科普 神奇的宇宙----图片(每天更新中)

wsbswdx

Cosmic Rays

Explanation: Have you ever been hit by a beam of high energy particles from above? Surely you have -- it happens all of the time. Showers of high energy particles occur when energetic cosmic rays strike the top of the Earth's atmosphere. Cosmic rays were discovered unexpectedly in 1912. It is now known that most cosmic rays are atomic nuclei. Most are hydrogen nuclei, some are helium nuclei, and the rest heavier elements. The relative abundance changes with cosmic ray energy -- the highest energy cosmic rays tend to be heavier nuclei. Although many of the low energy cosmic rays come from our Sun, the origins of the highest energy cosmic rays remains unknown and a topic of much research. This drawing illustrates air showers from very high energy cosmic rays. Cosmic rays may even be important to Earth's weather -- common lightning may be triggered by passing cosmic rays.

wsbswdx

The Comet and the Galaxy

Explanation: The Moon almost ruined this photograph. During late March and early April 1997, Comet Hale-Bopp passed nearly in front of the Andromeda Galaxy. Here the Great Comet of 1997 and the Great Galaxy in Andromeda were photographed together on 1997 March 24th. The problem was the brightness of the Moon. The Moon was full that night and so bright that long exposures meant to capture the tails of Hale-Bopp and the disk of M31 would capture instead only moonlight reflected off the Earth's atmosphere. By the time the Moon would set, this opportunity would be gone. That's why this picture was taken during a total lunar eclipse.

wsbswdx

Perseid in the Light

Explanation: Dark skies are favored for viewing meteor showers -- so many are pessimistic about this year's Perseids. While the Perseid meteor shower is scheduled to peak this weekend, bright light from an almost full Moon will also flood the night and mask the majority of relatively faint meteors. Still, skygazing in the evening before the Moon rises (before about 10 PM local time) could reveal spectacular earthgrazing meteors. Persisting even later into the moonlit night can reward northern hemisphere watchers looking for occasional Perseid fireballs. In fact, astronomer Jimmy Westlake imaged this bright Perseid meteor despite the combination of moonlight and auroral glow over Colorado skies in August of 2000.

wsbswdx

Galactic Center Star Clusters

Explanation: If you had x-ray vision, the central regions of our Galaxy would not be hidden from view by cosmic dust clouds. Instead, the Milky Way toward Sagittarius might look something like this. Pleasing to look at, the gorgeous false-color representation of x-ray data from the Chandra Observatory shows high energies in blue, medium in green, and low energy x-rays in red. The mosaic spans about 130 light-years at the 26,000 light-year distance of the Galactic Center. It reveals massive, x-ray emitting star clusters in a crowded environment. In particular, the Galactic Center cluster and the enormous black hole Sagittarius A* are within the bright region near the bottom. Two other star clusters, the Arches, and the Quintuplet lie near the top. Cluster interactions with dense molecular clouds in the region may produce some of the diffuse emission detected in the Chandra x-ray view.

wsbswdx

Magellanic Morning

Explanation: This early morning skyscape recorded near Winton, Queensland, Australia, looks toward the southeast. Low clouds are seen in silhouette against the first hints of sunlight, while two famous cosmic clouds, the Clouds of Magellan, also hover in the brightening sky. The Small Magellanic Cloud (SMC, upper right), and the Large Magellanic Cloud (LMC) are prominent wonders of the southern sky, named for the 16th century Portuguese explorer Ferdinand Magellan. They are small, irregular galaxies in their own right, satellites of our much larger, spiral Milky Way galaxy. The SMC is about 210,000 light-years and the LMC about 180,000 light-years away. At lower left, bright star Canopus (Alpha Carinae), denizen of the Milky Way, is a mere 310 light-years distant.

wsbswdx

Horse Head Shaped Reflection Nebula IC 4592

Explanation: Do you see the horse's head? What you are seeing is not the famous Horsehead nebula toward Orion but rather a fainter nebula that only takes on a familiar form with deeper imaging. The main part of the above imaged molecular cloud complex is a reflection nebula cataloged as IC 4592. Reflection nebulas are actually made up of very fine dust that normally appears dark but can look quite blue when reflecting the light of energetic nearby stars. In this case, the source of much of the reflected light is a star at the eye of the horse. That star is part of Nu Scorpii, one of the brighter star systems toward the constellation of Scorpius. A second reflection nebula dubbed IC 4601 is visible surrounding two stars on the far right.

