Two States of Pulsar PSR B0943+10

This illustration shows the two states of emission observed from pulsar PSR B0943+10, which is well known for switching between a 'bright' and 'quiet' mode at radio wavelengths. Observations of PSR B0943+10, performed simultaneously with ESA's XMM-Newton X-ray observatory and ground-based radio telescopes, revealed that this source exhibits variations in its X-ray emission that mimic in reverse the changes seen in radio waves. No current model is able to predict what could cause such sudden and drastic changes to the pulsar's entire magnetosphere and result in such a curious emission.

In the upper part of the illustration, the artist's impression on the left shows the pulsar with glowing cones of radiation stemming from its magnetic poles – a state referred to as 'radio-bright' mode. Radio emission from pulsars is known to arise from these cones, and we see it pulsate because the pulsar's rotation and magnetic axes are misaligned. The graphs on the right side show data from X-ray observations, performed with XMM-Newton (upper graph), and from radio observations, performed with the Low Frequency Array (LOFAR; lower graph). The upper graph shows that, in the 'radio-bright' mode, the pulsar does not shine brightly in X-rays. The lower graph shows a bright and pulsating emission at radio wavelengths.

In the lower part of the illustration, the artist's impression on the left shows the pulsar in a different state, with glowing 'hot-spots' that are located at its magnetic poles. In particular, the illustration shows the pulsar in a state characterized by bright X-ray emission, arising from the polar caps, and relatively low radio emission from the cones that stem from the pulsar's magnetic poles ('X-ray-bright/radio-quiet' mode). The graphs on the right side show how, in this mode, the pulsar exhibits a brighter and pulsating X-ray emission, whereas the radio emission is fainter but still pulsating.

Illustration credit: ESA/ATG medialab; ESA/XMM-Newton; ASTRON/LOFAR

Note: For more information, see Baffling Pulsar Leaves Astronomers in the Dark.

NGC 1999

A new image from the Atacama Pathfinder Experiment (APEX) telescope in Chile shows a beautiful view of clouds of cosmic dust in the region of Orion. While these dense interstellar clouds seem dark and obscured in visible-light observations, APEX’s LABOCA camera can detect the heat glow of the dust and reveal the hiding places where new stars are being formed. The image shows the region around the reflection nebula NGC 1999 in visible light, with the APEX observations overlaid in brilliant orange tones that seem to set the dark clouds on fire.

Image credit: ESO/APEX (MPIfR/ESO/OSO)/T. Stanke et al./Digitized Sky Survey 2

Note: For more information, see Setting the Dark on Fire.

Arctic Sea Ice: 1978-2010

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Time series of Arctic sea ice concentration in September from 1978 to 2010.

Video credit: ESA/DLR

Dark Materials in Vesta's Southern Hemisphere

This map shows the distribution of dark materials throughout the southern hemisphere of the giant asteroid Vesta. The circles, diamonds, and stars show where the dark material appears in craters, spots and topographic highs. The dashed line depicts the rim of the Veneneia basin, the black line the rim of the younger Rheasilvia basin.

The red and white indicate high topography and blue and violet indicate low topography.

Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Note: For more information, see Picture This: Vesta's Dark Materials in Dawn's View.

A Day in the Life of Venus Express

The movie begins from a staggering 66,000 km above the south pole, staring down into the swirling south polar vortex. From this bird’s-eye view, half of the planet is in darkness, the ‘terminator’ marking the dividing line between the day and night sides of the planet.

The movie is based on images snapped by the Venus Monitoring Camera over a period of 18 hours during one of the spacecraft’s 24-hour orbits around the planet on 7–8 January last year. The video was compiled using public data from the Venus Express data archive and was released as an ESA space science image of the week feature.

Video credit: ESA/MPS/DLR/IDA, M. Pérez-Ayúcar & C. Wilson. Text credit: ESA (1) and ESA (2).

