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SEASONAL CHANGES IN MARS' NO
These images, which seem to
| Description |
These images, which seem to have been taken while NASA's Hubble Space Telescope (HST) was looking directly down on the Martian North Pole, were actually created by assembling mosaics of three sets of images taken by HST in October, 1996 and in January and March, 1997 and projecting them to appear as they would if seen from above the pole. This first mosaic is a view which could not actually be seen in nature because at this season a portion of the pole would have actually been in shadow, the last view, taken near the summer solstice, would correspond to the Midnight Sun on Earth with the pole fully illuminated all day. The resulting polar maps begin at 50 degrees N latitude and are oriented with 0 degrees longitude at the 12 o'clock position. This series of pictures captures the seasonal retreat of Mars' north polar cap. October 1996 (early spring in the Northern hemisphere): In this map, assembled from images obtained between Oct. 8 and 15, the cap extends down to 60 degrees N latitude, nearly it's maximum winter extent. (The notches are areas where Hubble data were not available). A thin, comma-shaped cloud of dust can be seen as a salmon-colored crescent at the 7 o'clock position. The cap is actually fairly circular about the geographic pole at this season, the bluish "knobs" where the cap seems to extend further are actually clouds that occurred near the edges of the three separate sets of images used to make the mosaic. January 1997 (mid-spring): Increased warming as spring progresses in the northern hemisphere has sublimated the carbon dioxide ice and frost below 70 degrees north latitude. The faint darker circle inside the cap boundary marks the location of circumpolar sand dunes (see March '97 map), these dark dunes are warmed more by solar heating than are the brighter surroundings, so the surface frost sublimates from the dunes earlier than from the neighboring areas. Particularly evident is the marked hexagonal shape of the polar cap at this season, noted previously by HST in 1995 and Mariner 9 in 1972, this may be due to topography, which isn't well known, or to wave structure in the circulation. This map was assembled from WFPC2 images obtained between Dec. 30, 1996 and Jan. 4, 1997. March 30, 1997 (early summer): The cap has fully retreated to its remnant core of water-ice. This residual cap is actually almost cut into two by a large, horn-shaped canyon called Chasma Borealis which is cut deeply into the polar terrain. The HST images also reveal a curious layered terrain which is evidence of past climatic changes on Mars. The sublimation of all of the carbon dioxide has exposed the ring of dark sand dunes which encircle the North Polar Cap. Outliers of ice persist south of the polar sand sea (between the 3 o'clock and 9 o'clock positions). The bright circular features at 3, 6, and 9 o'clock are ice-filled craters. All images were taken with the Wide Field and Planetary Camera 2. The color is constructed from images taken in red (673 nm) , blue (410 nm) and green (502 nm) light. The resolution at the North Pole ranges from about 115 km/pixel in October '96 to about 45 km/pixel in March '97. Credit: Phil James (Univ. Toledo), Todd Clancy (Space Science Inst., Boulder, CO), Steve Lee (Univ. Colorado), and NASA |
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Hubble Captures Full View of
| title |
Hubble Captures Full View of Uranus's Rings on Edge |
| date |
08.14.2007 |
| description |
NASA's Hubble Space Telescope captures a rare view of the entire ring system of the planet Uranus, tilted edge-on to Earth. The rings were photographed with Hubble's Wide Field Planetary Camera 2 on August 14, 2007. The edge-on rings appear as spikes above and below the planet. The rings cannot be seen running fully across the face of the planet because the bright glare of the planet has been blocked out in the HST photo (a small amount of residual glare appears as a fan-shaped image artifact, along with an edge between the exposure for the inner and outer rings). A much shorter color exposure of the planet has been photo-composited to show its size and position relative to the ring plane. Earthbound astronomers only see the rings' edge every 42 years as the planet follows a leisurely 84-year orbit about the Sun. However, the last time the rings were tilted edge-on to Earth astronomers didn't even know they existed. The fainter outer rings appear in the 2003 Hubble Space Telescope images, but were not noticed there until they were seen in the 2005 images and the previous ones were analyzed more carefully. Uranus has a total of 13 dusty rings. Credit: NASA [ http://www.nasa.gov/ ], ESA [ http://www.spacetelescope.org/ ], and M. Showalter (SETI Institute) |
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Hubble Spots Northern Hemisp
| title |
Hubble Spots Northern Hemispheric Clouds on Uranus |
| date |
07.31.1997 |
| description |
Using visible light, astronomers for the first time this century have detected clouds in the northern hemisphere of Uranus. The newest images, taken July 31 and Aug. 1, 1997 with NASA Hubble Space Telescope's Wide Field and Planetary Camera 2, show banded structure and multiple clouds. Using these images, Dr. Heidi Hammel (Massachusetts Institute of Technology) and colleagues Wes Lockwood (Lowell Observatory) and Kathy Rages (NASA Ames Research Center) plan to measure the wind speeds in the northern hemisphere for the first time. Uranus is sometimes called the "sideways" planet, because its rotation axis tipped more than 90 degrees from the planet's orbit around the Sun. The "year" on Uranus lasts 84 Earth years, which creates extremely long seasons - winter in the northern hemisphere has lasted for nearly 20 years. Uranus has also been called bland and boring, because no clouds have been detectable in ground-based images of the planet. Even to the cameras of the Voyager spacecraft in 1986, Uranus presented a nearly uniform blank disk, and discrete clouds were detectable only in the southern hemisphere. Voyager flew over the planet's cloud tops near the dead of northern winter (when