http://www.zorg.ch/forum.php Zorg RSS Feed de-DE Sat, 04 Sep 2010 20:59:25 http://www.zorg.ch/gallery.php?show=pic&picID=13576&parent_id=13576#112751 Sat, 04 Sep 2010 00:00:07 [z]Barbara Harris http://www.zorg.ch/gallery.php?show=pic&picID=13576&parent_id=13576#112751 The Small Cloud of Magellan

Explanation: Portuguese navigator Ferdinand Magellan and his crew had plenty of time to study the southern sky during the first circumnavigation of planet Earth. ...]]> The Small Cloud of Magellan

Explanation: Portuguese navigator Ferdinand Magellan and his crew had plenty of time to study the southern sky during the first circumnavigation of planet Earth. As a result, two celestial wonders easily visible for southern hemisphere skygazers are known as the Clouds of Magellan. These cosmic clouds are now understood to be dwarf irregular galaxies, satellites of our larger spiral Milky Way Galaxy. The Small Magellanic Cloud actually spans 15,000 light-years or so and contains several hundred million stars. About 210,000 light-years away in the constellation Tucana, it is more distant than other known Milky Way satellite galaxies, including the Canis Major and Sagittarius Dwarf galaxies and the Large Magellanic Cloud. This sharp image also includes two foreground globular star clusters NGC 362 (bottom right) and 47 Tucanae. Spectacular 47 Tucanae is a mere 13,000 light-years away and seen here to the left of the Small Magellanic Cloud. Take a short survey about viewing astronomy images on mobile devices.

Credit & Copyright]]> http://www.zorg.ch/gallery.php?show=pic&picID=13575&parent_id=13575#112750 Fri, 03 Sep 2010 00:00:04 [z]Barbara Harris http://www.zorg.ch/gallery.php?show=pic&picID=13575&parent_id=13575#112750 The Bubble Nebula

Explanation: Blown by the wind from a massive star, this interstellar apparition has a surprisingly familiar shape. Cataloged as NGC 7635, it is also known s...]]> The Bubble Nebula

Explanation: Blown by the wind from a massive star, this interstellar apparition has a surprisingly familiar shape. Cataloged as NGC 7635, it is also known simply as The Bubble Nebula. Although it looks delicate, the 10 light-year diameter bubble offers evidence of violent processes at work. Above and right of the Bubble's center is a hot, O-type star, several hundred thousand times more luminous and approximately 45 times more massive than the Sun. A fierce stellar wind and intense radiation from that star has blasted out the structure of glowing gas against denser material in a surrounding molecular cloud. The intriguing Bubble Nebula lies a mere 11,000 light-years away toward the boastful constellation Cassiopeia. A false-color Hubble palette was used to create this sharp image and shows emission from sulfur, hydrogen, and oxygen atoms in red, green, and blue hues. The image data was recorded using a small telescope under clear, steady skies, from Mount Wilson Observatory. Battle of the APODs (Poll): Which APOD should be last week's APOW?

Credit & Copyright]]> http://www.zorg.ch/gallery.php?show=pic&picID=13574&parent_id=13574#112748 Thu, 02 Sep 2010 00:00:05 [z]Barbara Harris http://www.zorg.ch/gallery.php?show=pic&picID=13574&parent_id=13574#112748 Earth and Moon from MESSENGER

Explanation: What does Earth look like from the planet Mercury? The robotic spacecraft MESSENGER found out as it looked toward the MESSENGER found out as it looked toward the Earth during its closest approach to the Sun about three months ago. The Earth and Moon are visible as the double spot on the lower left of the above image. Now MESSENGER was not at Mercury when it took the above image, but at a location from which the view would be similar. From Mercury, both the Earth and its comparatively large moon will always appear as small circles of reflected sunlight and will never show a crescent phase. MESSENGER has zipped right by Mercury three times since being launched in 2004, and is scheduled to enter orbit around the innermost planet in March of 2011. New Mirror: APOD available in Persian from Iran.

Credit & Copyright]]> http://www.zorg.ch/gallery.php?show=pic&picID=13573&parent_id=13573#112747 Wed, 01 Sep 2010 00:00:05 [z]Barbara Harris http://www.zorg.ch/gallery.php?show=pic&picID=13573&parent_id=13573#112747 The Annotated Galactic Center

Explanation: The sky toward the center of our Galaxy is filled with a wide variety of celestial wonder...]]> The Annotated Galactic Center

Explanation: The sky toward the center of our Galaxy is filled with a wide variety of celestial wonders, many of which are visible from a dark location with common binoculars. Constellations near the Galactic Center include Sagittarius, Libra, Scorpius, Scutum, and Ophiuchus. Nebulas include Messier objects M8, M16, M20, as well as the Pipe and Cat's Paw nebulas. Visible open star clusters include M6, M7, M21, M23, M24, and M25, while globular star cluster M22 is also visible. A hole in the dust toward the Galactic Center reveals a bright region filled with distant stars known as Baade's Window, which is visible between M7 and M8. Moving your cursor over the above image the will bring up an un-annotated version. Poll: Which images would you select for future APODs?