Sizes of Kepler Exoplanet Candidates

Since the last Kepler catalog was released in February 2012, the number of candidates discovered in the Kepler data has increased by 20 percent and now totals 2,740 potential planets orbiting 2,036 stars. Based on observations conducted May 2009 to March 2011, the most dramatic increases are seen in the number of Earth-size and super Earth-size candidates discovered, which grew by 43 and 21 percent respectively.

Scientists analyzed more than 13,000 transit-like signals called 'threshold crossing events' to eliminate known spacecraft instrumentation and astrophysical false positives, phenomena that masquerade as planetary candidates, to identify the potential new planets.

The complete list of Kepler planet candidates is available in an interactive table at the NASA Exoplanet Archive. The archive is funded by NASA's Exoplanet Exploration Program to collect and make public data to support the search for and characterization of exoplanets and their host stars.

Illustration credit: NASA/Ames/JPL-Caltech

Note: For more information, see Billions and Billions of Planets; also, NASA's Kepler Discovers 461 New Planet Candidates.

Betelgeuse

The red supergiant star Betelgeuse is seen here in a new view from the Herschel Space Observatory, a European Space Agency mission with important NASA participation.

Betelgeuse (center) is surrounded by a clumpy envelope of material in its immediate vicinity. The arcs to the left are material ejected from the star as it evolved into a red supergiant, and were shaped by its bow shock interaction with the interstellar medium. A faint linear bar of dust is illuminated at left, and may represent a dusty filament connected to the local galactic magnetic field, or the edge of an interstellar cloud. If so, then Betelgeuse's motion across the sky implies that the arcs will hit the wall in 5,000 years time, with the star itself colliding with the wall 12,500 years later.

This image was taken by Herschel's Photodetecting Array Camera and Spectrometer (PACS).

Photo credit: ESA/Herschel/PACS/L. Decin et al.

Note: For more information, see Betelgeuse’s Enigmatic Environment and Betelgeuse Star Braces for Crash with Strange Bar.

Dunes in a Noachis Terra Crater

Sand dunes on Mars are studied for many reasons. Recent investigations have focused on dune and ripples movement.

In this observation, we look at dunes within a crater in Noachis Terra. Zooming in to one of these areas (and here is the context image) we see the edges of two dunes separated by a field of ripples and rocks. We can compare this area to another image taken two Mars years ago. In the older image, there are many dark wispy features that cover the dunes. These are dust devil tracks, which formed when vortices removed a thin layer of dust off the surface, revealing a darker substrate.

In addition, there are dark sand streaks extending westward from the eastern dune. Blinking between these images shows that virtually all traces of the dust devil tracks and dark streaks have disappeared in the two Mars years. There is also little evidence for dune or ripple movement (however, these images have not yet been orthorectified for a detailed analysis).

In this region, it is likely that dust is periodically deposited and then removed off the dunes. The presence of dust may shield the dunes and ripples from significant movement, such that the observed changes are but thin layers of dust being removed and minor sand streaks that blow off the dunes.

This is a stereo pair with ESP_030080_1245.

Photo credit: NASA/JPL/University of Arizona

Note: The "blink" images, mentioned above, are well worth looking at. Here is the gif file below:

Orion Service Module

This artist's concept of the Orion Service Module was introduced today. When the Orion spacecraft blasts off atop NASA’s Space Launch System rocket in 2017, attached will be the ESA-provided service module – the powerhouse that fuels and propels the Orion spacecraft.

Orion will be the most advanced spacecraft ever designed and carry astronauts farther into space than ever before. It will sustain astronauts during space travel and provide safe re-entry from deep space and emergency abort capability. Orion will be launched by NASA's Space Launch System (SLS), a heavy-lift rocket that will provide an entirely new capability for human exploration beyond low Earth orbit. Designed to be flexible for launching spacecraft for crew and cargo missions, SLS will enable new missions of exploration and expand human presence across the solar system.

The service module of the Orion spacecraft will provide support to the crew module from launch through separation prior to atmospheric re-entry.

Image Credit: NASA

Note: For more information, see Orion.

