.

Astronomers have discovered the first Earth-size planet outside the solar system that has a rocky composition like that of Earth. Kepler-78b whizzes around its host star every 8.5 hours, making it a blazing inferno and not suitable for life as we know it. The results are published in two papers in the journal Nature.

"The news arrived in grand style with the message: 'Kepler-10b has a baby brother,'" said Natalie Batalha, Kepler mission scientist at NASA's Ames Research Center in Moffett Field, California. Batalha led the team that discovered Kepler-10b, a larger but also rocky planet identified by NASA's Kepler spacecraft.

"The message expresses the joy of knowing that Kepler's family of exoplanets is growing," Batalha reflects. "It also speaks of progress. The Doppler teams are attaining higher precision, measuring masses of smaller planets at each turn. This bodes well for the broader goal of one day finding evidence of life beyond Earth."

Kepler-78b was discovered using data from NASA's Kepler space telescope, which for four years simultaneously and continuously monitored more than 150,000 stars, looking for telltale dips in their brightness caused by crossing, or transiting, planets.

Two independent research teams then used ground-based telescopes to confirm and characterize Kepler-78b. To determine the planet's mass, the teams employed the radial velocity method to measure how much the gravitational tug of an orbiting planet causes its star to wobble. Kepler, on the other hand, determines the size or radius of a planet by the amount of starlight blocked when it passes in front of its host star.

A handful of planets the size or mass of Earth have been discovered. Kepler-78b is the first to have both a measured mass and size. With both quantities known, scientists can calculate a density and determine what the planet is made of.

Kepler-78b is 1.2 times the size of Earth and 1.7 times more massive, resulting in a density that is the same as Earth's. This suggests that Kepler-78b is also made primarily of rock and iron. Its star is slightly smaller and less massive than the sun and is located about 400 light-years from Earth in the constellation Cygnus.

One team, led by Andrew Howard from the University of Hawaii in Honolulu, made follow-up observations using the W. M. Keck Observatory on Mauna Kea in Hawaii. More information on their research can be found at: http://www.ifa.hawaii.edu/info/press-releases/Kepler-78b/.

The other team led by Francesco Pepe from the University of Geneva, Switzerland, did their ground-based work at the Roque de los Muchachos Observatory on La Palma in the Canary Islands. More information on their research can be found at http://www.cfa.harvard.edu/news/2013-25.

This result will be one of many discussed next week at the second Kepler science conference November 4 to 8 at Ames. More than 400 astrophysicists from Australia, China, Europe, Latin America and the U.S. will convene to present their latest results using publicly accessible data from Kepler. More information about the conference is at: http://nexsci.caltech.edu/conferences/KeplerII/index.shtml.

Illustration credit: David A. Aguilar (CfA)

Wednesday, October 30, 2013

The Chandra Archive Collection


Chandra Archive Collection: An assortment of images from Chandra’s public repository.

This collection of images represents the thousands of observations that are permanently stored and accessible to the world in the Chandra Data Archive (CDA). This sample showcases the wide range of objects that Chandra has observed during its over 14-year mission, including the remains of exploded stars, cosmic nurseries where stars are being born, and galaxies both similar to our Milky Way and those that are much different. In each of these images, the Chandra data are blue or purple and have been combined with those from other wavelengths.

Image credit: NASA/CXC/SAO

Note: For more information, see Chandra Archive Collection: Preserving the Legacy of the X-ray Universe. This link will provide brief summaries on all of the objects shown in the above image.

Tuesday, October 29, 2013

Trio of Planetary Nebulas by Spitzer


This trio of ghostly images from NASA's Spitzer Space Telescope shows the disembodied remains of dying stars called planetary nebulas. Planetary nebulas are a late stage in a sun-like star's life, when its outer layers have sloughed off and are lit up by ultraviolet light from the central star. They come in a variety of shapes, as indicated by these three spooky structures.

In all of the images, infrared light at wavelengths of 3.6 microns is rendered in blue, 4.5 microns in green, and 8.0 microns in red.

