科普 神奇的宇宙----图片(每天更新中)

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Moon and Mars Tonight

Explanation: The Full Moon and a brilliant, ruddy Mars will share the sky tonight. Skygazers can easily enjoy the celestial pairing as the two are separated by a degree or even less. In fact, seen from parts of northern North America and Europe, the Moon will actually occult (pass in front of) the Red Planet. Mars is so bright because it is near opposition, opposite the Sun in Earth's sky and near its closest approach to planet Earth. But Mars is not nearly as bright as the Moon, also opposite the Sun tonight. In this striking preview of tonight's sky show, backyard astronomer John Harms was able to photograph an almost Full Moon near Mars last month. His simple, single exposure relied on clouds to block some of the overwhelming moonlight.

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Tyrrhenian Sea and Solstice Sky

Explanation: Today the Solstice occurs at 0608 Universal Time, the Sun reaching its southernmost declination in planet Earth's sky. Of course, the December Solstice marks the beginning of winter in the northern hemisphere and summer in the south. When viewed from northern latitudes, the Sun will make its lowest arc through the sky along the southern horizon. So in the north, the Solstice day has the shortest length of time between sunrise and sunset and fewest hours of daylight. This striking composite image follows the Sun's path through the December Solstice day of 2005 in a beautiful blue sky, looking down the Tyrrhenian Sea coast from Santa Severa toward Fiumicino, Italy. The view covers about 115 degrees in 43 separate, well-planned exposures from sunrise to sunset.

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Horizon to Horizon

Explanation: Scroll right and journey from horizon to horizon as your gaze sweeps through the zenith in the night sky over Beg-Meil, France. Recorded on December 13th, the entertaining panorama (image key) covers 210 degrees in 21 separate exposures, beginning on the beach with bright star Sirius rising in the southeast. Look up (pan right) to encounter the nebula rich constellation of Orion and continue on to find the lovely Pleiades star cluster. Farther along, higher in the sky, is the famous Comet Holmes, still gracing the northern hemisphere's night with its remarkable expanding coma. Finally, just before diving into the urban glow from city lights along the northwestern horizon (far right), check out the double star cluster in Perseus and take in the cosmic streak of a bright Geminid Meteor.

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Reflections on the 1970s

Explanation: The 1970s are sometimes ignored by astronomers. In particular, this beautiful grouping of reflection nebulae in Orion - NGC 1977, NGC 1975, and NGC 1973 - are usually overlooked in favor of the substantial glow from the nearby stellar nursery better known as the Orion Nebula. Found along Orion's sword just north of the bright Orion Nebula complex, these reflection nebulae are also associated with Orion's giant molecular cloud about 1,500 light-years away, but are dominated by the characteristic blue color of interstellar dust reflecting light from hot young stars. North is down in this sharp color telescopic image from New South Wales, Australia, so the more familiar Orion Nebula borders the top of the view. NGC 1977 stretches across the field just above center, separated from NGC 1973 (below left) and NGC 1975 (below right) by darker regions of obscuring dust. Many northern hemisphere observers claim to see the general shape of a running man in the cosmic dust cloud but, of course, they're looking at the view upside down.

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Stars and Dust through Baade's Window

Explanation: Billions of stars light up the direction toward the center of our Galaxy. The vast majority of these stars are themselves billions of years old, rivaling their home Milky Way Galaxy in age. Together with interstellar dust, these old stars combine to create this yellowish starscape. Although the opaque dust obscures the true Galactic center in visible light, there is a low density hole in the dust on the right of the image. The region, named Baade's Window for the German astronomer who studied it, is used to inspect distant stars and to determine the internal geometry of the Milky Way. Baade's Window lies toward the constellation of the Archer (Sagittarius).

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Unusual Silica Rich Soil Discovered on Mars

Explanation: You're rolling across Mars when you unexpectedly uncover some unusually light soil. You stop. You turn. You return to inspect the soil and find out it is almost purely silica -- the main ingredient in quartz and glass. Such soil has never been found on Mars before. What created this soil? Since you are the robotic rover Spirit currently rolling across Mars, you send the images and data back to Earth for analysis. Your scientist friends from the blue water planet say that such soil on Earth is usually created by either volcanic steam or a hot spring. The second hypothesis in particular indicates, once again, a wet past for part of Mars, as possibly hot water saturated with silica deposited the white soil. Intriguingly, on Earth, living microbes typically flourish under either condition. Pictured above, the uncovered light soil is visible on the right.

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Saturn's Ancient Rings

Explanation: How old are Saturn's rings? No one is quite sure. One possibility is that the rings formed relatively recently in our Solar System's history, perhaps only about 100 million years ago when a moon-sized object broke up near Saturn. Evidence for a young ring age includes a basic stability analysis for rings, and the fact that the rings are so bright and relatively unaffected by numerous small dark meteor impacts. New evidence, however, raises the possibility that some of Saturn's rings may be billions of years old and so almost as old as Saturn itself. Inspection of images by the Saturn-orbiting Cassini spacecraft indicates that some of Saturn's ring particles temporarily bunch and collide, effectively recycling ring particles by bringing fresh bright ices to the surface. Seen here, Saturn's rings were imaged in their true colors by the robotic Cassini in late October. Icy bright Tethys, a moon of Saturn likely brightened by a sandblasting rain of ice from sister moon Enceladus, is visible in front of the darker rings.