Credit & Copyright]]> http://www.zorg.ch/gallery.php?show=pic&picID=13572&parent_id=13572#112744 Tue, 31 Aug 2010 00:00:05 [z]Barbara Harris http://www.zorg.ch/gallery.php?show=pic&picID=13572&parent_id=13572#112744 Comanche Outcrop on Mars Indicates Hospitable Past

Explanation: Could life once have survived on Mars? Today, neither animal nor plant life from ...]]> Comanche Outcrop on Mars Indicates Hospitable Past

Explanation: Could life once have survived on Mars? Today, neither animal nor plant life from Earth could survive for very long on Mars because at least one key ingredient -- liquid water -- is essentially absent on the red planet's rusty surface. Although evidence from the martian rovers indicates that long ago Mars might once have had liquid water on its surface, that water might also have been too acidic for familiar life forms to thrive. Recently, however, a newly detailed analysis of an unusual outcropping of rock and soil chanced upon in 2005 by the robotic Spirit rover has uncovered a clue indicating that not all of Mars was always so acidic. The mound in question, dubbed Comanche Outcrop and visible near the top of the above image, appears to contain unusually high concentrations of elements such as magnesium iron carbonate. The above image is shown in colors exaggerated to highlight the differences in composition. Since these carbonates dissolve in acid, the persistence of these mounds indicates that water perhaps less acidic and more favorable for life might have once flowed across Mars. More detailed analyses and searches for other signs will surely continue. Teachers & Students: Take an online, textbook-free, video class on Introductory Astronomy for free.

Credit & Copyright]]> http://www.zorg.ch/gallery.php?show=pic&picID=13571&parent_id=13571#112742 Mon, 30 Aug 2010 00:00:04 [z]Barbara Harris http://www.zorg.ch/gallery.php?show=pic&picID=13571&parent_id=13571#112742 The Local Fluff

Explanation: The stars are not alone. In the disk of our Milky Way Galaxy about 10 percent of visible matter is in the form of gas, called the Milky Way Galaxy about 10 percent of visible matter is in the form of gas, called the interstellar medium (ISM). The ISM is not uniform, and shows patchiness even near our Sun. It can be quite difficult to detect the local ISM because it is so tenuous and emits so little light. This mostly hydrogen gas, however, absorbs some very specific colors that can be detected in the light of the nearest stars. A working map of the local ISM within 10 light-years based on recent observations is shown above. These observations show that our Sun is moving through a Local Interstellar Cloud as this cloud flows outwards from the Scorpius-Centaurus Association star forming region. Our Sun may exit the Local Interstellar Cloud, also called the Local Fluff, during the next 10,000 years. Much remains unknown about the local ISM, including details of its distribution, its origin, and how it affects the Sun and the Earth.

Credit & Copyright]]> http://www.zorg.ch/gallery.php?show=pic&picID=13570&parent_id=13570#112739 Sun, 29 Aug 2010 00:00:04 [z]Barbara Harris http://www.zorg.ch/gallery.php?show=pic&picID=13570&parent_id=13570#112739 Hole in the Sun

Explanation: This ominous, dark shape sprawling across the face of the Sun is a coronal hole -- a low density region extending above the surface where the solar magnetic field open...]]> Hole in the Sun

Explanation: This ominous, dark shape sprawling across the face of the Sun is a coronal hole -- a low density region extending above the surface where the solar magnetic field opens freely into interplanetary space. Studied extensively from space since the 1960s in ultraviolet and x-ray light, coronal holes are known to be the source of the high-speed solar wind, atoms and electrons which flow outward along the open magnetic field lines. During periods of low activity, coronal holes typically cover regions just above the Sun's poles. But this extensive coronal hole dominated the Sun's northern hemisphere earlier this week, captured here in extreme ultraviolet light by cameras onboard the Solar Dynamics Observatory. The solar wind streaming from this coronal hole triggered auroral displays on planet Earth.