Exposed Cranium Nebula (left)
The brain-like orb called PMR 1 has been nicknamed the "Exposed Cranium" nebula by Spitzer scientists. This planetary nebula, located roughly 5,000 light-years away in the Vela constellation, is host to a hot, massive dying star that is rapidly disintegrating, losing its mass. The nebula's insides, which appear mushy and red in this view, are made up primarily of ionized gas, while the outer green shell is cooler, consisting of glowing hydrogen molecules.

Ghost of Jupiter Nebula (middle)
The Ghost of Jupiter, also known as NGC 3242, is located roughly 1,400 light-years away in the constellation Hydra. Spitzer's infrared view shows off the cooler outer halo of the dying star, colored here in red. Also evident are concentric rings around the object, the result of material being periodically tossed out in the star's final death throes.

Little Dumbbell Nebula (right)
This planetary nebula, known as NGC 650 or the Little Dumbbell, is about 2,500 light-years from Earth in the Perseus constellation. Unlike the other spherical nebulas, it has a bipolar or butterfly shape due to a "waist," or disk, of thick material, running from lower left to upper right. Fast winds blow material away from the star, above and below this dusty disk. The ghoulish green and red clouds are from glowing hydrogen molecules, with the green area being hotter than the red.

Image credit: NASA/JPL-Caltech/Harvard-Smithsonian CfA

Note: For more information, see A Ghostly Trio from NASA's Spitzer Space Telescope.

Monday, October 28, 2013

Titan's North Polar Lakes and Evaporite Deposits


This false-color mosaic, made from infrared data collected by NASA's Cassini spacecraft, reveals the differences in the composition of surface materials around hydrocarbon lakes at Titan, Saturn's largest moon. Titan is the only other place in the solar system that we know has stable liquid on its surface, though its lakes are made of liquid ethane and methane rather than liquid water. While there is one large lake and a few smaller ones near Titan's south pole, almost all of Titan's lakes appear near the moon's north pole.

Scientists mapped near-infrared colors onto the visible color spectrum. Red in this image was assigned a wavelength of 5 microns (10 times longer than visible light), green 2.0 microns (four times longer than visible light), and blue 1.3 microns (2.6 times longer than visible light).

The orange areas are thought to be evaporite -- the Titan equivalent of salt flats on Earth. The evaporated material is thought to be organic chemicals originally from Titan's haze particles that once dissolved in liquid methane. They appear orange in this image against the greenish backdrop of Titan's typical bedrock of water ice.

In this mosaic, Kraken Mare, which is Titan's largest sea and covers about the same area as Earth's Caspian Sea and Lake Superior combined, can be seen spreading out with many tendrils on the upper right,. The big dark zone up and left of Kraken is Ligeia Mare, the second largest sea. Below Ligeia, shaped similar to a sports fan's foam finger that points just up from left, is Punga Mare, the third largest Titan Sea. Numerous other smaller lakes dot the area. Titan's north pole is located in the geographic location just above the end of the "finger" of Punga Mare.

Figure 1 highlights a high-resolution strip and shows the north pole marked with a red cross. Other smaller lakes are also labeled.

The data shown here were obtained by Cassini's visual and infrared mapping spectrometer during a close flyby of Titan on September 12, 2013.

Until now, the spectrometer has only been able to capture distant, oblique or partial views of this area. The September 12, 2013, flyby provided better viewing geometry. And sunlight has begun to pierce the winter darkness that shrouded Titan's north pole at the time of Cassini's arrival in the Saturn system nine years ago. A thick cap of haze that once hung over the north pole has also dissipated as northern summer approaches. And, thankfully, Titan's beautiful, almost cloudless, rain-free weather continued during this flyby.

The resolution varies across this composite view depending on when each cube of data was acquired, but the best surface sampling is 2 miles (3 kilometers) per pixel.

Views of this area by other Cassini instruments include PIA17471, PIA17472, PIA17473 and PIA14584 from the imaging science subsystem; and PIA10008 and PIA17031 from the radar mapper. An earlier VIMS view can be seen at PIA16845.


