Astronomy and Stars
Discussions about astronomy and stars. As we look further out what can we find in the universe beyond Earth's atmosphere?
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Darth Vader take heart. Astronomers have discovered a powerful ultraviolet laser beam, several times brighter than our Sun, shooting toward Earth from a super-hot "death star." The observations, made with the Hubble telescope, have identified a gas cloud that acts as a natural ultraviolet laser near the huge, unstable star called Eta Carinae ? one of the most massive and energetic stars in our Milky Way Galaxy. The interstellar laser may result from Eta Carinae's violently chaotic eruptions, in which it blasts parts of itself out into space, like an interstellar geyser. This illustration depicts a gas cloud [left], which acts as a natural ultraviolet laser near Eta Cari…
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This Hubble telescope picture of Saturn captures a rare storm that appears as a white arrowhead-shaped feature near the planet's equator. An upwelling of warmer air, similar to a terrestrial thunderhead, generates the storm. The east-west extent of this storm is equal to the diameter of the Earth (about 7,900 miles). Hubble provides new details about the effects of Saturn's prevailing winds on the storm. These winds shape a dark "wedge" that eats into the left side of the bright central cloud. The new image shows that the storm's motion and size have changed little since its discovery in September 1994. View the full article
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The Hubble telescope's crisp vision has captured a first-time view of one of the smallest stars in our Milky Way Galaxy. Called Gliese 623b or Gl623b, the diminutive star [right of center] is 10 times less massive than the Sun and 60,000 times fainter. (If it were as far away as the Sun, it would be only eight times brighter than the full Moon). Located 25 light-years from Earth in the constellation Hercules, Gl623b is the smaller component of a double-star system, where the separation between the two members is only twice the distance between Earth and the Sun (approximately 200 million miles). The small star completes one orbit around its larger companion every four y…
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This NASA Hubble Space Telescope (HST) image of the central portion of a remote cluster of galaxies (CL 0939+4713) as it looked when the universe was two-thirds of its present age. Hubble's high resolution allows astronomers to study, for the first time, the shapes of galaxies as they were long ago. The Space Telescope pictures are sharp enough to distinguish between various forms of spiral galaxies. Most of the spiral, or disk, galaxies have odd features, suggesting they were easily distorted within the environment of the rich cluster. Hubble reveals a number of mysterious "fragments" of galaxies interspersed through the cluster. View the full article
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Astronomers using the Hubble telescope as a "time machine" have obtained the clearest views yet of distant galaxies that existed when the universe was a fraction of its current age. A series of remarkable pictures, spanning the life history of the cosmos, are providing the first clues to the life history of galaxies. The Hubble results suggest that elliptical galaxies developed remarkably quickly into their present shapes. However, spiral galaxies that existed in large clusters evolved over a much longer period - the majority being built and then torn apart by dynamic processes in a restless universe. These pictures of faraway galaxies, located 5 to 10 billion light-yea…
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Scientists for the first time have made images of the surface of Saturn's giant, haze-shrouded moon, Titan. They mapped light and dark features over the surface of the satellite during nearly a complete 16-day rotation. One prominent bright area they discovered is a surface feature 2,500 miles across, about the size of the continent of Australia. Titan, which is larger than Mercury and slightly smaller than Mars, is the only body in the solar system, other than Earth, that may have oceans and rainfall on its surface. The oceans and rain are composed of ethane-methane rather than water. View the full article
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An international team of astronomers has uncovered a galaxy in our own cosmic back yard. Though only ten million light-years away (or five times the distance of the Andromeda galaxy - closest assemblage of stars to our Milky Way Galaxy), this newly discovered city of more than 100 billion stars has gone undetected previously because it is hidden from view behind our Milky Way galaxy. View the full article
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This Hubble telescope snapshot of the planet Uranus reveals the planet's rings, at least five of the inner moons, and bright clouds in the Southern Hemisphere. Hubble allows astronomers to revisit the planet at a level of detail not possible since the Voyager 2 spacecraft flew by the planet briefly, nearly a decade ago. This picture is a combination of images showing the motion of the inner moons. Each inner moon appears as a string of three dots. Thanks to Hubble's capabilities, astronomers will be able to precisely determine the moons' orbits. View the full article
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Astronomers using the Hubble telescope have announced the most accurate distance measurement yet to the remote galaxy M100, located in the Virgo cluster of galaxies. This measurement will help provide a precise calculation of the expansion rate of the universe, called the Hubble Constant, which is crucial to determining the age and size of the universe. They calculated the distance - 56 million light-years - by measuring the brightness of several Cepheid variable stars in the galaxy. Cepheid variables are a class of pulsating star used as "milepost markers" to calculate the distance to nearby galaxies. The bottom image shows a region of M100. This Hubble telescope image…
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The Hubble telescope has provided new insights into how stars may have formed many billions of years ago in the early universe. Hubble observations of a pair of star clusters suggest they might be linked through stellar evolution processes. The pair of clusters is 166,000 light-years from Earth in the Large Magellanic Cloud in the southern constellation Doradus. The clusters are unusually close together for being distinct and separate objects, suggesting that they might be evolutionary relatives. View the full article
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Until now, the dim, small stars were considered ideal candidates for dark matter. Whatever dark matter is, its gravitational pull ultimately will determine whether the universe will expand forever or will someday collapse. Picking a region in our Milky Way Galaxy, astronomers predicted that Hubble should have spied 38 red dwarf stars if this class of objects harbored most of the dark matter. The diamond-shaped symbols in the left-hand image illustrate what scientists expected to see. Instead, they saw no stars. View the full article
