NASA's Hubble Space Telescope shows a rare view of a pair of overlapping galaxies, called NGC 3314. The two galaxies appear to be colliding, but they are actually separated by tens of millions of light-years, or about ten times the distance between our Milky Way and the neighboring Andromeda galaxy. The chance alignment of the two galaxies, as seen from Earth, gives a unique look at the silhouetted spiral arms in the closer face-on spiral, NGC 3314A. The motion of the two galaxies indicates that they are both relatively undisturbed and that they are moving in markedly different directions. #

The star HD 44179 is surrounded by an extraordinary structure known as the Red Rectangle. It acquired its moniker because of its shape and its apparent color when seen in early images from Earth. This strikingly detailed Hubble image reveals how, when seen from space, the nebula, rather than being rectangular, is shaped like an X with additional complex structures of spaced lines of glowing gas, a little like the rungs of a ladder. The star at the center is similar to the Sun, but at the end of its lifetime, pumping out gas and other material to make the nebula, and giving it the distinctive shape. It also appears that the star is a close binary that is surrounded by a dense torus of dust -- both of which may help to explain the very curious shape. The Red Rectangle is an unusual example of what is known as a proto-planetary nebula. These are old stars, on their way to becoming planetary nebulae. Once the expulsion of mass is complete a very hot white dwarf star will remain and its brilliant ultraviolet radiation will cause the surrounding gas to glow. The Red Rectangle is found about 2,300 light-years away in the constellation Monoceros (the Unicorn). #

A small portion of the Carina Nebula, one of the largest seen star-birth regions in the galaxy. Towers of cool hydrogen laced with dust rise from the wall of the nebula. The image captures the top of a three-light-year-tall pillar of gas and dust that is being eaten away by the brilliant light from nearby bright stars. The pillar is also being pushed apart from within, as infant stars buried inside it fire off jets of gas that can be seen streaming from towering peaks like arrows sailing through the air. #

Jupiter's volcanic moon Io passing above the turbulent clouds of the giant planet, on July 24, 1996. The conspicuous black spot on Jupiter is Io's shadow. The shadow is about the same size as Io (3,640 kilometers or 2,262 miles across) and sweeps across the face of Jupiter at 17 kilometers per second (38,000 miles per hour). The smallest details visible on Io and Jupiter are about 100 miles across. Bright patches visible on Io are regions of sulfur dioxide frost. #

Resembling comets streaking across the sky, these four speedy stars are plowing through regions of dense interstellar gas, creating brilliant arrowhead structures and trailing tails of glowing gas. The stars in these NASA Hubble Space Telescope images are among 14 young runaway stars spotted by the Advanced Camera for Surveys between October 2005 and July 2006. #

The full beauty of the Cat's Eye Nebula (NGC 6543), seen in a detailed view from Hubble's Advanced Camera for Surveys (ACS), showing a bull's eye pattern of eleven or even more concentric rings, or shells, around the Cat's Eye. Each 'ring' is actually the edge of a spherical bubble seen projected onto the sky -- that's why it appears bright along its outer edge. Observations suggest the star ejected its mass in a series of pulses at 1,500-year intervals. These convulsions created dust shells, each of which contain as much mass as all of the planets in our solar system combined (still only one percent of the Sun's mass). These concentric shells make a layered, onion-skin structure around the dying star. The view from Hubble is like seeing an onion cut in half, where each skin layer is discernible. #

This object, known as Messier 54, could be just another globular cluster, but this dense and faint group of stars was in fact the first globular cluster found that lies outside our own galaxy. Discovered by the famous astronomer Charles Messier in 1778, Messier 54 belongs to a satellite of the Milky Way called the Sagittarius Dwarf Elliptical Galaxy. Messier had no idea of the significance of his discovery at the time, and it wasn't until over two centuries later, in 1994, that astronomers found Messier 54 to be part of the miniature galaxy and not our own. Current estimates indicate that the Sagittarius dwarf, and hence the cluster, is situated almost 90,000 light-years away -- more than three times as far from the center of our galaxy than the Solar System. Ironically, even though this globular cluster is now understood to lie outside the Milky Way, it will actually become part of it in the future. The strong gravitational pull of our galaxy is slowly engulfing the Sagittarius dwarf, which will eventually merge with the Milky Way creating one much larger galaxy. #

