Vesta Topography and Gravity Maps

This set of images from NASA's Dawn mission shows topography of the southern hemisphere of the giant asteroid Vesta and a map of Vesta's gravity variations that have been adjusted to account for Vesta's shape. The shaded relief map on the left shows the outlines of the two ancient basins, Rheasilvia and Veneneia. On the right is a map of the residual gravity field created by removing the gravity due to the hills and valleys within the crustal layer, revealing the signature of variations in density.

Red shows the strongest gravitational pull in this scheme, measured in milligal units, and dark blue shows the weakest. Milligals are a unit of acceleration due to gravity. The large central peak of the Rheasilvia basin, which appears as the yellow area just above and to the left of center, has a small positive residual gravity anomaly. This indicates the crust there is denser, coming from deeper within the body, or perhaps is less fractured. The gravity lows near the basin rim on the right, shown in dark blue, likely indicate rock that is lighter as a result of being pulverized by the two impacts.

The topography model is derived from framing camera images from Dawn's high-altitude mapping orbit (420 miles or 680 kilometers above the surface) and the gravity data come from the low-altitude mapping orbit (130 miles or 210 kilometers above the surface).

This video from NASA's Dawn mission shows that the gravity field of Vesta closely matches the surface topography of the giant asteroid Vesta. The video shows shaded topography from Dawn's framing camera on the left, with troughs and craters visible, and color-contoured data from Dawn's gravity experiment on the right. Red shows the areas with a higher than average gravity field and blue-purple shows the areas where the field is weaker on average. The highest topography, on the rim of the Rheasilvia basin deep in the southern hemisphere, shows a particularly strong gravity field. The dashed line indicates the north-south axis.

The topography model is derived from framing camera images from Dawn's high-altitude mapping orbit (420 miles or 680 kilometers above the surface), and the gravity data come from the low-altitude mapping orbit (130 miles or 210 kilometers above the surface).

Vesta takes approximately 5.34 hours to make a rotation.

Map credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA; video credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

WISE J180956.27-330500.2

It's a dust bunny of cosmic proportions. Astronomers used images from NASA's Wide-field Infrared Survey Explorer, or WISE, to locate an aging star shedding loads of dust (orange dot at upper left). Only one other star, called Sakurai's Object, has been caught erupting with such large amounts of dust. The process is a natural part of aging for stars like our Sun. As they puff up into red giants, they shed dust that is later recycled back into other stars, planets, and in the case of our solar system, living creatures.

In this image, infrared data from WISE and a past all-sky survey mission, the Infrared Astronomical Satellite (IRAS), have been combined. Color is used to show similar observations taken almost thirty years apart; the recent WISE data are color-coded green and red, while the older IRAS data are blue.

The picture reveals that the newfound dusty star, called WISE J180956.27-330500.2, was not seen at all by IRAS, which surveyed the sky in 1983 (it is the only bright star in this field that does not have a corresponding blue halo). Astronomers say the star has brightened by a factor of 100. This appears to have been caused by a sudden eruption in the star around 15 years ago. Dust freshly created in this event is heated by starlight and glows at infrared wavelengths.

The image also demonstrates that WISE and its state-of-the-art technology produced, as expected, much crisper images than its predecessors. The blue IRAS data show both stars, and, higher up in the picture, interstellar dust.

Data from IRAS show 12-micron infrared light (blue); data from WISE show 12- and 22-micron infrared light (green and red, respectively).

Photo credit: NASA/JPL-Caltech/UCLA

Note: For more information, see NASA's WISE Catches Aging Star Erupting With Dust.

Olympus Mons Topographical Map

Olympus Mons color-coded according to height from white (highest) to blue (lowest), based on images captured by the High Resolution Stereo Camera (HRSC) on board ESA's Mars Express. New data (see M. Beuthe et al., 2012) find that Olympus Mons is built on a rigid lithosphere whereas the nearby Tharsis Montes partially sank into a less rigid lithosphere, suggesting that there were large spatial variations in the heat flux from the mantle at the time of their formation.

Photo credit: ESA/DLR/FU Berlin (G. Neukum)

Note: For more information, see Mars Express Explores the Roots of Martian Volcanoes.