the northern hemisphere was completely shrouded in darkness). Spring has finally come to the northern hemisphere of Uranus. The newest images, both the visible-wavelength ones described here and those taken a few days earlier with the Near Infrared and Multi-Object Spectrometer (NICMOS) by Erich Karkoschka (University of Arizona), show a planet with banded structure and detectable clouds. Two images are shown here. The "aqua" image (on the left) is taken at 5,470 Angstroms, which is near the human eye's peak response to wavelength. Color has been added to the image to show what a person on a spacecraft near Uranus might see. Little structure is evident at this wavelength, though with image-processing techniques, a small cloud can be seen near the planet's northern limb (rightmost edge). The "red" image (on the right) is taken at 6,190 Angstroms, and is sensitive to absorption by methane molecules in the planet's atmosphere. The banded structure of Uranus is evident, and the small cloud near the northern limb is now visible. Scientists are expecting that the discrete clouds and banded structure may become even more pronounced as Uranus continues in its slow pace around the Sun. "Some parts of Uranus haven't seen the Sun in decades," says Dr. Hammel, "and historical records suggest that we may see the development of more banded structure and patchy clouds as the planet's year progresses." Some scientists have speculated that the winds of Uranus are not symmetric around the planet's equator, but no clouds were visible to test those theories. The new data will provide the opportunity to measure the northern winds. Hammel and colleagues expect to have results soon. The Wide Field/Planetary Camera 2 was developed by the Jet Propulsion Laboratory and managed by, the Goddard Spaced Flight Center for NASA's Office of Space Science. This image and other images and data received from the Hubble Space Telescope are posted on the World Wide Web on the Space Telescope Science Institute home page at URL http://oposite.stsci.edu *Image Credit*: Heidi Hammel (Massachusetts Institute of Technology), NASA |
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Neptune's Stormy Disposition
| title |
Neptune's Stormy Disposition |
| date |
08.11.1998 |
| description |
Using powerful ground-and space-based telescopes, scientists have obtained a moving look at some of the wildest, weirdest weather in the solar system. Combining simultaneous observations of Neptune made with the Hubble Space Telescope and NASA's Infrared Telescope Facility on Mauna Kea, Hawaii, a team of scientists led by Lawrence A. Sromovsky of the University of Wisconsin-Madison has captured the most insightful images to date of a planet whose blustery weather -- monster storms and equatorial winds of 900 miles per hour -- bewilders scientists. The weather on Neptune, the eighth planet from the sun, is an enigma to begin with. The mechanism that drives its near-supersonic winds and giant storms has yet to be determined. On Earth, weather is driven by energy from the sun as it heats the atmosphere and oceans. On Neptune, the sun is 900 times dimmer and scientists have yet to understand how Neptune's weather-generating machinery can be so efficient. "It's an efficient weather machine compared to Earth," said Sromovsky. "It seems to run on almost no energy." In an effort to dissect the distant planet's atmosphere and monitor its bizarre weather, Sromovsky and his colleagues obtained a series of measurements and images over the span of three of Neptune's rotations. From those observations, Sromovsky said it is possible to measure Neptune's circulation and view a "strange menagerie of variable, discrete cloud features and zonal bands" of weather. Moreover, the new observations enabled Sromovsky's team to probe some of the deeper features of the atmosphere and to map Neptune's cloud tops. "We can show some clouds are higher than others, that altitudes vary," he said. Knowing something about the topography of Neptune's clouds, provides a direct way to measure Neptune's powerful winds. A looming mystery, he said, is the fate of huge dark spots, possibly giant storms. When the planetary probe Voyager visited Neptune in 1989, it detected the Great Dark Spot, a pulsating feature nearly the size of the Earth itself. Two years ago, Hubble observations showed the spot had disappeared, and that another, smaller spot had emerged. But instead of growing to a large-scale storm like the Great Dark Spot, the new spot appears to be trapped at a fixed latitude and may be declining in intensity, said Sromovsky, a senior scientist at UW-Madison's Space Science and Engineering Center. "They behave like storms, and the Great Dark Spot was an exaggerated features we haven't seen on any other planet. They seem to come and go, and rather than an exciting development of these dark spots, they dissipate." Another strange aspect of the distant planet's weather are distinct bands of weather that run parallel to the Neptunian equator. The weather bands encircle the planet and, in some respects, may be similar to the equatorial region of the Earth where tropical heat provides abundant energy to make clouds. "We can see regions of latitude where Neptune, consistently generates bright clouds," said Sromovsky. The regions are both above and below the planet's equator, but he added that it was uncertain what their explanation is in terms of atmospheric circulation. Sromovsky said that compared to the look provided by the Voyager spacecraft, Neptune is a different place: "The character of Neptune is different from what it was at the time of Voyager. The planet seems stable, yet different." Sromovsky's Hubble observations were made with Wide Field Planetary Camera 2 and the Near Infrared Camera and Multi-Object Spectrometer. The different instruments allowed observations to be made in a variety of wavelengths, each providing a different set of information about Neptune's clouds, their structures and how they circulate. *Image Credit*: NASA |
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Mars and Acidalia
| Title |
Mars and Acidalia |
| Full Description |