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The Holographic Principle

Explanation: Is this picture worth a thousand words? According to the Holographic Principle, the most information you can get from this image is about 3 x 1065 bits for a normal sized computer monitor. The Holographic Principle, yet unproven, states that there is a maximum amount of information content held by regions adjacent to any surface. Therefore, counter-intuitively, the information content inside a room depends not on the volume of the room but on the area of the bounding walls. The principle derives from the idea that the Planck length, the length scale where quantum mechanics begins to dominate classical gravity, is one side of an area that can hold only about one bit of information. The limit was first postulated by physicist Gerard 't Hooft in 1993. It can arise from generalizations from seemingly distant speculation that the information held by a black hole is determined not by its enclosed volume but by the surface area of its event horizon. The term "holographic" arises from a hologram analogy where three-dimension images are created by projecting light though a flat screen. Beware, other people looking at the above image may not claim to see 3 x 1065 bits -- they might claim to see a teapot.

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Mountains of Creation

Explanation: This fantastic skyscape lies at the eastern edge of giant stellar nursery W5, about 7,000 light-years away in the constellation Cassiopeia. An infrared view from the Spitzer Space Telescope, it features interstellar clouds of cold gas and dust sculpted by winds and radiation from a hot, massive star outside the picture (just above and to the right). Still swaddled within the cosmic clouds, newborn stars are revealed by Spitzer's penetrating gaze, their formation also triggered by the massive star. Fittingly dubbed "Mountains of Creation", these interstellar clouds are about 10 times the size of the analogous Pillars of Creation in M16, made famous in a 1995 Hubble Space Telescope view. W5 is also known as IC 1848 and together with IC 1805 it is part of a complex region popularly dubbed the Heart and Soul Nebulae. The Spitzer image spans about 70 light-years at the distance of W5.

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Hurricane Ivan from the Space Station

Explanation: Ninety percent of the houses on Grenada were damaged by the destructive force of Hurricane Ivan. At its peak, Ivan was a Category 5 hurricane, the highest power category on the Saffir-Simpson Scale, and created sustained winds in excess of 200 kilometers per hour. Ivan was the largest hurricane to strike the US in 2004, and, so far, the 10th most powerful in recorded history. As it swirled in the Atlantic Ocean, the tremendous eye of Hurricane Ivan was photographed from above by the orbiting International Space Station. The name Ivan has now been retired from Atlantic Ocean use by the World Meteorological Organization.

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Apollo 17: Shorty Crater Panorama

Explanation: In December of 1972, Apollo 17 astronauts Eugene Cernan and Harrison Schmitt spent about 75 hours on the Moon in the Taurus-Littrow valley, while colleague Ronald Evans orbited overhead. This sharp panorama is digitally stitched together from pictures taken by Cernan as he and Schmitt roamed the valley floor. Starting with a view of the imposing South Massif, scrolling the panorama to the right will reveal Schmitt and the lunar rover at the edge of Shorty Crater, near the spot where geologist Schmitt discovered orange lunar soil. The Apollo 17 crew returned with 110 kilograms of rock and soil samples, more than was returned from any of the other lunar landing sites. Now thirty five years later, Cernan and Schmitt are still the last to walk on the Moon.

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T Tauri and Hind's Variable Nebula

Explanation: The orange star centered in this remarkable telescopic skyview is T Tauri, prototype of the class of T Tauri variable stars. Nearby it is a dusty yellow cosmic cloud historically known as Hind's Variable Nebula (NGC 1555/1554). Over 400 light-years away, at the edge of a molecular cloud, both star and nebula are seen to vary significantly in brightness but not necessarily at the same time, adding to the mystery of the intriguing region. T Tauri stars are now generally recognized as young (less than a few million years old), sun-like stars still in the early stages of formation. To further complicate the picture, infrared observations indicate that T Tauri itself is part of a multiple system and suggest that the associated Hind's Nebula may also contain a very young stellar object. The dramatic color image spans about 4 light-years at the estimated distance of T Tauri.

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Mars Rover Races to Survive

Explanation: The Martian rover Spirit is now in the race of its life. The rolling robot is trying to reach an outpost to spend the winter, but it keeps getting bogged down in soft sand on Mars. Earth scientists hope that Spirit can reach a slope on the northern edge of the unusual feature dubbed Home Plate, before the end of this month when northern winter will be phasing in on Mars. Reaching this slope will likely allow the rover to tilt enough toward the Sun to create a needed increase in the efficiency of its energy-absorbing solar panels. This map shows the path of Spirit from July 2004 until just last month.