NGC 6604

The star cluster NGC 6604 is shown in this image taken by the Wide Field Imager attached to the 2.2-meter MPG/ESO telescope at the La Silla Observatory in Chile. NGC 6604 is the bright grouping towards to the upper left of the image. It is a young star cluster that is the densest part of a more widely scattered association containing about one hundred brilliant blue-white stars. The picture also shows the cluster’s associated nebula — a cloud of glowing hydrogen gas that is called Sh2-54 — as well as dust clouds.

Photo credit: ESO

Note: For more information, see A Cluster Within a Cluster.

Messier 104 - The Sombrero Galaxy

The infrared vision of NASA's Spitzer Space Telescope has revealed that the Sombrero galaxy -- named after its appearance in visible light to a wide-brimmed hat -- is in fact two galaxies in one. It is a large elliptical galaxy (blue-green) with a thin disk galaxy (partly seen in red) embedded within. Previous visible-light images led astronomers to believe the Sombrero was simply a regular flat disk galaxy.

Spitzer's infrared view highlights the stars and dust. The starlight detected at 3.5 and 4.6 microns is represented in blue-green while the dust detected at 8.0 microns appears red. This image allowed astronomers to sample the full population of stars in the galaxy, in addition to its structure.

The flat disk within the galaxy is made up of two portions. The inner disk is composed almost entirely of stars, with no dust. Beyond this is a slight gap, then an outer ring of intermingled dust and stars, seen here in red.

Photo credit: NASA/JPL-Caltech

Note: For more information, see PIA15427: Sombrero Galaxy Not So Flat After All and NASA's Spitzer Finds Galaxy With Split Personality.

Moskva at Night

Moscow appears at the center of this nighttime image photographed by the Expedition 30 crew aboard the International Space Station, flying at an altitude of approximately 240 miles on March 28, 2012. A solar array panel for the space station is on the left side of the frame. The view is to the north-northwest from a nadir of approximately 49.4 degrees north latitude and 42.1 degrees east longitude, about 100 miles west-northwest of Volgograd. The Aurora Borealis, airglow and daybreak frame the horizon.

Photo credit: NASA

Venus in the Ultraviolet

Venus Monitoring Camera image taken in the ultraviolet (0.365 micrometres), from a distance of about 30,000 km.

It shows numerous high-contrast features, caused by an unknown chemical in the clouds that absorbs ultraviolet light, creating the bright and dark zones.

With data from Venus Express, scientists have learned that the equatorial areas on Venus that appear dark in ultraviolet light are regions of relatively high temperature, where intense convection brings up dark material from below. In contrast, the bright regions at mid-latitudes are areas where the temperature in the atmosphere decreases with depth. The temperature reaches a minimum at the cloud tops suppressing vertical mixing. This annulus of cold air, nicknamed the ‘cold collar’, appears as a bright band in the ultraviolet images.

Photo credit: ESA/MPS/DLR/IDA

Messier 83 in Visible Light and Infrared

This video fades between the view of Messier 83 in visible light captured by the Wide Field Imager at ESO’s La Silla Observatory in Chile and the new HAWK-I image taken in the infrared. In the infrared, the dust that obscures many stars becomes nearly transparent, making the spiral arms less dramatic but revealing a whole host of new stars that are otherwise invisible.

Video credit: ESO/M. Gieles
Acknowledgement: Mischa Schirmer

Expected Dark Matter Distribution Around the Milky Way

This annotated artist’s impression shows the Milky Way galaxy. The blue halo of material surrounding the galaxy indicates the expected distribution of the mysterious dark matter. New measurements based on the movements of stars show that the amount of dark matter in this region around the Sun is far smaller than predicted and have indicated that there is no significant dark matter at all in our neighborhood. The blue sphere centered on the Sun’s position shows the approximate size of the newly surveyed volume, but not its precise shape.

Illustration credit: ESO/L. Calçada

Note: For more information, see Serious Blow to Dark Matter Theories?

Composite of 30 Doradus by Hubble, Spitzer and Chandra

Tarantula Nebula: A massive star-forming region located about 160,000 light years away.

This composite of 30 Doradus, aka the Tarantula Nebula, contains data from Chandra (blue), Hubble (green), and Spitzer (red). Located in the Large Magellanic Cloud, the Tarantula Nebula is one of the largest star-forming regions close to the Milky Way. Chandra's X-rays detect gas that has been heated to millions of degrees by stellar winds and supernovas. This high-energy stellar activity creates shock fronts, which are similar to sonic booms. Hubble reveals the light from massive stars at various stages of star birth, while Spitzer shows where the relatively cooler gas and dust lie.