Taking advantage of Mars's closest approach to Earth in eight years, astronomers using NASA's Hubble Space Telescope have taken the space- based observatory's sharpest views yet of the Red Planet. The telescope's Wide Field and Planetary Camera 2 snapped these images between April 27 and May 6, when Mars was 54 million miles (87 million kilometers) from Earth. From this distance the telescope could see Martian features as small as 12 miles (19 kilometers) wide. The telescope obtained four images, which, together, show the entire planet. Each view depicts the planet as it completes one quarter of its daily rotation. In these views the north polar cap is tilted toward the Earth and is visible prominently at the top of each picture. The images were taken in the middle of the Martian northern summer, when the polar cap had shrunk to its smallest size. During this season the Sun shines continuously on the polar cap. Previous telescopic and spacecraft observations have shown that this summertime "residual" polar cap is composed of water ice, just like Earth's polar caps. These Hubble telescope snapshots reveal that substantial changes in the bright and dark markings on Mars have occurred in the 20 years since the NASA Viking spacecraft missions first mapped the planet. The Martian surface is dynamic and ever changing. Some regions that were dark 20 years ago are now bright red, some areas that were bright red are now dark. Winds move sand and dust from region to region, often in spectacular dust storms. Over long timescales many of the larger bright and dark markings remain stable, but smaller details come and go as they are covered and then uncovered by sand and dust. This image is centered near the location of the Pathfinder landing site. Dark sand dunes that surround the polar cap merge into a large, dark region called Acidalia. This area, as shown by images from the Hubble telescope and other spacecraft, is composed of dark, sand-sized grains of pulverized volcanic rock. Below and to the left of Acidalia are the massive Martian canyon systems of Valles Marineris, some of which form long linear markings that were once thought by some to be canals. Early morning clouds can be seen along the left limb of the planet, and a large cyclonic storm composed of water ice is churning near the polar cap. |
| Date |
06/30/1999 |
| NASA Center |
Hubble Space Telescope Center |
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Mars and Elysium
| Title |
Mars and Elysium |
| Full Description |
Taking advantage of Mars's closest approach to Earth in eight years, astronomers using NASA's Hubble Space Telescope have taken the space- based observatory's sharpest views yet of the Red Planet. The telescope's Wide Field and Planetary Camera 2 snapped these images between April 27 and May 6, when Mars was 54 million miles (87 million kilometers) from Earth. From this distance the telescope could see Martian features as small as 12 miles (19 kilometers) wide. The telescope obtained these four images, which, together, show the entire planet. Each view depicts the planet as it completes one quarter of its daily rotation. In these views the north polar cap is tilted toward the Earth and is visible prominently at the top of each picture. The images were taken in the middle of the Martian northern summer, when the polar cap had shrunk to its smallest size. During this season the Sun shines continuously on the polar cap. Previous telescopic and spacecraft observations have shown that this summertime "residual" polar cap is composed of water ice, just like Earth's polar caps. These Hubble telescope snapshots reveal that substantial changes in the bright and dark markings on Mars have occurred in the 20 years since the NASA Viking spacecraft missions first mapped the planet. The Martian surface is dynamic and ever changing. Some regions that were dark 20 years ago are now bright red, some areas that were bright red are now dark. Winds move sand and dust from region to region, often in spectacular dust storms. Over long timescales many of the larger bright and dark markings remain stable, but smaller details come and go as they are covered and then uncovered by sand and dust. This image is centered near another volcanic region known as Elysium. This area shows many small, dark markings that have been observed by the Hubble telescope and other spacecraft to change as a result of the movement of sand and dust across the Martian surface. In the upper left of this image, at high northern latitudes, a large chevron-shaped area of water ice clouds mark a storm front. Along the right limb, a large cloud system has formed around the Olympus Mons volcano. |
| Date |
06/30/1999 |
| NASA Center |
Hubble Space Telescope Center |
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Mars and Syrtis Major
| Title |
Mars and Syrtis Major |
| Full Description |
Taking advantage of Mars's closest approach to Earth in eight years, astronomers using NASA's Hubble Space Telescope have taken the space- based observatory's sharpest views yet of the Red Planet. The telescope's Wide Field and Planetary Camera 2 snapped these images between April 27 and May 6, when Mars was 54 million miles (87 million kilometers) from Earth. From this distance the telescope could see Martian features as small as 12 miles (19 kilometers) wide. The telescope obtained four images, which, together, show the entire planet. Each view depicts the planet as it completes one quarter of its daily rotation. In these views the north polar cap is tilted toward the Earth and is visible prominently at the top of each picture. The images were taken in the middle of the Martian northern summer, when the polar cap had shrunk to its smallest size. During this season the Sun shines continuously on the polar cap. Previous telescopic and spacecraft observations have shown that this summertime "residual" polar cap is composed of water ice, just like Earth's polar caps. These Hubble telescope snapshots reveal that substantial changes in the bright and dark markings on Mars have occurred in the 20 years since the NASA Viking spacecraft missions first mapped the planet. The Martian surface is dynamic and ever changing. Some regions that were dark 20 years ago are now bright red, some areas that were bright red are now dark. Winds move sand and dust from region to region, often in spectacular dust storms. Over long timescales many of the larger bright and dark markings remain stable, but smaller details come and go as they are covered and then uncovered by sand and dust. The dark feature known as Syrtis Major was first seen telescopically by the astronomer Christiaan Huygens in the 17th century. Many small, dark, circular impact craters can be seen in this region, attesting to the Hubble telescope's ability to reveal fine detail on the planet's surface. To the south of Syrtis is a large circular feature called Hellas. Viking and more recently Mars Global Surveyor have revealed that Hellas is a large and deep impact crater. These Hubble telescope pictures show it to be filled with surface frost and water ice clouds. Along the right limb, late afternoon clouds have formed around the volcano Elysium. |