LHA 120-N11 in the Large Magellanic Cloud

Nearly 200,000 light-years from Earth, the Large Magellanic Cloud, a satellite galaxy of the Milky Way, floats in space, in a long and slow dance around our galaxy. As the Milky Way's gravity gently tugs on its neighbor's gas clouds, they collapse to form new stars. In turn, these light up the gas clouds in a kaleidoscope of colors, visible in this image from the NASA/ESA Hubble Space Telescope.

Photo credit: NASA, ESA. Acknowledgment: Josh Lake

Note: For more information, see A Hidden Treasure in the Large Magellanic Cloud.

Curiosity's Tracks in Gale Crater

This image was acquired for color coverage of the region that the Curiosity rover may explore, but we acquired some extra RED (monochromatic) coverage of the rover tracks.

This image shows the entire distance traveled from the landing site (dark smudge at left) to its location as of 2 January 2013 (the rover is bright feature at right). The tracks are not seen where the rover has recently driven over the lighter-toned surface, which may be more indurated than the darker soil.

Photo credit: NASA/JPL/University of Arizona

Lupus 3 Nebula and Associated Stars

This evocative image shows a dark cloud where new stars are forming along with a cluster of brilliant stars that have already emerged from their dusty stellar nursery. This cloud is known as Lupus 3 and it lies about 600 light-years from Earth in the constellation of Scorpius (The Scorpion). It is likely that the Sun formed in a similar star formation region more than four billion years ago. This picture was taken with the MPG/ESO 2.2-meter telescope at the La Silla Observatory in Chile and is the best image ever taken of this little-known object.

Photo credit: ESO/F. Comeron

Note: For more information, see Light from the Darkness.

New Blue Impact Crater on Mercury

In the lower left portion of today's image is a small, young, rayed impact crater. The rays have a typical bluish cast in this color presentation. The relatively blue color in this case is caused partly by the extreme youth of the rays (surfaces exposed to the space environment of Mercury for long periods tend to "redden" and darken). In addition, the crater formed in a dark, bluish terrain called the "Low Reflectance Material." The tan area toward the top of the image is "intermediate terrain."

Date acquired: November 30, 2011
Image Mission Elapsed Time (MET): 231181189, 231181209, 231181193
Image ID: 1078917, 1078922, 1078918
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filters: 9, 7, 6 (996, 748, 433 nanometers) in red, green, and blue.
Center Latitude: -34.19°
Center Longitude: 133.6° E
Resolution: 647 meters/pixel
Scale: The small rayed crater is about 16 km (10 mi.) in diameter.
Incidence Angle: 54.9°
Emission Angle: 3.9°
Phase Angle: 58.7°

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

NGC 6872

This composite of the giant barred spiral galaxy NGC 6872 combines visible light images from the European Southern Observatory's Very Large Telescope with far-ultraviolet (1,528 angstroms) data from NASA's GALEX and 3.6-micron infrared data acquired by NASA's Spitzer Space Telescope. A previously unsuspected tidal dwarf galaxy candidate (circled) appears only in the ultraviolet, indicating the presence of many hot young stars. IC 4970, the small disk galaxy interacting with NGC 6872, is located above the spiral's central region. The spiral is 522,000 light-years across from the tip of one outstretched arm to the tip of the other, which makes it about five times the size of our home galaxy, the Milky Way. Images of lower resolution from the Digital Sky Survey were used to fill in marginal areas not covered by the other data.

Photo credit: NASA's Goddard Space Flight Center/ESO/JPL-Caltech/DSS

Note: For more information, see NASA's Galex Reveals the Largest-Known Spiral Galaxy and PIA16613: Dwarf Galaxy Spotted.

The Huygens Experience

Eight years ago today [14 January 2013], ESA’s Huygens bounced, slid and wobbled its way to rest on the surface of Saturn’s moon Titan, the first time a probe had touched down on an alien world in the outer Solar System.

The animation was created using real data recorded by Huygen’s instruments, allowing us to witness this historical moment as if we had been there.

