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Hubble Heritage Archive - 2005 Hubble Heritage Archive: 1998 | 1999 | 2000 | 2001 | 2002 | 2003 | 2004 | 2005 | 2006 Gemini | Apollo | Hubble Space Telescope
January 2005 January's Hubble Heritage image is of the barred spiral galaxy NGC 1300. 69 million light-years from us, the galaxy lies in the constellation Eridanus; this image covers approximately 5.5 arcminutes across (110,000 light-years). The image is combined from data taken in September 2004. This image is a composite of four filters (B (F435W), V (F555W), I (F814W), and H-α (F658N)). The Hubble telescope has captured a display of starlight, glowing gas, and silhouetted dark clouds of interstellar dust in this grand image of the barred spiral galaxy NGC 1300. NGC 1300 is considered to be prototypical of barred spiral galaxies. Barred spirals differ from normal spiral galaxies in that the arms of the galaxy do not spiral all the way into the center, but are connected to the two ends of a straight bar of stars containing the nucleus at its center. At Hubble's resolution, a myriad of fine details is revealed throughout the galaxy's arms, disk, bulge, and nucleus. Blue and red supergiants, clusters, and star-forming regions are well resolved across the spiral arms, and dust lanes trace out fine structures in the disk and bar. Numerous more distant galaxies are visible in the background, and are seen even through the densest regions of NGC 1300. The nucleus of NGC 1300 shows an extraordinary "grand-design" spiral structure that is about 3,300 light-years (1 kpc) in diameter. Only galaxies with large-scale bars appear to have these grand-design inner spiral disks. Models suggest that the gas in a bar can be funneled inwards, and then spiral into the center through the grand-design disk, where it can potentially fuel a central black hole. NGC 1300 is not known to have an active nucleus, however, indicating either that there is no central black hole, or that it is not accreting matter. The image was constructed from exposures taken by the Advanced Camera for Surveys onboard Hubble. Starlight and dust are seen in blue, visible, and infrared light. Bright star clusters are highlighted in red by their associated emission from glowing hydrogen gas. Due to the galaxy's large size, two adjacent pointings of the telescope were necessary to cover the extent of the spiral arms. February 2005
The latest image of the star V838 Mon reveals dramatic changes in the illumination of surrounding dusty cloud structures. The effect, called a light echo, has been unveiling never-before-seen dust patterns ever since the star suddenly brightened for several weeks in early 2002. The illumination of interstellar dust comes from the red supergiant star at the middle of the image, which gave off a pulse of light three years ago, somewhat similar to setting off a flashbulb in a darkened room. The dust surrounding V838 Mon may have been ejected from the star during a previous explosion, similar to the 2002 event. The echoing of light through space is similar to the echoing of sound through air. As light from the stellar explosion continues to propagate outwards, different parts of the surrounding dust are illuminated, just as a sound echo bounces off of objects near the source, and later, objects further from the source. Eventually, when light from the back side of the nebula begins to arrive, the light echo will give the illusion of contracting, and finally it will disappear. With the star 20,000 light-years away from Earth in the direction of the constellation Monoceros, the star is at the outer edge of our Milky Way galaxy. The Hubble telescope has imaged V838 Mon and its light echo several times since the star's outburst. Each time Hubble observes the event, different thin sections of the dust are seen as the pulse of illumination continues to expand away from the star at the speed of light, producing a constantly changing appearance. During the outburst event whose light reached Earth in 2002, the normally faint star suddenly brightened, becoming 600,000 times more luminous than our Sun. March 2005 March's Hubble Heritage image is of the dwarf irregular galaxy NGC 1427A. 62 million light-years from us, the galaxy lies in the constellation Fornax; this image covers approximately 2.8 arcminutes across (51,000 light-years). The image is combined from data taken on January 9 2004 for 2.4 hours. This image is a composite of five filters (g (F475W), r (F635W), N II (F660N), i (F775W), and z (F850LP)). The irregular galaxy NGC 1427A is a