Image credit: NASA/JPL-Caltech/University of Arizona/University of Idaho

Note: For more information, see Cassini Gets New Views of Titan's Land of Lakes.

Sunday, October 27, 2013

Saturn


A swing high above Saturn by NASA's Cassini spacecraft revealed this stately view of the golden-hued planet and its main rings. The view is in natural color, as human eyes would have seen it. This mosaic was made from 36 images in three color filters obtained by Cassini's imaging science subsystem on October 10, 2013. The observation and resulting image mosaic were planned as one of three images for Cassini's 2013 Scientist for a Day essay contest.

Saturn sports differently colored bands of weather in this image. For instance, a bright, narrow wave of clouds around 42 degrees north latitude appears to be some of the turbulent aftermath of a giant storm that reached its violent peak in early 2011. The mysterious six-sided weather pattern known as the hexagon is visible around Saturn's north pole.

When Cassini arrived in 2004, more of the northern hemisphere sported a bluish hue and it was northern winter. The golden tones dominated the southern hemisphere, where it was southern summer. But as the seasons have turned and northern spring is in full swing, the colors have begun to change in each hemisphere as well. Golden tones have started to dominate in the northern hemisphere and the bluish color in the north is now confined to a tighter circle around the north pole. The southern hemisphere has started getting bluer, too.

The rings shown here include Saturn's main rings. The innermost D ring, and the C, B and A rings are easily seen. The F ring is also there, but not easily seen without enhancing the contrast of the image. (Rings were named in order of their discovery rather than their position around Saturn.) The rings also cast a shadow on Saturn at the limb of the planet in the lower right quadrant.

Cassini is currently in a set of tilted orbits known as "inclined orbits" that allow it to swing up over the north pole and below the south pole. Much of Cassini's time is spent close to the equatorial plane, where most of Saturn's rings and moons are located.

Image credit: NASA/JPL-Caltech/SSI/Cornell

Note: For more information, see Cassini Swings Above Saturn to Compose a Portrait.

Saturday, October 26, 2013

Light Echos from Sagittarius A*


Sagittarius A*: The supermassive black hole about 26,000 light years from Earth at the center of the Milky Way.

Researchers have found evidence that the normally dim region very close to the supermassive black hole at the center of the Milky Way galaxy flared up with at least two bright outbursts in the past few hundred years. This image is from a new study of Chandra observations taken over twelve years that shows rapid variations in the X-ray emission from gas clouds surrounding the supermassive black hole. The phenomenon, known as a "light echo," provides astronomers an opportunity to piece together what objects like Sgr A* were doing long before there were X-ray telescopes to observe them.

Scale: Image is 18.5 arcmin across. (about 140 light years).

Image credit: NASA/CXC/APC/Université Paris Diderot/M.Clavel et al

Note: For more information, see Sagittarius A*: A Glimpse of the Violent Past of Milky Way's Giant Black Hole

Friday, October 25, 2013

Makeup of Universe Before and After Planck Research


Planck's high-precision cosmic microwave background map has allowed scientists to extract the most refined values yet of the Universe's ingredients. Normal matter that makes up stars and galaxies contributes just 4.9% of the Universe's mass/energy inventory. Dark matter, which is detected indirectly by its gravitational influence on nearby matter, occupies 26.8%, while dark energy, a mysterious force thought to be responsible for accelerating the expansion of the Universe, accounts for 68.3%.

The 'before Planck' figure is based on the WMAP 9-year data release presented by Hinshaw et al., (2012).

Illustration credit: ESA

Note: For more information, see Last Command Sent to ESA's Planck Space Telescope; also, PIA17449: Planck and the Cosmic Microwave Background (Artist Concept) and Last Command Sent to Planck Space Telescope.

Thursday, October 24, 2013

Shapley Supercluster


While scanning the sky for the oldest cosmic light, ESA’s Planck satellite has captured snapshots of some of the largest objects populating the Universe today: galaxy clusters and superclusters.

Several hundred galaxies and the huge amounts of gas that permeate them are depicted in this view of the core of the Shapley Supercluster, the largest cosmic structure in the local Universe.