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This series of eight NASA Hubble Space Telescope "snapshots" shows the evolution of the P-Q complex, also called the "gang of four" region, of comet P/Shoemaker-Levy 9. The eight individual frames chronicle changes in the comet during the 12 months before colliding with Jupiter. The sequence shows that the relative separations of the various cometary fragments, thought to range in size from about 500 meters to almost 4 km (2.5 miles) across, changed dramatically over this period. The apparent separation of Q1 and Q2 was only about 1100 kilometers (680 miles) on 1 July 1993 and increased to 28,000 kilometers (17,400 miles) by 20 July 1994. View the full article
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These four NASA Hubble Space Telescope images of Jupiter, as seen in visible (violet) and far-ultraviolet (UV) wavelengths, show the remarkable spreading of the clouds of smoke and dust thrown into the atmosphere after the impacts of the fragments of comet P/Shoemaker-Levy 9. These dark regions provide the only information ever obtained on the wind direction and speed in Jupiter's upper atmosphere. View the full article
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In the Jupiter campaign, scientists wanted to see how the comet collisions affected the Jovian aurorae, rapid and irregular displays of colorful light in a planet's night sky caused by the leakage of charged particles from the magnetosphere into the atmosphere. Following the impacts, some of the resulting debris became electrically charged and traveled along Jupiter's magnetic field lines and created new aurorae in Jupiter's northern hemisphere, as shown in this image. Scientists had never before observed aurorae this far south of where aurorae are typically seen in Jupiter's northern hemisphere. View the full article
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This series of snapshots, taken with NASA's Hubble Space Telescope, shows evolution of the comet P/Shoemaker-Levy 9 impact region called the D/G complex. This feature was produced by two nuclei of comet P/Shoemaker-Levy 9 that collided with Jupiter on 17 and 18 July 1994, respectively, and was later modified again by the impact of the S fragment on 21 July 1994. View the full article
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This series of color-composite maps of Jupiter, assembled from images taken with NASA's Hubble Space Telescope, allows astronomers to trace changes in the dark impact sites that resulted from the July 1994 impact of comet P/Shoemaker-Levy 9 with the giant planet. Through computer image processing, researchers "peel" the atmosphere of Jupiter off its globe and spread it flat into a map. These cylindrical projections show the entire atmosphere of Jupiter in one map. The HST's images show clearly that dark material produced in the comet explosion has continued to spread in Jupiter's atmosphere. However, the "band" of dark material is still clumpy, which suggests that the maj…
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In the weeks following comet P/Shoemaker-Levy 9's spectacular July collision with Jupiter, a team of Hubble telescope astronomers has pored over imaging and spectroscopic data gleaned during the interplanetary bombardment. Their initial findings, combined with results from other space-borne and ground-based telescopes, shed new light on Jupiter's atmospheric winds, its immense magnetic field, the mysterious dark debris from the impacts, and the composition of the doomed comet itself. These four Hubble telescope images of Jupiter, as seen in visible and far-ultraviolet wavelengths, show the remarkable dispersion of the clouds of smoke and dust thrown into the atmosphere …
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Astronomers using NASA's Hubble Space Telescope (HST) have found, to their surprise, that a relatively nearby galaxy harbors a powerful quasar. This active galaxy, known as Cygnus A, is the second strongest radio source in the sky. View the full article
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A natural color NASA Hubble Space Telescope view of the full disk of the giant planet Jupiter shows numerous comet Shoemaker-Levy 9 impact sites as seen on July 22, 1994. View the full article
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Ultraviolet image of Jupiter taken by the Wide Field Camera of the Hubble Space Telescope. The image shows Jupiter's atmosphere at a wavelength of 2550 Angstroms after many impacts by fragments of comet Shoemaker-Levy 9. View the full article
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This is a NASA's Hubble Space Telescope image of the impact sites of fragments "D" and "G" from Comet Shoemaker-Levy 9 which collided with the giant planet Jupiter. The picture has been image processed to correct for the curvature of the disk of Jupiter, so that the spot appears flat, as if the viewer were hovering directly overhead. The large feature was created by the impact of comet fragment "G" which impacted Jupiter on July 18, 1994. The smaller feature to the left was created on July 17, by the impact of comet fragment "D". View the full article
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This series of images, which spans more than five days beginning at 5:33 p.m. EDT on July 16, 1994, was obtained with NASA's Hubble Space Telescope's Wide Field Planetary Camera-2 using the methane filter that reveals details in Jupiter's higher atmosphere. These images show the development of the ejecta from site A, formed by the impact of the first fragment of comet P/Shoemaker-Levy 9. View the full article
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Image of Jupiter with NASA's Hubble Space Telescope's Planetary Camera. Eight impact sights are visible. From left to right are the E/F complex (barely visible on the edge of the planet), the star shaped H site, the impact sites for tiny N, Q1, small Q2, and R, and on the far right limb the D/G complex. The D/G complex also shows extended haze at the edge of the planet. The features are rapidly evolving on timescales of days. The smallest features in the this image are less than 200 kilometers across. This image is a color composite of three filters at 9530, 5500, and 4100 Angstroms. View the full article
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This Hubble telescope image of the giant planet Jupiter reveals the impact sites of two fragments from comet Shoemaker-Levy 9. Twenty-one large chunks of the comet rained down upon Jupiter in July 1994. The impact sites, located in the planet's Southern Hemisphere, are the dark spots in the upper left of the photograph. View the full article
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These images of Jupiter, by NASA's Hubble Space Telescope, reveal the impact sites of fragments "D" and "G" from Comet Shoemaker-Levy 9. The upper right corners of each image points north, showing the impact sites located in Jupiter's southern hemisphere at a latitude of 44 degrees. View the full article
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