spectacular example of a stellar rumble. Under the gravitational grasp of a large gang of galaxies, called the Fornax cluster, the small bluish galaxy is plunging headlong into the group at 600 km/sec (400 mi/sec). NGC 1427A shows numerous hot, blue stars in this image. These blue stars have been formed very recently, showing that star formation is occurring extensively throughout the galaxy. As the galaxy rams into the center of the Fornax cluster (located off the image to the upper left) the galaxy becomes distorted, forming an arrowhead in the direction of its high-velocity motion. Galaxy clusters, like the Fornax cluster, contain hundreds or even thousands of individual galaxies. Within the Fornax cluster, there is a considerable amount of gas lying between the galaxies. When the gas within NGC 1427A collides with the Fornax gas, it is compressed to the point that it starts to collapse under its own gravity. This leads to formation of the myriad of new stars seen across NGC 1427A. The tidal forces of nearby galaxies in the cluster may also play a role in triggering star formation on such a massive scale. NGC 1427A will not survive long as an identifiable galaxy passing through the cluster. Within the next billion years, it will be completely disrupted, spilling its stars and remaining gas into intergalactic space within the Fornax cluster. To the upper left of NGC 1427A is a background galaxy that happens to lie near Hubble's line of sight but is 25 times further away. In contrast to the irregularly shaped NGC 1427A, the background galaxy is a spiral, somewhat similar to our own Milky Way. Stars are forming in its symmetric pinwheel-shaped spiral arms, which can be traced into the galaxy's bright nucleus. This galaxy is, however, less dominated by very young stars than NGC 1427A, giving it an overall yellower color. At even greater distances, background galaxies of various shapes and colors are scattered across the Hubble image. Astronomers are using the data to investigate the star-formation patterns throughout the object, to verify a prediction that there should be a relation between the ages of stars and their positions within the galaxy. This will help them understand how the gravitational influence of the cluster has affected the internal workings of this galaxy, and how this galaxy has responded to passing through the cluster environment. The disruption of objects like NGC 1427A, and even larger galaxies like our own Milky Way, is an integral part of the formation and evolution of galaxy clusters. Such events are believed to have been very common during the early evolution of the universe, but the rate of galaxy destruction is tapering off at the present time. Thus the impending destruction of NGC 1427A provides a glimpse of an early and much more chaotic time in our universe.
Like dust bunnies that lurk in corners and under beds, surprisingly complex loops and blobs of cosmic dust lie hidden in the giant elliptical galaxy NGC 1316. This image reveals the dust lanes and star clusters of this giant galaxy that give evidence that it was formed from a past merger of two gas-rich galaxies. The combination of Hubble's superb spatial resolution and the sensitivity of the Advanced Camera for Surveys (ACS), installed onboard Hubble in 2002 and used for these images, enabled uniquely accurate measurements of a class of red star clusters in NGC 1316. Astronomers conclude that these star clusters constitute clear evidence of the occurrence of a major collision of two spiral galaxies that merged together a few billion years ago to shape NGC 1316 as it appears today. NGC 1316 is on the outskirts of a nearby cluster of galaxies in the southern constellation of Fornax, at a distance of about 60 million light-years. It is one of the brightest ellipticals in the Fornax galaxy cluster. NGC 1316, also known as Fornax A, is one of the strongest and largest radio sources in the sky, with radio lobes extending over several degrees of sky (several times larger than the full moon, and well off the Hubble image). NGC 1316's violent history is evident in various ways. Wide-field imagery from Cerro Tololo Interamerican Observatory in Chile shows a bewildering variety of ripples, loops and plumes immersed in the galaxy's outer envelope. Amongst these so-called "tidal" features, the narrow ones are believed to be the stellar remains of other spiral galaxies that merged with NGC 1316 some time during the last few billion years. The inner regions of the galaxy shown in the Hubble image reveal a complicated system of dust lanes and