Credit & Copyright]]> http://www.zorg.ch/gallery.php?show=pic&picID=13569&parent_id=13569#112736 Sat, 28 Aug 2010 00:00:07 [z]Barbara Harris http://www.zorg.ch/gallery.php?show=pic&picID=13569&parent_id=13569#112736 Brighter Than Mars

Explanation: Even though you may have just read an email claiming Mars will be incredibly bright tonight, the brightest star on the horizon is not Mars. F...]]> Brighter Than Mars

Explanation: Even though you may have just read an email claiming Mars will be incredibly bright tonight, the brightest star on the horizon is not Mars. From central Iran on August 24th, the brightest star in this twilight desert skyview is Venus, aka the Evening Star. But a bright Mars is in the picture, just above and right of more brilliant Venus. Despite claims in the internet's annually returning Mars Hoax that Mars will be as big and bright as the Full Moon, this celestial scenario is very similar to the western sky you can see tonight. Along with Mars, the still beautiful vista includes Spica, alpha star of the constellation Virgo, above and left of Venus. Farther right of Venus, Saturn peeks through the sunset's fading glow just above the clouds. Near the opposite horizon, the Full Moon illuminating the desert is about 400,000 times brighter than Mars. Note: APOD tweets are available over Twitter.

Credit & Copyright]]> http://www.zorg.ch/gallery.php?show=pic&picID=13568&parent_id=13568#112735 Fri, 27 Aug 2010 00:00:04 [z]Barbara Harris http://www.zorg.ch/gallery.php?show=pic&picID=13568&parent_id=13568#112735 M27: Not a Comet

Explanation: While hunting for comets in the skies above 18th century France, astronomer Charles Messier diligently kept a list of the things he encountered that were de...]]> M27: Not a Comet

Explanation: While hunting for comets in the skies above 18th century France, astronomer Charles Messier diligently kept a list of the things he encountered that were definitely not comets. This is number 27 on his now famous not-a-comet list. In fact, 21st century astronomers would identify 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 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 over 2.5 light-years across and about 1,200 light-years away in the constellation Vulpecula. This impressive color composite highlights details within the well-studied central region and fainter, seldom imaged features in the nebula's outer halo. It includes narrowband images recorded using filters sensitive to emission from oxygen atoms, shown in blue-green hues, and hydrogen atoms in red. Poll: Which of last week's APODs should be the APOW?

Credit & Copyright]]> http://www.zorg.ch/gallery.php?show=pic&picID=13566&parent_id=13566#112732 Wed, 25 Aug 2010 00:00:05 [z]Barbara Harris http://www.zorg.ch/gallery.php?show=pic&picID=13566&parent_id=13566#112732 Galaxy Cluster Abell 1689 Magnifies the Dark Universe

Explanation: What's the matter with this cluster of galaxies? To find out what forms matter takes in the Abell 1689 cluster requires not...]]> Galaxy Cluster Abell 1689 Magnifies the Dark Universe

Explanation: What's the matter with this cluster of galaxies? To find out what forms matter takes in the Abell 1689 cluster requires not only deep images from telescopes like the Hubble Space Telescope, but detailed computer modeling as well. To start, almost every fuzzy yellow patch in the above image is an entire galaxy. A close inspection, however, shows that many background galaxies are strangely magnified and distorted into long curving arcs by the gravitational lens deflections of the cluster. Computer analyses of the placement and smoothness of these arcs indicate that in addition to the matter in the galaxies you can see, the cluster must also contain a significant amount of dark matter such as the model digitally superposed in purple. Now Abell 1689 remains enigmatic because the arcs are so numerous and diverse that no single dark matter model has emerged that can explain them all and still remain consistent with dark matter models needed to constrain their motion. Still, the detailed information available from clusters of galaxies like Abell 1689 gives hope that one day full solutions will be found that will not only fully reveal the dark matter in clusters, but also reveal the amounts of dark energy in the universe needed to lie along the line of sight to the distant arcs. Students and Teachers: Free video online Astro 101 course

Credit & Copyright]]> http://www.zorg.ch/gallery.php?show=pic&picID=13565&parent_id=13565#112731 Tue, 24 Aug 2010 00:00:05 [z]Barbara Harris http://www.zorg.ch/gallery.php?show=pic&picID=13565&parent_id=13565#112731 A Milky Way Shadow at Loch Ard Gorge

Explanation: Have you ever seen the Milky Way's glow create shadows? To do so, conditions need to be just right. First and foremost, the sky must be relatively clear of clouds so that the long band of the Milky Way's central disk can be seen. The surroundings must be very near to completely dark, with no bright artificial lights visible anywhere. Next, the Moon cannot be anywhere above the horizon, or its glow will dominate the landscape. Last, the shadows can best be caught on long camera exposures. In the above image taken in Port Campbell National Park, Victoria, Australia, seven 15-second images of the ground and de-rotated sky were digitally added to bring up the needed light and detail. In the foreground lies Loch Ard Gorge, named after a ship that tragically ran aground in 1878. The two rocks pictured are the remnants of a collapsed arch and are named Tom and Eva after the only two people who survived that Loch Ard ship wreck. A close inspection of the water just before the rocks will show reflections and shadows in light thrown by our Milky Way galaxy. Low clouds are visible moving through the serene scene in this movie. Keep looking up: Jack Horkheimer: 1938-2010. Do you remember watching Jack?

