This infrared image from NASA's Wide-field Infrared Survey Explorer, or WISE, shows a cosmic rosebud blossoming with new stars. The stars, called the Berkeley 59 cluster, are the blue dots to the right of the image center. They are ripening out of the dust cloud from which they formed, and at just a few million years old, are young on stellar time scales.
The rosebud-like red glow surrounding the hot, young stars is warm dust heated by the stars. Green "leafy" nebulosity enfolds the cluster, showing the edges of the dense, dusty cloud. This green material is from heated polycyclic aromatic hydrocarbons, molecules that can be found on Earth in barbecue pits, exhaust pipes and other places where combustion has occurred.
Red sources within the green nebula indicate a second generation of stars forming at the surface of the natal cloud, possibly as a consequence of heating and compression from the younger stars. A supernova remnant associated with this region, called NGC 7822, indicates that a massive star has already exploded, blowing the cloud open in a "champagne flow" and leaving behind this floral remnant. Blue dots sprinkled throughout are foreground stars in our Milky Way galaxy.
Berkeley 59 and NGC 7822 are located in the constellation of Cepheus at a distance of about 3,300 light-years from Earth.
Infrared light is color coded in this picture as follows: blue shows 3.4-micron light; cyan, 4.6-micron light; green, 12-micron light; and red, 22-micron light.
This image, taken with the powerful HAWK-I infrared camera on ESO’s Very Large Telescope at Paranal Observatory in Chile, shows NGC 1365. This beautiful barred spiral galaxy is part of the Fornax cluster of galaxies, and lies about 60 million light-years from Earth. The picture was created from images taken through Y, J, H and K filters and the exposure times were 4, 4, 7 and 12 minutes respectively.
An extraordinary jet trailing behind a runaway pulsar is seen in this composite image that contains data from NASA's Chandra X-ray Observatory (purple), radio data from the Australia Compact Telescope Array (green), and optical data from the 2MASS survey (red, green, and blue). The pulsar - a spinning neutron star - and its tail are found in the lower right of this image. The tail stretches for 37 light years , making it the longest jet ever seen from an object in the Milky Way galaxy.
The pulsar, originally discovered by ESA's INTEGRAL satellite, is called IGR J1104-6103 and is moving away from the center of the supernova remnant where it was born at a speed between 2.5 million and 5 million miles per hour. This supersonic pace makes IGR J1104-6103 one of the fastest moving pulsars ever observed.
A massive star ran out of fuel and collapsed to form the pulsar along with the supernova remnant, the debris field seen as the large purple structure in the upper left of the image. The supernova remnant (known as SNR MSH 11-61A) is elongated along the top-right to bottom left direction, roughly in line with the tail's direction. These features and the high speed of the pulsar suggest that jets could have played an important role in the supernova explosion that formed IGR J1104-6103.
In addition to its exceptional length, the tail behind IGR J1104-6103 has other interesting characteristics. For example, there is a distinct corkscrew pattern in the jet. This pattern suggests that the pulsar is wobbling like a top as it spins, while shooting off the jet of particles.
Another interesting feature of this image is a structure called a pulsar wind nebula (PWN), a cocoon of high-energy particles that enshrouds the pulsar and produces a comet-like tail behind it. Astronomers had seen the PWN in previous observations, but the new Chandra and ATCA data show that the PWN is almost perpendicular to the direction of the jet. This is intriguing because usually the pulsar's direction of motion, its jet, and its PWN are aligned with one another.
One possibility requires an extremely fast rotation speed for the iron core of the star that exploded as the supernova. A problem with this scenario is that such fast speeds are not commonly expected to be achievable.
This artist's rendition shows the Huygens probe floating in a methane/ethane lake on Titan. Hydrocarbons produced in the atmosphere eventually condense and rain down on the surface. So, Titan may have lakes of ethane and methane. Mountains of rock and ice are visible in the distance.
In this night view, long after the probe mission is over, the surface of Titan is illuminated by sunlight reflected by Saturn and passing through Titan's thick atmosphere. To the human eye, the atmosphere is opaque, but in the infrared there are "windows" (or wavelengths) where the atmosphere is more transparent, as indicated in this artwork.
Image Credit: Gregor Kervina
Explanation from: http://saturn-archive.jpl.nasa.gov/photos/imagedetails/index.cfm?imageId=627
A team of scientists has studied the galaxy cluster Abell 2744, nicknamed Pandora’s Cluster. They have pieced together the cluster’s complex and violent history using telescopes in space and on the ground, including ESO’s Very Large Telescope and the Hubble Space Telescope. Abell 2744 seems to be the result of a simultaneous pile-up of at least four separate galaxy clusters and this complex collision has produced strange effects that have never been seen together before.