The animation takes into account Titan’s atmospheric conditions, including the Sun and wind direction, the behavior of the parachute (with some artistic interpretation only on the movement of the ropes after touchdown), and the dynamics of the landing itself.

Even the stones immediately facing Huygens were rendered to match the photograph of the landing site returned from the probe, which is revealed at the end of the animation.

Split into four sequences, the animation first shows a wide-angle view of the descent and landing followed by two close-ups of the touchdown from different angles, and finally a simulated view from Huygens itself – the true Huygens experience.

New results published last year revealed that on first contact with Titan’s surface, Huygens dug a hole 12 cm deep, before bouncing out and sliding 30–40 cm across a flat surface.

The probe then wobbled back and forth five times until coming to a standstill about 10 seconds after touchdown – this is best seen in the final two sequences.

A ‘fluffy’ dust-like material – most likely organic aerosols that are known to drizzle out of the Titan atmosphere – was thrown up and suspended for around four seconds around the probe following the impact. The dust was easily lifted, suggesting it was most likely dry and that there had not been any ‘rain’ of liquid ethane or methane for some time prior to the landing.

Huygens was released from the international Cassini spacecraft on Christmas Day 2004, arriving at Titan three weeks later. Cassini has been in orbit around Saturn since July 2004, and will continue operations until 2017.

Video credit: ESA. Text credit: ESA.

Note: For more information, see When Huygens Met Titan.

Cloudless British Isles

The lush landscapes of Ireland, Great Britain and northern France are pictured in this rare cloud-free view, acquired by Envisat on 28 March 2012.

To the west, thousands of lakes speckle the island of Ireland. Brown rugged cliffs along the coast frame its plush green interior. In the lower-right corner, the river Seine flows through Paris (seen here as a gray area) and snakes toward the English Channel. Following mainland Europe’s coastline north, we can see the Rhine–Meuse–Scheldt delta followed by part of the intertidal Wadden Sea in the extreme top-right corner. The green and tan-tinted swirls in the seas and channels are due to sediments being transported in the water. Sediment is particularly concentrated around Britain’s southeastern coast, carried by the River Thames through London and into the North Sea.

This image is featured on the Earth from Space video program.

Photo credit: ESA

Vela Pulsar Jet

Vela Pulsar Jet: A jet of high-energy particles associated with the Vela pulsar, a rapidly rotating neutron star about 1,000 light years from Earth in the constellation Vela.

This deep image from NASA's Chandra X-ray Observatory shows the Vela pulsar, a neutron star that was formed when a massive star collapsed. In the upper right is a fast moving jet of particles produced by the pulsar. The pulsar is about 1,000 light years from Earth, and makes over 11 complete rotations every second. As the pulsar spins, it spews out a jet of charged particles that race out along the pulsar’s rotation axis at about 70% of the speed of light. A movie shows dramatic changes in the jet, suggesting that the pulsar may be slowly wobbling, or precessing, as it spins. If this evidence is confirmed, it would be the first time that a neutron star has been found to be precessing. In this image the jet's shape is blurred because images at different times have been added together.

Scale: Movie is 4.8 x 3.6 arcmin (1.4 x 1.0 light years).

Video credit: NASA/CXC/Univ of Toronto/M.Durant et al.

Note: For more information, see Vela Pulsar Jet: New Chandra Movie Features Neutron Star Action.

47 Tucanae

This bright cluster of stars is 47 Tucanae (NGC 104), shown here in an image taken by ESO’s VISTA (Visible and Infrared Survey Telescope for Astronomy) from the Paranal Observatory in Chile. This cluster is located around 15,000 light-years away from us and contains millions of stars, some of which are unusual and exotic. This image was taken as part of the VISTA Magellanic Cloud survey, a project that is scanning the region of the Magellanic Clouds, two small galaxies that are very close to our Milky Way.

Credit: ESO/M.-R. Cioni/VISTA Magellanic Cloud Survey. Acknowledgment: Cambridge Astronomical Survey Unit.