| Date |
06/30/1999 |
| NASA Center |
Hubble Space Telescope Center |
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Mars and Tharsis
| Title |
Mars and Tharsis |
| Full Description |
Taking advantage of Mars's closest approach to Earth in eight years, astronomers using NASA's Hubble Space Telescope have taken the space- based observatory's sharpest views yet of the Red Planet. The telescope's Wide Field and Planetary Camera 2 snapped these images between April 27 and May 6, when Mars was 54 million miles (87 million kilometers) from Earth. From this distance the telescope could see Martian features as small as 12 miles (19 kilometers) wide. The telescope obtained four images, which together show the entire planet. Each view depicts the planet as it completes one quarter of its daily rotation. In these views the north polar cap is tilted toward the Earth and is visible prominently at the top of each picture. The images were taken in the middle of the Martian northern summer, when the polar cap had shrunk to its smallest size. During this season the Sun shines continuously on the polar cap. Previous telescopic and spacecraft observations have shown that this summertime "residual" polar cap is composed of water ice, just like Earth's polar caps. These Hubble telescope snapshots reveal that substantial changes in the bright and dark markings on Mars have occurred in the 20 years since the NASA Viking spacecraft missions first mapped the planet. The Martian surface is dynamic and ever changing. Some regions that were dark 20 years ago are now bright red, some areas that were bright red are now dark. Winds move sand and dust from region to region, often in spectacular dust storms. Over long timescales many of the larger bright and dark markings remain stable, but smaller details come and go as they are covered and then uncovered by sand and dust. This image is centered on the region of the planet known as Tharsis, home of the largest volcanoes in the solar system. The bright, ring- like feature just to the left of center is the volcano Olympus Mons, which is more than 340 miles (550 kilometers) across and 17 miles (27 kilometers) high. Thick deposits of fine-grained, windblown dust cover most of this hemisphere. The colors indicate that the dust is heavily oxidized ("rusted"), and millions (or perhaps billions) of years of dust storms have homogenized its composition. Prominent late afternoon clouds along the right limb of the planet can be seen. |
| Date |
06/30/1999 |
| NASA Center |
Hubble Space Telescope Center |
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N81 in the Small Magellanic
| Title |
N81 in the Small Magellanic Cloud |
| Full Description |
A NASA Hubble Space Telescope "family portrait" of young, ultra-bright stars nested in their embryonic cloud of glowing gases. The celestial maternity ward, called N81, is located 200,000 light-years away in the Small Magellanic Cloud (SMC), a small irregular satellite galaxy of our Milky Way. Hubble's exquisite resolution allows astronomers to pinpoint 50 separate stars tightly packed in the nebula's core within a 10 light- year diameter - slightly more than twice the distance between earth and the nearest star to our sun. The closest pair of stars is only 1/3 of a light-year apart (0.3 arcseconds in the sky). This furious rate of mass loss from these super-hot stars is evident in the Hubble picture that reveals dramatic shapes sculpted in the nebula's wall of glowing gases by violent stellar winds and shock waves. A pair of bright stars in the center of the nebula is pouring out most of the ultraviolet radiation to make the nebula glow. Just above them, a small dark knot is all that is left of the cold cloud of molecular hydrogen and dust the stars were born from. Dark absorption lanes of residual dust trisect the nebula. The nebula offers a unique opportunity for a close-up glimpse at the firestorm' accompanying the birth of extremely massive stars, each blazing with the brilliance of 300,000 of our suns. Such galactic fireworks were much more common billions of years ago in the early universe, when most star formation took place. The "natural- color" view was assembled from separate images taken with the Wide Field and Planetary Camera 2, in ultraviolet light and two narrow emission lines of ionized Hydrogen (H-alpha, H-beta). |
| Date |
09/24/1997 |
| NASA Center |
Hubble Space Telescope Center |
|
Nursery of New Stars
| Title |
Nursery of New Stars |
| Full Description |
This is a Hubble Space Telescope image (right) of a vast nebula called NGC 604, which lies in the neighboring spiral galaxy M33, located 2.7 million light-years away in the constellation Triangulum. This is a site where new stars are being born in a spiral arm of the galaxy. Though such nebulae are common in galaxies, this one is particularly large, nearly 1,500 light-years across. The nebula is so vast it is easily seen in ground-based telescopic images (left). At the heart of NGC 604 are over 200 hot stars, much more massive than our Sun (15 to 60 solar masses). They heat the gaseous walls of the nebula making the gas fluoresce. Their light also highlights the nebula's three-dimensional shape, like a lantern in a cavern. By studying the physical structure of a giant nebula, astronomers may determine how clusters of massive stars affect the evolution of the interstellar medium of the galaxy. The nebula also yields clues to its star formation history and will improve understanding of the starburst process when a galaxy undergoes a "firestorm" of star formation. The image was taken on January 17, 1995 with Hubble's Wide Field and Planetary Camera 2. Separate exposures were taken in different colors of light to study the physical properties of the hot gas (17,000 degrees Fahrenheit, 10,000 degrees Kelvin |