When huge clusters of galaxies crash together, the resulting mess is a treasure trove of information for astronomers. By investigating one of the most complex and unusual colliding clusters in the sky, an international team of astronomers has pieced together the history of a cosmic crash that took place over a period of 350 million years.
Julian Merten, one of the lead scientists for this new study of cluster Abell 2744, explains: “Like a crash investigator piecing together the cause of an accident, we can use observations of these cosmic pile-ups to reconstruct events that happened over a period of hundreds of millions of years. This can reveal how structures form in the Universe, and how different types of matter interact with each other when they are smashed together.”
“We nicknamed it Pandora’s Cluster because so many different and strange phenomena were unleashed by the collision. Some of these phenomena had never been seen before,” adds Renato Dupke, another member of the team.
Abell 2744 has now been studied in more detail than ever before by combining data from ESO’s Very Large Telescope (VLT), the Japanese Subaru telescope, the NASA/ESA Hubble Space Telescope, and NASA’s Chandra X-Ray Observatory.
The galaxies in the cluster are clearly visible in the VLT and Hubble images. Although the galaxies are bright they make up less than 5% of the mass there. The rest is gas (around 20%), which is so hot that it shines only in X-rays, and dark matter (around 75%), which is completely invisible. To understand what was going on in the collision the team needed to map the positions of all three types of matter in Abell 2744.
Dark matter is particularly elusive as it does not emit, absorb or reflect light (hence its name), but only makes itself apparent through its gravitational attraction. To pinpoint the location of this mysterious substance the team exploited a phenomenon known as gravitational lensing. This is the bending of light rays from distant galaxies as they pass through the gravitational fields present in the cluster. The result is a series of telltale distortions in the images of galaxies in the background of the VLT and Hubble observations. By carefully plotting the way that these images are distorted, it is possible to map quite accurately where the hidden mass — and hence the dark matter — actually lies.
By comparison, finding the hot gas in the cluster is simpler as NASA’s Chandra X-ray Observatory can observe it directly. These observations are not just crucial to find out where the gas is, but also to show the angles and speeds at which different components of the cluster came together.
When the astronomers looked at the results they found many curious features. “Abell 2744 seems to have formed from four different clusters involved in a series of collisions over a period of some 350 million years. The complicated and uneven distribution of the different types of matter is extremely unusual and fascinating,” says Dan Coe, the other lead author of the study.
It seems that the complex collision has separated out some of the hot gas and dark matter so that they now lie apart from each other, and from the visible galaxies. Pandora’s Cluster combines several phenomena that have only ever been seen singly in other systems.
Near the core of the cluster is a “bullet”, where the gas of one cluster collided with that of another to create a shock wave. The dark matter passed through the collision unaffected.
In another part of the cluster there seem to be galaxies and dark matter, but no hot gas. The gas may have been stripped away during the collision, leaving behind no more than a faint trail.
Even odder features lie in the outer parts of the cluster. One region contains lots of dark matter, but no luminous galaxies or hot gas. A separate ghostly clump of gas has been ejected, which precedes rather than follows the associated dark matter. This puzzling arrangement may be telling astronomers something about how dark matter behaves and how the various ingredients of the Universe interact with each other.
Galaxy clusters are the biggest structures in the cosmos, containing literally trillions of stars. The way they form and develop through repeated collisions has profound implications for our understanding of the Universe. Further studies of the Pandora’s Cluster, the most complex and fascinating merger yet found, are in progress.
Image Credit: NASA, ESA, ESO, CXC & D. Coe (STScI)/J. Merten (Heidelberg/Bologna)
Explanation from: https://www.eso.org/public/news/eso1120/
This NASA/ESA Hubble Space Telescope image presents the Arches Cluster, the densest known star cluster in the Milky Way. It is located about 25 000 light-years from Earth in the constellation of Sagittarius (The Archer), close to the heart of our galaxy, the Milky Way. It is, like its neighbour the Quintuplet Cluster, a fairly young astronomical object at between two and four million years old.
The Arches cluster is so dense that in a region with a radius equal to the distance between the Sun and its nearest star there would be over 100 000 stars!
At least 150 stars within the cluster are among the brightest ever discovered in the the Milky Way. These stars are so bright and massive, that they will burn their fuel within a short time, on a cosmological scale, just a few million years, and die in spectacular supernova explosions. Due to the short lifetime of the stars in the cluster, the gas between the stars contains an unusually high amount of heavier elements, which were produced by earlier generations of stars.
