X-Ray Sun

X-rays stream off the sun in this image showing observations from by NASA's Nuclear Spectroscopic Telescope Array, or NuSTAR, overlaid on a picture taken by NASA's Solar Dynamics Observatory (SDO). This is the first picture of the sun taken by NuSTAR. The field of view covers the west limb of the sun.

The NuSTAR data, seen in green and blue, reveal solar high-energy emission (green shows energies between 2 and 3 kiloelectron volts, and blue shows energies between 3 and 5 kiloelectron volts). The high-energy X-rays come from gas heated to above 3 million degrees.

The red channel represents ultraviolet light captured by SDO at wavelengths of 171 angstroms, and shows the presence of lower-temperature material in the solar atmosphere at 1 million degrees.

This image shows that some of the hotter emission tracked by NuSTAR is coming from different locations in the active regions and the coronal loops than the cooler emission shown in the SDO image.

Image credit: NASA/JPL-Caltech/GSFC

Note: For more information, see Sun Sizzles in High-Energy X-Rays.

il Gioiello Galactic Cluster

il Gioiello Cluster: A galaxy cluster located about 9.6 billion light years from Earth.

The most massive cluster of galaxies with an age of 800 million years or younger has been discovered and studied. X-ray data from Chandra allowed astronomers to accurately determine the mass and other properties of this cluster, nicknamed the "Gioiello" (Italian for "Jewel") cluster. This composite image of the Gioiello Cluster contains X-rays from Chandra (purple), infrared data from Herschel (red), and an optical image from Subaru (red, green, and blue). Results like this help
astronomers better understand how galaxy clusters, the largest structures in the Universe held together by gravity, have evolved over time.

Scale: Image is 3.7 arcmin across (about 6.2 million light years).

Image credit: X-ray: NASA/CXC/INAF/P.Tozzi, et al; Optical: NAOJ/Subaru and ESO/VLT; Infrared: ESA/Herschel

Note: For more information, see il Gioiello Cluster: NASA's Chandra Weighs Most Massive Galaxy Cluster in Distant Universe.

X-Ray Emissions from Dwarf Galaxy J1329+3234

This image depicts the X-ray emission from dwarf galaxy J1329+3234 (center in this image), and from a background AGN (lower right), measured by XMM-Newton in June 2013.

Located over 200 million light-years away, the dwarf galaxy contains a few hundred million stars and is similar in size to the Small Magellanic Cloud, one of our nearest neighboring galaxies.

Astronomers were intrigued to discover infrared signatures of an accreting black hole when they studied this galaxy with NASA's WISE spacecraft in 2013. When they subsequently observed the galaxy with ESA's XMM-Newton X-ray observatory they were surprised to detect X-ray emission over 100 times stronger than expected for this galaxy.

The combined X-ray and infrared properties of this galaxy can only be explained by the presence of a massive black hole residing in J1329+3234, similar to the super-massive black holes found at the centers of much more massive galaxies.

The image is constructed from 2-10 keV X-ray emission and has been smoothed. The color code represents the intensity of X-ray emission with blue being more intense and red less intense. The white bar indicates a width of 10 arcseconds, equivalent to 3.3 kpc at the distance of this galaxy. North is up, east to the left.

Image credit: ESA/XMM-Newton/N. Secrest, et al. (2015)

Note: For more information, see XMM-Newton Spots Monster Black Hole Hidden in Tiny Galaxy.

Galaxy Cluster XDCPJ0044.0-2033

This multi-telescope composite combines X-ray, infrared and optical data of the galaxy cluster XDCPJ0044.0-2033.

The purple/pink in the image corresponds to infrared emission measured by Herschel and X-ray emission detected with NASA's Chandra telescope.

Infrared data from ESA's Herschel telescope has revealed where interstellar dust in the cluster's core is being heated by young, hot, stars. This is the first time that star formation has been found in the core of a cluster of this size and age.

The X-ray data were used to map the mass of this giant cluster.

These data have been combined with optical and near-infrared images of the cluster captured by the National Astronomical Observatory of Japan's Subaru telescope and the European Southern Observatory Very Large Telescope, the data from which are colored red, green and blue in this image.

XDCPJ0044.0-2033 is a massive galaxy cluster with an estimated mass of about four hundred thousand billion times that of our Sun. It lies at a redshift of almost 1.6, meaning that we see it as it was 9.6 billion years ago.

Image credit: X-ray: NASA/CXC/INAF/P.Tozzi, et al; Optical: NAOJ/Subaru and ESO/VLT; Infrared: ESA/Herschel/J. Santos, et al.

Note: For more information, see Herschel's View of the Early Universe Reveals Galaxy Cluster Fireworks

Color-Coded Image of the Milky Way's Cold Dust

Covering a portion of the sky about 55°, the image was obtained by Planck’s High Frequency Instrument at a frequency of 857 GHz (corresponding to a wavelength of 350 micrometers). The dark horizontal band is the plane of our Galaxy, seen in cross-section from our vantage point. The colors represent the intensity of heat radiation by dust.

Image credit: ESA and the HFI Consortium

Note: For more information, see Planck Image of a Region in the Constellation Perseus; also, see New Planck Images Reveal Large-Scale Structure in Milky Way and Planck's View of Orion.

The Horsehead Nebula in Infrared

Sometimes a horse of a different color hardly seems to be a horse at all, as, for example, in this newly released image from NASA's Spitzer Space Telescope. The famous Horsehead nebula makes a ghostly appearance on the far right side of the image, but is almost unrecognizable in this infrared view. In visible-light images, the nebula has a distinctively dark and dusty horse-shaped silhouette, but when viewed in infrared light, dust becomes transparent and the nebula appears as a wispy arc.

The Horsehead is only one small feature in the Orion Molecular Cloud Complex, dominated in the center of this view by the brilliant Flame nebula (NGC 2024). The smaller, glowing cavity falling between the Flame nebula and the Horsehead is called NGC 2023. These regions are about 1,200 light-years away.

The two carved-out cavities of the Flame nebula and NGC 2023 were created by the destructive glare of recently formed massive stars within their confines. They can be seen tracing a spine of glowing dust that runs through the image.

The Flame nebula sits adjacent to the star Alnitak, the westernmost star in Orion's belt, seen here as the bright blue dot near the top of the nebula.