| Date |
01/17/1995 |
| NASA Center |
Hubble Space Telescope Center |
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Peering into the Heart of th
| Title |
Peering into the Heart of the Crab Nebula |
| Full Description |
In the year 1054 A.D., Chinese astronomers were startled by the appearance of a new star, so bright that it was visible in broad daylight for several weeks. Today, the Crab Nebula is visible at the site of the "Guest Star." Located about 6,500 light-years from Earth, the Crab Nebula is the remnant of a star that began its life with about 10 times the mass of our own Sun. Its life ended on July 4, 1054 when it exploded as a supernova. In this image, NASA's Hubble Space Telescope has zoomed in on the center of the Crab to reveal its structure with unprecedented detail. The Crab Nebula data were obtained by Hubble's Wide Field and Planetary Camera 2 in 1995. Images taken with five different color filters have been combined to construct this new false-color picture. Resembling an abstract painting by Jackson Pollack, the image shows ragged shards of gas that are expanding away from the explosion site at over 3 million miles per hour. The core of the star has survived the explosion as a pulsar, visible in the Hubble image as the lower of the two moderately bright stars to the upper left of center. The pulsar is a neutron star that spins on its axis 30 times a second. It heats its surroundings, creating the ghostly diffuse bluish-green glowing gas cloud in its vicinity, including a blue arc just to its right. The colorful network of filaments is the material from the outer layers of the star that was expelled during the explosion. The picture is somewhat deceptive in that the filaments appear to be close to the pulsar. In reality, the yellowish green filaments toward the bottom of the image are closer to us, and approaching at some 300 miles per second. The orange and pink filaments toward the top of the picture include material behind the pulsar, rushing away from us at similar speeds. The various colors in the picture arise from different chemical elements in the expanding gas, including hydrogen (orange), nitrogen (red), sulfur (pink), and oxygen (green). The shades of color represent variations in the temperature and density of the gas, as well as changes in the elemental composition. Kris Davidson (U. Minn.) led the research team of William P. Blair (JHU), Robert A. Fesen (Dartmouth), Alan Uomoto (JHU), Gordon M. MacAlpine (U. Mich.), and Richard B.C. Henry (U. Okla.) in the collection of the HST data. The Hubble Heritage Team created the color image from black and white data processed by Dr. Blair. |
| Date |
06/01/2000 |
| NASA Center |
Hubble Space Telescope Center |
|
Cometary Knots Around A Dyin
| Title |
Cometary Knots Around A Dying Star |
| Full Description |
These gigantic, tadpole-shaped objects are probably the result of a dying star's last gasps. Dubbed "cometary knots" because their glowing heads and gossamer tails resemble comets, the gaseous objects probably were formed during a star's final stages of life. Hubble astronomer C. Robert O'Dell and graduate student Kerry P. Handron of Rice University in Houston, Texas discovered thousands of these knots with the Hubble Space Telescope while exploring the Helix nebula, the closest planetary nebula to Earth at 450 light-years away in the constellation Aquarius. Although ground-based telescopes have revealed such objects, astronomers have never seen so many of them. The most visible knots all lie along the inner edge of the doomed star's ring, trillions of miles away from the star's nucleus. Although these gaseous knots appear small, they're actually huge. Each gaseous head is at least twice the size of our solar system, each tail stretches for 100 billion miles, about 1,000 times the distance between the Earth and the Sun. Astronomers theorize that the doomed star spews hot, lower-density gas from its surface, which collides with cooler, higher-density gas that had been ejected 10,000 years before. The crash fragments the smooth cloud surrounding the star into smaller, denser finger-like droplets, like dripping paint. This image was taken in August, 1994 with Hubble's Wide Field Planetary Camera 2. The red light depicts nitrogen emission ([NII] 6584A), green, hydrogen (H-alpha, 6563A), and blue, oxygen (5007A). |
| Date |
08/01/1994 |
| NASA Center |
Hubble Space Telescope Center |
|
Fireworks of Star Formation
| Title |
Fireworks of Star Formation Light Up a Galaxy |
| Full Description |
Located some 13 million light-years from Earth, NGC 4214 is currently forming clusters of new stars from its interstellar gas and dust. In this Hubble image, we can see a sequence of steps in the formation and evolution of stars and star clusters. The picture was created from exposures taken in several color filters with Hubble's Wide Field Planetary Camera 2. NGC 4214 contains a multitude of faint stars covering most of the frame, but the picture is dominated by filigreed clouds of glowing gas surrounding bright stellar clusters. The youngest of these star clusters are located at the lower right of the picture, where they appear as about half a dozen bright clumps of glowing gas. Young, hot stars have a whitish to bluish color in the Hubble image, because of their high surface temperatures, ranging from 10,000 up to about 50,000 degrees Celsius. The radiation and wind forces from the young stars literally blow bubbles in the gas. Over millions of years, the bubbles increase in size as the stars inside them grow older. Moving to the lower left from the youngest clusters, we find an older star cluster, around which a gas bubble has inflated to the point that there is an obvious cavity around the central cluster. The most spectacular feature in the Hubble picture lies near the center of NGC 4214. This object is a cluster of hundreds of massive blue stars, each of them more than 10,000 times brighter than our own Sun. A vast heart-shaped bubble, inflated by the combined stellar winds and radiation pressure, surrounds the cluster. The expansion of the bubble is augmented as the most massive stars in the center reach the ends of their lives and explode as supernovae. The principal astronomers are: John MacKenty, Jesus Maiz-Apellaniz (Space Telescope Science Institute), Colin Norman (Johns Hopkins University), Nolan Walborn (Space Telescope Science Institute), Richard Burg (Johns Hopkins University), Richard Griffiths (Carnegie Mellon University), and Rosemary Wyse (Johns Hopkins University). |
