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Explanation: Why is this galaxy so thin? Many disk galaxies are actually just as thin as NGC 5866, pictured above, but are not seen edge-on from our vantage point. One galaxy that is situated edge-on is our own Milky Way Galaxy. Classified as a lenticular galaxy, NGC 5866 has numerous and complex dust lanes appearing dark and red, while many of the bright stars in the disk give it a more blue underlying hue. The blue disk of young stars can be seen extending past the dust in the extremely thin galactic plane, while the bulge in the disk center...

Explanation: The total solar eclipse of March 8/9 will be the only total eclipse in 2016. Crossing the international date line, the New Moon's dark shadow traces a limited, narrow path for viewing the total phase, making landfall in Indonesia and mostly tracking across the Pacific Ocean. A much larger region will be witness to a partially eclipsed Sun though, during morning hours on March 9 for southeast Asia and northeast Australia, and before sunset March 8 for Hawaii and Alaska. Safely viewing the eclipse can actually be very easy. One technique is demonstrated in this shoe group portrait from...

Explanation: What is that changing object in a cold hydrocarbon sea of Titan? Radar images from the robotic Cassini spacecraft orbiting Saturn have been recording the surface of the cloud-engulfed moon Titan for years. When imaging the flat -- and hence radar dark -- surface of the methane and ethane lake called Ligeia Mare, an object appeared in 2013 July just was not there in 2007. Subsequent observations in 2014 August found the object remained -- but had changed. In an image released last week, the mystery object seems to have disappeared in 2015 January. The featured false-color image shows...

Explanation: One of the most spectacular solar sights is an erupting prominence. In 2011, NASA's Sun-orbiting Solar Dynamic Observatory spacecraft imaged an impressively large prominence erupting from the surface. The dramatic explosion was captured in ultraviolet light in the above time lapse video covering 90 minutes, where a new frame was taken every 24 seconds. The scale of the prominence is huge -- the entire Earth would easily fit under the flowing curtain of hot gas. A solar prominence is channeled and sometimes held above the Sun's surface by the Sun's magnetic field. A quiescent prominence typically lasts about a...

Explanation: Looking toward the south from an altitude of 400 kilometers, this stunning snapshot from orbit finds bright lights of Tokyo and cities across central and southern Japan, planet Earth shining upward through broken clouds. The spacefaring perspective was captured last July by astronaut Scott Kelly during his stay on board the International Space Station. Thin stripes of airglow follow the curve of the planet's dark limb, while beyond lie stars of the constellation Centaurus and the southern sky. Their solar panels extended, a docked Soyuz (bottom) and Progress spacecraft are posed in the foreground. Kelly returned to planet Earth...

Explanation: NGC 134 is probably not the best known spiral galaxy in the constellation Sculptor. Still, the tantalizing island universe is a clearly a telescopic treasure in southern skies. It shares a bright core, clumpy dust lanes, and loosely wrapped spiral arms with spiky foreground stars of the Milky Way and the more diminutive galaxy NGC 131 in this sharp cosmic vista. From a distance of about 60 million light-years, NGC 134 is seen tilted nearly edge-on. It spans some 150,000 light-years, making it even larger than our own Milky Way galaxy. NGC 134's warped disk and faint extensions give...

Explanation: Some of the Solar System's largest moons rose together on February 23. On that night, a twilight pairing of a waning gibbous Moon and Jupiter was captured in this sharp telescopic field of view. The composite of short and long exposures reveals the familiar face of our fair planet's own large natural satellite, along with a line up of the ruling gas giant's four Galilean moons. Left to right, the tiny pinpricks of light are Callisto, Io, Ganymede, [Jupiter], and Europa. Closer and brighter, our own natural satellite appears to loom large. But Callisto, Io, and Ganymede are actually...

Explanation: Image Credit & Copyright: Explanation: What's that in the sky? Earlier this month, in the sky high above Hong Kong, China, not just one unusual type of cloud appeared -- but two. In the foreground was a long lenticular cloud, a cloud that forms near mountains from uprising air and might appear to some as an alien spaceship. Higher in the sky, and further in the background, was a colorful iridescent cloud. Iridescent clouds are composed of water droplets of similar size that diffract different colors of sunlight by different amounts. Furthest in the background is the Sun, blocked...

Explanation: The party is still going on in spiral galaxy NGC 3310. Roughly 100 million years ago, NGC 3310 likely collided with a smaller galaxy causing the large spiral galaxy to light up with a tremendous burst of star formation. The changing gravity during the collision created density waves that compressed existing clouds of gas and triggered the star-forming party. The featured image from the Gemini North Telescope shows the galaxy in great detail, color-coded so that pink highlights gas while white and blue highlight stars. Some of the star clusters in the galaxy are quite young, indicating that starburst...

Explanation: Today, February 29th, is a leap day - a relatively rare occurrence. In 46 BC, Julius Caesar, featured here in a self-decreed minted coin, created a calendar system that added one leap day every four years. Acting on advice by Alexandrian astronomer Sosigenes, Caesar did this to make up for the fact that the Earth's year is slightly more than 365 days. In modern terms, the time it takes for the Earth to circle the Sun is slightly more than the time it takes for the Earth to rotate 365 times (with respect to the Sun -- actually we...

