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Messier 63: The Sunflower Galaxy Credit & Copyright: Tony Hallas Explanation: A bright spiral galaxy of the northern sky, Messier 63 is about 25 million light-years distant in the loyal constellation Canes Venatici. Also cataloged as NGC 5055, the majestic island universe is nearly 100,000 light-years across, about the size of our own Milky Way. Known by the popular moniker, The Sunflower Galaxy, M63 sports a bright yellowish core and sweeping blue spiral arms, streaked with cosmic dust lanes and dotted with pink star forming regions. But this deep exposure also shows remarkable faint loops and extensions of the galaxy's...

A Protected Night Sky Over Flagstaff Credit and Copyright: Dan & Cindy Duriscoe, FDSC, Lowell Obs., USNO Explanation: This sky is protected. Yesterday marked the 50 year anniversary of the first lighting ordinance ever enacted, which restricted searchlight advertisements from sweeping the night skies above Flagstaff, Arizona, USA. Flagstaff now enjoys the status of being the first International Dark Sky City, and maintains a lighting code that limits lights from polluting this majestic nighttime view. The current dark skies over Flagstaff not only enable local astronomers to decode the universe but allow local sky enthusiasts to see and enjoy a...

Sky Delights Over Sweden Credit and Copyright: P-M Hedén (Clear Skies, TWAN) Explanation: This night was a sky enthusiast's delight. While relaxing in Sweden last week, many a cosmic wonder was captured with a single snapshot. They are described here from near to far. In the foreground are nearby trees and more distant snow covered mountains. In silhouette, Clouds can be seen just above the horizon, and a careful eye can even discern the more distant green and red auroras which occur in Earth's upper atmosphere. Red emission nebulas dot the sky, including the Heart and Soul Nebulas, IC...

Phobos: Doomed Moon of Mars Credit: HiRISE, MRO, LPL (U. Arizona), NASA Explanation: This moon is doomed. Mars, the red planet named for the Roman god of war, has two tiny moons, Phobos and Deimos, whose names are derived from the Greek for Fear and Panic. These martian moons may well be captured asteroids originating in the main asteroid belt between Mars and Jupiter or perhaps from even more distant reaches of the Solar System. The larger moon, Phobos, is indeed seen to be a cratered, asteroid-like object in this stunning color image from the Mars Reconnaissance Orbiter, recorded at...

Curious Cometary Knots in the Helix Nebula Credit: C. R. O'Dell and K. Handron (Rice University), NASA Explanation: What causes unusual knots of gas and dust in planetary nebulas? Seen also in the Ring Nebula, the Dumbbell Nebula and the Eskimo Nebula, the knots' existence was not initially predicted and their origins are still not well understood. Pictured above is a fascinating image of the Helix Nebula by the Hubble Space Telescope showing tremendous detail of its mysterious gaseous knots. The above cometary knots have masses similar to the Earth but have radii typically several times the orbit of Pluto....

Stickney Crater Credit: HiRISE, MRO, LPL (U. Arizona), NASA Explanation: Stickney Crater, the largest crater on the martian moon Phobos, is named for Chloe Angeline Stickney Hall, mathematician and wife of astronomer Asaph Hall. Asaph Hall discovered both the Red Planet's moons in 1877. Over 9 kilometers across, Stickney is nearly half the diameter of Phobos itself, so large that the impact that blasted out the crater likely came close to shattering the tiny moon. This stunning, enhanced-color image of Stickney and surroundings was recorded by the HiRISE camera onboard the Mars Reconnaissance Orbiter as it passed within some six...

A Large Magellanic Cloud Deep Field Credit & Copyright: Yuri Beletsky (ESO) Explanation: Is this a spiral galaxy? No. Actually, it is the Large Magellanic Cloud (LMC), the largest satellite galaxy of our own Milky Way Galaxy. The LMC is classified as a dwarf irregular galaxy because of its normally chaotic appearance. In this deep and wide exposure, however, the full extent of the LMC becomes visible. Surprisingly, during longer exposures, the LMC begins to resemble a barred spiral galaxy. The Large Magellanic Cloud lies only about 180,000 light-years distant towards the constellation of Dorado. Spanning about 15,000 light-years, the...