patches. These are thought to be the remains of the interstellar medium associated with one or more of the spiral galaxies swallowed by NGC 1316. The U.S. team of scientists, led by Dr. Paul Goudfrooij of the Space Telescope Science Institute in Baltimore, Maryland, used the ACS onboard Hubble to study star clusters in several nearby giant elliptical galaxies. Their study of NGC 1316 focused on globular clusters, which are compact stellar systems with hundreds of thousands to millions of stars formed at the same time. The unprecendented sensitivity of the Hubble ACS data permitted the team to detect faint globular clusters previously impossible to reach. By counting the number of globular clusters detected as a function of their brightness they could, for the first time, see evidence of the gradual disruption of star clusters created during a past merger of gas-rich galaxies. They found that the relative number of low-mass clusters is significantly lower in the inner regions than in the outer regions, by an amount consistent with theoretical predictions. The team's results have improved our understanding of how elliptical galaxies and their star clusters may have formed during galaxy mergers and then evolve to resemble "normal" elliptical galaxies after several billions of years. April 2005 April's Hubble Heritage image is of the Eagle Nebula, AKA M16, AKA NGC 6611, AKA IC 4703. 6500 light-years from us, the nebula lies in the constellation Serpens; this image covers approximately 3.2 arcminutes across (6 light-years). The image is combined from data taken in November 4-7, 2004, for a total or 3.4 hours. This image is a composite of five filters (B (F435W), V (F555W), I (F814W), H-α and N II (F658N), and O III (F502N)). This object is a billowing tower of cold gas and dust rising from a stellar nursery called the Eagle Nebula. The soaring tower is 9.5 light-years (about 57 trillion miles) high, about twice the distance from our Sun to the next nearest star. Stars in M16 are born in clouds of cold hydrogen gas that reside in chaotic neighborhoods, where energy from young stars sculpts fantasy-like landscapes in the gas. The tower may be a giant incubator for those newborn stars. A torrent of ultraviolet light from a band of massive, hot, young stars (off the top of the image) is eroding the pillar. The starlight also is responsible for illuminating the tower's rough surface. Ghostly streamers of gas can be seen boiling off this surface, creating the haze around the structure and highlighting its three-dimensional shape. The column is silhouetted against the background glow of more distant gas. The edge of the dark hydrogen cloud at the top of the tower is resisting erosion, in a manner similar to that of brush among a field of prairie grass that is being swept up by fire. The fire quickly burns the grass but slows down when it encounters the dense brush. In this celestial case, thick clouds of hydrogen gas and dust have survived longer than their surroundings in the face of a blast of ultraviolet light from the hot, young stars. Inside the gaseous tower, stars may be forming. Some of those stars may have been created by dense gas collapsing under gravity. Other stars may be forming due to pressure from gas that has been heated by the neighboring hot stars. The first wave of stars may have started forming before the massive star cluster began venting its scorching light. The star birth may have begun when denser regions of cold gas within the tower started collapsing under their own weight to make stars. The bumps and fingers of material in the center of the tower are examples of these stellar birthing areas. These regions may look small but they are roughly the size of our solar system. The fledgling stars continued to grow as they fed off the surrounding gas cloud. They abruptly stopped growing when light from the star cluster uncovered their gaseous cradles, separating them from their gas supply. Ironically, the young cluster's intense starlight may be inducing star formation in some regions of the tower. Examples can be seen in the large, glowing clumps and finger-shaped protrusions at the top of the structure. The stars may be heating the gas at the top of the tower and creating a shock front, as seen by the bright rim of material tracing the edge of the nebula at top, left. As the heated gas expands, it acts like a battering ram, pushing against the darker cold gas. The intense pressure compresses the gas, making it easier for stars to form. This scenario may continue as the shock front moves slowly down the tower.