wsbswdx

A Cerro Tololo Sky

Explanation: High atop a Chilean mountain lies one of the premier observatories of the southern sky: the Cerro Tololo Inter-American Observatory (CTIO). Pictured above is the dome surrounding one of the site's best known instruments, the 4-meter Blanco Telescope. Far behind the dome are thousands of individual stars and diffuse light from three galaxies: the Small Magellanic Cloud (upper left), the Large Magellanic Cloud (lower left), and our Milky Way Galaxy (right). Also visible just to Blanco's right is the famous superposition of four bright stars known as the Southern Cross. A single 20 second exposure, this digital image was recorded with a sensitive detector intended for astronomical imaging.

wsbswdx

Still Life with NGC 2170

Explanation: In this beautiful celestial still life composed with a cosmic brush, dusty nebula NGC 2170 shines at the upper left. Reflecting the light of nearby hot stars, NGC 2170 is joined by other bluish reflection nebulae and a compact red emission region against a backdrop of stars. Like the common household items still life painters often choose for their subjects, the clouds of gas, dust, and hot stars pictured here are also commonly found in this setting - a massive, star-forming molecular cloud in the constellation Monoceros. The giant molecular cloud, Mon R2, is impressively close, estimated to be only 2,400 light-years or so away. At that distance, this canvas would be about 15 light-years across.

wsbswdx

Burns Cliff Anaglyph

Explanation: Get out your red/blue glasses and gaze across Burns Cliff along the inner wall of Endurance crater on Mars! The view from the perspective of Mars rover Opportunity is a color anaglyph - two different images are presented to the left and right eyes by color filters to produce the 3D effect. Scroll the picture to the right to see the full 180 degree panorama. Still returning science data and images, both Spirit and Opportunity rovers completed 2 years of Mars exploration in January. Opportunity spent the month of July on the road to Victoria crater. The stereo pair of images used to create this view are based on image data recorded in November 2004.

wsbswdx

M27: Not A Comet

Explanation: While searching the skies above 18th century France for comets, astronomer Charles Messier diligently recorded this object as number 27 on his list of things which are definitely not comets. So what is it? Well, 20th century astronomers would classify it as a Planetary Nebula ... but it's not a planet either, even though it may appear round and planet-like in a small telescope. Messier 27 (M27) is now known to be an excellent example of a gaseous emission nebula created as a sun-like star runs out of nuclear fuel in its core. The nebula forms as the star's outer layers are expelled into space, with a visible glow generated by atoms excited by the dying star's intense but invisible ultraviolet light. Known by the popular name of the Dumbbell Nebula, the beautifully symmetric interstellar gas cloud is about 1,200 light-years away in the constellation Vulpecula. This intriguing color composite view was recorded through narrow band filters sensitive to emission from hydrogen atoms (shown in red) and oxygen atoms (shown in blue/green).

wsbswdx

Methane Rain Possible on Titan

Explanation: Might it rain cold methane on Saturn's Titan? Recent analyses of measurements taken by the Huygen's probe that landed on Titan in 2005 January indicate that the atmosphere is actually saturated with methane at a height of about 8 kilometers. Combined with observations of a damp surface and lakes near the poles, some astrobiologists conclude that at least a methane drizzle is common on parts of Titan. Other astrobiologists reported computer models of the clouded moon that indicate that violent methane storms might even occur, complete with flash floods carving channels in the landscape. The later scenario is depicted in the above drawing of Titan. Lightning, as also depicted above, might well exist on Titan but has not been proven. The findings increase speculation that a wet Titanian surface might be hospitable to unusual forms of life.

风云007

建议：

要是中英文都有的描述，那就更是帅了，可以学习天文英语
继续努力！

zjjhyun

风云说的是，强烈支持！

wsbswdx

Comet Hale-Bopp Over Val Parola Pass

Explanation: Comet Hale-Bopp, the Great Comet of 1997, became much brighter than any surrounding stars. It was seen even over bright city lights. Away from city lights, however, it put on quite a spectacular show. Here Comet Hale-Bopp was photographed above Val Parola Pass in the Dolomite mountains surrounding Cortina d'Ampezzo, Italy. Comet Hale-Bopp's blue ion tail, consisting of ions from the comet's nucleus, is pushed out by the solar wind. The white dust tail is composed of larger particles of dust from the nucleus driven by the pressure of sunlight, that orbit behind the comet. Observations showed that Comet Hale-Bopp's nucleus spins about once every 12 hours.