The supercluster was discovered in the 1930s by American astronomer Harlow Shapley, as a remarkable concentration of galaxies in the Centaurus constellation.

Boasting more than 8000 galaxies and with a total mass more than ten million billion times the mass of the Sun, it is the most massive structure within a distance of about a billion light-years from our Milky Way Galaxy.

The hot gas pervading galaxy clusters shines brightly in X-rays, but it is also visible at microwave wavelengths, which Planck sees as a distinctive signature in the Cosmic Microwave Background – the afterglow of the Big Bang.

Looking for this signature – called the Sunyaev–Zel’dovich effect – Planck has already spotted more than 1000 galaxy clusters, including several superclusters and pairs of interacting clusters.

This composite image of the core of the Shapley Supercluster combines the gas detected with Planck at large scales between the members of the supercluster (shown in blue) with that detected in X-rays within the galaxy clusters of Shapley using the Rosat satellite (pink), as well as a view of its rich population of galaxies as observed at visible wavelengths in the Digitised Sky Survey.

The largest pink blobs of X-rays identify the two galaxy clusters Abell 3558 on the right and Abell 3562 on the left, as well as a couple of smaller groups between them.

The image measures 3.2 x 1.8 square degrees and shows the central portion of the Shapley Supercluster. It was produced by reconstructing the Sunyaev–Zel’dovich effect from the Planck frequency maps, and was first published in a Planck Collaboration paper in March 2013.

Image credit: ESA & Planck Collaboration / Rosat/ Digitised Sky Survey

Wednesday, October 23, 2013

Comet ISON


This NASA/ESA Hubble Space Telescope picture shows C/2012 S1, better known as Comet ISON, as it appeared in our skies on 9 October.

In this image, the comet’s solid nucleus is unresolved because it is so small. If it had broken apart – a possibility as the Sun slowly warms it up during its approach – Hubble would have likely seen evidence for multiple fragments instead.

ISON will be brightest in our skies in late November, just before and after it hurtles past the Sun. As it grows brighter, it may even become visible as a naked-eye object, before it fades throughout December – the month of its closest approach to Earth.

Depending on its fate as it passes close to the Sun, it could become spectacular or, on the contrary, it could completely disintegrate. Many observatories, as well as several ESA and NASA missions, aim to observe this icy visitor over the coming months.

Photo credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)

Tuesday, October 22, 2013

Earth, by Juno


On October 9, NASA's Juno spacecraft flew past Earth, using our home planet's gravity to get the final boost it needed to reach Jupiter. The JunoCam instrument captured this monochrome view of Earth, and other instruments were tested to ensure they work as designed during a close planetary encounter.

The Juno spacecraft was launched from NASA's Kennedy Space Center in Florida on August 5, 2011. Juno's rocket, the Atlas 551, was only capable of giving Juno enough energy or speed to reach the asteroid belt, at which point the Sun's gravity pulled Juno back toward the inner solar system. The Earth flyby gravity assist put Juno on course for arrival at Jupiter on July 4, 2016.

Photo credit: NASA/JPL-Caltech/Malin Space Science Systems

Note: For more information, see PIA17516: Juno's Earth Flyby (Artist's Rendering).

Monday, October 21, 2013

Asteroid 2013 TV135


This diagram shows the orbit of asteroid 2013 TV135 (in blue), which has just a one-in-63,000 chance of impacting Earth. Its risk to Earth will likely be further downgraded as scientists continue their investigations.

Newly discovered asteroid 2013 TV135 made a close approach to Earth on September 16, when it came within about 4.2 million miles (6.7 million kilometers). The asteroid is initially estimated to be about 1,300 feet (400 meters) in size and its orbit carries it as far out as about three quarters of the distance to Jupiter's orbit and as close to the sun as Earth's orbit. It was discovered on October 8, 2013, by astronomers working at the Crimean Astrophysical Observatory in Ukraine. As of October 14, asteroid 2013 TV135 is one of 10,332 near-Earth objects that have been discovered.