Scale: Image is 13 arcmin across (about 600 light years across).

Photo credit: X-ray: NASA/CXC/PSU/L.Townsley et al.; Optical: NASA/STScI; Infrared: NASA/JPL /PSU/L.Townsley et al.

Note: For more information, see Tarantula Nebula (30 Doradus): A New View of the Tarantula Nebula.

New Understanding of Magnetars

This illustration depicts a magnetar: a spinning neutron star, characterized by rotation periods between 2 and 10 seconds, occasional episodes of extremely enhanced emission, and intense, short bursts of X-rays and gamma rays; these highly energetic events are presumed to be powered by an intense magnetic field.

A new, comprehensive study of the magnetar 1E 1547.0-5408 (see Kuiper et al., 2012), using data from INTEGRAL, RXTE and Swift, revealed unusual behavior - the creation of both pulsed and unpulsed luminous non-thermal X-ray emission after a star quake. This is consistent with a model (Beloborodov, 2009) in which a star quake twists magnetic field lines that are anchored to the star's surface. When these twisted lines unravel they release magnetic energy and produce the observed radiation.

In this illustration, the curves converging at the poles of the magnetar represent the dipolar magnetic field lines; the entangled lines inside the magnetar symbolize the internal magnetic field.

Illustration credit: ESA

Note: For more information, see Massive Glitch Moves Magnetar Modeling Forward.

30 Doradus

30 Doradus is the brightest star-forming region in our galactic neighborhood and home to the most massive stars ever seen. The nebula resides 170,000 light-years away in the Large Magellanic Cloud, a small, satellite galaxy of our Milky Way. No known star-forming region in our galaxy is as large or as prolific as 30 Doradus.

The image comprises one of the largest mosaics ever assembled from Hubble photos and includes observations taken by Hubble's Wide Field Camera 3 and Advanced Camera for Surveys, combined with observations from the European Southern Observatory's MPG/ESO 2.2-meter telescope which trace the location of glowing hydrogen and oxygen.

The image is being released to celebrate Hubble's 22nd anniversary.

Photo credit: NASA, ESA, ESO, D. Lennon and E. Sabbi (ESA/STScI), J. Anderson, S. E. de Mink, R. van der Marel, T. Sohn, and N. Walborn (STScI), N. Bastian (Excellence Cluster, Munich), L. Bedin (INAF, Padua), E. Bressert (ESO), P. Crowther (Sheffield), A. de Koter (Amsterdam), C. Evans (UKATC/STFC, Edinburgh), A. Herrero (IAC, Tenerife), N. Langer (AifA, Bonn), I. Platais (JHU) and H. Sana (Amsterdam)

Note: For more information, see Hubble's Panoramic View of a Turbulent Star-Making Region. See also Close-Up Images of Features in the Tarantula Nebula and Labelled View of the Tarantula Nebula.

Shadow from a Solar Eclipse

The International Space Station (ISS) was in position to view the umbral (ground) shadow cast by the Moon as it moved between Earth and the Sun during a solar eclipse on March 29, 2006. This astronaut image captures the umbral shadow across southern Turkey, northern Cyprus and the Mediterranean Sea.

Photo credit: NASA

DLSCL J0916.2+2951: The Musketball Cluster

DLSCL J0916.2+2951: A merger of galaxy clusters about 5.2 billion light years from Earth.

This composite image shows Chandra (red) and Hubble (yellow and white) data of the galaxy cluster system that has been nicknamed the "Musket Ball" cluster. Astronomers call it this because the newly discovered cluster is older and slower than the Bullet Cluster, a famous system in which "normal" matter has been wrenched apart from dark matter. Chandra detects the normal matter as hot gas, while optical emission reveals the presence of dark matter through the effect of gravitational lensing (blue). DLSCL J0916.2+2951 is further along in its evolution than the Bullet Cluster, giving scientists valuable insight into a different phase of how galaxy clusters -- the largest known objects held together by gravity -- grow and change after major collisions.

Scale: Image is 6.4 arcmin across. (8 million light years across.)