wsbswdx

The Milky Way over Utah

Explanation: If sometimes it appears that the entire Milky Way Galaxy is raining down on your head, do not despair. It happens twice a day. As the Sun rises in the East, wonders of the night sky become less bright than the sunlight scattered by our own Earth's atmosphere, and so fade from view. They will only rotate back into view when the Earth again eclipses our bright Sun at dusk. This battle between heaven and Earth was captured dramatically over a rock formation at Capitol Reef National Park Utah, USA in 2003 May. Dark dust, millions of stars, and bright glowing red gas highlight the plane of our Milky Way Galaxy, which lies on average thousands of light years behind Earth's mountains.

wsbswdx

Possible Methane Lakes on Titan

Explanation: Have methane lakes been discovered on Saturn's Titan? That exciting possibility was uncovered from analyses of radar images returned last week by the robotic Cassini spacecraft now orbiting Saturn. The above image is a radar reflection from terrain near Titan's North Pole and spans a region about 200 kilometers across. Evidence that the dark areas might be pools of liquid hydrocarbons includes an extreme smoothness implied by the lack of a return radar signal, and apparently connected tributaries. If true, Titan would be only the second body in our Solar System, after Earth, found to possess liquids on the surface. Future observations from Cassini during Titan flybys might test the methane lake hypothesis, as comparative wind affects on the regions are studied.

wsbswdx

Valles Marineris: The Grand Canyon of Mars

Explanation: The largest canyon in the Solar System cuts a wide swath across the face of Mars. Named Valles Marineris, the grand valley extends over 3,000 kilometers long, spans as much as 600 kilometers across, and delves as much as 8 kilometers deep. By comparison, the Earth's Grand Canyon in Arizona, USA is 800 kilometers long, 30 kilometers across, and 1.8 kilometers deep. The origin of the Valles Marineris remains unknown, although a leading hypothesis holds that it started as a crack billions of years ago as the planet cooled. Recently, several geologic processes have been identified in the canyon. The above mosaic was created from over 100 images of Mars taken by Viking Orbiters in the 1970s.

wsbswdx

Four Supernova Remnants

Explanation: These four panels show x-ray images of expanding cosmic debris clouds, tens of light-years across, in nearby galaxy the Large Magellanic Cloud. The supernova remnants (SNRs) are the results of two types of stellar explosions and are arranged in order of apparent age or the time since light from the initial explosion first reached planet Earth. Clockwise starting at the upper left are remnants aged 600 years, 1,500 years, 10,000 years and 13,000 years. The first three result from a Type Ia explosion - the destruction of a white dwarf star by a thermonuclear blast triggered by mass accreted from a stellar companion. The fourth (lower left) is a Type II explosion - triggered by the final collapse of the core of a massive star. A neutron star, the remnant of the collapsed core, lies at its center.

wsbswdx

The Swarm

Explanation: What do you call a group of black holes ... a flock, a brace, a swarm? Monitoring a region around the center of our Galaxy, astronomers have indeed found evidence for a surprisingly large number of variable x-ray sources - likely black holes or neutron stars in binary star systems - swarming around the Milky Way's own central supermassive black hole. Chandra Observatory combined x-ray image data from their monitoring program is shown above, with four variable sources circled and labeled A-D. While four sources may not make a swarm, these all lie within only three light-years of the central supermassive black hole known as Sgr A* (the bright source just above C). Their detection implies that a much larger concentration of black hole systems is present. Repeated gravitational interactions with other stars are thought to cause the black hole systems to spiral inward toward the Galactic Center region.

wsbswdx

NGC 7331 and Beyond

Explanation: Spiral galaxy NGC 7331 is often touted as an analog to our own Milky Way. About 50 million light-years distant in the northern constellation Pegasus, NGC 7331 was recognized early on as a spiral nebula and is actually one of the brighter galaxies not included in Charles Messier's famous 18th century catalog. Since the galaxy's disk is inclined to our line-of-sight, long telescopic exposures often result in an image that evokes a strong sense of depth. The effect is further enhanced in this well-framed view by the galaxies that lie beyond this beautiful island universe. The background galaxies are about one tenth the apparent size of NGC 7331 and so lie roughly ten times farther away.