Credit & Copyright]]> http://www.zorg.ch/gallery.php?show=pic&picID=13564&parent_id=13564#112730 Mon, 23 Aug 2010 00:00:04 [z]Barbara Harris http://www.zorg.ch/gallery.php?show=pic&picID=13564&parent_id=13564#112730 Hoag's Object: A Strange Ring Galaxy

Explanation: Is this one galaxy or two? This question came to light in 1950 when astronomer Art Hoag chanced upon this unusual Art Hoag chanced upon this unusual extragalactic object. On the outside is a ring dominated by bright blue stars, while near the center lies a ball of much redder stars that are likely much older. Between the two is a gap that appears almost completely dark. How Hoag's Object formed remains unknown, although similar objects have now been identified and collectively labeled as a form of ring galaxy. Genesis hypotheses include a galaxy collision billions of years ago and the gravitational affect of a central bar that has since vanished. The above photo taken by the Hubble Space Telescope in July 2001 reveals unprecedented details of Hoag's Object and may yield a better understanding. Hoag's Object spans about 100,000 light years and lies about 600 million light years away toward the constellation of the Snake (Serpens). Coincidentally, visible in the gap (at about one o'clock) is yet another ring galaxy that likely lies far in the distance.

Credit & Copyright]]> http://www.zorg.ch/gallery.php?show=pic&picID=13563&parent_id=13563#112729 Sun, 22 Aug 2010 00:00:05 [z]Barbara Harris http://www.zorg.ch/gallery.php?show=pic&picID=13563&parent_id=13563#112729 Perseid Storm

Explanation: Storms on the distant horizon and comet dust raining through the heavens above are combined in this alluring nightscape. The scene nightscape. The scene was recorded in the early hours of August 13 from the Keota Star Party site on the Pawnee National Grasslands of northeastern Colorado, USA. Looking east across the prairie, the composite of 8 consecutive exposures each 30 seconds long captures the flash of lightning and a bright Perseid meteor. On the right, even the clouds can't block the light from brilliant planet Jupiter, whose mythological namesake knew how to handle both lightning bolts and meteors. Of course, this meteor's streak points back toward the shower's radiant in the heroic constellation Perseus, sharing a starry background that includes the Pleiades star cluster poised above the storm clouds. Just above the bright meteor lies the faint Andromeda Galaxy.

Credit & Copyright]]> http://www.zorg.ch/gallery.php?show=pic&picID=13562&parent_id=13562#112728 Sat, 21 Aug 2010 00:00:04 [z]Barbara Harris http://www.zorg.ch/gallery.php?show=pic&picID=13562&parent_id=13562#112728 NGC 1365: Majestic Island Universe

Explanation: Barred spiral galaxy NGC 1365 is truly a majestic island universe some 200,000 light-years acr...]]> NGC 1365: Majestic Island Universe

Explanation: Barred spiral galaxy NGC 1365 is truly a majestic island universe some 200,000 light-years across. Located a mere 60 million light-years away toward the chemical constellation Fornax, NGC 1365 is a dominant member of the well-studied Fornax galaxy cluster. This impressively sharp color image shows intense star forming regions at the ends of the bar and along the spiral arms, and details of dust lanes cutting across the galaxy's bright core. At the core lies a supermassive black hole. Astronomers think NGC 1365's prominent bar plays a crucial role in the galaxy's evolution, drawing gas and dust into a star-forming maelstrom and ultimately feeding material into the central black hole.

Credit & Copyright]]> http://www.zorg.ch/gallery.php?show=pic&picID=13561&parent_id=13561#112727 Fri, 20 Aug 2010 00:00:05 [z]Barbara Harris http://www.zorg.ch/gallery.php?show=pic&picID=13561&parent_id=13561#112727 Pelican Nebula Close-up

Explanation: The prominent ridge of emission featured in this intensely colorful skyscape is designated IC 5067. P...]]> Pelican Nebula Close-up

Explanation: The prominent ridge of emission featured in this intensely colorful skyscape is designated IC 5067. Part of a larger emission nebula with a distinctive shape, popularly called The Pelican Nebula, the ridge spans about 10 light-years and follows the curve of the cosmic pelican's head and neck. Fantastic, dark shapes inhabiting the view are clouds of cool gas and dust sculpted by energetic radiation from hot, massive stars. But stars are also forming within the dark shapes. In fact, twin jets emerging from the tip of the central, dark tendril are the telltale signs of an embedded protostar cataloged as Herbig-Haro 555. The Pelican Nebula itself, also known as IC 5070, is about 2,000 light-years away. To find it, look northeast of bright star Deneb in the high flying constellation Cygnus. Rare chance: Ask APOD editor Jerry T. Bonnell questions about APOD.

Credit & Copyright]]>