Southern Orion: From Belt to Witch Credit & Copyright: Stéphane Guisard Explanation: Do you recognize the belt of Orion in this image? The familiar trio of stars, visible to the unaided eye, can be found across the upper left. Otherwise, the southern part of the constellation Orion has taken on a new look in this unusually deep and wide view First note that the lower left belt star, Alnitak, is the easternmost star in Orion's belt. Left of Alnitak is the Flame Nebula, with clouds of bright emission and dramatic dark dust lanes. Directly below Alnitak, a close inspection will...

Mysterious White Rock Fingers on Mars Credit: G. Neukum (FU Berlin) et al., Mars Express, DLR Mars Express Explanation: What caused this unusual white rock formation on Mars? Intrigued by the possibility that they could be salt deposits left over as an ancient lakebed dried-up, detailed studies of these fingers now indicate that this is not correct. The light material appears to have eroded away from the surrounding area, indicating a very low-density composition, possibly consistent with volcanic ash or windblown dust. The stark contrast between the rocks and the surrounding sand is compounded by the sand's unusual darkness. This...

Layers in Aureum Chaos Credit: HiRISE, MRO, LPL (U. Arizona), NASA Explanation: At first glance these undulating shapes in shades of blue might look like waves on an ocean. Seen here in a false-color image from the Mars Reconnaissance Orbiter's HiRISE camera, they are actually layered rock outcrops found in Aureum Chaos. The larger Aureum Chaos region is a chaotic jumble of eroded terrain in the eastern part of Mars' immense canyon Valles Marineris. Distinct layers composing these outcrops could have been laid down by dust or volcanic ash settling from the atmosphere, sand carried by martian winds, or sediments...

South of Orion Credit & Copyright: Johannes Schedler (Panther Observatory) Explanation: This tantalizing array of nebulae and stars can be found about 2 degrees south of the famous star-forming Orion Nebula. The region abounds with energetic young stars producing jets and outflows that push through the surrounding material at speeds of hundreds of kilometers per second. The interaction creates luminous shock waves known as Herbig-Haro (HH) objects. For example, the graceful, flowing arc just right of center is cataloged as HH 222, also called the Waterfall Nebula. Seen below the Waterfall, HH 401 has a distinctive cone shape. The bright...

Globular Cluster M55 from CFHT Credit & Copyright: Jean-Charles Cuillandre (CFHT), Hawaiian Starlight, CFHT Explanation: The fifty-fifth entry in Charles Messier's catalog, M55 is a large and lovely globular cluster of around 100,000 stars. Only 20,000 light-years away in the constellation Sagittarius, M55 appears to earth-bound observers to be nearly 2/3 the size of the full moon. Globular star clusters like M55 roam the halo of our Milky Way Galaxy as gravitationally bound populations of stars known to be much older than stellar groups found in the Galactic disk. Astronomers who make detailed studies of globular cluster stars can accurately...

Close Up of Enceladus' Tiger Stripes Credit: Paul Shenk (LPI), USRA; Cassini Imaging Team, SSI, JPL, ESA, NASA Explanation: Could life exist beneath Enceladus? A recent flyby of Saturn's icy moon has bolstered this fascinating idea. Two years ago, images from the robotic Cassini spacecraft orbiting Saturn led astronomers to the undeniable conclusion that Saturn's moon Enceladus was spewing fountains of gas and ice crystals through cracks in its surface dubbed tiger stripes. Last month, Cassini dove through some of these plumes and determined that they contained water vapor laced with small amounts of methane as well as simple and...