Photo credit: X-ray: NASA/CXC/UCDavis/W.Dawson et al; Optical: NASA/STScI/UCDavis/W.Dawson et al.

Note: For more information, see DLSCL J0916.2+2951: Discovery of the Musket Ball Cluster.

Fomalhaut's Ring by ALMA

This view shows a new picture of the dust ring around the bright star Fomalhaut from the Atacama Large Millimeter/submillimeter Array (ALMA). The underlying blue picture shows an earlier picture obtained by the NASA/ESA Hubble Space Telescope. The new ALMA image has given astronomers a major breakthrough in understanding a nearby planetary system and provided valuable clues about how such systems form and evolve. Note that ALMA has so far only observed a part of the ring.

Photo credit: ALMA (ESO/NAOJ/NRAO). Visible light image: the NASA/ESA Hubble Space Telescope

Acknowledgment: A.C. Boley (University of Florida, Sagan Fellow), M.J. Payne, E.B. Ford, M. Shabran (University of Florida), S. Corder (North American ALMA Science Center, National Radio Astronomy Observatory), and W. Dent (ALMA, Chile), P. Kalas, J. Graham, E. Chiang, E. Kite (University of California, Berkeley), M. Clampin (NASA Goddard Space Flight Center), M. Fitzgerald (Lawrence Livermore National Laboratory), and K. Stapelfeldt and J. Krist (NASA Jet Propulsion Laboratory)

Note: For more information, see ALMA Reveals Workings of Nearby Planetary System.

Artist's Concept of a Blazar

This artist's concept shows a "feeding," or active, supermassive black hole with a jet streaming outward at nearly the speed of light. Such active black holes are often found at the hearts of elliptical galaxies. Not all black holes have jets, but when they do, the jets can be pointed in any direction. If a jet happens to shine at Earth, the object is called a blazar.

Blazars are categorized differently than other active black holes with jets because they have unique properties when viewed by telescopes. They give off a full range of light, dominated by high-energy gamma rays. As particles in the jets are accelerated to almost the speed of light, they give off a specific infrared signature, which NASA's Wide-field Infrared Survey Explorer (WISE) can detect. Astronomers have taken advantage of this fact, and used the WISE all-sky catalog to uncover more than 200 new blazars so far.

Illustration credit: NASA/JPL-Caltech

Note: For more information, see PIA15424: Lone Blazar; also, see NASA's WISE Mission Sees Skies Ablaze With Blazars.

Perpetual Ocean

Driven by wind and other forces, currents on the ocean surface cover our planet. Some span hundreds to thousands of miles across vast ocean basins in well-defined flows. Others are confined to particular regions and form slow-moving, circular pools. Seen from space, the circulating waters offer a study in both chaos and order. The visualization below, based on ocean temperature, salinity, sea surface height and sea ice data collected during field observations and by NASA satellites between July 2005 and December 2007, highlights many of the world's most important ocean surface currents. Watch powerful, fast-moving currents like the Gulf Stream in the Atlantic Ocean and the Kuroshio in the Pacific Ocean carry warm waters northeastward at speeds greater than 4 mph. View coastal currents such as the Agulhas in the Southern Hemisphere transporting equatorial waters from the Indian Ocean farther southwards. Explore the image collection to compare the direction and unique flow pattern of each of these major currents.

Video credit: NASA/Goddard Space Flight Center

Fomalhaut and its Debris Disc

This image shows the thermal emission from the young star Fomalhaut and the debris disc surrounding it, as recorded with ESA's Herschel Space Observatory at a wavelength of 70 microns. Together with other data, this image suggests that the dust in Fomalhaut's debris disc consists of 'fluffy' aggregates: large conglomerates of small dust grains with lots of empty space in the structure.

Fluffy dust aggregates are believed to arise from collisions between comets. The radiation pressure exerted by the star, however, is expected to blow out small dust particles very efficiently, expelling grains from the disc immediately after they are produced by comet collisions. In order to explain the observed emission from Fomalhaut's debris disc, astronomers invoke a steady production of dust particles via comet collisions, with an average rate of 2000 daily collisions between comets with a size of one kilometer across or, alternatively, of 2 daily collisions between 10-kilometre-diameter comets.

The total mass of Fomalhaut's debris disc amounts to 110 times the mass of the Earth. This translates into a very large number of comets, ranging between 10^11 and 10^13, depending on their sizes. This is comparable to the mass of the primordial Kuiper Belt, which astronomers estimate to be of the order of 30 Earth masses.