Note: For more information, see A Jumble of Exotic Stars.

Brown Dwarf 2MASSJ22282889-431026

This artist's conception illustrates the brown dwarf named 2MASSJ22282889-431026. NASA's Hubble and Spitzer space telescopes observed the object to learn more about its turbulent atmosphere. Brown dwarfs are more massive and hotter than planets but lack the mass required to become sizzling stars. Their atmospheres can be similar to the giant planet Jupiter's.

Spitzer and Hubble simultaneously observed the object as it rotated every 1.4 hours. The results suggest wind-driven, planet-size clouds.

Illustration credit: NASA/JPL-Caltech

Note: For more information, see PIA16608: Anatomy of Brown Dwarf's Atmosphere (Artist Concept), PIA16612: Probing Brown Dwarf Layers, and NASA Telescopes See Weather Patterns in Brown Dwarf.

Possible Hydrocarbon Ice in Titan's Lakes

Lakes on Saturn's moon Titan reflect radio waves in varying ways in this image from NASA's Cassini spacecraft. Scientists think the variations in reflectivity, or brightness, have to do with the smoothness or texture of the surface. If a lake is fully liquid, it looks dark, but if it is only partially liquid, it looks brighter.

In this image taken from Titan's high northern latitudes on May 22, 2012, the lakes on the left are full of liquid hydrocarbons and the lakes on the top right are only partially filled, or represent saturated ground (i.e., a mudflat). The lakes in this image are each about 35 to 45 kilometers (22 to 30 miles) across, or about the size of Lake Tahoe on the California-Nevada border. Some of the differences in reflectivity could also be explained by the presence of floating hydrocarbon ice.

This image was obtained by Cassini's radar mapper at a scale of about 350 meters (1,100 feet) per pixel. It is presented in polar stereographic projection with a logarithmic stretch.

For perspective, a wider view of these lakes can be seen in PIA16167.

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

Note: For more information, see PIA16634: Floating Ice on Titan Lakes? and Cassini Suggests Icing on a Lake.

Asteroid Belts in the Vega System

Astronomers have discovered what appears to be a large asteroid belt around the bright star Vega, as illustrated here at left in brown. The ring of warm, rocky debris was detected using NASA's Spitzer Space Telescope, and the European Space Agency's Herschel Space Observatory, in which NASA plays an important role.

In this diagram, the Vega system, which was already known to have a cooler outer belt of comets (orange), is compared to our solar system with its asteroid and Kuiper belts. The relative size of our solar system compared to Vega is illustrated by the small drawing in the middle. On the right, our solar system is scaled up four times.

The comparison illustrates that both systems have inner and outer belts with similar proportions. The gap between the inner and outer debris belts in both systems works out to a ratio of about 1-to-10, with the outer belt 10 times farther away from its host star than the inner belt.

Astronomers think that the gap in the Vega system may be filled with planets, as is the case in our solar system.

Image credits: Upper: NASA/JPL-Caltech; Lower: NASA/JPL-Caltech

Note: For more information, see NASA, ESA Telescopes Find Evidence for Asteroid Belt Around Vega.

Seeing this material, the Minister can't help but think of the movie Contact, which takes place (at the very end of the movie) on a planet in the Vega system. Calling Jodie Foster! :)

IC 342

This new view of spiral galaxy IC 342, also known as Caldwell 5, includes data from NASA's Nuclear Spectroscopic Telescope Array, or NuSTAR. High-energy X-ray data from NuSTAR have been translated to the color magenta, and superimposed on a visible-light view highlighting the galaxy and its star-studded arms. NuSTAR is the first orbiting telescope to take focused pictures of the cosmos in high-energy X-ray light; previous observations of this same galaxy taken at similar wavelengths blurred the entire object into one pixel.