The newest candidate for Most Distant Galaxy Yet Known. This newly discovered galaxy, named MACS0647-JD, is very young and only a tiny fraction of the size of our Milky Way. The object is observed 420 million years after the big bang, when the universe was 3 percent of its present age of 13.7 billion years. The inset shows a close-up of the young dwarf galaxy. This is the latest discovery from a large program that uses massive clusters of galaxies as natural zoom lenses to reveal distant galaxies in the early universe. Called the Cluster Lensing And Supernova survey with Hubble (CLASH), the program allows astronomers to use the gravity of massive galaxy clusters to magnify distant galaxies behind them, an effect called gravitational lensing. In this Hubble observation, astronomers used the massive galaxy cluster MACS J0647+7015 as the giant cosmic telescope. The bright yellow galaxies near the center of the image are cluster members. The cluster's gravity boosted the light from the faraway galaxy, making its image appear approximately eight times brighter than it otherwise would. #

NGC 1999, a dust filled bright nebula surrounding a vast hole of empty space in the constellation Orion. Hubble Heritage astronomers, in collaboration with scientists in Texas and Ireland, used Hubble's Wide Field Planetary Camera 2 to obtain this color image. #

A Multi-Wavelength View of Radio Galaxy Hercules A. Spectacular jets powered by the gravitational energy of a supermassive black hole in the core of the elliptical galaxy Hercules A illustrate the combined imaging power of two of astronomy's cutting-edge tools, the Hubble Space Telescope's Wide Field Camera 3, and the recently upgraded Karl G. Jansky Very Large Array (VLA) radio telescope in New Mexico. Some two billion light-years away, the yellowish elliptical galaxy in the center of the image appears quite ordinary as seen by Hubble in visible wavelengths of light. The galaxy is roughly 1,000 times more massive than the Milky Way and harbors a 2.5-billion-solar-mass central black hole that is 1,000 times more massive than the black hole in the Milky Way. But the innocuous-looking galaxy, also known as 3C 348, has long been known as the brightest radio-emitting object in the constellation Hercules. Emitting nearly a billion times more power in radio wavelengths than our Sun, the galaxy is one of the brightest extragalactic radio sources in the entire sky. The VLA radio data reveal enormous, optically invisible jets that, at one-and-a-half million light-years wide, dwarf the visible galaxy from which they emerge. The jets are very-high-energy plasma beams, subatomic particles and magnetic fields shot at nearly the speed of light from the vicinity of the black hole. The outer portions of both jets show unusual ring-like structures suggesting a history of multiple outbursts from the supermassive black hole at the center of the galaxy. The innermost parts of the jets are not visible because of the extreme velocity of the material, which causes relativistic effects that beam the light away from us. Far from the galaxy, the jets become unstable and break up into the rings and wisps. #

A composite color infrared image of the center of our Milky Way galaxy reveals a new population of massive stars and new details in complex structures in the hot ionized gas swirling around the central 300 light-years. This sweeping panorama is the sharpest infrared picture ever made of the Galactic core. It offers a nearby laboratory for how massive stars form and influence their environment in the often violent nuclear regions of other galaxies. #

A nearly perfect ring of hot, blue stars pinwheels about the yellow nucleus of an unusual galaxy known as Hoag's Object. This image captures a face-on view of the galaxy's ring of stars, revealing more detail than any existing photo of this object. The entire galaxy is about 120,000 light-years wide, which is slightly larger than our Milky Way Galaxy. The blue ring, which is dominated by clusters of young, massive stars, contrasts sharply with the yellow nucleus of mostly older stars. What appears to be a "gap" separating the two stellar populations may actually contain some star clusters that are almost too faint to see. Curiously, an object that bears an uncanny resemblance to Hoag's Object can be seen in the gap at the one o'clock position. The object is probably a background ring galaxy. #

