NGC 6357 - The Lobster Nebula

This image from ESO’s VISTA telescope captures a celestial landscape of vast, glowing clouds of gas and tendrils of dust surrounding hot young stars. This infrared view reveals the stellar nursery known as NGC 6357 in a new light. It was taken as part of the VISTA Variables in the Vía Láctea (VVV) survey, which is currently scanning the Milky Way in a bid to map our galaxy’s structure and explain how it formed.

Photo credit: ESO/VVV Survey/D. Minniti. Acknowledgement: Ignacio Toledo

Note: For more information, see Sweeping the Dust from a Cosmic Lobster.

HH 151

This image shows an object known as HH 151, a bright jet of glowing material trailed by an intricate, orange-hued plume of gas and dust. It is located some 460 light-years away in the constellation of Taurus (The Bull), near to the young, tumultuous star HL Tau.

In the first few hundred thousand years of life, new stars like HL Tau pull in material that falls towards them from the surrounding space. This material forms a hot disc that swirls around the coalescing body, launching narrow streams of material from its poles. These jets are shot out at speeds of several hundred kilometers per second and collide violently with nearby clumps of dust and gas, creating wispy, billowing structures known as Herbig-Haro objects — like HH 151 seen in the image above.

Such objects are very common in star-forming regions. They are short-lived, and their motion and evolution can actually be seen over very short timescales, on the order of years. They quickly race away from the newly-forming star that emitted them, colliding with new clumps of material and glowing brightly before fading away.

Image credit: ESA/Hubble & NASA. Acknowledgement: Gilles Chapdelaine

Mercury Global Map

A global color map of Mercury's surface has been created by mosaicking thousands of sets of images obtained by the MESSENGER Wide Angle Camera (WAC). The colors shown here are related to variations in the spectral reflectance across the planet. This view captures both compositional differences and differences in how long materials have been exposed at Mercury's surface. Young crater rays, arrayed radially around fresh impact craters, appear light blue or white. Medium- and dark-blue areas are a geologic unit of Mercury's crust known as the "low-reflectance material," thought to be rich in a dark, opaque mineral. Tan areas are plains formed by eruption of highly fluid lavas. The large circular area near the top center is the Caloris impact basin, whose interior is filled with smooth, somewhat younger volcanic plains. Small orangish spots are materials deposited by explosive volcanic eruptions.

The color base map shown here consists of MDIS images taken through eight different color filters. It is part of a global color map that covers more than 99% of Mercury's surface with an average resolution of about 1 kilometer per pixel.

Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS). This is an enhanced-color presentation created from a statistical combination of images taken through eight of the WAC filters.

Video credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington; text credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Note: Available on the original NASA webpage are two different size maps available for download: a smaller 6.5 MB video and a larger 23 MB video.

Soyuz and Progress Docked to the ISS

Soyuz TMA-03M and Progress as seen by ESA astronaut, Andre Kuipers, during his mission, PromISSe.

Photo credit: ESA/NASA

SN 1006

Very detailed new observations with ESO’s Very Large Telescope (VLT) of the remains of a thousand-year-old supernova have revealed clues to the origins of cosmic rays.

The image on the left shows the entire SN 1006 supernova remnant, as seen in radio (red), X-ray (blue) and visible light (yellow). The second panel, corresponding to the small square region marked at the left, is a NASA/ESA Hubble Space Telescope close up view of the remarkably narrow region of the shock front, where the material from the supernova is colliding with interstellar medium. The third panel shows how the integral field unit of the VIMOS instrument splits up the image into many small regions, the light from each of which is spread out into a spectrum of its component colors. When these spectra are analyzed, maps of the properties of the underlying object can be derived. The example shown here at the right is a map of one property of the gas (the width a spectral line), which is surprisingly variable, and implies, along with other indicators, the presence of very high-speed protons.

This remarkable image was created from pictures taken by different telescopes in space and on the ground. It shows the thousand-year-old remnant of the brilliant SN 1006 supernova, as seen in radio (red), X-ray (blue) and visible light (yellow).