The two magenta spots are blazing black holes first detected at lower-energy X-ray wavelengths by NASA's Chandra X-ray Observatory. With NuSTAR's complementary data, astronomers can start to home in on the black holes' mysterious properties. The black holes appear much brighter than typical stellar-mass black holes, such as those that pepper our own galaxy, yet they cannot be supermassive black holes or they would have sunk to the galaxy's center. Instead, they may be intermediate in mass, or there may be something else going on to explain their extremely energetic state. NuSTAR will help solve this puzzle.

IC 342 lies 7 million light-years away in the Camelopardalis constellation. The outer edges of the galaxy cannot be seen in this view.

This image shows NuSTAR X-ray data taken at 10 to 35 kiloelectron volts.

The visible-light image is from the Digitized Sky Survey.

Photo credit:
NASA/JPL-Caltech/DSS

Note: For more information, see NASA's NuSTAR Catches Black Holes in Galaxy Web.

Cassiopeia A by NuSTAR

This new view of the historical supernova remnant Cassiopeia A, located 11,000 light-years away, was taken by NASA's Nuclear Spectroscopic Telescope Array, or NuSTAR. Blue indicates the highest energy X-ray light, where NuSTAR has made the first resolved image ever of this source. Red and green show the lower end of NuSTAR's energy range, which overlaps with NASA's high-resolution Chandra X-ray Observatory.

Light from the stellar explosion that created Cassiopeia A is thought to have reached Earth about 300 years ago, after traveling 11,000 years to get here. While the star is long dead, its remains are still bursting with action. The outer blue ring is where the shock wave from the supernova blast is slamming into surrounding material, whipping particles up to within a fraction of a percent of the speed of light. NuSTAR observations should help solve the riddle of how these particles are accelerated to such high energies

X-ray light with energies between 10 and 20 kiloelectron volts are blue; X-rays of 8 to 10 kiloelectron volts are green; and X-rays of 4.5 to 5.5 kiloelectron volts are red.

The starry background picture is from the Digitized Sky Survey.

Photo credit: NASA/JPL-Caltech/DSS

Sharpless 2-64 (aka W 40)

Six hundred newly forming stars are crowded into these colorful filaments of dust that form a stellar nursery seen by ESA’s Herschel space observatory.

The nebulous blue area, known as W40 or Sharpless 2-64, is roughly 1000 light-years away in the constellation Aquila, and is about 25 light-years across.

Photo credit: ESA and SPIRE & PACS consortia, Ph. André (CEA Saclay) for Gould’s Belt Key Programme Consortia

NGC 604 in Messier 33

Stars are sometimes born in the midst of chaos. About 3 million years ago in the nearby galaxy M33, a large cloud of gas spawned dense internal knots which gravitationally collapsed to form stars. NGC 604 was so large, however, it could form enough stars to make a globular cluster.

Many young stars from this cloud are visible in this image from the Hubble Space Telescope, along with what is left of the initial gas cloud. Some stars were so massive they have already evolved and exploded in a supernova. The brightest stars that are left emit light so energetic that they create one of the largest clouds of ionized hydrogen gas known, comparable to the Tarantula Nebula in our Milky Way's close neighbor, the Large Magellanic Cloud.

Photo credit: NASA

NGC 1097

The Hubble Space Telescope captured a spectacular image of the bright star-forming ring that surrounds the heart of the barred spiral galaxy NGC 1097. In this image, the larger-scale structure of the galaxy is barely visible: its comparatively dim spiral arms, which surround its heart in a loose embrace, reach out beyond the edges of this frame.

This face-on galaxy, lying 45 million light-years away from Earth in the southern constellation of Fornax (The Furnace), is particularly attractive for astronomers. NGC 1097 is a Seyfert galaxy. Lurking at the very center of the galaxy, a supermassive black hole 100 million times the mass of our sun is gradually sucking in the matter around it. The area immediately around the black hole shines powerfully with radiation coming from the material falling in.

The distinctive ring around the black hole is bursting with new star formation due to an inflow of material toward the central bar of the galaxy. These star-forming regions are glowing brightly thanks to emission from clouds of ionized hydrogen. The ring is around 5000 light-years across, although the spiral arms of the galaxy extend tens of thousands of light-years beyond it.