A team of astronomers using NASA's Hubble Space Telescope reported the discovery of a fifth moon orbiting the icy dwarf planet Pluto on July 11, 2012. The moon is estimated to be irregular in shape and 6 to 15 miles across. It is in a 58,000-mile-diameter circular orbit around Pluto that is assumed to be co-planar with the other satellites in the system. Provisionally designated S/2012 (134340) 1, or P5, the latest moon was detected in nine separate sets of images taken by Hubble's Wide Field Camera 3 on June 26, 27, and 29, 2012 and July 7 and 9, 2012. This discovery increases the number of known moons orbiting Pluto to five. Pluto is at center, and, counterclockwise, from top left, are its moons Nix, P5 (very small), Hydra, Charon, and P4. #

A planetary nebula in the making of a proto-planetary nebula. A dying star (hidden behind dust and gas in the center of the nebula) has ejected massive amounts of gas. Parts of the gas have reached tremendous velocities of up to one-and-a-half million kilometers per hour. Shown in blue is light from hydrogen and ionised nitrogen arising from supersonic shocks where the gas stream rams into the surrounding material. #

The giant elliptical galaxy in the center of this image is the most massive and brightest member of the galaxy cluster Abell 2261. Spanning a little more than one million light-years, the galaxy is about 10 times the diameter of our Milky Way galaxy. The bloated galaxy is a member of an unusual class of galaxies with a diffuse core filled with a fog of starlight. Normally, astronomers would expect to see a concentrated peak of light around a central black hole. The Hubble observations revealed that the galaxy's puffy core, measuring about 10,000 light-years, is the largest yet seen. The observations present a mystery, and studies of this galaxy may provide insight into how black hole behavior may shape the cores of galaxies. The immense gravity of the galaxy warps the light passing by, smearing out the images of background galaxies, as seen by Hubble. (NASA, ESA, M. Postman (STScI), T. Lauer #

Resembling a nightmarish beast rearing its head from a crimson sea, this celestial object is actually just a pillar of gas and dust. Called the Cone Nebula (in NGC 2264) -- so named because in ground-based images it has a conical shape - this monstrous pillar resides in a turbulent star-forming region. This picture shows the upper 2.5 light-years of the Cone. The entire pillar is seven light-years long. #

The barred spiral galaxy NGC 1073, found in the constellation of Cetus (The Sea Monster). Our own galaxy, the Milky Way, is thought to be a similar barred spiral, and the study of galaxies such as NGC 1073 can help astronomers learn more about our celestial home. #

NGC 3132 is a striking example of a planetary nebula. This expanding cloud of gas, surrounding a dying star, is known to amateur astronomers in the southern hemisphere as the "Eight-Burst" or the "Southern Ring" Nebula. #

Herbig-Haro 110 is a geyser of hot gas from a newborn star that splashes up against and ricochets from the dense core of a cloud of molecular hydrogen. This image was taken with Hubble's Advanced Camera for Surveys in 2004 and 2005 and the Wide Field Camera 3 in April 2011. #

Galaxies, galaxies everywhere - as far as the NASA/ESA Hubble Space Telescope can see. This view of thousands of galaxies is the deepest visible-light image of the cosmos. part of what is called the Hubble Ultra Deep Field, this galaxy-studded view represents a "deep" core sample of the universe, cutting across billions of light-years. The snapshot includes galaxies of various ages, sizes, shapes, and colors. The smallest, reddest galaxies, about 100, may be among the most distant known, existing when the universe was just 800 million years old. The nearest galaxies - the larger, brighter, well-defined spirals and ellipticals - thrived about 1 billion years ago, when the cosmos was 13 billion years old. In vibrant contrast to the rich harvest of classic spiral and elliptical galaxies, there is a zoo of oddball galaxies littering the field. Some look like toothpicks; others like links on a bracelet. A few appear to be interacting. These oddball galaxies chronicle a period when the universe was younger and more chaotic. Order and structure were just beginning to emerge. The Ultra Deep Field observations, taken by the Advanced Camera for Surveys, represent a narrow, deep view of the cosmos. In ground-based photographs, the patch of sky in which the galaxies reside (just one-tenth the diameter of the full Moon) is largely empty. Located in the constellation Fornax, the region is so empty that only a handful of stars within the Milky Way galaxy can be seen in the image. The image required 800 exposures taken over the course of 400 Hubble orbits around Earth. The total amount of exposure time was 11.3 days, taken between Sept. 24, 2003 and January 16, 2004. #