With only a week of observations for an orbital period that spans almost four years, its future orbital path is still quite uncertain, but this asteroid could be back in Earth's neighborhood in 2032. However, NASA's Near-Earth Object Program Office states the probability this asteroid could then impact Earth is only one in 63,000. The object should be easily observable in the coming months and once additional observations are provided to the Minor Planet Center in Cambridge, Massachusetts, the initial orbit calculations will be improved and the most likely result will be a dramatic reduction, or complete elimination, of any risk of Earth impact.

"To put it another way, that puts the current probability of no impact in 2032 at about 99.998 percent," said Don Yeomans, manager of NASA's Near-Earth Object Program Office at the Jet Propulsion Laboratory in Pasadena, California. "This is a relatively new discovery. With more observations, I fully expect we will be able to significantly reduce, or rule out entirely, any impact probability for the foreseeable future."

NASA detects, tracks and characterizes asteroids and comets passing close to Earth using both ground- and space-based telescopes. The Near-Earth Object Observations Program, commonly called "Spaceguard," discovers these objects, characterizes a subset of them and identifies their orbits to determine if any could be potentially hazardous to our planet.

Image credit: NASA/JPL-Caltech

Sunday, October 20, 2013

Phobos Occulting Deimos


This movie clip shows the larger of Mars' two moons, Phobos, passing in front of the smaller Martian moon, Deimos, as observed by NASA's Mars rover Curiosity. The series of 41 images is shown at increased speed. The actual elapsed time is 55 seconds.

The images were taken by the telephoto-lens camera of the Mast Camera pair (right Mastcam) on Curiosity on August 1, 2013, during the 351st Martian day, or sol, of Curiosity's work on Mars. These observations of Phobos and Deimos help researchers make knowledge of the moons' orbits even more precise.

On Phobos, Stickney Crater is visible on the bottom. It is on the leading hemisphere of Phobos. Hall Crater, in the south, is the prominent feature on the right hand side.

Video credit: NASA/JPL-Caltech/Malin Space Science Systems/Texas A&M University

Note: For more information, see PIA17350: Two Moons of Mars in One Enhanced View, PIA17351: Illustration Comparing Apparent Sizes of Moons, PIA17352: Smoothed Movie of Phobos Passing Deimos in Martian Sky, PIA17353: Before and After Occultation of Deimos by Phobos, and NASA Rover Gets Movie as a Mars Moon Passes Another.

Saturday, October 19, 2013

Planck's View of the Universe


This animation highlights some of the many discoveries made by ESA’s Planck space telescope over its 4.5 year observing career, from new discoveries in our home Milky Way Galaxy stretching back to the first few moments after the Big Bang 13.82 billion years ago.

Video credit: ESA

Note: For more information, see Celebrating the Legacy of ESA's Planck Mission.

Friday, October 18, 2013

J1000+0221 - Most Distant Gravitational Lens


This picture from the NASA/ESA Hubble Space Telescope shows the most distant gravitational lens yet discovered. The glow at the center of this picture is the central regions of a normal galaxy. By chance it is precisely aligned with a much more remote, young star-forming galaxy. The light from the more distant object is bent around the nearer object by its strong gravitational pull to form a ring of multiple images. The chance of finding such an exact alignment is very small, suggesting that there may be more star-forming galaxies in the early Universe than expected.

Photo credit: NASA/ESA/A. van der Wel

Note: For more information, see Most Distant Gravitational Lens Helps Weigh Galaxies.

Thursday, October 17, 2013

NGC 1433


This detailed view shows the central parts of the nearby active galaxy NGC 1433. The dim blue background image, showing the central dust lanes of this galaxy, comes from the NASA/ESA Hubble Space Telescope. The colored structures near the center are from recent ALMA observations that have revealed a spiral shape, as well as an unexpected outflow, for the first time.

Image credit: ALMA (ESO/NAOJ/NRAO)/NASA/ESA/F. Combes

Note: For more information, see ALMA Probes Mysteries of Jets from Giant Black Holes.