In this infrared image from Spitzer, blue represents light emitted at a wavelength of 3.6-microns, and cyan (blue-green) represents 4.5-microns, both of which come mainly from hot stars. Green represents 8-micron light and red represents 24-micron light. Relatively cooler objects, such as the dust of the nebulae, appear green and red. Some regions along the top and bottom of the image extending beyond Spitzer's observations were filled in using data from NASA's Wide-field Infrared Survey Explorer, or WISE, which covered similar wavelengths across the whole sky.

Image credit: NASA/JPL-Caltech

Note: For more information, see Horsehead of a Different Color.

Kepler K2 Mission

This artist concept shows NASA's planet-hunting Kepler spacecraft operating in a new mission profile called K2. In May, the spacecraft began its new mission observing in the ecliptic plane, the orbital path of Earth around the sun, depicted by the grey-blue line marked by opaque cross-like shapes. Each shape represents the field-of-view of an observing campaign.

Using publicly available data collected by the spacecraft in February during the performance concept test to prove K2 would work, astronomers confirmed the first exoplanet detected by the K2 mission. The newly confirmed planet, HIP 116454b, is two-and-a-half times the diameter of Earth, and closely orbits a star smaller and cooler than our sun once every nine days, making the planet too hot for life as we know it. The star and planet are 180 light-years from Earth toward the constellation Pisces.

Illustration credit: NASA/Ames/JPL-Caltech

Note: For more information, see NASA's Kepler Reborn, Makes First Exoplanet Find of New Mission and Reborn Kepler Spacecraft Finds 'Super-Earth'.

Perihelion Cliff

From the location where it came to rest after bounces, the Philae lander of the European Space Agency's Rosetta mission captured this view of a cliff on the nucleus of comet 67P/Churyumov-Gerasimenko. The feature is called "Perihelion Cliff." The image is from the lander's CIVA camera.

Image credit: ESA/Rosetta/Philae/CIVA

Note: For more information, see
* PIA19094: Comet Lander's View During First Bounce
* PIA19096: Philae Lander's Setting on Comet's Surface
* PIA19097: Philae Lander's Setting on Comet, with Cliff-Image Inset
* Rosetta Orbiter to Swoop Down On Comet in February
* Rosetta to Swoop Down on Comet in February

Messier 47

This spectacular image of the star cluster Messier 47 was taken using the Wide Field Imager camera, installed on the MPG/ESO 2.2-meter telescope at ESO’s La Silla Observatory in Chile. This young open cluster is dominated by a sprinkling of brilliant blue stars but also contains a few contrasting red giant stars.

Image credit: ESO

Note: For more information, see The Hot Blue Stars of Messier 47.

NGC 2207 and IC 2163

NGC 2207: NGC 2207 and IC 2163 are two spiral galaxies in the process of merging.

X-ray data from Chandra have revealed that NGC 2207 and IC 2163, currently in the process of colliding with one another, have produced one of the most bountiful collections of super bright X-ray lights called "ultraluminous X-ray sources" (ULXs). The true nature of ULXs is still debated, but they are likely a peculiar type of X-ray binary. In this composite image, X-ray data from Chandra are pink, optical light data from Hubble are red, green, and blue (appearing as blue, white, orange and brown), and infrared data from Spitzer are in red.

Scale: Image is 5 arcmin across (about 180,000 light years).

Image credit: X-ray: NASA/CXC/SAO/S.Mineo et al, Optical: NASA/STScI, Infrared: NASA/JPL-Caltech

Note: For more information, see NGC 2207 and IC 2163: Galactic Get-Together has Impressive Light Display, PIA18903: Galactic Gathering Gives Impressive Light Display, and Galactic Gathering Gives Sparkling Light Display.

Rosetta Comet Water Different From Earth Water

This composite is a mosaic comprising four individual NAVCAM images taken from 19 miles (31 kilometers) from the center of comet 67P/Churyumov-Gerasimenko on November 20, 2014. The image resolution is 10 feet (3 meters) per pixel.

The European Space Agency's Rosetta spacecraft has found the water vapor from comet 67P/Churyumov-Gerasimenko to be significantly different from that found on Earth. The discovery fuels the debate on the origin of our planet's oceans.

The measurements, by the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) instrument, were made in the month following the arrival of the spacecraft on August 6. It is one of the most anticipated early results of the mission, because the origin of Earth's water is still an open question.

Comets are time capsules containing primitive material left over from the epoch when the sun and its planets formed. Rosetta's lander obtained the first images taken from a comet's surface and will provide analysis of the comet's possible primordial composition. Rosetta will be the first spacecraft to witness at close proximity how a comet changes as it is subjected to the increasing intensity of the sun's radiation. Observations will help scientists learn more about the origin and evolution of our solar system and the role comets may have played in seeding Earth with water, and perhaps even life.

Image and top paragraph text credit: ESA/Rosetta/NAVCAM; bottom three paragraph text credit: NASA/JPL

Note: For more information, see:
* First Measurements of Comet’s Water Ratio
* Rosetta Instrument Reignites Debate on Earth's Oceans
* Rosetta Fuels Debate on Origin of Earth's Oceans
* Rosetta Reignites Debate on Earth's Oceans

The Disintegration of Comet ISON

Some had hoped comet ISON would be the comet of the century, lighting Earth’s skies during the latter months of 2013. Instead, it was barely visible for ground-based observers, but the Solar and Heliospheric Observatory (SOHO) had a ring-side seat to watch its disintegration.

This image is a montage spanning three days from 28–30 November 2013. The comet enters the image at the lower right, passes round the Sun and exits the frame towards the upper right. The bright star to the lower left is the red supergiant star Antares.

Astronomers had been tracking the comet for more than a year as it edged closer to the Sun, and by late November it had passed into the field of view of SOHO’s LASCO C3 camera. It was to skim the Sun, just 1,165,000 km above the fiery surface.

This is approximately 50 times closer to the Sun than innermost planet Mercury, and the comet was officially termed a ‘sungrazer’. If it survived the encounter it was expected to become extremely bright and be a well-placed object, visible to the naked eye in Earth’s night sky.

Calculations based on its orbit show that ISON began its journey towards the Sun about 3 million years ago, dislodged from its distant orbit by a passing star. Now, its fate would be sealed within days.