Photo credit: NASA/ESA/Hubble

Solar Eruption

A solar eruption gracefully rose up from the sun on December 31, 2012, twisting and turning. Magnetic forces drove the flow of plasma, but without sufficient force to overcome the sun’s gravity much of the plasma fell back into the sun.

The length of the eruption extends about 160,000 miles out from the Sun. With Earth about 7,900 miles in diameter, this relatively minor eruption is about 20 times the diameter of our planet.

› See video and relative size of Earth to eruption on 'Solar Ballet on the Sun' feature.

Image credit: NASA/SDO

Lunar Gravity Map by Grail

This image shows the variations in the lunar gravity field as measured by NASA's Gravity Recovery and Interior Laboratory (GRAIL) during the primary mapping mission from March to May 2012. Very precise microwave measurements between two spacecraft, named Ebb and Flow, were used to map gravity with high precision and high spatial resolution. The field shown resolves blocks on the surface of about 12 miles (20 kilometers) and measurements are three to five orders of magnitude improved over previous data. Red corresponds to mass excesses and blue corresponds to mass deficiencies. The map shows more small-scale detail on the far side of the moon compared to the nearside because the far side has many more small craters.

› See video

Image credit: NASA/JPL-Caltech/MIT/GSFC

ALMA Observations of the Disc and Gas Streams Around HD 142527

Observations made with the Atacama Large Millimeter/submillimeter Array (ALMA) telescope of the disc of gas and cosmic dust around the young star HD 142527, showing vast streams of gas flowing across the gap in the disc. These are the first direct observations of these streams, which are expected to be created by giant planets guzzling gas as they grow, and which are a key stage in the birth of giant planets.

The dust in the outer disc is shown in red. Dense gas in the streams flowing across the gap, as well as in the outer disc, is shown in green. Diffuse gas in the central gap is shown in blue. The gas filaments can be seen at the three o'clock and ten o'clock positions, flowing from the outer disc towards the center. The dense gas observed is HCO+, and the diffuse gas is CO. The outer disk is roughly two light-days across. If this were our own Solar System, the Voyager 1 probe — the most distant manmade object from Earth — would be at approximately the inner edge of the outer disk.

Image credit: ALMA (ESO/NAOJ/NRAO), S. Casassus et al.

Note: For more information, see ALMA Sheds Light on Planet-Forming Gas Streams.

Gas Bridge Between Abell 399 and Abell 401

Planck has discovered a bridge of hot gas that connects galaxy clusters Abell 399 (lower center) and Abell 401 (top left). The galaxy pair is located about a billion light-years from Earth, and the gas bridge extends approximately 10 million light-years between them.

The image shows the two galaxy clusters as seen at optical wavelengths with ground-based telescopes and through the Sunyaev-Zel'dovich effect (in orange) with the Planck satellite.

Image credits: Sunyaev–Zel’dovich effect: ESA Planck Collaboration; optical image: STScI Digitized Sky Survey

ESO 499-G37

The Hubble Space Telescope has spotted the spiral galaxy ESO 499-G37, seen here against a backdrop of distant galaxies, scattered with nearby stars.

The galaxy is viewed from an angle, allowing Hubble to reveal its spiral nature clearly. The faint, loose spiral arms can be distinguished as bluish features swirling around the galaxy’s nucleus. This blue tinge emanates from the hot, young stars located in the spiral arms. The arms of a spiral galaxy have large amounts of gas and dust, and are often areas where new stars are constantly forming.

The galaxy’s most characteristic feature is a bright elongated nucleus. The bulging central core usually contains the highest density of stars in the galaxy, where typically a large group of comparatively cool old stars are packed in this compact, spheroidal region.

One feature common to many spiral galaxies is the presence of a bar running across the center of the galaxy. These bars are thought to act as a mechanism that channels gas from the spiral arms to the center, enhancing the star formation.

Image credit: NASA/Hubble