| Date |
01/06/2000 |
| NASA Center |
Hubble Space Telescope Center |
|
First Picture of Mars
| Title |
First Picture of Mars |
| Full Description |
Sand dunes and large rocks are revealed in this panoramic image of Mars, the first photograph taken by Viking 1's Camera 1 on July 23, 1976. The horizon is approximately 3 kilometers (2 miles) away. The left and right thirds of the picture are the same area that were photographed on July 20 (Sol 0) by camera 2 and provide stereo coverage. The middle third reveals a part of the Martian Surface not seen on the July 20th panorama. The late afternoon sun is high in the sky over the left side of the picture. The support struts of the S-band high-gain antenna extends to the top of the picture. The American flags are located on the two RTG (Radioisotope Thermoeletric Generator) wind screens. In the middle third of the picture the rocky surface is covered by thick deposits of wind-blown material, forming numerous dunes. At the center of the picture on the horizon are two low hills which may be part of the rim of the distant crater. Two very large rocks are visible in the middle ground, the nearer one is 3 meters (10 feet) in diameter and is 8 meters (25 feets) from the spacecraft. A cloud layer is visible halfway between the horizon and the top of the picture. The meterology boom is located right of center. Behind it, the "White Mesa" is visible, which could be seen on the far left side of the Sol 0 Camera 2 panorama. In the nearer ground are numerous rocks about 10cm (4 inches) across, with horse-shoe shaped scour marks on their upwind side and wind tails in their lee. The fine grained material in the front of them contains small pits formed by impact of material kicked out by the lander's descent rocket engines. |
| Date |
07/23/1976 |
| NASA Center |
Headquarters |
|
Galactic Silhouettes
| Title |
Galactic Silhouettes |
| Full Description |
This new image from NASA's Hubble Space Telescope and its Wide Field and Planetary Camera 2 (WFPC2) shows the unique galaxy pair called NGC 3314. Through an extraordinary chance alignment, a face-on spiral galaxy lies precisely in front of another larger spiral. This line-up provides us with the rare chance to visualize dark material within the front galaxy, seen only because it is silhouetted against the object behind it. Dust lying in the spiral arms of the foreground galaxy stands out where it absorbs light from the more distant galaxy. This silhouetting shows us where the interstellar dust clouds are located, and how much light they absorb. The outer spiral arms of the front galaxy appear to change from bright to dark, as they are projected first against deep space, and then against the bright background of the other galaxy. NGC 3314 lies about 140 million light-years from Earth, in the direction of the southern hemisphere constellation Hydra. The bright blue stars forming a pinwheel shape near the center of the front galaxy have formed recently from interstellar gas and dust. A small, red patch near the center of the image is the bright nucleus of the background galaxy, NGC 3314b. It is reddened for the same reason the setting sun looks red. When light passes through a volume containing small particles (molecules in the Earth's atmosphere or interstellar dust particles in galaxies), its color becomes redder. The Hubble Heritage color image of NGC 3314 was constructed from archival images taken with WFPC2 in April 1999 by Drs. William Keel and Ray White III (University of Alabama) in blue and infrared light, combined with new images obtained by the Heritage team in March 2000 using blue, green and red filters. |
| Date |
05/11/2000 |
| NASA Center |
Hubble Space Telescope Center |
|
Supernova SN1987A in the Lar
| Title |
Supernova SN1987A in the Large Magellanic Cloud |
| Full Description |
Glittering stars and wisps of gas create a breathtaking backdrop for the self-destruction of a massive star, called supernova 1987A, in the Large Magellanic Cloud, a nearby galaxy. Astronomers in the Southern hemisphere witnessed the brilliant explosion of this star on Feb. 23, 1987. Shown in this NASA Hubble Space Telescope image, the supernova remnant, surrounded by inner and outer rings of material, is set in a forest of ethereal, diffuse clouds of gas. This three-color image is composed of several pictures of the supernova and its neighboring region taken with the Wide Field and Planetary Camera 2 in Sept. 1994, Feb. 1996 and July 1997. The many bright blue stars nearby the supernova are massive stars, each more than six times heftier than our Sun. They are members of the same generation of stars as the star that went supernova about 12 million years ago. The presence of bright gas clouds is another sign of the youth of this region, which still appears to be a fertile breeding ground for new stars. In a few years the supernova's fast moving material will sweep the inner ring with full force, heating and exciting its gas, and will produce a new series of cosmic fireworks that will offer a striking view for more than a decade. |
| Date |
02/04/1999 |
| NASA Center |
Hubble Space Telescope Center |
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Hubble Reopens Eye on the Un
| Title |
Hubble Reopens Eye on the Universe |
| Full Description |