Saturday, October 12, 2013

The Milky Way's Galactic Center in Infrared


This image, not unlike a pointillist painting, shows the star-studded center of the Milky Way towards the constellation of Sagittarius. The crowded center of our galaxy contains numerous complex and mysterious objects that are usually hidden at optical wavelengths by clouds of dust — but many are visible here in these infrared observations from Hubble.

However, the most famous cosmic object in this image still remains invisible: the monster at our galaxy’s heart called Sagittarius A*. Astronomers have observed stars spinning around this supermassive black hole (located right in the center of the image), and the black hole consuming clouds of dust as it affects its environment with its enormous gravitational pull.

Infrared observations can pierce through thick obscuring material to reveal information that is usually hidden to the optical observer. This is the best infrared image of this region ever taken with Hubble, and uses infrared archive data from Hubble’s Wide Field Camera 3, taken in September 2011.

Photo credit: NASA, ESA, and G. Brammer

Friday, October 11, 2013

PGC 6240


The beautiful, petal-like shells of galaxy PGC 6240 are captured here in intricate detail by the NASA/ESA Hubble Space Telescope, set against a sky full of distant background galaxies. PGC 6240 is an elliptical galaxy approximately 350,000,000 light years away in the southern constellation of Hydrus (The Water Snake). It is orbited by a number of globular clusters that contain both young and old stars – thought to be a result of a galactic merger in the recent past.

Photo credit: ESA/Hubble & NASA. Acknowledgement: Judy Schmidt

Note: For more information, see Soft Shells and Strange Star Clusters.

Thursday, October 10, 2013

IC 2220 - The Toby Jug Nebula


Located about 1200 light-years from Earth in the southern constellation of Carina (The Ship’s Keel), the Toby Jug Nebula, more formally known as IC 2220, is an example of a reflection nebula. It is a cloud of gas and dust illuminated from within by the central star, designated HD 65750.

Photo credit: ESO

Note: For more information, see A Close Look at the Toby Jug Nebula.

Sunday, October 6, 2013

Centaurs May be Comets


New observations from NASA's NEOWISE project reveal the hidden nature of centaurs, objects in our solar system that have confounded astronomers for resembling both asteroids and comets. The centaurs, which orbit between Jupiter and Neptune, were named after the mythical half-horse, half-human creatures called centaurs due to their dual nature. This artist's concept shows a centaur creature together with asteroids on the left and comets at right.

The results suggest that roughly two-thirds of the centaur population have cometary origins, hailing from the frigid outer reaches of our solar system. It is not clear if the remaining one-third of the population is made up of asteroids.

NEOWISE, the asteroid-hunting portion of NASA's Wide-field Infrared Survey Explorer, was able to crack the centaur mystery thanks to its ability to see the infrared properties of the small objects. The infrared data, together with previous visible-light observations, showed that many of the centaurs are dark like soot and blue-gray in color, telltale signs of comets.

Image credit: NASA/JPL-Caltech

Note: For more information, see NASA's WISE Finds Mysterious Centaurs May Be Comets.

Saturday, October 5, 2013

NGC 2452


This NASA/ESA Hubble Space Telescope image shows the planetary nebula NGC 2452, located in the southern constellation of Puppis. The blue haze across the frame is what remains of a star like our Sun after it has depleted all its fuel. When this happens, the core of the star becomes unstable and releases huge numbers of incredibly energetic particles that blow the star's atmosphere away into space.

At the center of this blue cloud lies what remains of the nebula's progenitor star. This cool, dim, and extremely dense star is actually a pulsating white dwarf, meaning that its brightness varies over time as gravity causes waves that pulse throughout the small star's body.

Image credit: ESA/Hubble & NASA; Acknowledgements: Luca Limatola, Budeanu Cosmin Mirel

Friday, October 4, 2013

Barchan Dunes in Noachis Terra


This field of dunes lies on the floor of an old crater in Noachis Terra, one of the oldest places on Mars.

When there are perfect conditions for producing sand dunes--steady wind in one direction and just enough sand--barchan sand dunes form. The word "barchan" is a Russian term because this type of dune was first described in the desert regions of Turkistan.