On 27 November, the comet brightened dramatically by a factor of about ten. Yet just before it reached closest approach to the Sun, it began to fade. This was a strong indicator that the heart of the comet, the icy nucleus, had broken up. Many expected it would disperse completely but, at first, it looked as if they were wrong.

Comet ISON appeared to survive the close approach, emerging on the other side of the Sun. Some still hoped for a bright display in the night skies. But they were to be disappointed. Quickly, the comet began to disappear. A recent analysis of SOHO data showed that the nucleus had indeed disintegrated just before closest approach to the Sun. Nothing appreciable was left of it, just a lot of dust and vapor.

The disintegration of comet ISON provided scientists with an exceptional chance to see a comet inside and out. Another rare opportunity is being provided by comet 67P/Churyumov-Gerasimenko. ESA’s Rosetta spacecraft caught up with this comet early in August 2014 and deployed the lander Philae to the surface in November. The orbiter will accompany comet 67P/C-G along its orbit and through its closest approach to the Sun, which takes it between the orbits of Mars and Earth. While this comet is unlikely to suffer the same fate as comet ISON, it will provide an unsurpassed insight into the nature of comets.

Image credit: ESA/NASA

NGC 3532

The MPG/ESO 2.2-meter telescope at ESO’s La Silla Observatory in Chile captured this richly colorful view of the bright star cluster NGC 3532. Some of the stars still shine with a hot bluish color, but many of the more massive ones have become red giants and glow with a rich orange hue.

Image credit: ESO/G. Beccari

Note: For more information, see A Colorful Gathering of Middle-Aged Stars.

Supernova Remnants MSH 11-62 and G327.1-1.1

MSH 11-62 and G327.1-1.1: Two new Chandra images of supernova remnants reveal intricate structures left behind after massive stars exploded.

A long observation with Chandra of the supernova remnant MSH 11-62 reveals an irregular shell of hot gas, shown in red, surrounding an extended nebula of high energy X-rays, shown in blue. Even though scientists have yet to detect any pulsations from the central object within MSH 11-62, the structure around it has many of the same characteristics as other pulsar wind nebulas. The reverse shock and other, secondary shocks within MSH 11-62 appear to have begun to crush the pulsar wind nebula, possibly contributing to its elongated shape. (Note: the orientation of this image has been rotated by 24 degrees so that north is pointed to the upper left.)

The Chandra image of G327.1-1.1 shows an outward-moving shock wave (faint red color) and a bright pulsar wind nebula (blue). The pulsar wind nebula appears to have been distorted by the combined action of a reverse shock wave, which may have flattened it, and by the motion of the pulsar, which created a comet, or lobster-like tail. An asymmetric supernova explosion may have given a recoil kick to the pulsar, causing it to move rapidly and drag the pulsar wind nebula along with it. Two structures resembling lobster claws protrude from near the head of the pulsar wind nebula. The origin of these features, which may be produced by the interaction of the pulsar wind with the reverse shock, is unknown.

Image credit: NASA/CXC/GSFC/T.Temim et al.

Note: For more information, see MSH 11-62 and G327.1-1.1: Supernova Shock Waves, Neutron Stars, and Lobsters.

Europa Remastered

The puzzling, fascinating surface of Jupiter's icy moon Europa looms large in this newly-reprocessed color view, made from images taken by NASA's Galileo spacecraft in the late 1990s. This is the color view of Europa from Galileo that shows the largest portion of the moon's surface at the highest resolution.

The view was previously released as a mosaic with lower resolution and strongly enhanced color (see PIA02590). To create this new version, the images were assembled into a realistic color view of the surface that approximates how Europa would appear to the human eye.

The scene shows the stunning diversity of Europa's surface geology. Long, linear cracks and ridges crisscross the surface, interrupted by regions of disrupted terrain where the surface ice crust has been broken up and re-frozen into new patterns.

Color variations across the surface are associated with differences in geologic feature type and location. For example, areas that appear blue or white contain relatively pure water ice, while reddish and brownish areas include non-ice components in higher concentrations. The polar regions, visible at the left and right of this view, are noticeably bluer than the more equatorial latitudes, which look more white. This color variation is thought to be due to differences in ice grain size in the two locations.

Images taken through near-infrared, green and violet filters have been combined to produce this view. The images have been corrected for light scattered outside of the image, to provide a color correction that is calibrated by wavelength. Gaps in the images have been filled with simulated color based on the color of nearby surface areas with similar terrain types.

This global color view consists of images acquired by the Galileo Solid-State Imaging (SSI) experiment on the spacecraft's first and fourteenth orbits through the Jupiter system, in 1995 and 1998, respectively. Image scale is 1 mile (1.6 kilometers) per pixel. North on Europa is at right.

Image credit: NASA/JPL-Caltech/SETI Institute

Note: For more information, see NASA Issues 'Remastered' View of Jupiter's Moon Europa.

Four Globular Clusters in Fornax

This NASA/ESA Hubble Space Telescope image shows four globular clusters in the dwarf galaxy Fornax.

New observations of the clusters – large balls of stars that orbit the centers of galaxies – show they are very similar to those found in our galaxy, the Milky Way. The finding is at odds with leading theories on how these clusters form – in these theories, globular clusters should be nestled among large quantities of old stars – and so the mystery of how these objects came to exist deepens.

Left to right: Fornax 1, Fornax 2, Fornax 3 and Fornax 5. Their positions within the galaxy are shown in image heic1425g.

Image credit: NASA, ESA, S. Larsen (Radboud University, the Netherlands)

Note: For more information, see The Riddle of the Missing Stars - Hubble Observations Cast Further Doubt on How Globular Clusters Formed.

Simulation of a Large Scale Structure

This very detailed simulation of large scale structure was created as part of the Illustris simulation. The distribution of dark matter is shown in blue and the gas distribution in orange. This simulation is for the current state of the Universe and is centered on a massive galaxy cluster. The region shown is about 300 million light-years across.

Illustration credit: Illustris Collaboration

Note: For more information, see Spooky Alignment of Quasars Across Billions of Light-Years.