Top image credit: ESO, Radio: NRAO/AUI/NSF/GBT/VLA/Dyer, Maddalena & Cornwell, X-ray: Chandra X-ray Observatory; NASA/CXC/Rutgers/G. Cassam-Chenaï, J. Hughes et al., Visible light: 0.9-metre Curtis Schmidt optical telescope; NOAO/AURA/NSF/CTIO/Middlebury College/F. Winkler and Digitized Sky Survey.

Bottom image credit: Radio: NRAO/AUI/NSF/GBT/VLA/Dyer, Maddalena & Cornwell, X-ray: Chandra X-ray Observatory; NASA/CXC/Rutgers/G. Cassam-Chenaï, J. Hughes et al., Visible light: 0.9-metre Curtis Schmidt optical telescope; NOAO/AURA/NSF/CTIO/Middlebury College/F. Winkler and Digitized Sky Survey.

Note: For more information, see Clues to the Mysterious Origin of Cosmic Rays

Galaxy with Gas Outflows

This illustration shows a galaxy in the early Universe that is releasing material via two symmetric outflows triggered by the supermassive black hole hosted at its center.

The effects of supermassive black holes on their host galaxies pose a tricky puzzle: numerical simulations suggest that star formation in early galaxies might be suppressed by the activity of the supermassive black holes at their centers. In some galaxies, the central black hole accretes matter at extraordinarily high rates, giving rise to very bright emission across the electromagnetic spectrum; these galaxies are said to host an active galactic nucleus (AGN). The accretion process is accompanied by the outflow of material and, if it is powerful enough, this may eventually drain the galaxy's reservoir of gas, halting its star-forming activity.

Illustration credit: ESA/ATG medialab

Note: For more information, see Black Holes and Star Formation: A Herschel Perspective.

SNR W49B

W49B: A supernova remnant that is located about 26,000 light years from Earth.

This highly distorted supernova remnant may contain the most recent black hole formed in the Milky Way galaxy. The composite image combines X-rays from Chandra (blue and green), radio data from the Very Large Array (pink), and infrared data from the Palomar Observatory (yellow). Most supernova explosions that destroy massive stars are generally symmetrical. In the W49B supernova,however, it appears that the material near its poles was ejected at much higher speeds than that at its equator. There is also evidence that the explosion that produced W49B left behind a black hole and not a neutron star like most other supernovas.

Scale: Image is 8.5 arcmin across. (60 light years)

Photo credit: X-ray: NASA/CXC/MIT/L.Lopez et al.; Infrared: Palomar; Radio: NSF/NRAO/VLA

Note: For more information, see W49B: Rare Explosion May Have Created Our Galaxy's Youngest Black Hole.

NGC 6520 and Barnard 86

This image from the Wide Field Imager on the MPG/ESO 2.2-meter telescope at ESO’s La Silla Observatory in Chile, shows the bright star cluster NGC 6520 and its neighbor, the strangely shaped dark cloud Barnard 86. This cosmic pair is set against millions of glowing stars from the brightest part of the Milky Way — a region so dense with stars that barely any dark sky is seen across the picture.

Photo credit: ESO

Note: For more information, see "A drop of ink on the luminous sky."

Voyager 1 in the Depletion Region

This artist's concept shows NASA's Voyager 1 spacecraft in a new region at the edge of our solar system where the magnetic field lines generated by our sun are piling up and intensifying. Voyager 1 is in an area scientists are calling the depletion region where the magnetic field acts as a kind of "magnetic highway." In this region, energetic ions from inside the heliosphere, the magnetic bubble that the sun blows around itself, escape out, and energetic ions from interstellar space zoom in. (To learn more about how this region acts as a magnetic highway, see PIA16486.) The depletion region is the outermost known layer of the heliosphere.