Despite its brightness the Arches Cluster cannot be seen with the naked eye. The visible light from the cluster is completely obscured by gigantic clouds of dust in this region. To make the cluster visible astronomers have to use detectors which can collect light from the X-ray, infrared, and radio bands, as these wavelengths can pass through the dust clouds. This observation shows the Arches Cluster in the infrared and demonstrates the leap in Hubble’s performance since its 1999 image of same object.
Image Credit: NASA & ESA
Explanation from: https://www.spacetelescope.org/images/potw1521a/
This picture of the open star cluster NGC 7380 is a mosaic of images from the WISE mission spanning an area on the sky of about 5 times the size of the full Moon. NGC 7380 is located in the constellation Cepheus about 7,000 light-years from Earth within the Milky Way Galaxy. The star cluster is embedded in a nebula, sometimes called the Wizard Nebula, which spans some 110 light-years. The stars of NGC 7380 have emerged from this star forming region in the last 5 million years or so, making it a relatively young cluster.
NGC 7380 was discovered by Caroline Herschel in 1787. Her brother, William Herschel, discovered infrared light in 1800. All four infrared detectors aboard WISE were used to make this image. Color is representational: blue and cyan represent infrared light at wavelengths of 3.4 and 4.6 microns, which is primarily light from stars. Green and red represent light at 12 and 22 microns, which is primarily emission from warm dust.
Massive stars can wreak havoc on their surroundings, as can be seen in this new view of the Carina nebula from NASA's Spitzer Space Telescope. The bright star at the center of the nebula is Eta Carinae, one of the most massive stars in the galaxy. Its blinding glare is sculpting and destroying the surrounding nebula.
Eta Carinae is a true giant of a star. It is around 100 times the mass of our Sun and is burning its nuclear fuel so quickly that it is at least one million times brighter than the Sun. It has brightened and faded over the years, and some astronomers think it could explode as a supernova in the not-too-distant future.
Such a tremendous outflow of energy comes at a great cost to the surrounding nebula. The infrared light from the star destroys particles of dust, sculpting cavities and leaving pillars of denser material that point back to the star. Spitzer's infrared vision lets us see the dust, shown in red, as well as clouds of hot, glowing gas that appear green.
Spitzer released an image of a small part of this nebula in 2005. Subsequent observations greatly expanded our view of the entire region, and the data were combined and reprocessed as part of the extended Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE) project.
The infrared images were captured with the Spitzer's infrared array camera. The pictures are three-channel composites, showing emission from wavelengths of 3.6 microns (blue), 4.5 microns (green), and 8.0 microns (red).
This dune field formed near the base of the North Polar cap. Dunes require a source of loose particulate material to form. The source of the northern dune fields around the polar cap may be from the layers of dusty ice that are eroded by strong polar winds.
This image was taken during the Martian northern summer, so there is no frost present on the dunes. The dunes closest to the base of the polar cap are long and parallel, indicating strong winds from the direction of the cap. As they get farther away from the polar cap, they start to form more crescent shaped dunes, called barchan dunes.
Repeated observations by HiRISE of dunes like these show measurable changes in some locations. This discovery adds to the growing evidence that there are active processes happening all over the surface of Mars today.
Image Credit: NASA/JPL-Caltech/Univ. of Arizona
Explanation from: http://photojournal.jpl.nasa.gov/catalog/PIA11181
A spectacular image of an unusual spiral galaxy in the Coma Galaxy Cluster has been created from data taken by the Advanced Camera for Surveys on the NASA/ESA Hubble Space Telescope. It reveals fine details of the galaxy, NGC 4921, as well as an extraordinary rich background of more remote galaxies stretching back to the early Universe.
The Coma Galaxy Cluster, in the northern constellation of Coma Berenices, the hair of Queen Berenice, is one of the closest very rich collections of galaxies in the nearby Universe. The cluster, also known as Abell 1656, is about 320 million light-years from Earth and contains more than 1000 members. The brightest galaxies, including NGC 4921 shown here, were discovered back in the late 18th century by William Herschel.
The galaxies in rich clusters undergo many interactions and mergers that tend to gradually turn gas-rich spirals into elliptical systems without much active star formation. As a result there are far more ellipticals and fewer spirals in the Coma Cluster than are found in quieter corners of the Universe.
NGC 4921 is one of the rare spirals in Coma, and a rather unusual one — it is an example of an "anaemic spiral" where the normal vigorous star formation that creates a spiral galaxy’s familiar bright arms is much less intense. As a result there is just a delicate swirl of dust in a ring around the galaxy, accompanied by some bright young blue stars that are clearly separated out by Hubble’s sharp vision. Much of the pale spiral structure in the outer parts of the galaxy is unusually smooth and gives the whole galaxy the ghostly look of a vast translucent jellyfish.