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The Universe Nearby

Explanation: What does the universe nearby look like? This plot shows over one and a half million of the brightest stars and galaxies in the nearby universe detected by the Two Micron All Sky Survey (2MASS) in infrared light. The resulting image is an incredible tapestry of stars and galaxies that provides limits on how the universe formed and evolved. Across the center are stars that lie in the plane of our own Milky Way Galaxy. Away from the Galactic plane, vast majority of the dots are galaxies, color coded to indicate distance, with blue dots representing the nearest galaxies in the 2Mass survey, and red dots indicating the most distant survey galaxies that lie at a redshift near 0.1. Named structures are annotated. Many galaxies are gravitationally bound together to form clusters, which themselves are loosely bound into superclusters, which in turn are sometimes seen to align over even larger scale structures.

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A Jet from the Sun

Explanation: What powers the solar wind? Our Sun is known to emit a powerful wind of particles with gusts that can even affect astronauts and satellites orbiting Earth. The cause of the solar wind has been debated for decades but is thought to be rooted in Alfvén waves generated by the ever changing magnetic field of the Sun. Newly released images from the Japanese Hinode satellite appear to bolster this hypothesis, imaging an average of 240 daily plasma jets that are excellent candidates to fuel the outwardly moving Alfvén waves. The jets and waves are themselves ultimately created by magnetic reconnection events, rapid events where lines of constant magnetic field suddenly move extremely rapidly, dragging electrons and protons along with them. On the image left, one such jet is visible in X-ray light. Bright spots show relatively energetic regions elsewhere on the Sun.

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The Fairy of Eagle Nebula

Explanation: The dust sculptures of the Eagle Nebula are evaporating. As powerful starlight whittles away these cool cosmic mountains, the statuesque pillars that remain might be imagined as mythical beasts. Pictured above is one of several striking dust pillars of the Eagle Nebula that might be described as a gigantic alien fairy. This fairy, however, is ten light years tall and spews radiation much hotter than common fire. The greater Eagle Nebula, M16, is actually a giant evaporating shell of gas and dust inside of which is a growing cavity filled with a spectacular stellar nursery currently forming an open cluster of stars. The above image in scientifically re-assigned colors was released as part of the fifteenth anniversary celebration of the launch of the Hubble Space Telescope.

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Star Trails at Dawn

Explanation: Just fix your camera to a tripod and you too can make an image of graceful trails traced by the stars as planet Earth rotates on its axis. Made on September 14 from Montlaux, France, this wide-angle view nicely shows the stars near the celestial equator tracing nearly straight lines in projection, while stars north and south of the equator, respectively, appear to circle the north and south celestial poles. Featured are the stars of Orion (right of center), brilliant Venus rising (left) as bright star Sirius rises in the south (bottom center), and a polar orbiting Iridium satellite (upper left). Beautiful dawn sky colors seem painted along the horizon. This remarkable picture was constructed from 477 consecutive 30 second digital exposures recorded over 4.3 hours and later combined.

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Double Cluster in Perseus

Explanation: Skygazers recently following Comet Holmes have probably also chanced across this lovely starfield, not far from the comet on the sky in the constellation Perseus. Some 7,000 light-years away, this pair of open or galactic star clusters is an easy binocular target and is visible to the unaided eye from dark sky areas. In fact, it was cataloged in 130 BC by Greek astronomer Hipparchus. Now known as h and chi Persei, or NGC 869(left) and NGC 884, the clusters themselves are separated by only a few hundred light-years and contain stars much younger and hotter than the Sun. In addition to being physically close together, the clusters' ages based on their individual stars are similar - evidence that both clusters were likely a product of the same star-forming region.

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Mars in View

Explanation: Very good telescopic views of Mars can be expected in the coming weeks as the Red Planet nears opposition on December 24th. Of course, opposition means opposite the Sun in planet Earth's sky - an arrangement that occurs every 26 months for Mars. Because of Mars' more elliptical orbit, the actual date of closest approach to Earth will be December 18, when Mars will be within about 88 million kilometers of our fair planet. Situated in the constellation Gemini and rising after evening twilight, the bright, ruddy disk of Mars will reach nearly 16 arcseconds in diameter (about 1/100th the diameter of the Full Moon). In this already exceptional image taken on November 18, north is down and surface markings around the sprawling, dark, albedo feature Syrtis Major are remarkably clear. The image was recorded with a video camera and filters on a 1 meter telescope at Pic Du Midi, a mountain top observatory in the French Pyrenees. Taking advantage of the shorter travel distance near opposition, NASA launched the Phoenix lander to Mars in August, scheduled to arrive in May 2008.

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The Cocoon Nebula from CFHT

Explanation: What creates the colors of the Cocoon Nebula? The Cocoon Nebula, cataloged as IC 5146, is a strikingly beautiful nebula located about 4,000 light years away toward the constellation of the Swan (Cygnus). Inside the Cocoon Nebula is a newly developing open cluster of stars. Like other stellar nurseries, the Cocoon Nebula holds, at the same time, a bright red emission nebula, blue reflection nebulas, and dark absorption nebulas. Given different mixtures, these three processes create a host of colors in this image taken recently by the Canada-France-Hawaii Telescope (CFHT) in Hawaii, USA. Speculation based on recent measurements holds that the massive star towards the left of the picture opened a hole in an existing molecular cloud through which much of the glowing material flows. The same star, which formed about 100,000 years ago, now provides the energy source for much of the emitted and reflected light from this nebula.