This peculiar galaxy pair is called Arp 116. Arp 116 is composed of a giant elliptical galaxy known as Messier 60 (or M60) and a much smaller spiral galaxy, NGC 4647. M60 is the third brightest galaxy in the Virgo cluster of galaxies, a collection of more than 1,300 galaxies. M60 has a diameter of 120,000 light-years, and a mass of about one trillion times that of the Sun. A huge black hole of 4.5 billion solar masses lies at its center, one of the most massive black holes ever found. The faint bluish spiral galaxy NGC 4647 is about two-thirds of M60 in size and much lower in mass -- roughly the size of our galaxy, the Milky Way. Astronomers have long tried to determine whether these two galaxies are actually interacting. Although looking at them from Earth they overlap, there is no evidence of new star formation, which would be one of the clearest signs that the two galaxies are indeed interacting. However, recent studies of very detailed Hubble images suggest the onset of some tidal interaction between the two. M60 lies roughly 54 million light-years away from Earth; NGC 4647 is about 63 million light-years away. #

First prize winner of the 2012 Hubble Hidden Treasures competition, image processing category. Josh Lake (USA) submitted this stunning image of NGC 1763, part of the N11 star-forming region in the Large Magellanic Cloud. ESA/Hubble had previously published an image of an area just adjacent to this, based on observations by the same team. Josh took a different approach, producing a bold two-color image which contrasts the light from glowing hydrogen and nitrogen. The image is not in natural colors -- hydrogen and nitrogen produce almost indistinguishable shades of red light that our eyes would struggle to tell apart -- but Josh's processing separates them out into blue and red, dramatically highlighting the structure of the region. As well as narrowly topping the jury's vote, Josh Lake also won the public vote. #

Thanks to the presence of a natural "zoom lens" in space, this is a close-up look at one of the brightest distant "magnified" galaxies in the universe known to date. It is one of the most striking examples of gravitational lensing, where the gravitational field of a foreground galaxy bends and amplifies the light of a more distant background galaxy. In this image the light from a distant galaxy, nearly 10 billion light-years away, has been warped into a nearly 90-degree arc of light in the galaxy cluster RCS2 032727-132623. The galaxy cluster lies 5 billion light-years away. The background galaxy's image is not only stretched by the lensing, but split into multiple apparent images, across the upper left and at lower right. #

A pair of one-half light-year long interstellar 'twisters' -- eerie funnels and twisted-rope structures - in the heart of the Lagoon Nebula (M8) which lies 5,000 light-years away in the direction of the constellation Sagittarius. #

The Sombrero galaxy, Messier 104 (M104). The galaxy's hallmark is a brilliant white, bulbous core encircled by the thick dust lanes comprising the spiral structure of the galaxy. As seen from Earth, the galaxy is tilted nearly edge-on. We view it from just six degrees north of its equatorial plane. This brilliant galaxy was named the Sombrero because of its resemblance to the broad rim and high-topped Mexican hat. At a relatively bright magnitude of +8, M104 is just beyond the limit of naked-eye visibility and is easily seen through small telescopes. The Sombrero lies at the southern edge of the rich Virgo cluster of galaxies and is one of the most massive objects in that group, equivalent to 800 billion suns. The galaxy is 50,000 light-years across and is located 28 million light-years from Earth. (NASA/ESA and The Hubble Heritage Team STScI/AURA) # I wish you all a Merry Christmas, Feliz Navidad, Joyeux Noël, and Fröhliche Weihnachten, and a wish for Peace on Earth in the New Year. #