Magnetic field lines form a spiral around the solar system because of the rotation of the sun (see PIA15179), and at the edge of the solar system they form roughly parallel lines. At the end of 2004, Voyager 1 passed the termination shock, where the solar wind abruptly slowed down and compressed, and the intensity of the magnetic field tripled as the distance between magnetic field lines decreased by one-third. By mid-2010, Voyager entered a stagnation region where the wind slowed almost to a stop and the magnetic field intensity increased twice again as the magnetic field lines were pressed closer together. In August 2012, Voyager 1 entered the outermost known layer where the depletion of energetic ions allowed the field lines to compress even closer together. Scientists believe the field lines are piling up because an interstellar wind outside is pushing back.

Illustration credit: NASA/JPL-Caltech

IC 2184

(This photo brought to you by the letter...)

This large “flying V” is actually two distinct objects — a pair of interacting galaxies known as IC 2184. Both the galaxies are seen almost edge-on in the large, faint northern constellation of Camelopardalis (The Giraffe), and can be seen as bright streaks of light surrounded by the ghostly shapes of their tidal tails.

These tidal tails are thin, elongated streams of gas, dust and stars that extend away from a galaxy into space. They occur when galaxies gravitationally interact with one another, and material is sheared from the outer edges of each body and flung out into space in opposite directions, forming two tails. They almost always appear curved, so when they are seen to be relatively straight, as in this image, it is clear that we are viewing the galaxies side-on.

Also visible in this image are bursts of bright blue, pinpointing hot regions where the stars from both galaxies have begun to crash together during the merger.

The image consists of visible and infrared observations from Hubble’s Wide Field and Planetary Camera 2.

Photo credit: ESA/Hubble & NASA

Habitable Planets Around Red Dwarf Stars

The artist's conception shows a hypothetical planet with two moons orbiting in the habitable zone of a red dwarf star. Using publicly available data from NASA’s Kepler space telescope, astronomers at the Harvard-Smithsonian Center for Astrophysics (CfA) estimate that six percent of red dwarf stars have an Earth-sized planet in the "habitable zone," the range of distances from a star where the surface temperature of an orbiting planet might be suitable for liquid water.

The majority of the sun's closest stellar neighbors are red dwarfs. Researchers now believe that an Earth-size planet with a moderate temperature may be just 13 light-years away.

Astronomers don't know if life could exist on a planet orbiting a red dwarf. However, this finding suggests that the most common type of the star in the galaxy may provide many more cosmic neighborhoods to search for planets that may be like our own.

Illustration credit: D. Aguilar/Harvard-Smithsonian Center for Astrophysics

Note: For more information, see Kepler Data Suggest Earth-size Planets May Be Next Door.

Asteroid 2012 DA14

This movie shows the asteroid 2012 DA14 flying safely by Earth, as seen by the Gingin Observatory in Australia around the time of its closest approach, 11:24:42 a.m. PST (2:24:42 p.m. EST, or 19:24:24 UTC), February 15, 2013.

At that time, the asteroid was about 17,150 miles (27,600 kilometers) above Earth's surface.

The asteroid appears streaked because the telescope was focused on the stars while the asteroid passed through the field of view.

Video credit: Courtesy of Gingin Observatory/Tonello; text credit: NASA/JPL

Note: For more information, see:
* PIA16735: Approach of Asteroid 2012 DA14 from Samford Valley Observatory
* PIA16737: Asteroid 2012 DA14 as Seen from Siding Spring, Australia
* PIA16738: Outbound Near-Earth Asteroid, as Seen from Spain
* Near-Earth Asteroid Makes Preview Appearance
* NASA to Chronicle Close Earth Flyby of Asteroid
* Russia Meteor Not Linked to Asteroid Flyby
* Possible Seismic Activity on Asteroid 2012 DA14

The Chelyabinsk Meteor

Video footage purports to show fragments of a meteorite coming to Earth over Russia after it explodes in the sky. Videos show trails left by the shards across the sky in the Chelyabinsk region and the destruction left on the area's streets. This video has been obtained from Youtube and has not all been independently verified.

Video credit: The Guardian

Note: For more information, see Trace of an Alien Visitor.