Weak Lensing Distorts the Universe Credit: S. Colombi (IAP), CFHT Team Explanation: Is the distant universe really what it appears to be? Astronomers hope not. Intervening dark matter, which is normally invisible, might show its presence by distorting images originating in the distant universe, much the way an old window distorts images originating on the other side. By noting the degree to which background galaxies appear unusually flat and unusually similar to neighbors, the dark matter distribution producing these weak gravitational lensing distortions can be estimated. Analysis of the shapes of 200,000 distant galaxies imaged with the Canada-France-Hawaii Telescope (CFHT)...

Spiral Galaxy NGC 2841 Credit & Copyright: Johannes Schedler (Panther Observatory) Explanation: Some 50 million light-years distant, spiral galaxy NGC 2841 can be found in the northern constellation of Ursa Major. This sharp view of the gorgeous island universe shows off a striking yellow nucleus and galactic disk with tightly wound spiral arms. NGC 2841 has a diameter of over 150,000 light-years, even larger than our own Milky Way Galaxy. The galaxy's dust lanes and turbulent star-forming regions are found along the spiral arms, but X-ray images suggest that resulting winds and stellar explosions create plumes of hot gas extending...

Across the Universe Credit: NASA Swift Team, Stefan Immler (GSFC) et al. Explanation: How far can you see? Even the faintest stars visible to the eye are merely hundreds or thousands of light-years distant, all well within our own Milky Way Galaxy. Of course, if you know where to look you can also spot the Andromeda Galaxy as a pale, fuzzy cloud, around 2.5 million light-years away. But staring toward the northern constellation Bootes on March 19th, even without binoculars or telescope you still could have witnessed a faint, brief, flash of light from a gamma-ray burst. The source of...

An astronaut, Don Pettit, has put together a 10-minute movie of what cities look like at night as seen from space. He shot these images while he was Science Officer aboard ISS Expedition 6 about 5 years ago. He recently posted this on YouTube.This video "Cities at Night; an Orbital Tour Around the World" is a video made from digital still images.A bit of trivia.... most of the music during the movie is from royalty-free clips from Adobe Auditions, but for the Australian sequences, Don played his own didgeridoo that he had with him in space aboard ISS. As you...

The NGC 3576 Nebula Credit & Copyright: Ken Crawford (Rancho Del Sol Observatory), Macedon Ranges Observatory Explanation: An intriguing and beautiful nebula, NGC 3576 drifts through the Sagittarius arm of our spiral Milky Way Galaxy. Within the region, episodes of star formation are thought to contribute to the complex and suggestive shapes. Powerful winds from the nebula's embedded, young, massive stars shape the looping filaments. The dramatic false-color image also highlights the contributions of hydrogen, sulfur, and oxygen, energized by intense ultraviolet radiation, to the nebular glow. But the glow also silhouettes dense clouds of dust and gas. For example,...

Saturn and Titan from Cassini Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA Explanation: Spectacular vistas of Saturn and its moon continue to be recorded by the Cassini spacecraft. Launched from Earth in 1997, robotic Cassini entered orbit around Saturn in 2004 and has revolutionized much of humanity's knowledge of Saturn, its expansive and complex rings, and it many old and battered moons. Soon after reaching Saturn, Cassini released the Huygen's probe which landed on Titan, Saturn's largest moon, and send back unprecedented pictures from below Titan's opaque cloud decks. Recent radar images of Titan from Cassini indicate flat regions...

<\img> Molecular Cloud Barnard 68 Credit: FORS Team, 8.2-meter VLT Antu, ESO Explanation: Where did all the stars go? What used to be considered a hole in the sky is now known to astronomers as a dark molecular cloud. Here, a high concentration of dust and molecular gas absorb practically all the visible light emitted from background stars. The eerily dark surroundings help make the interiors of molecular clouds some of the coldest and most isolated places in the universe. One of the most notable of these dark absorption nebulae is a cloud toward the constellation Ophiuchus known as...