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Circles in the Sky Credit & Copyright: Jean-Marc Lecleire Explanation: Gazing skyward on a sunny day in May, photographer Jean-Marc Lecleire captured this engaging display of ice halos forming complete circles in the sky. Recorded with a fish-eye lens from a spot near the grand Château de Chambord in France, the picture looks straight up, spanning almost 180 degrees from horizon to horizon. Surrounding the Sun is a halo formed by sunlight refracting through hexagonal-shaped ice crystals in high, thin clouds. The halo is circular and exactly 22 degrees in radius, but it looks squashed because of the distortion...

Sideways Galaxy NGC 3628 Credit & Copyright:,/b> Keith Quattrocchi Explanation: Dark dust lanes cut across the middle of this gorgeous island universe, a strong hint that NGC 3628 is a spiral galaxy seen sideways. About 35 million light-years away in the northern springtime constellation Leo, NGC 3628 also bears the distinction of being the only member of the well known Leo triplet of galaxies not in Charles Messier's famous catalog. Otherwise similar in size to our Milky Way Galaxy, the disk of NGC 3628 is clearly seen to fan out near the edges. A faint arm of material also extends...

A Supply Ship Docks with the International Space Station Credit: ISS Expedition 16 Crew, NASA Explanation: Looking out a window of the International Space Station brings breathtaking views. Visible vistas include a vast and colorful Earth, a deep dark sky, and an occasional spaceship sent to visit the station. Visible early last month was a Soyuz TMA-12 spacecraft carrying not only supplies but also three newcomers. The three new astronauts were Expedition 17 commander Sergei Volkov, flight engineer Oleg Kononenko, and spaceflight participant So-yeon Yi. Yi returned to Earth a few days later, while Volkov and Konenenko are scheduled to...

Ancient Craters of Southern Rhea Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA Explanation: Saturn's ragged moon Rhea has one of the oldest surfaces known. Estimated as changing little in the past billion years, Rhea shows craters so old they no longer appear round – their edges have become compromised by more recent cratering. Like Earth's Moon, Rhea's rotation is locked on Saturn, and the above image shows part of Rhea's surface that always faces Saturn. Rhea's leading surface is more highly cratered than its trailing surface. Rhea is composed mostly of water-ice but is thought to include about 25...

The M81 Galaxy Group Through the Integrated Flux Nebula Credit & Copyright: Jordi Gallego Explanation: Large galaxies and faint nebula highlight this deep image of the M81 Group of galaxies. First and foremost in the above wide-angle 12-hour exposure is the grand design spiral galaxy M81, the largest galaxy visible in the image. M81 is gravitationally interacting with M82 just below it, a big galaxy with an unusual halo of filamentary red-glowing gas. Around the image many other galaxies from the M81 Group of galaxies can be seen. Together with other galaxy congregates including our Local Group of galaxies and...

Retrograde Mars Credit & Copyright: Tunç Tezel (TWAN) Explanation: Why would Mars appear to move backwards? Most of the time, the apparent motion of Mars in Earth's sky is in one direction, slow but steady in front of the far distant stars. About every two years, however, the Earth passes Mars as they orbit around the Sun. During the most recent such pass over the last year, the proximity of Mars made the red planet appear larger and brighter than usual. Also during this time, Mars appeared to move backwards in the sky, a phenomenon called retrograde motion. Pictured above...

Moon Meets Mercury Credit & Copyright: P-M Hedén (Clear Skies, TWAN) Explanation: On Tuesday, May 6, while standing on planet Earth and sweeping your binoculars along the western horizon just after sunset, you might have encountered this arresting skyscape. The view features a slender crescent Moon and bright planet Mercury separated on the sky by only about 2 degrees. Cradled in the sunlit lunar crescent, the night side of the Moon is faintly illuminated by earthshine -- sunlight reflected from planet Earth. Of course, the clouds in silhouette and fading twilight colors are common elements in pictures of the sky...

Galaxies Collide in NGC 3256 Credit: NASA, ESA, Hubble Heritage (STScI / AURA) - ESA/Hubble Collaboration, & A. Evans (UVa, NRAO, SUNYSB) Explanation: Galaxies don't normally look like this. NGC 3256 actually shows a current picture of two galaxies that are slowly colliding. Quite possibly, in hundreds of millions of years, only one galaxy will remain. Today, however, NGC 3256 shows intricate filaments of dark dust, unusual tidal tails of stars, and a peculiar center that contains two distinct nuclei. Although it is likely that no stars in the two galaxies will directly collide, the gas, dust, and ambient magnetic...

A Persistent Electrical Storm on Saturn Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA Explanation: How do large storms evolve on Saturn? On Earth, a hurricane can persist for weeks, while the Great Red Spot on Jupiter has been in existence for over 150 years. On Saturn, a storm system has now set a new endurance record, now being discernable for greater than three months. Electrical signals were detected from the storm in late November of 2007, while the above image was taken in early March 2008. The storm has roughly the width of planet Earth. Planetary scientists hypothesize that...

Link only - it's 2200 pixels wideAlborz Mountain Miky Way Credit & Copyright: Babak Tafreshi (TWAN) Explanation: Snow-capped stratovolcano Mt. Damavand climbs to 5,670 meters (18,598 feet) near the left edge in this panoramic view of the world at night. Pan to the right and your gaze will sweep across the arch of our Milky Way Galaxy above the Alborz Mountain Range bordering the Caspian Sea. Near the center of the panorama, recorded in the predawn hours of April 4th, bright stars Deneb and Altair lie close to the curve of the Milky Way, above the glow of the...