The International Space Station (February 2008)

Backdropped by the blackness of space, the International Space Station is seen from Space Shuttle Atlantis as the two spacecraft begin their relative separation. Earlier the STS-122 and Expedition 16 crews concluded almost nine days of cooperative work onboard the Shuttle and Station. Undocking of the two spacecraft occurred at 10:24 CET on 18 February 2008.

Photo credit: NASA

LRLL 54361 and its Surroundings

This infrared image from the NASA/ESA Hubble Space Telescope shows an image of protostellar object LRLL 54361 and its rich cosmic neighborhood, a region called IC 348.

The protostar, which is the bright object with fan-like beams of light coming from it, located towards the right of the image, is letting off flashes of light every 25.3 days.

Photo image: NASA, ESA, and J. Muzerolle (STScI)

Note: For more information, see Hubble Captures Strobe Flashes From a Young Star. Also, PIA16689: Artist's Impression of Pulsating Object LRLL 54361 and PIA16690: Protostar LRLL 54361. Also, NASA Telescopes Discover Strobe-Like Flashes in Young Stars.

Atget Crater

Though Mercury is not known for having an especially colorful surface, some regions show a strong local contrast in color. Like other craters in Caloris, the interior and ejecta of Atget are darker and bluer than the typical brown volcanic plains. These craters help scientists to get a look at the three-dimensional compositional variations with the Caloris basin, and provide a way to judge the thickness of the volcanic plains (over 2 km here!). North is up in this image.

Date acquired: December 09, 2012
Image Mission Elapsed Time (MET): 263555174, 263555178, 263555194
Image ID: 3108404, 3108405, 3108409
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filters: 9, 7, and 6 (996, 748, and 433 nanometers) in red, green, and blue
Center Latitude: 25.92°
Center Longitude: 166.2° E
Resolution: 224 meters/pixel
Scale: Atget is 100 km (62 mi.) in diameter
Incidence Angle: 25.9°
Emission Angle: 52.6°
Phase Angle: 78.5°

Photo credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Comet C/2012 S1 (ISON)

This series of images of comet C/2012 S1 (ISON) was taken by the Medium-Resolution Imager of NASA's Deep Impact spacecraft over a 36-hour period on January 17 and 18, 2013. At the time, the spacecraft was 493 million miles (793 million kilometers) from the comet.

Video credit: NASA/JPL-Caltech/UMD; text credit: NASA/JPL-Caltech

Note: For more information, see NASA's Deep Impact Spacecraft Eyes Comet ISON.

Sharpless 2-296

This image shows the intricate structure of part of the Seagull Nebula, known more formally as IC 2177. These wisps of gas and dust are known as Sharpless 2-296 (officially Sh 2-296) and form part of the “wings” of the celestial bird. This region of the sky is a fascinating muddle of intriguing astronomical objects — a mix of dark and glowing red clouds, weaving amongst bright stars. This new view was captured by the Wide Field Imager on the MPG/ESO 2.2-meter telescope at ESO’s La Silla Observatory in Chile.

Photo credit: ESO

Note: For more information, see The Wings of the Seagull Nebula.

Messier 42 - The Orion Nebula

The Orion nebula is featured in this sweeping image from NASA's Wide-field Infrared Survey Explorer, or WISE. The constellation of Orion is prominent in the evening sky throughout the world from about December through April of each year. The nebula (also cataloged as Messier 42) is located in the sword of Orion, hanging from his famous belt of three stars. The star cluster embedded in the nebula is visible to the unaided human eye as a single star, with some fuzziness apparent to the most keen-eyed observers. Because of its prominence, cultures all around the world have given special significance to Orion. The Maya of Mesoamerica envision the lower portion of Orion, his belt and feet (the stars Saiph and Rigel), as being the hearthstones of creation, similar to the triangular three-stone hearth that is at the center of all traditional Maya homes. The Orion nebula, lying at the center of the triangle, is interpreted by the Maya as the cosmic fire of creation surrounded by smoke.