Barchans have a gentle slope on the upwind side and a much steeper slope on the lee side where horns or a notch often forms. The wind in this case came from the southwest. Observing dunes on Mars can tell us how strong the winds are, as well as their direction. If pictures are taken at regular intervals, one may see changes in the dunes and in ripples on the dunes' surface.

The color in the photograph is not the same as we would see with our eyes because an extra color (infrared) is added. Our eyes cannot detect infrared, but it is used because it can give us clues to the composition of the surface. On Mars dunes are often dark in color because they were formed from the common, volcanic rock basalt. In the dry environment, dark minerals in basalt, like olivine and pyroxene, do not break down as quickly as they do on Earth. Although rare, some dark sand is found on Earth, for example in Hawaii which also has many volcanoes discharging basalt.

Photo credit: NASA/JPL/University of Arizona

Thursday, October 3, 2013

Gravitational Lensing of CMB Light


This artist’s impression shows how photons in the Cosmic Microwave Background (CMB, as detected by ESA’s Planck space telescope) are deflected by the gravitational lensing effect of massive cosmic structures as they travel across the Universe. Gravitational lensing creates tiny, additional distortions to the mottled pattern of the CMB temperature fluctuations. A small fraction of the CMB is polarized; one component of this polarized light, B-modes, have been given an additional signature by gravitational lensing. This imprint has been found for the first time by combining data from the ground-based South Pole Telescope and ESA’s Herschel space observatory.

Image credit: ESA and the Planck Collaboration

Note: For more information, see PIA17448: Ancient Light Deflected, Long-Sought Pattern of Ancient Light Detected and Herschel Throws New Light on Oldest Cosmic Light.

Wednesday, October 2, 2013

E-Modes and B-Modes in the CMB Polarization from SPT and Herschel Data


A small portion of the Cosmic Microwave Background (CMB) is polarized, and the pattern observed in the polarized fraction can be split in two components, called E-modes and B-modes. These carry very different and complementary information about both the early and the late Universe. This image shows the data from the National Science Foundation's South Pole Telescope (SPT) and ESA's Herschel Space Observatory that were used to achieve the first detection of B-modes in the CMB polarization.

When the CMB photons travel through the large-scale structure of the Universe, they get deflected by large concentrations of mass such as galaxies, galaxy clusters and the dark matter halos in which these are embedded. One of the effects of this distortion is a mixing of E- and B-modes: part of the signal contained in E-modes is transferred to the B-modes.

The left panel shows the E-mode component of the polarized CMB as detected by SPT. The E-modes are affected by gravitational lensing, and the effect of such distortion is encrypted in the image.

The central panel shows the projected gravitational potential of the large-scale distribution of matter present on the line of sight to the CMB in the same field as the one observed by SPT. The gravitational potential has been inferred using data from Herschel, which probed the light emitted by stars and re-radiated by cosmic dust in all galaxies across cosmic history.

Since gravitational lensing turns part of the E-modes into B-modes, it is possible to combine the observed (and distorted) E-modes with the intervening gravitational potential that distorts them, to estimate the resulting B-modes caused by the gravitational lensing effect. The right panel shows the B-modes of the CMB polarization estimated in this way.

Image credit: D. Hanson, et al., 2013, Physical Review Letters

Note: For more information, see Herschel Throws New Light on Oldest Cosmic Light.

Tuesday, October 1, 2013

Cloudy Skies Over Kepler-7B


Kepler-7b (left), which is 1.5 times the radius of Jupiter (right), is the first exoplanet to have its clouds mapped. This artist's concept shows what those clouds might look like. The cloud map was produced using data from NASA's Kepler and Spitzer space telescopes.

The map shows that clouds cover the western side of the gaseous planet, leaving the east cloud-free. Researchers speculate the clouds are made up of minerals containing silicates.

Kepler-7b is one of the puffiest, or least dense, planets known. While it is 1.5 times the size of Jupiter is has only about half the mass.

Photo credit: NASA/JPL-Caltech/MIT

Note: For more information, see NASA Space Telescopes Find Patchy Clouds on Exotic World.