Shaping NGC 6188 Credit & Copyright:,/b> John Ebersole Explanation: Dark shapes with bright edges winging their way through dusty NGC 6188 are tens of light-years long. The emission nebula is found near the edge of an otherwise dark large molecular cloud in the southern constellation Ara, about 4,000 light-years away. Formed in that region only a few million years ago, the massive young stars of the embedded Ara OB1 association sculpt the fantastic shapes and power the nebular glow with stellar winds and intense ultraviolet radiation. The recent star formation itself was likely triggered by winds and supernova explosions, from...

The Giants of Omega Centauri Credit: NASA, JPL-Caltech, Martha Boyer (Univ. Minnesota), et al. Explanation: Globular star cluster Omega Centauri is some 15,000 light-years away and 150 light-years in diameter. Packed with about 10 million stars, Omega Cen is the largest of 200 or so known globular clusters that roam the halo of our Milky Way galaxy. This intriguing color picture combines a visible light image of the cluster in blue hues with infrared image data from the Spitzer Space Telescope. The Spitzer data includes images in two infrared bands, one shown in green and one in red. Both infrared...

Arp 272 Credit: NASA, ESA, Hubble Heritage (STScI / AURA) - ESA/Hubble Collaboration, K. Noll (STScI) Explanation: Linking spiral arms, two large colliding galaxies are featured in this Hubble Space Telescope view, part of a series of cosmic snapshots released to celebrate the Hubble's 18th anniversary. Recorded in astronomer Halton Arp's Atlas of Peculiar Galaxies as Arp 272, the pair is otherwise known as NGC 6050 and IC 1179. They lie some 450 million light-years away in the Hercules Galaxy Cluster. At that estimated distance, the picture spans over 150 thousand light-years. Although this scenario does look peculiar, galaxy collisions...

Star Forming Region NGC 3582 Credit & Copyright: T. A. Rector (U. Alaska), T. Abbott, NOAO, AURA, NSF Explanation: What's happening in the NGC 3582 nebula? Bright stars and interesting molecules are forming. The complex nebula resides in the star forming region called RCW 57. Visible in this image are dense knots of dark interstellar dust, bright stars that have formed in the past few million years, fields of glowing hydrogen gas ionized by these stars, and great loops of gas expelled by dying stars. A recent detailed study of NGC 3582 uncovered at least 33 massive stars in the...

The Galactic Center Radio Arc Credit: Farhad Zadeh et al. (Northwestern), VLA, NRAO Explanation: What causes this unusual structure near the center of our Galaxy? The long parallel rays slanting across the top of the above radio image are known collectively as the Galactic Center Radio Arc and jut straight out from the Galactic plane. The Radio Arc is connected to the Galactic center by strange curving filaments known as the Arches. The bright radio structure at the bottom right likely surrounds a black hole at the Galactic center and is known as Sagittarius A*. One origin hypothesis holds that...

M86 in the Virgo Cluster Credit & Copyright: Greg Morgan (Sierra Remote Observatories) Explanation: Bright lenticular galaxy M86 is near center of this cosmic view, at the heart of the Virgo Galaxy Cluster. Other bright galaxies in the neighborhood include M84 at the upper right, edge-on spiral NGC4388 near the right edge, a striking pair of interacting galaxies, Markarian's Eyes, in the lower left corner, and edge-on spiral NGC 4402 at about 11 o'clock. With well over a thousand members, the Virgo Cluster is the closest large cluster of galaxies. On average the cluster galaxies are measured to be about...

Cygnus Without Stars Credit & Copyright: Igor Chekalin Explanation: The sky is full of hydrogen, though it can take a sensitive camera and telescope to see it. For example, this twelve-degree-wide view of the northern part of the constellation Cygnus reveals cosmic clouds of hydrogen gas along the plane of our Milky Way galaxy. The mosaic of telescopic images was recorded through an h-alpha filter that transmits only visible red light from glowing hydrogen atoms. Further digital processing has removed most of what is left of the myriad, point-like Milky Way stars from the scene, though bright Deneb, alpha...

The Fox Fur Nebula from CFHT Credit & Copyright: Jean-Charles Cuillandre (CFHT) & Giovanni Anselmi (Coelum Astronomia), Hawaiian Starlight Explanation: This interstellar beast is formed of cosmic dust and gas interacting with the energetic light and winds from hot young stars. The shape, visual texture, and color, combine to give the region the popular name Fox Fur Nebula. The characteristic blue glow on the left is dust reflecting light from the bright star S Mon, just beyond the left edge of the image. Mottled pink and brown areas are a combination of the cosmic dust and reddish emission from ionized...

Spiral Galaxies in Collision Credit: Debra Meloy Elmegreen (Vassar College) et al., & the Hubble Heritage Team (AURA/STScI/NASA) Explanation: Billions of years from now, only one of these two galaxies will remain. Until then, spiral galaxies NGC 2207 and IC 2163 will slowly pull each other apart, creating tides of matter, sheets of shocked gas, lanes of dark dust, bursts of star formation, and streams of cast-away stars. Astronomers predict that NGC 2207, the larger galaxy on the left, will eventually incorporate IC 2163, the smaller galaxy on the right. In the most recent encounter that peaked 40 million years...

IC 2948: The Running Chicken Nebula Credit & Copyright: Steve Crouch Explanation: Bright nebulae abound in and around the expansive southern constellation of Centaurus. This one, cataloged as IC 2948 is near the star Lambda Centauri and not far on the sky from the better known Eta Carinae Nebula. Embedded in the reddish glowing cloud of hydrogen gas, typical of emission nebulae found in massive star-forming regions, is the energetic young star cluster IC 2944. Seen in silhouette near the top of the view are small, dark clouds of obscuring cosmic dust. Called Thackeray's Globules for their discoverer, they are...