This metaphor of a cosmic fire of creation is apt. The Orion nebula is an enormous cloud of dust and gas where vast numbers of new stars are being forged. It is one of the closest sites of star formation to Earth and therefore provides astronomers with the best view of stellar birth in action. Many other telescopes have been used to study the nebula in detail, finding wonders such as planet-forming disks forming around newly forming stars. WISE was an all-sky survey giving it the ability to see these sites of star formation in a larger context. This view spans more than six times the width of the full moon, covering a region nearly 100 light-years across. In it, we see the Orion nebula surrounded by large amounts of interstellar dust, colored green.

Astronomers now realize that the Orion nebula is part of the larger Orion molecular cloud complex, which also includes the Flame nebula. This complex in our Milky Way galaxy is actively making new stars. It is filled with dust warmed by the light of the new stars within, making the dust glow in infrared light.

Color in this image represents specific infrared wavelengths. Blue represents light emitted at 3.4-micron wavelengths and cyan (blue-green) represents 4.6 microns, both of which come mainly from hot stars. Relatively cooler objects, such as the dust of the nebulae, appear green and red. Green represents 12-micron light and red represents 22-micron light.

Image credit: NASA/JPL-Caltech/UCLA

Note: For more information, see WISE Feels the Heat from Orion's Sword.

Smooth vs. Fragmented Stellar Winds

Artist's impression comparing a smooth stellar wind (left) with a highly fragmented stellar wind (right) of a massive star like Zeta Puppis. A decade's-worth of observations with ESA's XMM-Newton have revealed that the wind of Zeta Puppis is fragmented into hundreds of thousands of individual hot (red) and cool (blue) clumps. Studying stellar winds is vital not only to understand mass loss from the star itself and thus its expected lifetime, but also how the winds inject material and energy into the surrounding environment and influence the birth and death of other stars.

Illustration credit: ESA - C. Carreau/Nazé et al.

Notes: For more information, see Massive Stellar Winds are Made of Tiny Pieces. Also, for a much larger TIFF file of the above illustration, see New View of Stellar Winds.

Messier 106

This image combines Hubble observations of M 106 with additional information captured by amateur astronomers Robert Gendler and Jay GaBany. Gendler combined Hubble data with his own observations to produce this stunning color image.

M 106 is a relatively nearby spiral galaxy, a little over 20 million light-years away.

Photo credit: NASA, ESA, the Hubble Heritage Team (STScI/AURA), and R. Gendler (for the Hubble Heritage Team). Acknowledgment: J. GaBany, A. van der Hoeven

Note: For more information, see A Spiral Galaxy With a Secret. Also, Hubble view of M 106.

ESO 121-6

This thin, glittering streak of stars is the spiral galaxy ESO 121-6, which lies in the southern constellation of Pictor (The Painter's Easel). Viewed almost exactly side-on, the intricate structure of the swirling arms is hidden, but the full length of the galaxy can be seen — including the intense glow from the central bulge, a dense region of tightly packed young stars sitting at the center of the spiral arms.

Tendrils of dark dust can be seen across the frame, partially obscuring the bright center of the galaxy and continuing out towards the smattering of stars at its edges, where the dust lanes and shapes melt into the inky background. Numerous nearby stars and galaxies are visible as small smudges in the surrounding sky, and the brightest stars are dazzlingly prominent towards the bottom left of the image.

ESO 121-6 is a galaxy with patchy, loosely wound arms and a relatively faint central bulge. It actually belongs to a group of galaxies, a clump of no more than 50 similar structures all loosely bound to one another by gravity. The Milky Way is also a member of a galactic group, known as the Local Group.

Photo credit: ESA/Hubble & NASA

Protoplanetary Disk Around TW Hydrae

This illustration depicts the protoplanetary disc around the nearby young star TW Hydrae. With an age of about ten million years, TW Hydrae is located about 180 light-years away, towards the constellation Hydra, or the Sea Serpent.

Protoplanetary discs form around young stars from leftover material from the stellar formation process, which consists mainly of molecular hydrogen gas. This material orbits the star in a protoplanetary disc for several millions of years before it condenses into planets or is dispersed away by winds driven by the radiation of the star. In addition, trace amounts of cosmic dust and other gas species are present in the disc.