Geological Map of Vesta

This high-resolution geological map of Vesta is derived from Dawn spacecraft data. Brown colors represent the oldest, most heavily cratered surface. Purple colors in the north and light blue represent terrains modified by the Veneneia and Rheasilvia impacts, respectively. Light purples and dark blue colors below the equator represent the interior of the Rheasilvia and Veneneia basins. Greens and yellows represent relatively young landslides or other downhill movement and crater impact materials, respectively. This map unifies 15 individual quadrangle maps published this week in a special issue of Icarus. Map is a Mollweide projection, centered on 180 degrees longitude using the Dawn Claudia coordinate system.

Map credit: NASA/JPL-Caltech/ASU

Note: For more information, see PIA18789: Geological Time Scale of Vesta and Geologic Maps of Vesta from NASA's Dawn Mission Published.

Philae Drifting Across Comet 67P/Churyumov-Gerasimenko

These incredible images show the breathtaking journey of Rosetta’s Philae lander as it approached and then rebounded from its first touchdown on Comet 67P/Churyumov–Gerasimenko on 12 November 2014.

The mosaic comprises a series of images captured by Rosetta’s OSIRIS camera over a 30 minute period spanning the first touchdown. The time of each of image is marked on the corresponding insets and is in GMT. A comparison of the touchdown area shortly before and after first contact with the surface is also provided.

The images were taken with Rosetta’s OSIRIS narrow-angle camera when the spacecraft was 17.5 km from the comet center, or roughly 15.5 km from the surface. They have a resolution of 28 cm/pixel and the enlarged insets are 17 x 17 m.

From left to right, the images show Philae descending towards and across the comet before touchdown. The image taken after touchdown, at 15:43 GMT, confirms that the lander was moving east, as first suggested by the data returned by the CONSERT experiment, and at a speed of about 0.5 m/s.

The final location of Philae is still not known, but after touching down and bouncing again at 17:25 GMT, it reached there at 17:32 GMT. The imaging team is confident that combining the CONSERT ranging data with OSIRIS and navcam images from the orbiter and images from near the surface and on it from Philae’s ROLIS and CIVA cameras will soon reveal the lander’s whereabouts.

The insets are provided separately via the blog: OSIRIS spots Philae drifting across the comet.

Image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

Note: For more information, see:
* PIA18875: First Touchdown Site of Comet Lander
* PIA18879: First Panoramic View from Comet Lander
* PIA18897: Rosetta Lander Captured Before/After Bounce
* First Touchdown
* Philae Spotted by Rosetta After First Landing
* Searching for Philae
* First Comet Panoramic
* First Touchdown Close-Up 1
* Three Touchdowns for Rosetta's Lander
* Pioneering Philae Completes Main Mission Before Hibernation
* Rosetta's 'Philae' Makes Historic First Landing on a Comet
* Rosetta's Comet Lander Landed Three Times
* Philae Landing: Acquisition of Signal from Spacecraft and Lander (Video)
* Philae Landing: Touchdown Highlights (Video)
* Philae Touchdown: Lander Status and First Descent Image (Video)
* OSIRIS Spots Philae Drifting Across the Comet

Sagittarius A*

Sagittarius A*: The Milky Way's supermassive black hole, about 26,000 light years from Earth.

The supermassive black hole at the center of the Milky Way may be producing tiny particles,called neutrinos, that have virtually no mass and carry no electric charge. This Chandra image shows the region around the black hole, known as Sagittarius A*, in low, medium, and high-energy X-rays (red,green, and blue respectively.) Scientists have found a connection to outbursts generated by the black hole and seen by Chandra and other X-ray telescopes with the detection of high-energy neutrinos in an observatory under the South Pole.

Scale: Image is 12 arcmin across (about 91 light years).

Image credit: NASA/CXC/Univ. of Wisconsin/Y.Bai. et al.

Note: For more information, see Sagittarius A*: NASA X-ray Telescopes Find Black Hole May Be a Neutrino Factory.

Comet 67P/Churyumov-Gerasimenko During Philae's Descent

This image of comet 67P/Churyumov-Gerasimenko was acquired by the Philae lander of the European Space Agency's Rosetta mission during Philae's descent toward the comet on November 12, 2014. Philae's ROLIS (ROsetta Lander Imaging System) took the image at 14:38:41 UTC (6:38:41 a.m., PST) at a distance of approximately two miles (three kilometers) from the surface. The landing site is imaged with a resolution of about 10 feet (three meters) per pixel.

The ROLIS instrument is a down-looking imager that acquires images during the descent and doubles as a multi-spectral close-up camera after the landing. The aim of the ROLIS experiment is to study the texture and microstructure of the comet's surface. It was developed by the German Aerospace Center's Institute of Planetary Research, Berlin.

The lander separated from the orbiter at 09:03 UTC (1:03 a.m. PST) for touch down on comet 67P seven hours later.

Rosetta and Philae had been riding through space together for more than 10 years. Philae is the first probe to achieve a soft landing on a comet, and Rosetta is the first to rendezvous with a comet and follow it around the sun. The information collected by Philae at one location on the surface will complement that collected by the Rosetta orbiter for the entire comet.

Image credit: ESA/Rosetta/Philae/DLR

Note: This is the major story for today, and just the ESA and NASA by themselves have numerous news stories, photos and videos available. For more information, see:
* How to Land on a Comet
* PIA18871: Rosetta Mission Selfie at 10 Miles
* PIA18872: Rosetta Mission Selfie at 30 Miles
* PIA18873: Farewell, Philae
* PIA18870: Farewell Shot of Rosetta by Philae Lander
* European Spacecraft Set to Harpoon a Comet Today
* Separation
* Confirmation of Separation of the Philae Lander from Rosetta
* Separation Signal Confirmed
* Farewell Rosetta
* Farewell Philae - Narrow-Angle View (1)
* Farewell Philae - Narrow-Angle View (2)
* Farewell Philae - Wide-Angle View
* Philae Descending to the Comet – Wide-Angle View
* Lander Departure
* ROLIS Descent Image
* Highlights: Rosetta Mission Comet Landing Up to Lander Separation (Video)
* Rosetta and Philae Go for Separation
* Rosetta and Philae Separation Confirmed
* Confirmation of Separation of the Philae Lander from Rosetta
* Touchdown! Rosetta's Philae Probe Lands on Comet

Smooth Terrain on Comet 67P/Churyumov-Gerasimenko

A patch of relatively smooth ground on the nucleus surface of comet 67P/Churyumov-Gerasimenko appears in this image taken by the navigation camera on the European Space Agency's Rosetta spacecraft during the second half of October 2014. The spacecraft has been orbiting this comet since August 2014 and will release its lander, Philae, on November 12 to land on the comet's nucleus.