Photo credit: ESA/Herschel/PACS/Bram Acke, KU Leuven, Belgium

Note: For more information, see Herschel Images Extrasolar Analogue of the Kuiper Belt; for a graphic that compares the size of the Fomalhaut planetary system to that of our own solar system, see Comparison of Fomalhaut's Debris Disc with the Solar System. Also, Herschel Spots Comet Massacre Around Nearby Star.

Chaos in Orion

Baby stars are creating chaos 1,500 light-years away in the cosmic cloud of the Orion Nebula. Four massive stars make up the bright yellow area in the center of this false-color image for NASA's Spitzer Space Telescope. Green indicates hydrogen and sulfur gas in the nebula, which is a cocoon of gas and dust. Red and orange indicate carbon-rich molecules. Infant stars appear as yellow dots embedded in the nebula.

Photo credit: NASA

Mapping the Heliosphere

Data from NASA's Cassini spacecraft have enabled scientists to create this map of the heliosphere, the bubble of charged particles around our Sun.

Charged particles stream out from our Sun in a phenomenon known as solar wind. The solar wind interacts with the matter between stars, which is known as the interstellar medium. The mingling of interstellar medium and solar wind creates particles called energetic neutral atoms, which stream back towards the Sun.

The ion and neutral camera on Cassini's magnetospheric imaging instrument detects energetic neutral atoms. This map shows those in the range of 5,200 to 13,500 electron volts. The regions with the highest intensity of particles are red and those with the lowest intensity of particles are blue.

Cassini detects a different spectrum of energetic neutral atoms than NASA's Interstellar Boundary Explorer (IBEX) does. The IBEX images show lower-energy particles. NASA's Voyager mission collects data on energetic ions in the region that is the source of the energetic neutral atoms.

The area where IBEX found a ribbon of high-intensity particles is outlined in white. The locations of Voyager 1 and Voyager 2 are indicated with the labels "V1" and "V2." The label "nose" indicates the direction that our solar system is traveling through the interstellar medium. The label "tail" indicates the region in the direction opposite the nose.

Image credit: NASA/JPL/JHUAPL

The Large Magellanic Cloud in Infrared

This image shows the Large Magellanic Cloud galaxy in infrared light as seen by the Herschel Space Observatory, a European Space Agency-led mission with important NASA contributions, and NASA's Spitzer Space Telescope. In the instruments' combined data, this nearby dwarf galaxy looks like a fiery, circular explosion. Rather than fire, however, those ribbons are actually giant ripples of dust spanning tens or hundreds of light-years. Significant fields of star formation are noticeable in the center, just left of center and at right. The brightest center-left region is called 30 Doradus, or the Tarantula Nebula, for its appearance in visible light.

The colors in this image indicate temperatures in the dust that permeates the Cloud. Colder regions show where star formation is at its earliest stages or is shut off, while warm expanses point to new stars heating surrounding dust. The coolest areas and objects appear in red, corresponding to infrared light taken up by Herschel's Spectral and Photometric Imaging Receiver at 250 microns, or millionths of a meter. Herschel's Photodetector Array Camera and Spectrometer fills out the mid-temperature bands, shown here in green, at 100 and 160 microns. The warmest spots appear in blue, courtesy of 24- and 70-micron data from Spitzer.

Photo credit: ESA/NASA/JPL-Caltech/STScI

The British Isles and the North Atlantic

Flying at an altitude of about 240 miles over the eastern North Atlantic, the Expedition 30 crew aboard the International Space Station photographed this nighttime scene. This view looks northeastward. Center point coordinates are 46.8 degrees north latitude and 14.3 degrees west longitude. The night lights of the cities of Ireland, in the foreground, and the United Kingdom, in the back and to the right, are contrasted by the bright sunrise in the background. The greens and purples of the Aurora Borealis are seen along the rest of the horizon.

This image was taken on March 28, 2012.

Photo credit: NASA

Centaurus A in Far and Infrared and X-Rays

The peculiar galaxy Centaurus A as seen in longer infrared wavelengths and X-rays. Inner structural features seen in this image are helping scientists to understand the mechanisms and interactions within the galaxy, as are the jets seen extending over thousands of light years from the black hole believed to be at its heart. Newly discovered clouds co-aligned with the jets can also be seen in the infrared data, which are colored red and orange. The X-ray image data in this combined picture are shown in blue/cyan/purple and highlight the highly energetic jet region as well as structures that co-align with the infrared and X-ray jet (top left).