The graceful, winding arms of the majestic spiral galaxy M51 appear like a grand spiral staircase sweeping through space. They are actually long lanes of stars and gas laced with dust. This sharpest-ever image of the Whirlpool Galaxy illustrates a spiral galaxy's grand design, from its curving spiral arms, where young stars reside, to its yellowish central core, a home of older stars. The galaxy is nicknamed the Whirlpool because of its swirling structure. The Whirlpool's most striking feature is its two curving arms, a hallmark of so-called grand-design spiral galaxies. Many spiral galaxies possess numerous, loosely shaped arms which make their spiral structure less pronounced. These arms serve an important purpose in spiral galaxies. They are star-formation factories, compressing hydrogen gas and creating clusters of new stars. In the Whirlpool, the assembly line begins with the dark clouds of gas on the inner edge, then moves to bright pink star-forming regions, and ends with the brilliant blue star clusters along the outer edge. Some astronomers believe that the Whirlpool's arms are so prominent because of the effects of a close encounter with NGC 5195, the small, yellowish galaxy at the outermost tip of one of the Whirlpool's arms. At first glance, the compact galaxy appears to be tugging on the arm. Hubble's clear view, however, shows that NGC 5195 is passing behind the Whirlpool. The small galaxy has been gliding past the Whirlpool for hundreds of millions of years. As NGC 5195 drifts by, its gravitational muscle pumps up waves within the Whirlpool's pancake-shaped disk. The waves are like ripples in a pond generated when a rock is thrown in the water. When the waves pass through orbiting gas clouds within the disk, they squeeze the gaseous material along each arm's inner edge. These dense clouds collapse, creating a wake of star birth, as seen in the bright pink star-forming regions. The largest stars eventually sweep away the dusty cocoons with a torrent of radiation, hurricane-like stellar winds, and shock waves from supernova blasts. Bright blue star clusters emerge from the mayhem, illuminating the Whirlpool's arms like city streetlights. June 2005 June's Hubble Heritage image is of the supernova remnant LMC N 63A. 160,000 light-years from us, the nebula lies in the constellation Dorado; this image covers approximately 1.4 arcminutes across (68 light-years). The image is combined from data taken on October 8, 1997, and September 12, 2000 for a total of 1.3 hours. This image is a composite of three filters (O III (F502N), H-α (F658N), and S II (F673N)). The supernova remnant is a member of N 63, a star-forming region in the Large Magellanic Cloud (LMC). Visible from the southern hemisphere, the LMC is an irregular galaxy lying 160,000 light-years from our own Milky Way galaxy. The LMC provides excellent examples of active star formation and supernova remnants to be studied with Hubble. Many of the stars in the immediate vicinity of N 63A are extremely massive. It is estimated that the progenitor of the supernova that produced the remnant seen here was about 50 times more massive than our own Sun. Such a massive star has strong stellar winds that can clear away its ambient medium, forming a wind-blown bubble. The supernova that formed N 63A is thought to have exploded inside the central cavity of such a wind-blown bubble, which was itself embedded in a clumpy portion of the LMC's interstellar medium. Images in the infrared, X-ray, and radio emission of this supernova remnant show the much more expanded bubble that totaly encompasses the optical emission seen by Hubble. Odd-shaped mini-clouds or cloudlets that were too dense for the stellar wind to clear away are now engulfed in the bubble interior. The supernova generated a propagating shock wave, that continues to move rapidly through the low-density bubble interior, and shocks these cloudlets, shredding them fiercely. Supernova remnants have long been thought to set off episodes of star formation when their expanding shock encounters nearby gas. As the HST images have illustrated, N 63A is still young and its ruthless shocks destroys the ambient gas clouds, rather than coercing them to collapse and form stars. Data obtained at various wavelengths from other detectors reveal on-going formation of stars at 10-15 light-years from N 63A. In a few million years, the supernova ejecta from N 63A would reach this star formation site and may be incorporated into the formation of planets around solar-type stars there, much like the early history of the solar system. July 2005