This image was taken from a distance of less than six miles (10 kilometers) from the surface. It is one of a series of images from Rosetta's navigation camera showing the varied and dramatic terrain of the nucleus. Some light contrast enhancements have been made to emphasize certain features and to bring out features in the shadowed areas. In reality, the comet is extremely dark - blacker than coal. The images, taken in black-and-white, are grey-scaled according to the relative brightness of the features observed, which depends on local illumination conditions, surface characteristics and composition of the given area.

Comets are time capsules containing primitive material left over from the epoch when the sun and its planets formed. Rosetta's lander will obtain the first images taken from a comet's surface and will provide the first analysis of a comet's composition by drilling into the surface. Rosetta also will be the first spacecraft to witness at close proximity how a comet changes as it is subjected to the increasing intensity of the sun's radiation. Observations will help scientists learn more about the origin and evolution of our solar system and the role comets may have played in seeding Earth with water, and perhaps even life.

Image credit: ESA/Rosetta/NAVCAM

Note: For more information, see PIA18867: Jagged Horizon on Rosetta's Destination Comet and PIA18869: Rough Terrain on Rosetta's Destination Comet.

Ram-Pressure Stripped Galaxy ESO 137-001

The MUSE instrument on ESO’s Very Large Telescope has provided researchers with the best view yet of a spectacular cosmic crash. Observations reveal for the first time the motion of gas as it is ripped out of the galaxy ESO 137-001 as it plows at high speed into a vast galaxy cluster. The results are the key to the solution of a long-standing mystery — why star formation switches off in galaxy clusters.

In this picture the colors show the motions of the gas filaments — red means the material is moving away from Earth compared to the galaxy and blue that it is approaching.

Note that the upper-left and lower-right parts of this picture have been filled in using the Hubble image of this object.

Image credit: ESO/M. Fumagalli

Note: For more information, see MUSE Reveals True Story Behind Galactic Crash.

Protoplanetary Disc Around HL Tauri

This is the sharpest image ever taken by ALMA — sharper than is routinely achieved in visible light with the NASA/ESA Hubble Space Telescope. It shows the protoplanetary disc surrounding the young star HL Tauri. These new ALMA observations reveal substructures within the disc that have never been seen before and even show the possible positions of planets forming in the dark patches within the system.

Image credit: ALMA (ESO/NAOJ/NRAO)

Note: For more information, see Revolutionary ALMA Image Reveals Planetary Genesis.

Artist’s Impression of Bright Exozodiacal Light

This artist’s view from an imagined planet around a nearby star shows the brilliant glow of exozodiacal light extending up into the sky and swamping the Milky Way. This light is starlight reflected from hot dust created as the result of collisions between asteroids, and the evaporation of comets. The presence of such thick dust clouds in the inner regions around some stars may pose an obstacle to the direct imaging of Earth-like planets in the future.

Illustration credit: ESO/L. Calçada

Note: For more information, see VLTI Detects Exozodiacal Light.

Sunglint Off of Titan's Kraken Mare

This near-infrared, color mosaic from NASA's Cassini spacecraft shows the sun glinting off of Titan's north polar seas. While Cassini has captured, separately, views of the polar seas (see PIA17470) and the sun glinting off of them (see PIA12481 and PIA18433) in the past, this is the first time both have been seen together in the same view.

The sunglint, also called a specular reflection, is the bright area near the 11 o'clock position at upper left. This mirror-like reflection, known as the specular point, is in the south of Titan's largest sea, Kraken Mare, just north of an island archipelago separating two separate parts of the sea.

This particular sunglint was so bright as to saturate the detector of Cassini's Visual and Infrared Mapping Spectrometer (VIMS) instrument, which captures the view. It is also the sunglint seen with the highest observation elevation so far -- the sun was a full 40 degrees above the horizon as seen from Kraken Mare at this time -- much higher than the 22 degrees seen in PIA18433. Because it was so bright, this glint was visible through the haze at much lower wavelengths than before, down to 1.3 microns.

The southern portion of Kraken Mare (the area surrounding the specular feature toward upper left) displays a "bathtub ring" -- a bright margin of evaporate deposits -- which indicates that the sea was larger at some point in the past and has become smaller due to evaporation. The deposits are material left behind after the methane & ethane liquid evaporates, somewhat akin to the saline crust on a salt flat.

The highest resolution data from this flyby -- the area seen immediately to the right of the sunglint -- cover the labyrinth of channels that connect Kraken Mare to another large sea, Ligeia Mare. Ligeia Mare itself is partially covered in its northern reaches by a bright, arrow-shaped complex of clouds. The clouds are made of liquid methane droplets, and could be actively refilling the lakes with rainfall.

The view was acquired during Cassini's August 21, 2014, flyby of Titan, also referred to as "T104" by the Cassini team.

The view contains real color information, although it is not the natural color the human eye would see. Here, red in the image corresponds to 5.0 microns, green to 2.0 microns, and blue to 1.3 microns. These wavelengths correspond to atmospheric windows through which Titan's surface is visible. The unaided human eye would see nothing but haze, as in PIA12528.

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

Note: For more information, see PIA18433: Sunglint on a Hydrocarbon Lake and Cassini Sees Sunny Seas on Titan.

Artist’s Impression of the Double-Star System GG Tauri-A

This artist’s impression shows the dust and gas around the double star system GG Tauri-A. Researchers using ALMA have detected gas in the region between two discs in this binary system. This may allow planets to form in the gravitationally perturbed environment of the binary. Half of Sun-like stars are born in binary systems, meaning that these findings will have major consequences for the hunt for exoplanets.

Illustration credit: ESO/L. Calçada

Note: For more information, see Planet-Forming Lifeline Discovered in a Binary Star System.

Perseus and Virgo Galactic Clusters

Perseus Cluster and Virgo Cluster: Two galaxy clusters about 250 million and 50 million light years away respectively.