The long exposure times and sharp vision of Hubble also allowed it to not just image NGC 4921 in exquisite detail but also to see far beyond into the distant Universe. All around, and even through the galaxy itself, thousands of much more remote galaxies of all shapes, sizes and colours are visible. Many have the spotty and ragged appearance of galaxies at a time before the familiar division into spirals and ellipticals had become established.
The Hubble images used to make this picture were originally obtained by a team led by Kem Cook (Lawrence Livermore National Laboratory, California). The team was using Hubble to search for Cepheid variable stars in NGC 4921 that could be used to measure the distance to the Coma Cluster and hence the expansion rate of the Universe. Unfortunately the failure of the Advanced Camera for Surveys in early 2007 meant that they had insufficient data to complete their original programme, although they hope to continue after the servicing mission. Very deep imaging data like this, which is available to anyone from the Hubble archives, may also be used for other interesting scientific explorations of this galaxy and its surroundings.
This image was created from 50 separate exposures through a yellow filter and another 30 exposures through a near-infrared filter using the Wide Field Channel of the Advanced Camera for Surveys on Hubble. The total exposure times were approximately seventeen hours and ten hours respectively.
Image Credit: NASA, ESA and K. Cook (Lawrence Livermore National Laboratory, USA)
Explanation from: https://www.spacetelescope.org/news/heic0901/
Astronomers have for a long time studied the glowing, cosmic clouds of gas and dust catalogued as NGC 6334 and NGC 6357, this gigantic new image from ESO’s Very Large Telescope Survey Telescope being only the most recent one. With around two billion pixels this is one of the largest images ever released by ESO. The evocative shapes of the clouds have led to their memorable names: the Cat’s Paw Nebula and the Lobster Nebula, respectively.
NGC 6334 is located about 5500 light-years away from Earth, while NGC 6357 is more remote, at a distance of 8000 light-years. Both are in the constellation of Scorpius (The Scorpion), near the tip of its stinging tail.
The British scientist John Herschel first saw traces of the two objects, on consecutive nights in June 1837, during his three-year expedition to the Cape of Good Hope in South Africa. At the time, the limited telescopic power available to Herschel, who was observing visually, only allowed him to document the brightest “toepad” of the Cat’s Paw Nebula. It was to be many decades before the true shapes of the nebulae became apparent in photographs — and their popular names coined.
The three toepads visible to modern telescopes, as well as the claw-like regions in the nearby Lobster Nebula, are actually regions of gas — predominantly hydrogen — energised by the light of brilliant newborn stars. With masses around 10 times that of the Sun, these hot stars radiate intense ultraviolet light. When this light encounters hydrogen atoms still lingering in the stellar nursery that produced the stars, the atoms become ionised. Accordingly, the vast, cloud-like objects that glow with this light from hydrogen (and other) atoms are known as emission nebulae.
Thanks to the power of the 256-megapixel OmegaCAM camera, this new Very Large Telescope Survey Telescope (VST) image reveals tendrils of light-obscuring dust rippling throughout the two nebulae. At 49511 x 39136 pixels this is one of the largest images ever released by ESO.
OmegaCAM is a successor to ESO’s celebrated Wide Field Imager (WFI), currently installed at the MPG/ESO 2.2-metre telescope on La Silla. The WFI was used to photograph the Cat’s Paw Nebula in 2010, also in visible light but with a filter that allowed the glow of hydrogen to shine through more clearly. Meanwhile, ESO’s Very Large Telescope has taken a deep look into the Lobster Nebula, capturing the many hot, bright stars that influence the object’s colour and shape.
Despite the cutting-edge instruments used to observe these phenomena, the dust in these nebulae is so thick that much of their content remains hidden to us. The Cat’s Paw Nebula is one of the most active stellar nurseries in the night sky, nurturing thousands of young, hot stars whose visible light is unable to reach us. However, by observing at infrared wavelengths, telescopes such as ESO’s VISTA can peer through the dust and reveal the star formation activity within.
Viewing nebulae in different wavelengths (colours) of light gives rise to different visual comparisons on the part of human observers. When seen in longer wavelength infrared light, for example, one portion of NGC 6357 resembles a dove, and the other a skull; it has therefore acquired the additional name of the War and Peace Nebula.
Messier 83 (also known as the Southern Pinwheel Galaxy, M83 or NGC 5236) is a barred spiral galaxy approximately 15 million light-years away in the constellation Hydra. It is one of the closest and brightest barred spiral galaxies in the sky, making it visible with binoculars.