NASA's Hubble Space Telescope has snapped an image of Comet 9P/Tempel 1 just days before the Deep Impact spacecraft was scheduled to rendezvous with the comet. This image, taken on the morning of June 30, 2005, shows an undisturbed and quiet comet. This Advanced Camera for Surveys (ACS) Wide Field Camera (WFC) image of Tempel 1 shows a slightly larger view of the comet than was seen in Hubble images taken with the ACS/High Resolution Camera. The Deep Impact Probe finally arrived at the comet after a seven-month flight. Images just before and just after the impact were taken by a multitude of telescopes on the ground and in space. The space-based cameras viewing the probe-cometary impact are the Deep Impact spacecraft, as well as those aboard three of NASA's Great Observatories - the Hubble Space Telescope, the Spitzer Space Telescope and Chandra X-ray Satellite. The observations by the Deep Impact camera and the Hubble telescope complement each other. The camera aboard the Deep Impact spacecraft provided a close-up view of the comet, from about 300 miles away. From its distance 80 million miles away, Hubble captured a broader view of the encounter. The difference between the views of Hubble and the Deep Impact spacecraft is like that between a satellite image of a hurricane and a photo from the center of the storm. The comet's name is derived from the amateur astronomer Ernst Wilhelm Leberecht Tempel of Marseilles, France, who discovered Comet Tempel 1 in 1867. Little is known about the history of the comet, except that it is a periodic comet that orbits the Sun every 5.5 years. It has probably made more than 100 passages through the inner solar system. Comet Tempel 1 is a potato-shaped object that is 8.7 miles (14 kilometers) wide and 2.5 miles (4 kilometers) long. The ACS/WFC image is a composite of data taken with blue and red filters onboard Hubble. A quiescent comet is seen in this pre-impact image along with elongated star trails. As the telescope was locked on the movement of the comet, the background stars left small trailed arcs during the time the exposures were taken. August 2005 August's Hubble Heritage image is of a galaxy field in Fornax. This image covers approximately 3.5 arcminutes across. The image is combined from data taken in September 2003 for a total of 39.6 hours. This image is a composite of four filters (B (F435W), V (F606W), I (F775W), and z (F850LP)). Gazing deep into the universe, NASA’s Hubble Space Telescope has spied a menagerie of galaxies. Located within the same tiny region of space, these numerous galaxies display an assortment of unique characteristics. Some are big and some are small. A few are relatively nearby, but most are far away. Hundreds of these faint galaxies have never been seen before until their light was captured by Hubble. This image represents a typical view of our distant universe. In taking this picture, Hubble is looking down a long corridor of galaxies stretching billions of light-years distant in space corresponding to looking billions of years back in time. The field shown in this picture covers a relatively small patch of sky, a fraction the area of the full moon, yet it is richly populated with a variety of galaxy types. A handful of large fully formed galaxies are scattered throughout the image. These galaxies are easy to see because they are relatively close to us. Several of the galaxies are spirals with flat disks that are oriented edge-on or face-on to our line of sight, or somewhere in between. Elliptical galaxies and more exotic galaxies with bars or tidal tails are also visible. Many galaxies that appear small in this image are simply farther away. These visibly smaller galaxies are so distant that their light has taken billions of years to reach us. We are seeing these galaxies, therefore, when they were much younger than the larger, nearby galaxies in the image. One red galaxy to the lower left of the bright central star is acting as a lens to a large galaxy directly behind it. Light from the farther galaxy is bent around the nearby galaxy’s nucleus to form a distorted arc. Sprinkled among the thousands of galaxies in this image are at least a dozen foreground stars that reside in our Milky Way Galaxy. The brightest of these foreground stars is the red object in the center of the image. The stars are easily discernable from galaxies because of their diffraction spikes, long cross-hair-like features that look like they are emanating from the centers of the stars. Diffraction spikes are an image artifact caused by bright starlight traveling through the telescope’s optical system. This image is a composite of multiple exposures of a single field taken by the Advanced Camera for Surveys. The image, taken in September 2003, was a bonus picture, taken when one of the other Hubble cameras was snapping photos for a science program. This image took nearly 40 hours to complete and is one of the longest exposures ever taken by Hubble. September 2005