Chandra observations of the Perseus and Virgo galaxy clusters have provided direct evidence that turbulence is helping to prevent stars from forming there. These new results could answer along-standing question about how these galaxy clusters keep their enormous reservoirs of hot gas from cooling down to form stars. Scientists targeted Perseus and Virgo because they are both extremely large and relatively bright, thus providing an opportunity to see details that would be very difficult to detect in other clusters.

Image credit: NASA/CXC/Stanford/I.Zhuravleva et al.

Note: For more information, see Perseus Cluster and Virgo Cluster: NASA's Chandra Observatory Identifies Impact of Cosmic Chaos on Star Birth.

Exocomets Around Beta Pictoris

This artist’s impression shows exocomets orbiting the star Beta Pictoris. Astronomers analyzing observations of nearly 500 individual comets made with the HARPS instrument at ESO’s La Silla Observatory have discovered two families of exocomets around this nearby young star. The first consists of old exocomets that have made multiple passages near the star. The second family, shown in this illustration, consists of younger exocomets on the same orbit, which probably came from the recent breakup of one or more larger objects.

Illustration credit: ESO/L. Calçada

Note: For more information, see Two Families of Comets Found Around Nearby Star.

Comet 67P/Churyumov-Gerasimenko's Jets

This image of 67P/Churyumov-Gerasimenko was taken by the Optical, Spectroscopic, and Infrared Remote Imaging System, Rosetta's main onboard scientific imaging system, on September 10, 2014. Jets of cometary activity can be seen along almost the entire body of the comet.

Image credit: ESA/Rosetta/MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

Note: For more information, see PIA18835: Rosetta Comet Spreads its Jets, Comet activity – 10 September 2014, Rosetta's Comet Scrambling Its Jets(JPL), and Rosetta Comet Scrambles its Jets (NASA Science News).

Six Images by Chandra

Chandra Archive Collection: Six images that combine Chandra data with those from other telescopes.

With the passing of Chandraʼs 15th anniversary, the Chandra Data Archive, which houses all of the missionʼs data, continues to grow each successive year. These images – that include a wide range of astronomical objects -- combine X-rays from Chandraʼs archive with data from other telescopes. This technique of creating “multi-wavelength” images allows scientists and the public to see how X-rays fit with data of other types of light, such as optical, radio, and infrared.

PSR B1509-58 (upper left)
Pareidolia is the psychological phenomenon where people see recognizable shapes in clouds, rock formations, or otherwise unrelated objects or data. When Chandra's image of PSR B1509-58, a spinning neutron star surrounded by a cloud of energetic particles, was released in 2009, it quickly gained attention because many saw a hand-like structure in the X-ray emission. In this new image of the system, X-rays from Chandra in gold are seen along with infrared data from NASA's Wide-field Infrared Survey Explorer (WISE) telescope in red, green, and blue. Pareidolia may strike again in this image as some people report seeing a shape of a face in WISE's infrared data.

RCW 38 (upper right)
A young star cluster about 5,500 light years from Earth, RCW 38 provides astronomers a chance to closely examine many young, rapidly evolving stars at once. In this composite image, X-rays from Chandra are blue, while infrared data from NASA's Spitzer Space Telescope are orange and additional infrared data from the 2MASS survey appears white. There are many massive stars in RCW 38 that will likely explode as supernovas. Astronomers studying RCW 38 are hoping to better understand this environment as our Sun was likely born into a similar stellar nursery.

Hercules A (middle left):
Some galaxies have extremely bright cores, suggesting that they contain a supermassive black hole that is pulling in matter at a prodigious rate. Astronomers call these "active galaxies," and Hercules A is one of them. In visible light (colored red, green and blue, with most objects appearing white), Hercules A looks like a typical elliptical galaxy. In X-ray light, however, Chandra detects a giant cloud of multimillion-degree gas (purple). This gas has been heated by energy generated by the infall of matter into a black hole at the center of Hercules A that is over 1,000 times as massive as the one in the middle of the Milky Way. Radio data (blue) show jets of particles streaming away from the black hole. The jets span a length of almost one million light years.

Kes 73 (middle right):
The supernova remnant Kes 73, located about 28,000 light years away, contains a so-called anomalous X-ray pulsar, or AXP, at its center. Astronomers think that most AXPs are magnetars, which are neutron stars with ultra-high magnetic fields. Surrounding the point-like AXP in the middle, Kes 73 has an expanding shell of debris from the supernova explosion that occurred between about 750 and 2100 years ago, as seen from Earth. The Chandra data (blue) reveal clumpy structures along one side of the remnant, and appear to overlap with infrared data (orange). The X-rays partially fill the shell seen in radio emission (red) by the Very Large Array. Data from the Digitized Sky Survey optical telescope (white) show stars in the field-of-view.

Mrk 573 (lower left):
Markarian 573 is an active galaxy that has two cones of emission streaming away from the supermassive black hole at its center. Several lines of evidence suggest that a torus, or doughnut of cool gas and dust may block some of the radiation produced by matter falling into supermassive black holes, depending on how the torus is oriented toward Earth. Chandra data of Markarian 573 suggest that its torus may not be completely solid, but rather may be clumpy. This composite image shows overlap between X-rays from Chandra (blue), radio emission from the VLA (purple), and optical data from Hubble (gold).

NGC 4736 (lower right):
NGC 4736 (also known as Messier 94) is a spiral galaxy that is unusual because it has two ring structures. This galaxy is classified as containing a "low ionization nuclear emission region," or LINER, in its center, which produces radiation from specific elements such as oxygen and nitrogen. Chandra observations (gold) of NGC 4736, seen in this composite image with infrared data from Spitzer (red) and optical data from Hubble and the Sloan Digital Sky Survey (blue), suggest that the X-ray emission comes from a recent burst of star formation. Part of the evidence comes from the large number of point sources near the center of the galaxy, showing that strong star formation has occurred. In other galaxies, evidence points to supermassive black holes being responsible for LINER properties. Chandra's result on NGC 4736 shows LINERs may represent more than one physical phenomenon.

Image credit: NASA/CXC/SAO

Note: For more information, see Chandra Archive Collection: Chandra's Archives Come to Life.