In its first glimpse of the heavens following the successful December 1999 servicing mission, NASA's Hubble Space Telescope captured a majestic view of a planetary nebula, the glowing remains of a dying, Sun-like star. This stellar relic, first spied by William Herschel in 1787, is nicknamed the "Eskimo" Nebula (NGC 2392) because, when viewed through ground-based telescopes, it resembles a face surrounded by a fur parka. In this Hubble telescope image, the "parka" is really a disk of material embellished with a ring of comet-shaped objects, with their tails streaming away from the central, dying star. The Eskimo's "face" also contains some fascinating details. Although this bright central region resembles a ball of twine, it is, in reality, a bubble of material being blown into space by the central star's intense "wind" of high-speed material. In this photo, one bubble lies in front of the other, obscuring part of the second lobe. Scientists believe that a ring of dense material around the star's equator, ejected during its red giant phase, created the nebula's shape. The bubbles are not smooth like balloons but have filaments of denser matter. Each bubble is about 1 light-year long and about half a light-year wide. Scientists are still puzzled about the origin of the comet-shaped features in the "parka." One possible explanation is that these objects formed from a collision of slow-and fast-moving gases. The Eskimo Nebula is about 5,000 light-years from Earth in the constellation Gemini. The picture was taken Jan. 10 and 11, 2000, with the Wide Field and Planetary Camera 2. The nebula's glowing gases produce the colors in this image: nitrogen (red), hydrogen (green), oxygen (blue), and helium (violet). |
| Date |
01/24/2000 |
| NASA Center |
Hubble Space Telescope Center |
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Hubble Observes the Moons an
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Hubble Observes the Moons and Rings of the Planet Uranus |
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Hubble Observes the Moons an
| Title |
Hubble Observes the Moons and Rings of the Planet Uranus |
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Hubble Peers Deep into the C
| Title |
Hubble Peers Deep into the Crowded Heart of the Densest Known Star Cluster |
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Hubble Views Saturn Ring-Pla
| Title |
Hubble Views Saturn Ring-Plane Crossing |
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Hubble Views Saturn Ring-Pla
| Title |
Hubble Views Saturn Ring-Plane Crossing |
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Hubble Spies a Really Cool S
| Title |
Hubble Spies a Really Cool Star |
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Hubble Provides the First Im
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Hubble Provides the First Images of Saturn's Aurorae |
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Hubble Confirms Abundance of
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Hubble Confirms Abundance of Protoplanetary Disks around Newborn Stars |
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Hubble Finds Thousands of Ga
| Title |
Hubble Finds Thousands of Gaseous Fragments Surrounding a Dying Star |
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Hubble's Close-Up View of a
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Hubble's Close-Up View of a Shock Wave from a Stellar Explosion |
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Hubble Tracks Jupiter Storms
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Hubble Tracks Jupiter Storms |
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Hubble Follows Rapid Changes
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Hubble Follows Rapid Changes in Jupiter's Aurora |
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Hubble Space Telescope Obser
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Hubble Space Telescope Observations of Neptune |
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Hubble Views Saturn Ring-Pla
| Title |
Hubble Views Saturn Ring-Plane Crossing |
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Hubble Observes the Fire and
| Title |
Hubble Observes the Fire and Fury of a Stellar Birth |
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Hubble Records a Black Hole'
| Title |
Hubble Records a Black Hole's Signature |
| General Information |
What is an Early Release Observation? A photograph of a celestial object that demonstrates the performance of a new Hubble camera. The colorful "zigzag" on the right is not the work of a flamboyant artist, but the signature of a super-massive black hole in the center of galaxy M84, discovered by the Hubble telescope's imaging spectrograph. The image on the left, also taken by Hubble, shows the core of the galaxy where the suspected black hole dwells. In a single exposure, astronomers mapped the motions of gas in the grip of the black hole's powerful gravitational pull by aligning Hubble's spectroscopic slit across the nucleus. |
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Hubble Space Telescope Finds
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Hubble Space Telescope Finds Stellar Graveyard |
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Panoramic Hubble Picture Sur
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Panoramic Hubble Picture Surveys Star Birth, Proto-Planetary Systems in the Great Orion Nebula |
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Hubble Sees Material Ejected
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Hubble Sees Material Ejected from Comet Hale-Bopp |
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Hubble Reveals Huge Crater o
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Hubble Reveals Huge Crater on the Surface of the Asteroid Vesta |
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Hubble Watches the Red Plane
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Hubble Watches the Red Planet as Mars Global Surveyor Begins Aerobraking |
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Hubble Finds Searchlight Bea
| Title |
Hubble Finds Searchlight Beams and Multiple Arcs around a Dying Star |
| General Information |
