Thursday, January 29, 2015

The Mouth of Cometary Globule CG4

Like the gaping mouth of a gigantic celestial creature, the cometary globule CG4 glows menacingly in this image from ESO’s Very Large Telescope. Although it looks huge and bright in this image it is actually a faint nebula and not easy to observe. The exact nature of CG4 remains a mystery.

Image credit: ESO

Note: For more information, see The Mouth of the Beast.

Thursday, January 8, 2015

Dark Nebula LDN 483

The Wide Field Imager (WFI) on the MPG/ESO 2.2-meter telescope at the La Silla Observatory in Chile snapped this image of the dark nebula LDN 483. The object is a region of space clogged with gas and dust. These materials are dense enough to effectively eclipse the light of background stars. LDN 483 is located about 700 light-years away in the constellation of Serpens (The Serpent).

Image credit: ESO

Note: For more information, see Where Did All the Stars Go?

Thursday, December 25, 2014

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.

Wednesday, December 24, 2014

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.

Tuesday, December 23, 2014

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.

Monday, December 22, 2014

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

Sunday, December 21, 2014

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.

Saturday, December 20, 2014

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.

Friday, December 19, 2014

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'.

Thursday, December 18, 2014

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.

Friday, December 12, 2014

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.

Thursday, December 11, 2014

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

Tuesday, December 2, 2014

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

Thursday, November 27, 2014

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.

Sunday, November 23, 2014

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.

Saturday, November 22, 2014

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.

Friday, November 21, 2014

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.

Thursday, November 20, 2014

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.

Wednesday, November 19, 2014

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.

Tuesday, November 18, 2014

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.


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

Saturday, November 15, 2014

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.

Thursday, November 13, 2014

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

Wednesday, November 12, 2014

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.

Tuesday, November 11, 2014

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.

Friday, November 7, 2014

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.

Tuesday, November 4, 2014

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.

Friday, October 31, 2014

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.

Thursday, October 30, 2014

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.

Tuesday, October 28, 2014

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.

Sunday, October 26, 2014

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.

Saturday, October 25, 2014

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.


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).