NGC 1291

This image from NASA's Spitzer Space Telescope, taken in infrared light, shows where the action is taking place in galaxy NGC 1291. The outer ring, colored red in this view, is filled with new stars that are igniting and heating up dust that glows with infrared light. The stars in the central area produce shorter-wavelength infrared light than that seen in the ring, and are colored blue. This central area is where older stars live, having long ago gobbled up the available gas supply, or fuel, for making new stars.

The galaxy is about 12 billion years old and is located in the Eridanus constellation. It is known as a barred galaxy because a central bar of stars (which looks like a blue "S" in this view) dominates its center.

When galaxies are young and gas-rich, stellar bars drive gas toward the center, feeding star formation. Over time, as the star-making fuel runs out, the central regions become quiescent and star-formation activity shifts to the outskirts of a galaxy. There, spiral density waves and resonances induced by the central bar help convert gas to stars. The outer ring, seen here in red, is one such resonance location, where gas has been trapped and ignited into a star-forming frenzy.

Image credit: NASA/JPL-Caltech

Note: For more information, see Galactic Wheel of Life Shines in Infrared.

Sextans A

A small galaxy, called Sextans A, is shown here in a multi-wavelength mosaic captured by the European Space Agency's Herschel mission, in which NASA is a partner, along with NASA's Galaxy Evolution Explorer (GALEX) and the National Radio Astronomy Observatory's Jansky Very Large Array observatory near Socorro, New Mexico. The galaxy is located 4.5 million light-years from Earth in the Sextans constellation.

The environment in this galaxy is similar to that of our infant universe because it lacks in heavy metals, or elements heavier than hydrogen and helium. Heavy metals act in some ways like fertilizers for stars, helping them form and grow. Scientists study galaxies like Sextans A to learn how stars still manage to slowly bloom under these poor-growing conditions. The research provides a better understanding of how the very first stars in our universe came to be.

In this image, the purple shows gas; blue shows young stars and the orange and yellow dots are newly formed stars heating up dust.

Image credit: ESA/NASA/JPL-Caltech/NRAO

Artist's Illustration of a Galactic Protocluster

This artist’s impression depicts the formation of a galaxy cluster in the early Universe. The galaxies are vigorously forming new stars and interacting with each other. Such a scene closely resembles the Spiderweb Galaxy (formally known as MRC 1138-262) and its surroundings, which is one of the best-studied protoclusters.

Illustration credit: ESO/M. Kornmesser

Note: For more information, see Construction Secrets of a Galactic Metropolis.

NGC 6302 - The Butterfly Nebula

Many celestial objects are beautiful – swirling spiral galaxies or glittering clusters of stars are notable examples. But some of the most striking scenes are created during the death throes of intermediate-mass stars, when great clouds of superheated gas are expelled into space. These dying breaths form planetary nebulas like NGC 6302, captured here in this image from the NASA/ESA Hubble Space Telescope.

Known perhaps more appropriately as the Bug or Butterfly Nebula, this complex nebula lies roughly 3800 light-years away from us within the Milky Way. It was formed when a star around five times the mass of our Sun became a red giant, ejected its outer layers, and became intensely hot. Its distinctive shape classifies it as a bipolar nebula, where fast-moving gas can escape more easily from the poles of the dying star than from around its equator. This creates a lobed structure reminiscent of an hourglass or, as in this case, a giant cosmic butterfly.

While this image is beautiful in its own right, the mix of colors actually tells us a lot about physical conditions within the nebula.

The red edges of the butterfly wings represent areas that emit light from the element nitrogen, due to the relatively low temperatures there. Conversely the white splashes closer to the nebula's center pinpoint light emitted by the element sulfur, marking regions of higher temperature and colliding gases closer to the central star.

This hot gas was expelled from the star and collided with slower-moving gas in its path, creating rippling shock waves through the nebula. An example of such a shock wave can be seen in the well-defined white blob towards the top right of the image.

Other colors identify emission from oxygen, helium and hydrogen gases. The observations making up this composite image were taken in optical and ultraviolet light on 27 July 2009, using Hubble's Wide Field Camera 3.

Image credit: NASA/ESA/Hubble SM4 ERO Team

Weather Map for WASP-43b

In this artist's illustration the Jupiter-sized planet WASP-43b orbits its parent star in one of the closest orbits ever measured for an exoplanet of its size – with a year lasting just 19 hours.

The planet is tidally locked, meaning it keeps one hemisphere facing the star, just as the Moon keeps one face toward Earth.

The color scale on the planet represents the temperature across its atmosphere. This is based on data from a recent study that mapped the temperature of WASP-43b in more detail than has been done for any other exoplanet.

Image credit: NASA, ESA, and Z. Levay (STScI)

Note: For more information, see Hubble Reveals Most Detailed Exoplanet Weather Map Ever.

Boulder Cheops

This image of the surface of Comet 67P/Churyumov-Gerasimenko was taken by Rosetta’s OSIRIS narrow-angle camera on 19 September 2014, from a distance of 28.5 km.

The image features a large boulder casting a long shadow on the surface of the comet. The boulder has a maximum dimension of about 45 meters and is the largest structure within a group of boulders located on the lower side of the comet’s larger lobe. This cluster of boulders reminded scientists of the famous pyramids at Giza near Cairo in Egypt, and thus it has been named Cheops for the largest of those pyramids, the Great Pyramid, which was built as a tomb for the pharaoh Cheops (also known as Kheops or Khufu) around 2550 BC.

Image credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

Grooves on Asteroid 21 Lutetia

A portion of asteroid Lutetia, looking into the 55 km-wide Massilia crater (red circular outline) with the North Pole Crater Cluster (NPCC) in the distance (purple outline). The grooves (or ‘lineaments’) are colored according to the crater to which they are associated, i.e. red for Massilia and purple for NPCC. The blue lineaments are associated with the ‘Suspicio’ crater, while the yellow lineaments are not associated with any crater discussed in this study.

Lutetia was imaged in July 2010 by ESA’s Rosetta spacecraft, while en route to Comet 67P/Churyumov-Gerasimenko. Rosetta took images of the 100 km-wide asteroid for about two hours during the flyby. At its closest approach, Rosetta was 3162 km from Lutetia. In the image shown here, north is up.

Image credit: Besse et al (2014); image: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

Note: For more information, see Lutetia's Dark Side Hosts Hidden Crater.