The nebula of dust and gas has two nearly symmetric lobes (or cones) of matter that are being ejected from a central star. Over the last 1,500 years, nearly one and a half times the mass of our Sun has been lost by the central star of the Boomerang Nebula in an ejection process known as a bipolar outflow. The nebula's name is derived from its symmetric structure as seen from ground-based telescopes. Hubble's sharp view is able to resolve patterns and ripples in the nebula very close to the central star that are not visible from the ground. Astronomers are uncertain of the cause of bipolar outflow in this, and many other, young nebulae like the Boomerang. It may be that a disk of slow-moving material is situated around the equator of the star, thereby blocking more rapidly moving ejected material there, and allowing only matter closer to the poles to be ejected. Another consideration may be that magnetic fields are responsible for constraining the material and thus causing the double-lobed shape of the nebula. Bipolar outflows are seen to occur both from very young stars ("protostars") that are still in the process of collapsing and forming, and from old stars nearing the ends of their lives that have become bloated red giants. The Boomerang is believed to be the ejected outer layers from an old red giant. Each lobe of the Boomerang Nebula is nearly one light-year in length, making the total length of the nebula half as long as the distance from our Sun to our nearest neighbors- the Alpha Centauri stellar system, located roughly 4 light-years away. These images of the Boomerang were taken in early 2005 with the Advanced Camera for Surveys onboard Hubble. A visible light filter was used in combination with a series of polarization filters. Similar to polarizing sunglasses that are used to reduce the amount of scattered light that enters our eyes on a sunny day, the telescope's polarizing filters allow only light of a specific polarization angle to pass through to the camera's detector. By combining images taken at different polarization angles, astronomers can study light scattering in the nebula and the properties of the small dust particles responsible for the scattering. The resultant image is a multi-hued composite of subtle pastel colors. October 2005 October's Hubble Heritage image is of the supernova remnant N132D in the Large Magellanic Cloud. 160,000 light-years from us, the nebula lies in the constellation Dorado; this image covers approximately 3.2 arcminutes across (148 light-years). The image is combined from data taken on January 21/22, 2004, and July 20, 2000, for a total of 24.4 hours. This image is a composite of five filters (g (F475W), V (F550M), H-α and N II (F658N), i (F775W), and z (F850LP)). Intricate wisps of glowing gas float amid a myriad of stars in this image created by combining data from NASA's Hubble Space Telescope and Chandra X-ray Observatory. The gas is a supernova remnant, cataloged as N132D, ejected from the explosion of a massive star that occurred some 3,000 years ago. This titanic explosion took place in the Large Magellanic Cloud, a nearby neighbor galaxy of our own Milky Way. The complex structure of N132D is due to the expanding supersonic shock wave from the explosion impacting the interstellar gas of the LMC. Deep within the remnant, the Hubble visible light image reveals a crescent-shaped cloud of pink emission from hydrogen gas, and soft purple wisps that correspond to regions of glowing oxygen emission. A dense background of colorful stars in the LMC is also shown in the Hubble image. The large horseshoe-shaped gas cloud on the left-hand side of the remnant is glowing in X-rays, as imaged by Chandra. In order to emit X-rays, the gas must have been heated to a temperature of about 18 million degrees Fahrenheit (10 million degrees Celsius). A supernova-generated shock wave traveling at a velocity of more than four million miles per hour (2,000 kilometers per second) is continuing to propagate through the low-density medium today. The shock front where the material from the supernova collides with ambient interstellar material in the LMC is responsible for these high temperatures. It is estimated that the star that exploded as a supernova to produce the N132D remnant was 10 to 15 times more massive than our own Sun. As fast-moving ejecta from the explosion slam into the cool, dense interstellar clouds in the LMC, complex shock fronts are created. A supernova remnant like N132D provides a rare opportunity for direct observation of stellar material, because it is made of gas that was recently hidden deep inside a star. Thus it provides information on stellar evolution and the creation of chemical elements such as oxygen through nuclear reactions in their cores. Such observations also help reveal how the interstellar medium (the gas that occupies the vast spaces between the stars) is enriched with chemical elements because of supernova explosions. Later on, these elements are incorporated into new generations of stars and their accompanying planets. Visible only from Earth's southern hemisphere, the LMC is an irregular galaxy lying about 160,000 light-years from the Milky Way. The supernova remnant appears to be about 3,000 years old, but since its light took 160,000 years to reach us, the explosion actually occurred some 163,000 years ago.