Astronomers using ESA's Herschel Space Observatory detected heavy molecular hydrogen in the protoplanetary disc around TW Hydrae, and have used this molecule as a tracer of the disc's main constituent – molecular hydrogen. This study has yielded the first accurate determination of the mass of a protoplanetary disc. With a mass equivalent to 50 times that of Jupiter, the disc around TW Hydrae is several times more massive than the primordial disc that gave birth to our Solar System.

At about ten million years, TW Hydrae is a relatively young star, but quite old to have retained a massive protoplanetary disc. The extremely accurate estimate of the disc's mass will benefit future observations of TW Hydrae and its environment, as astronomers investigate the various scenarios that could eventually lead to the formation of planets around this star.

Illustration credit: ESA/C. Carreau

Note: For more information, see Herschel Sizes Up Massive Protoplanetary Disc. Also, see PIA16683: Weighing Planetary Disks and Herschel Finds Past-Prime Star May Be Making Planets. Another post about TW Hydrae can be found here: Misty Star in the Sea Serpent.

Curiosity on Sol 157

This HiRISE observation was performed in conjunction with a CRISM observation so that they could get good spectral data on the scour zone created by the MSL descent rockets.

Our higher resolution HiRISE image will allow the CRISM team to compare their data with ours. The scour zone is where MSL touched down. The pair of bright white spots in the HiRISE image show the area immediately below where sky crane's rockets were pointed. Those areas were "blasted clean" and therefore show brightest. The larger dark scour zone is dark because the fine dust has been blown away from the area leaving darker materials.

However, we also captured Curiosity on its 157th Sol as it was exploring Yellowknife Bay and about to drill its first rock.

This is the first time that we've captured the rover tracks in color, and they show up as a pair of dark lines moving across the landscape.

Note: the above image is non map-projected, so approximate north is down.

Photo credit: NASA/JPL/University of Arizona

The Ionosphere of Venus Under Different Solar Wind Conditions

A comparison of the ionosphere of Venus under different solar wind conditions. The yellow lines indicate the solar magnetic field lines as they interact with the ionosphere.

When the solar wind's dynamic pressure is normal (left image) the ionosphere is confined to a region 150-300 km above the planet's day side. Positively charged particles (ions) travel quite quickly across the day-night terminator to create a similar ionosphere on the planet's night side.

When the solar wind pressure drops to a very low level (right image), the ionosphere expands to a higher altitude above the day side of Venus and weaker magnetic fields are created above the terminator. As a result, the region across which ions are able to travel from the day side to the night side becomes larger. This makes it easier for ions to flow across the terminator. Although the weaker pressure of the solar wind reduces the speed at which the ions travel toward the night side, the first effect outweighs the second, enabling the ionosphere to expand in the planet's wake. Observations from Venus Express show that the night-side ionosphere moved outward to at least 15,000 km from Venus' center over a period of only a few hours, creating a long, comet-like tail.

Illustration credit: ESA/Wei et al (2012)

Note: For more information, see The Tail of Venus and the Weak Solar Wind and Comet-Like Ionosphere at Venus.

Apollo 16 Lunar Rover Grand Prix

Apollo 16 astronauts John Young and Charlie Duke take the lunar rover for a spin on the surface of the moon in this film footage of what became known as the "lunar rover Grand Prix". This footage was shot on 16mm film and is silent.

Video credit: NASA

DEM L50

DEM L50: A superbubble located in the Large Magellanic Cloud about 160,000 light years from Earth.

DEM L50 (a.k.a. N186) is what astronomers call a superbubble. These objects are found in regions where massive stars have formed, raced through their evolution, and exploded as supernovas. The winds and shock waves from the supernovas carve out huge cavities in the gas and dust around them, creating superbubbles. This composite contains X-rays from Chandra (pink) and optical data from ground-based telescopes (red, green, and blue). The superbubble in DEM L50 is giving off about 20 times more X-rays than expected by standard models. Researchers think supernova shock waves striking the walls of the cavities and hot material evaporating from the cavity walls may be responsible for this additional X-ray emission.