Messier 82's Ultraluminous Pulsar

High-energy X-rays streaming from a rare and mighty pulsar (magenta), the brightest found to date, can be seen in this new image combining multi-wavelength data from three telescopes. The bulk of a galaxy called Messier 82 (M82), or the "Cigar galaxy," is seen in visible-light data captured by the National Optical Astronomy Observatory's 2.1-meter telescope at Kitt Peak in Arizona. Starlight is white, and lanes of dust appear brown. Low-energy X-ray data from NASA's Chandra X-ray Observatory are colored blue, and higher-energy X-ray data from NuSTAR are pink.

The magenta object is what's known as an ultraluminous X-ray source, or ULX -- a source of blazing X-rays. Previously, all ULXs were suspected to be massive black holes up to a few hundred times the mass of the sun. But NuSTAR spotted a pulsing of X-rays from this ULX (called M82 X-2) - a telltale sign of a pulsar, not a black hole. A pulsar is a type a neutron star -- a stellar core left over from a supernova explosion -- that sends out rotating beams of high-energy radiation. Scientists were surprised to find the pulsar at the root of the ULX because it shines with a luminosity that is more typical of heftier black holes.

NuSTAR data covers the X-ray energy range of 10 to 40 kiloelectron volts (keV), and Chandra covers the range .1 to 10 keV.

Image credit: NASA/JPL-Caltech/SAO/NOAO

Note: For more information, see:
* M82X-2: Suspected Black Hole Unmasked as Ultraluminous Pulsar
* PIA18840: Galaxy in Different Lights
* PIA18842: Mass Chart for Dead Stars and Black Holes
* PIA18843: NuSTAR Captures the Beat of a Dead Star (Animation)
* PIA18844: Ultraluminous X-ray Sources in M82 Galaxy
* PIA18845: Beacons of X-ray Light (Animation)
* NASA's NuSTAR Telescope Discovers Shockingly Bright Dead Star

Comet 67P/Churyumov-Gerasimenko (30 September 2014)

Four-image montage comprising images taken by Rosetta's navigation camera on 30 September from a distance of 18.1 km from the center of Comet 67P/Churyumov-Gerasimenko. Each of the four frames making up the montage measures about 1.4 kilometers across. The image features Site J, the primary landing site for Rosetta’s lander Philae.

Image credit: ESA/Rosetta/NAVCAM

Comet 67P/Churyumov-Gerasimenko's Dimensions

Comet 67P/Churyumov-Gerasimenko's dimensions, as measured from images taken by Rosetta's OSIRIS imaging system. The images shown in the graphic were taken by Rosetta's navigation camera on 19 August.

The larger lobe of the comet measures 4.1 x 3.2 x 1.3 km, while the smaller lobe is 2.5 x 2.5 x 2.0 km.

More details via the blog: Measuring Comet 67P/C-G

Credits: Image: ESA/Rosetta/NAVCAM; Dimensions: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

Gravity Gradients Frame Oceanus Procellarum

Topography of Earth's moon generated from data collected by the Lunar Orbiter Laser Altimeter, aboard NASA's Lunar Reconnaissance Orbiter, with the gravity anomalies bordering the Procellarum region superimposed in blue. The border structures are shown using gravity gradients calculated with data from NASA's Gravity Recovery and Interior Laboratory (GRAIL) mission. These gravity anomalies are interpreted as ancient lava-flooded rift zones buried beneath the volcanic plains (or maria) on the nearside of the Moon.

Launched as GRAIL A and GRAIL B in September 2011, the probes, renamed Ebb and Flow, operated in a nearly circular orbit near the poles of the moon at an altitude of about 34 miles (55 kilometers) until their mission ended in December 2012. The distance between the twin probes changed slightly as they flew over areas of greater and lesser gravity caused by visible features, such as mountains and craters, and by masses hidden beneath the lunar surface.

The twin spacecraft flew in a nearly circular orbit until the end of the mission on December 17, 2012, when the probes intentionally were sent into the moon's surface. NASA later named the impact site in honor of late astronaut Sally K. Ride, who was America's first woman in space and a member of the GRAIL mission team.

GRAIL's prime and extended science missions generated the highest-resolution gravity field map of any celestial body. The map will provide a better understanding of how Earth and other rocky planets in the solar system formed and evolved.

Image credit: NASA/Colorado School of Mines/MIT/GSFC/Scientific Visualization Studio

Note: For more information, see PIA18821: On the West Coast of the Ocean of Storms (Artist's Concept) and NASA Mission Points to Origin of 'Ocean of Storms' on Earth's Moon.

Comet 67P/Churyumov-Gerasimenko Jets Firing (26 September 2014)

The four images that make up a new montage of comet 67P/Churyumov-Gerasimenko were taken on September 26, 2014 by the European Space Agency's Rosetta spacecraft. At the time, Rosetta was about 16 miles (26 kilometers) from the center of the comet.

In the montage, a region of jet activity can be seen at the neck of the comet. These jets, originating from several discrete locations, are a product of ices sublimating and gases escaping from inside the nucleus.

The overlapping and slightly dissimilar angles of the four images that compose the montage are a result of the combined effect of the comet rotating between the first and last images taken in the sequence (about 10 degrees over 20 minutes), and the spacecraft movement during that same time.

Launched in March 2004, Rosetta was reactivated in January 2014 after a record 957 days in hibernation. Rosetta is composed of an orbiter and lander. Its objectives since arriving at comet 67P/Churyumov-Gerasimenko earlier this month are to study the celestial object up close in unprecedented detail, prepare for landing a probe on the comet's nucleus in November, and after the landing, track the comet's changes through 2015 as it sweeps past the sun.

Comets are time capsules containing primitive material left over from the epoch when the sun and its planets formed. Rosetta's lander will obtain the first images taken from a comet's surface and will provide comprehensive analysis of the comet's possible primordial composition by drilling into the surface. Rosetta also will be the first spacecraft to witness at close proximity how a comet changes as it is subjected to the increasing intensity of the sun's radiation. Observations will help scientists learn more about the origin and evolution of our solar system and the role comets may have played in seeding Earth with water, and perhaps even life.

Image credit: ESA/Rosetta

Note: For more information, see Rosetta Comet Fires Its Jets.