Every 26 months, Mars is opposite the Sun in our nighttime sky. Since the repair of NASA’s Hubble Space Telescope in 1993, Mars has been at such an "opposition" with the Sun six times. Mars was the closest in 2003 when it came within 35 million miles (56 million km) of Earth. The part of Mars that is tilted towards the Earth also shifts over time, resulting in the changing visibility of the polar caps. Clouds and dust storms as well as the size of the ice caps can change the appearance of Mars on time scales of days, weeks, and months. Other features of Mars, though, such as some of the large dark markings, have remained unchanged for centuries, and will probably look essentially like this for the next few millennia. The most recent image of Mars was snapped on October 28, within a day of its closest approach to Earth on the night of October 29. Hubble astronomers were also excited to have captured a regional dust storm on Mars that has been growing and evolving over the past few weeks. The dust storm, which is nearly in the middle of the planet in this Hubble view is about 930 miles (1500 km) long measured diagonally, which is about the size of the states of Texas, Oklahoma, and New Mexico combined. Astronomers with even modest-sized telescopes have been able to keep an eye on this storm. The smallest resolvable features in the image (small craters and wind streaks) are the size of a large city, about 12 miles (20 km) across. The occurrence of the dust storm is in close proximity to the NASA Mars Exploration Rover Opportunity's landing site in Sinus Meridiani. Dust in the atmosphere could block some of the sunlight needed to keep the rover operating at full power. On October 29/30, Mars and Earth reached the point in their orbits where the two planets were the closest they have been since August of 2003. The red planet, named after the Roman god of war, won't be this close again to Earth until 2018. At the 2005 closest approach Mars was at a distance of 43 million miles (69 million km), comparatively a stone's throw across the solar system. Mars goes through a 26-month cycle where its distance from Earth changes. At times when the distance is smallest between the two planets, Mars appears brighter in the sky for Earth viewers. November 2005 - Image is Early Release of Mars (see above) December 2005 December's Hubble Heritage image is of the cluster and nebula known as NGC 346 and N66, in the Small Magellanic Cloud. 210,000 light-years from us, the nebula lies in the constellation Tucana; this image covers approximately 4.7 arcminutes across (280 light-years). The image is combined from data taken in July 2004. This image is a composite of one filter (H-α (F658N)). A dramatic structure of arched, ragged filaments decorates this Hubble Space Telescope view of one of the most dynamic and intricately detailed star-forming regions in space. A ridge of material gently cradles a star cluster in its center. The cluster, known as NGC 346 is located 210,000 light-years away in the Small Magellanic Cloud (SMC), a satellite galaxy of our Milky Way. A torrent of radiation from the cluster's hot stars eats into denser areas creating the sculpture of dust and gas. The dark, intricately beaded edge of the ridge, seen in silhouette by Hubble, is particularly dramatic. It contains several small dust globules that point back towards the central cluster, like windsocks caught in a gale. Energetic outflows and radiation from hot young stars are eroding the dense outer portions of the star-forming region, formally known as N66, exposing new stellar nurseries. The diffuse fringes of the nebula prevent the energetic outflows from streaming directly away from the cluster, leaving instead a trail of filaments marking the swirling path of the outflows. The NGC 346 cluster, at the center of this Hubble image, is resolved into at least three sub-clusters and collectively contains dozens of hot, high-mass stars, more than half of the known high-mass stars in the entire SMC galaxy. A myriad of smaller, compact clusters is also visible throughout the region. Some of these mini-clusters appear to be embedded in dust and nebulosity, and they are sites of recent or ongoing star formation. Much of the starlight from these clusters is muted by local dust concentrations that are the remnants of the original molecular cloud that collapsed to form N66. The image appears in black and white to show the dramatic structure of this pure Hubble filter - H-α (pronounced H alpha) - which constrains light that is only emitted from doubly ionized hydrogen. In star forming regions, this filter is particularly useful in showing detail and structure from gas and dust. 
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The
Hubble Heritage team released a second image in March, the elliptical
galaxy NGC 1316, AKA Fornax A. 75 million light-years from us, the galaxy
lies in the constellation Fornax; this image covers approximately 2.7
arcminutes across (60,000 light-years). The images is combined from data
taken on March 4 and 7, 2003, for a total of 3.8 hours. This image is
a composite of three filters (B (F435W), V (F555W), and I (F814W)).
The
Hubble Heritage team released a second image in April, the face-on spiral
galaxy with companion, the Whirlpool Galaxy, AKA M51, AKA NGC 5194/5.
31 million light-years from us, the galaxy lies in the constellation
Canes Venatici; this image covers approximately 9.67 arcminutes across
(87,000 light-years). The images is combined from data taken January
18-22, 2005, for a total of 9.0 hours. This image is a composite of four
filters (B (F435W), V (F555W), I (F814W), and H-
The
Hubble Heritage team released a second image in October, the planet 