Image Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)
Planets, including those like our own Earth, form from epic collisions between asteroids and even bigger bodies, called proto-planets. Sometimes the colliding bodies are ground to dust, and sometimes they stick together to ultimately form larger, mature planets.
This artist's conception shows one such smash-up, the evidence for which was collected by NASA's Spitzer Space Telescope. Spitzer's infrared vision detected a huge eruption around the star NGC 2547-ID8 between August 2012 and 2013. Scientists think the dust was kicked up by a massive collision between two large asteroids. They say the smashup took place in the star's "terrestrial zone," the region around stars where rocky planets like Earth take shape.
NGC 2547-ID8 is a sun-like star located about 1,200 light-years from Earth in the constellation Vela. It is about 35 million years old, the same age our young sun was when its rocky planets were finally assembled via massive collisions -- including the giant impact on proto-Earth that led to the formation of the moon. The recent impact witnessed by Spitzer may be a sign of similar terrestrial planet building. Near-real-time studies like these help astronomers understand how the chaotic process works.
The Calabash Nebula — which has the technical name OH 231.8+04.2 — is a spectacular example of the death of a low-mass star like the Sun. This image taken by the NASA/ESA Hubble Space Telescope shows the star going through a rapid transformation from a red giant to a planetary nebula, during which it blows its outer layers of gas and dust out into the surrounding space. The recently ejected material is spat out in opposite directions with immense speed — the gas shown in yellow is moving close to a million kilometres an hour.
Astronomers rarely capture a star in this phase of its evolution because it occurs within the blink of an eye — in astronomical terms. Over the next thousand years the nebula is expected to evolve into a fully fledged planetary nebula.
The nebula is also known as the Rotten Egg Nebula because it contains a lot of sulphur, an element that, when combined with other elements, smells like a rotten egg — but luckily, it resides over 5000 light-years away in the constellation of Puppis (The Poop deck).
Dione's lit hemisphere faces away from Cassini's camera, yet the moon's darkened surface features are dimly illuminated in this image, due to Saturnshine.
Although direct sunlight provides the best illumination for imaging, light reflected off of Saturn can do the job as well. In this image, Dione (698 miles or 1,123 kilometers across) is above Saturn's day side, and the moon's night side is faintly illuminated by sunlight reflected off the planet's disk.
This view looks toward the Saturn-facing side of Dione. North on Dione is up and rotated 8 degrees to the right. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on October 23, 2016.
The view was obtained at a distance of approximately 313,000 miles (504,000 kilometers) from Dione. Image scale is 1.8 miles (3 kilometers) per pixel.
Image Credit: NASA/JPL-Caltech/Space Science Institute
Explanation from: http://photojournal.jpl.nasa.gov/catalog/PIA20514
Ground that has a lot of water ice mixed with dirt tends to crack in polygonal patterns bounded by short straight channels. In the South Polar region of Mars this type of terrain may be covered by a seasonal polar cap composed of dry ice.
In the spring as the seasonal cap sublimates gas is trapped underneath the seasonal ice layer until it can escape to an opening. At this site, faint rectangular channels in the surface are visible. The escaping carbon dioxide gas has exploited these channels and in the process, deepened them and added sinuosity to the formerly straight segments.
Image Credit: NASA/JPL-Caltech/Univ. of Arizona
Explanation from: http://photojournal.jpl.nasa.gov/catalog/PIA11238
A visible light image of the giant elliptical galaxy M 87, taken with the NASA/ESA Hubble Space Telescope's Wide Field Planetary Camera 2 in February 1998, reveals a brilliant jet of high-speed electrons emitted from the nucleus (diagonal line across image). The jet is produced by a 3-billion-solar-mass black hole.
Image Credit: NASA/ESA and John Biretta (STScI/JHU)
This image shows a three-colour composite of the N 70 nebula. It is a "Super Bubble" in the Large Magellanic Cloud (LMC), a satellite galaxy to the Milky Way system, located in the southern sky at a distance of about 160,000 light-years. This photo is based on CCD frames obtained with the FORS2 instrument in imaging mode in the morning of November 5, 1999. N 70 is a luminous bubble of interstellar gas, measuring about 300 light-years in diameter. It was created by winds from hot, massive stars and supernova explosions and the interior is filled with tenuous, hot expanding gas. An object like N70 provides astronomers with an excellent opportunity to explore the connection between the life-cycles of stars and the evolution of galaxies. Very massive stars profoundly affect their environment. They stir and mix the interstellar clouds of gas and dust, and they leave their mark in the compositions and locations of future generations of stars and star systems.