Explanation: IC 1848: The Soul Nebula Stars are forming in the Soul of the Queen of Aethopia. More specifically, a large star forming region called the Soul Nebula can be found in the direction of the constellation Cassiopeia, who Greek mythology credits as the vain wife of a King who long ago ruled lands surrounding the upper Nile river. The Soul Nebula houses several open clusters of stars, a large radio source known as W5, and huge evacuated bubbles formed by the winds of young massive stars. Located about 6,500 light years away, the Soul Nebula spans about 100 light...

Explanation: Gaze across the frozen canyons of northern Pluto in this contrast enhanced color scene, imaged last July by the New Horizons spacecraft. Currently known as Lowell Regio, the region has been informally named for Percival Lowell, founder of the Lowell Observatory. Also famous for his speculation that there were canals on Mars, in 1906 Lowell started the search that ultimately led to Pluto's discovery. Pluto's North Pole itself is above and left of center in the the frame. The pale bluish floor of the broad canyon on the left is about 70 kilometers (45 miles) wide, running vertically toward...

Explanation: The Tarantula Nebula is more than a thousand light-years in diameter, a giant star forming region within nearby satellite galaxy the Large Magellanic Cloud, about 180 thousand light-years away. The largest, most violent star forming region known in the whole Local Group of galaxies, the cosmic arachnid sprawls across this spectacular composite view constructed with space- and ground-based image data. Within the Tarantula (NGC 2070), intense radiation, stellar winds and supernova shocks from the central young cluster of massive stars, cataloged as R136, energize the nebular glow and shape the spidery filaments. Around the Tarantula are other star forming...

Explanation: Fans of planet Earth probably recognize its highest mountain, the Himalayan Mount Everest, on the left in this 3-panel skyscape of The World at Night. Shrouded in cloud Everest's peak is at 8,848 meters (29,029 feet) elevation above sea level. In the middle panel, stars trail above volcanic Mauna Kea forming part of the island of Hawaii. Festooned with astronomical observatories, its summit lies a mere 4,168 meters above sea level. Still, measured from its base starting below the ocean's surface, Mauna Kea is over 10,000 meters tall, making it Earth's tallest mountain from base to summit. At right,...

Explanation: Can you identify a familiar area in the northeast USA just from nighttime lights? It might be possible because many major cities are visible, including (right to left) New York, Philadelphia, Baltimore, Washington, Richmond and Norfolk -- Boston of the USA's Northeast megalopolis is not pictured. The featured image was taken in 2012 from the International Space Station. In the foreground are two Russian cargo ships with prominent solar panels. This Northeast megalopolis of the USA contains almost 20 percent of the people of the USA but only about 2 percent of the land area. Also known also as...

Explanation: Telescopes around the world are tracking a bright supernova that occurred in a nearby dusty galaxy. The powerful stellar explosion was first noted earlier this month. The nearby galaxy is the photogenic Centaurus A, visible with binoculars and known for impressive filaments of light-absorbing dust that cross its center. Cen A is featured here in a high-resolution archival Hubble Space Telescope image, with an inset image featuring the supernova taken from the ground only two days after discovery. Designated SN2016adj, the supernova is highlighted with crosshairs in the inset, appearing just to the left of a bright foreground star...

Explanation: Given some poetic license, there is now scientific evidence that hell has frozen over. To start, Greek mythology holds that Charon is the ferryman of the underworld. Next, recent analysis of data taken by the robotic New Horizons spacecraft that shot past Charon -- the namesake that is the largest moon of Pluto -- in July now indicates that the cause of the huge chasm that runs across the 1200-km moon was that a huge internal sea froze. And since water expands when it freezes, the already hardened outer crust could not contain it and cracked. To better picture...

Explanation: What's lighting up the Cigar Galaxy? M82, as this irregular galaxy is also known, was stirred up by a recent pass near large spiral galaxy M81. This doesn't fully explain the source of the red-glowing outwardly expanding gas, however. Evidence indicates that this gas is being driven out by the combined emerging particle winds of many stars, together creating a galactic superwind. The featured photographic mosaic highlights a specific color of red light strongly emitted by ionized hydrogen gas, showing detailed filaments of this gas. The filaments extend for over 10,000 light years. The 12-million light-year distant Cigar Galaxy...

Explanation: Want to take a relaxing interstellar vacation? Consider visiting Kepler-16b, a world in a binary star system. In fact Kepler-16b is the first discovered circumbinary planet. It was detected in a wide 229 day orbit around a close pair of cool, low-mass stars some 200 light-years away. The parent stars eclipse one another in their orbits, observed as a dimming of starlight. But Kepler-16b itself was discovered by following the additional very slight dimming produced during its transits. Like sci-fi planet Tatooine of Star Wars fame, two suns would set over its horizon. Still, Kepler 16b is probably not...

Explanation: Magnificent island universe NGC 2403 stands within the boundaries of the long-necked constellation Camelopardalis. Some 10 million light-years distant and about 50,000 light-years across, the spiral galaxy also seems to have more than its fair share of giant star forming HII regions, marked by the telltale reddish glow of atomic hydrogen gas. The giant HII regions are energized by clusters of hot, massive stars that explode as bright supernovae at the end of their short and furious lives. A member of the M81 group of galaxies, NGC 2403 closely resembles another galaxy with an abundance of star forming regions...