Photo credit: Far-infrared: ESA/Herschel/PACS/SPIRE/C.D. Wilson, MacMaster University, Canada; X-ray: ESA/XMM-Newton/EPIC

Note: For more information, see Multi Wavelength Video of Centaurus A; also, Dark Heart of a Cosmic Collision.

NGC 3801: The Beginning of the End of Star Formation

Time is running out for the galaxy NGC 3801, seen in this composite image combining light from across the spectrum, ranging from ultraviolet to radio. NASA's Galaxy Evolution Explorer and other instruments have helped catch the galaxy NGC 3801 in the act of destroying its cold, gaseous fuel for new stars. Astronomers believe this marks the beginning of its transition from a vigorous spiral galaxy to a quiescent elliptical galaxy whose star-forming days are long past.

Visible light from the Sloan Digital Sky Survey is seen in yellow shining from all of the galaxy's stars. Notice that NGC 3801 is starting to possess a broadly elliptical shape, the characteristic shape a galaxy assumes after forming from a merger of spiral galaxies. Some star formation is still taking place in NGC 3801, as shown in the ultraviolet by the Galaxy Evolution Explorer (colored blue), and in the dusty disk revealed in infrared light by NASA's Spitzer Space Telescope (red).

According to theory, that lingering star formation will soon be quenched by shock waves from two powerful jets shooting out of NGC 3801's central giant black hole. Radio emissions from those jets appear in this image in green. Like a cosmic leaf blower, the jets' expanding shock waves will blast away the remaining cool star-making gas in NGC 3801. The galaxy will become "red and dead," as astronomers say, full of old, red stars and lacking in any new stellar younglings.

Near-ultraviolet light from the Galaxy Evolution Explorer at a wavelength of 230 nanometers is rendered in blue, while visible light at 469 nanometers from Sloan is displayed in yellow. Infrared light at 8 microns from Spitzer is red, and radio emission at 20 centimeters from NRAO’s Very Large Array is overlaid in green.

Photo credit: NASA/JPL-Caltech/SDSS/NRAO/ASIAA

Note: For more information, see PIA15419: The Beginning of the End of Star Formation. Also, Cosmic 'Leaf Blower' Robs Galaxy of Star-Making Fuel.

ATV-3 Edoardo Amaldi

ESA's Automated Transfer Vehicle Edoardo Amaldi approaches the International Space Station to deliver 6596 kg of fuel, air, oxygen, scientific equipment, spare parts and crew supplies.

The two spacecraft docked at 00:31 CEST ( 22:31 GMT) on March 29 2012.

Photo credit: NASA

In this stunning photo, ATV Edoardo Amaldi approaches the ISS for docking on 28 March 2012. It was taken by NASA astronaut Don Pettit on board the ISS, and shows the ATV thrusters firing under automated control as the vessel nears the Russian module where it docked.

Photo credit: ESA/NASA/Don Pettit

NGC 2683

The NASA/ESA Hubble Space Telescope has spotted the "UFO Galaxy." NGC 2683 is a spiral galaxy seen almost edge-on, giving it the shape of a classic science fiction spaceship. This is why the astronomers at the Astronaut Memorial Planetarium and Observatory, Cocoa, Florida, gave it this attention-grabbing nickname.

While a bird's eye view lets us see the detailed structure of a galaxy (such as this Hubble image of a barred spiral), a side-on view has its own perks. In particular, it gives astronomers a great opportunity to see the delicate dusty lanes of the spiral arms silhouetted against the golden haze of the galaxy’s core. In addition, brilliant clusters of young blue stars shine scattered throughout the disc, mapping the galaxy’s star-forming regions.

Perhaps surprisingly, side-on views of galaxies like this one do not prevent astronomers from deducing their structures. Studies of the properties of the light coming from NGC 2683 suggest that this is a barred spiral galaxy, even though the angle we see it at does not let us see this directly.