Scale: Image is 20.5 arcmin (950 light years)

Image credit: X-ray: NASA/CXC/Univ of Michigan/A.E.Jaskot, Optical: NOAO/CTIO/MCELS

Note: For more information, see DEM L50: Stellar Effervescence on Display

Galaxy 2MASX J09442693+0429569

Galaxy 2MASX J09442693+0429569 imaged by Hubble. This elliptical galaxy has entered a transitional phase from a young, star-forming galaxy to an older, larger, "red and dead" galaxy. Here, two galaxies have collided, exhausting the gases in the surrounding area and stopping the process of star birth. By contrast, as Hubble looks deeper into the Universe, galaxies show much more vigorous star birth. A merger is also predicted to happen between our own Milky Way Galaxy and neighboring Andromeda in about four billion years.

Photo credit: ESA/Hubble & NASA, Acknowledgement: A. Zabludoff, N. Rose

Two New Views of the Andromeda Galaxy

In this new view of the Andromeda galaxy from the Herschel space observatory, cool lanes of forming stars are revealed in the finest detail yet. Herschel is a European Space Agency mission with important NASA participation.

Andromeda, also known as M31, is the nearest major galaxy to our own Milky Way at a distance of 2.5 million light-years, making it an ideal natural laboratory to study star formation and galaxy evolution.

Sensitive to the far-infrared light from cool dust mixed in with the gas, Herschel seeks out clouds of gas where stars are born. The new image reveals some of the very coldest dust in the galaxy -- only a few tens of degrees above absolute zero -- colored red in this image.

By comparison, warmer regions such as the densely populated central bulge, home to older stars, take on a blue appearance.

Intricate structure is present throughout the 200,000-light-year-wide galaxy with star-formation zones organized in spiral arms and at least five concentric rings, interspersed with dark gaps where star formation is absent.

Andromeda is host to several hundred billion stars. This new image of it clearly shows that many more stars will soon to spark into existence.

The ring-like swirls of dust filling the Andromeda galaxy stand out colorfully in this new image from the Herschel Space Observatory, a European Space Agency mission with important NASA participation.

The glow seen here comes from the longer-wavelength, or far, end of the infrared spectrum, giving astronomers the chance to identify the very coldest dust in our galactic neighbor. These light wavelengths span from 250 to 500 microns, which are a quarter to half of a millimeter in size. Herschel's ability to detect the light allows astronomers to see clouds of dust at temperatures of only a few tens of degrees above absolute zero. These clouds are dark and opaque at shorter wavelengths. The Herschel view also highlights spokes of dust between the concentric rings.

The colors in this image have been enhanced to make them easier to see, but they do reflect real variations in the data. The very coldest clouds are brightest in the longest wavelengths, and colored red here, while the warmer ones take on a bluish tinge.

These data, together with those from other observatories, reveal that other dust properties, beyond just temperature, are affecting the infrared color of the image. Clumping of dust grains, or growth of icy mantles on the grains towards the outskirts of the galaxy, appear to contribute to these subtle color variations.

These observations were made by Herschel's spectral and photometric imaging receiver (SPIRE) instrument. The data were processed as part of a project to improve methods for assembling mosaics from SPIRE observations. Light with a wavelength of 250 microns is rendered as blue, 350-micron is green, and 500-micron light is red. Color saturation has been enhanced to bring out the small differences at these wavelengths.

Top Image Credit: ESA/Herschel/PACS & SPIRE Consortium, O. Krause, HSC, H. Linz
Bottom Image Credit: ESA/NASA/JPL-Caltech/NHSC

Note: For more information, see Cool Andromeda, PIA16681: Andromeda's Colorful Rings and Cool, New Views of Andromeda Galaxy.

Venus

False-color image of cloud features seen on Venus by the Venus Monitoring Camera (VMC) on Venus Express. The image was captured from a distance of 30,000 km on 8 December 2011.

Photo credit: ESA/MPS/DLR/IDA