What is an American Astronomical Society Meeting release? A major news announcement issued at an American Astronomical Society meeting, the premier astronomy conference. This Hubble telescope picture of the Egg Nebula, also known as CRL2688, shows a pair of mysterious "searchlight" beams emerging from a hidden star and criss-crossed by numerous bright arcs. This image sheds new light on the poorly understood ejection of stellar matter that accompanies the slow death of Sun-like stars. The nebula is really a large cloud of dust and gas ejected by the star, expanding at a speed of 115,000 mph (20 km/s). A dense cocoon of dust [the dark band in the center] enshrouds the star and hides it from our view. Starlight escapes more easily in directions where the cocoon is thinner and is reflected towards us by dust particles in the cloud, giving it its overall appearance. Objects like CRL2688 are rare because they are in a very short evolutionary phase. However, they may hold the key to our understanding of how red giant stars transform themselves into planetary nebulae, the glowing remnants of dying stars. |
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Giant Star Birth Region in N
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Giant Star Birth Region in Neighboring Galaxy |
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Hubble Finds That Even Massi
| Title |
Hubble Finds That Even Massive Stars Just Fade Away |
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Hubble Uncovers Dust Disk ar
| Title |
Hubble Uncovers Dust Disk around a Massive Black Hole |
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Hale-Bopp Observations with
| Title |
Hale-Bopp Observations with Hubble and IUE Surprise Astronomers |
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Nearby Massive Star Cluster
| Title |
Nearby Massive Star Cluster Yields Insights into Early Universe |
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Hubble Camera Resumes Scienc
| Title |
Hubble Camera Resumes Science Operation with Picture of "Butterfly" in Space |
| General Information |
What is an Early Release Observation? A photograph of a celestial object that demonstrates the performance of a new Hubble camera. The Hubble telescope is back at work, capturing this view of the butterfly-wing-shaped nebula, NGC 2346. The nebula is about 2,000 light-years away from Earth in the direction of the constellation Monoceros. It represents the spectacular "last gasp" of a double-star system at the nebula's center. The image was taken March 6, 1997 as part of the re-commissioning of Hubble's previously installed scientific instruments following a successful servicing mission. |
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Hubble Peers into Heart of D
| Title |
Hubble Peers into Heart of Dying Star |
| General Information |
What is an Early Release Observation? A photograph of a celestial object that demonstrates the performance of a new Hubble camera. The Egg Nebula, also known as CRL 2688, is shown on the left as it appears in visible light and on the right as it looks in infrared light. Both Hubble views recount the last gasps of a dying, Sun-like star. Objects like the Egg Nebula are helping astronomers understand how stars like our Sun expel carbon and nitrogen ? elements crucial for life ? into space. Studies on the Egg Nebula show that these dying stars eject matter at high speeds along a preferred axis and may even have multiple jet-like outflows. The signature of the collision between this fast-moving material and the slower, out-flowing shells is the glow of hydrogen molecules [the red material] captured in the right-hand image. Read more: * Release Text [ http://hubblesite.org/newscenter/archive/releases/1997/11/text/ ] |
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A Mote in Hubble's Eye
| Title |
A Mote in Hubble's Eye |
| General Information |
What is Hubble Heritage? A monthly showcase of new and archival Hubble images. Go to the Heritage site. The Hubble telescope image is a typical Milky Way star field in the constellation Centaurus. Such snapshots can be used to study the evolution of stars that make up our galaxy. Most of the stars in this image lie near the center of our galaxy some 25,000 light-years distant. But one object, the blue curved streak [top right], is something much closer. An uncatalogued, mile-wide bit of rocky debris ? an asteroid ? orbiting the Sun only light-minutes away strayed into Hubble's field of view. An analysis of this asteroid indicates this asteroid's orbit could cross Mars's path. |
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Hubble Watches Uranus
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Hubble Watches Uranus |
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Hubble Witnesses the Final B
| Title |
Hubble Witnesses the Final Blaze of Glory of Sun-Like Stars |
| General Information |
What is a Space Science Update? Major Hubble discoveries on NASA television ... Astronomers explain their Hubble discoveries at a press conference, called a Space Science Update (SSU), broadcast on NASA television. The SSU includes a question and answer session with members of the media. The end of a Sun-like star's life was once thought to be simple: the star gracefully casts off a shell of glowing gas and then settles into a long retirement as a burned-out white dwarf. Now, a dazzling collection of detailed views from the Hubble telescope reveals surprisingly intricate, glowing patterns spun into space by aging stars: pinwheels, lawn sprinkler-style jets, elegant goblet shapes, and even some that look like a rocket engine's exhaust. In this picture of M2-9, twin lobes of material emanate from a central, dying star. Astronomers have dubbed this object the "Twin Jet Nebula" because of the shape of the lobes. If the nebula is sliced across the star, each side appears much like a pair of exhausts from jet engines. Indeed, because of the nebula's shape and the measured velocity of the gas, in excess of 200 miles per second, astronomers believe that the description as a super-super-sonic jet exhaust is quite apt. Read more: * Release Text [ http://hubblesite.org/newscenter/archive/releases/1997/38/text/ ] |
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