This image is produced from two adjacent fields observed in visible and infrared light by Hubble’s Advanced Camera for Surveys. A narrow strip which appears slightly blurred and crosses most the image horizontally is a result of a gap between Hubble’s detectors. This strip has been patched using images from observations of the galaxy made by ground-based telescopes, which show significantly less detail. The field of view is approximately 6.5 by 3.3 arcminutes.

Photo credit: ESA/Hubble & NASA

Cassiopeia A

Cassiopeia A: The debris from an exploded star located about 11,000 light years from Earth.

This two-panel graphic compares an artist's illustration (left) of a simplified picture of the inner layers of a star just before it exploded to form the Cassiopeia A supernova remnant with a Chandra image (right) of what we see today. The different elements are represented by different colors: iron (blue), sulfur and silicon (green), and magnesium, neon and oxygen (red). The Chandra image uses the same color scheme to show the distribution of iron, sulfur and magnesium in the supernova remnant. A comparison of the illustration and the Chandra element map shows clearly that most of the iron, which according to theoretical models of the pre-supernova was originally on the inside of the star, is now located near the outer edges of the remnant.

Scale: Image is 8.4 arcmin across. (about 27 light years)

Illustration credit: NASA/CXC/M.Weiss; X-ray: NASA/CXC/GSFC/U.Hwang & J.Laming

Note: For more information, see Cassiopeia A: A Star Explodes and Turns Inside Out.

M2-9, The Butterfly Nebula, by SOFIA

Researchers using NASA's Stratospheric Observatory for Infrared Astronomy (SOFIA) have captured infrared images of the last exhalations of a dying sun-like star.

The object observed by SOFIA, planetary nebula Minkowski 2-9, or M2-9 for short, is seen in this three-color composite image. The SOFIA observations were made at the mid-infrared wavelengths of 20, 24, and 37 microns. The 37-micron wavelength band detects the strongest emissions from the nebula and is impossible to observe from ground-based telescopes.

Objects such as M2-9 are called planetary nebulae due to a mistake made by early astronomers who discovered these objects while sweeping the sky with small telescopes. Many of these nebulae have the color, shape and size of Uranus and Neptune, so they were dubbed planetary nebulae. The name persists despite the fact that these nebulae are now known to be distant clouds of material, far beyond our solar system, that are shed by stars about the size of our sun undergoing upheavals during their final life stages.

Although the M2-9 nebular material is flowing out from a spherical star, it is extended in one dimension, appearing as a cylinder or hourglass. Astronomers hypothesize that planetary nebulae with such shapes are produced by opposing flows of high-speed material caused by a disk of material around the dying star at the center of the nebula. SOFIA's observations of M2-9 were designed to study the outflow in detail with the goal of better understanding this stellar life cycle stage that is important in our galaxy's evolution.

"The SOFIA images provide our most complete picture of the outflowing material on its way to being recycled into the next generation of stars and planets," said Michael Werner of NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, principal investigator of these observations. "We were gratified to see the lobes so clearly using SOFIA. These early results demonstrate the scientific potential of this important new observatory."

The observations were made using the Faint Object Infrared Camera for the SOFIA Telescope (FORCAST) instrument in June 2011 by a team consisting of astronomers from JPL, the California Institute of Technology, the University of California at Los Angeles, Cornell University and Ithaca College, Ithaca, N.Y. Preliminary analyses of these data were first presented in January 2012 at the American Astronomical Society meeting in Austin, Texas.

The SOFIA observatory combines an extensively modified Boeing 747SP aircraft and a 17-metric-ton reflecting telescope with an effective diameter of 2.5 meters (100 inches) to altitudes as high as 45,000 feet (14 km), above more than 99 percent of the water vapor in Earth's atmosphere that blocks most infrared radiation from celestial sources.

Photo credit: NASA/DLR/USRA/DSI/FORCAST Team

Super-Earth Gliese 667 Cc

This artist’s impression shows a sunset seen from the super-Earth Gliese 667 Cc. The brightest star in the sky is the red dwarf Gliese 667 C, which is part of a triple star system. The other two more distant stars, Gliese 667 A and B appear in the sky also to the right. Astronomers have estimated that there are tens of billions of such rocky worlds orbiting faint red dwarf stars in the Milky Way alone.

Illustration credit: ESO/L. Calçada

Note: For more information, see Many Billions of Rocky Planets in the Habitable Zones around Red Dwarfs in the Milky Way.