Twilight in a Western Sky Twilight in a Western Sky

A slender crescent Moon and inner planets Venus and Mercury never wander far from the Sun in planet Earth's skies. In the fading evening twilight of March 18, they line up near the western horizon in this atmospheric skyscape. While the celestial scene was enjoyed around the world, this photo captures the trio, with fainter Mercury at the far right, above the crags of Big Bend National Park in southwest Texas. Tonight the Moon will be full though, and rise opposite the Sun. Look for it high in the sky at midnight, near bright star Spica. via NASA https://ift.tt/2uAl3ls

NGC 2023 in the Horsehead s Shadow NGC 2023 in the Horsehead s Shadow

Carved by a bright young star in Orion's dusty molecular clouds, NGC 2023 is often overlooked in favor of the nearby dramatic silhouette of the Horsehead Nebula. In its own right it is seen as a beautiful star forming emission and reflection nebula though, a mere 1500 light-years distant. Surprisingly colorful and complex filaments are detailed in this rare NGC 2023 portrait. Scattered points of emission are also from the region's Herbig-Haro objects, associated with the energetic jets from newborn stars. The sharp telescopic view spans about 10 light-years at the estimated distance of NGC 2023. Off the right edge of the frame lies the more familiar cosmic Horsehead. via NASA https://ift.tt/2GREmZP

Blue Moon Tree Blue Moon Tree

Does an alignment like this occur only once in a blue moon? No, although it was during a blue moon that this single-shot image was taken. During a full moon that happened to be the second of the month -- the situation that defines a blue moon -- the photographer created the juxtaposition in late January by quickly moving around to find just the right spot to get the background Moon superposed behind the arc of a foreground tree. Unfortunately, in this case, there seemed no other way than getting bogged down in mud and resting the camera on a barbed-wire fence. The arc in the oak tree was previously created by hungry cows in Knight's Ferry, California, USA. Quirky Moon-tree juxtapositions like this can be created during any full moon though, given enough planning and time. Another opportunity will arise this weekend, coincidently during another blue moon. Then, the second blue moon in 2018 will occur, meaning that for the second month this year, two full moons will appear during a single month (moon-th). Double blue-moon years are relatively rare, with the last occurring in 1999, and the next in 2037. via NASA https://ift.tt/2GdqjRb

Announcing Nova Carinae 2018 Announcing Nova Carinae 2018

How bright will Nova Carinae 2018 become? The new nova was discovered only last week. Although novas occur frequently throughout the universe, this nova, cataloged as ASASSN-18fv, is so unusually bright in the skies of Earth that it is now easily visible through binoculars in the southern hemisphere. Identified by the arrow, the nova occurs near the direction of the picturesque Carina Nebula. A nova is typically caused by a thermonuclear explosion on the surface of a white dwarf star that is accreting matter from a binary companion, although details of this outburst are currently unknown. Both professional and amateur astronomers will be monitoring this unusual stellar outburst in the coming weeks, looking to see how Nova Carinae 2018 evolves, including whether it becomes bright enough to be visible to the unaided eye. via NASA https://ift.tt/2IO1TM1

NGC 602 and Beyond NGC 602 and Beyond

Near the outskirts of the Small Magellanic Cloud, a satellite galaxy some 200 thousand light-years distant, lies 5 million year young star cluster NGC 602. Surrounded by natal gas and dust, NGC 602 is featured in this stunning Hubble image of the region, augmented by images in the X-ray by Chandra, and in the infrared by Spitzer. Fantastic ridges and swept back shapes strongly suggest that energetic radiation and shock waves from NGC 602's massive young stars have eroded the dusty material and triggered a progression of star formation moving away from the cluster's center. At the estimated distance of the Small Magellanic Cloud, the Picture spans about 200 light-years, but a tantalizing assortment of background galaxies are also visible in this sharp multi-colored view. The background galaxies are hundreds of millions of light-years or more beyond NGC 602. via NASA https://ift.tt/2G66Qhr

NGC 253: Dusty Island Universe NGC 253: Dusty Island Universe

Shiny NGC 253 is one of the brightest spiral galaxies visible, and also one of the dustiest. Some call it the Silver Dollar Galaxy for its appearance in small telescopes, or just the Sculptor Galaxy for its location within the boundaries of the southern constellation Sculptor. Discovered in 1783 by mathematician and astronomer Caroline Herschel, the dusty island universe lies a mere 10 million light-years away. About 70 thousand light-years across, NGC 253 is the largest member of the Sculptor Group of Galaxies, the nearest to our own Local Group of Galaxies. In addition to its spiral dust lanes, tendrils of dust seem to be rising from a galactic disk laced with young star clusters and star forming regions in this sharp color image. The high dust content accompanies frantic star formation, earning NGC 253 the designation of a starburst galaxy. NGC 253 is also known to be a strong source of high-energy x-rays and gamma rays, likely due to massive black holes near the galaxy's center. Take a trip through extragalactic space in this short video flyby of NGC 253. via NASA http://ift.tt/2pvMXch

Camera Orion Camera Orion

Do you recognize this constellation? Although it is one of the most recognizable star groupings on the sky, Orion's icons don't look quite as colorful to the eye as they do to a camera. In this 20-image digitally-composed mosaic, cool red giant Betelgeuse takes on a strong orange tint as the brightest star at the upper left. Orion's hot blue stars are numerous, with supergiant Rigel balancing Betelgeuse at the lower right, and Bellatrix at the upper right Lined up in Orion's belt are three stars all about 1,500 light-years away, born from the constellation's well-studied interstellar clouds. Below Orion's belt a reddish and fuzzy patch that might also look familiar -- the stellar nursery known as Orion's Nebula. Finally, just barely visible to the unaided eye but quite striking here by camera is Barnard's Loop -- a huge gaseous emission nebula surrounding Orion's Belt and Nebula discovered over 100 years ago by the pioneering Orion photographer E. E. Barnard. via NASA http://ift.tt/2GRtZp2

The Nebra Sky Disk The Nebra Sky Disk

It is considered the oldest known illustration of the night sky. But what, exactly, does it depict, and why was it made? The Nebra sky disk was found with a metal detector in 1999 by treasure hunters near Nebra, Germany, in the midst of several bronze-age weapons. The ancient artifact spans about 30 centimeters and has been associated with the Unetice culture that inhabited part of Europe around 1600 BC. Reconstructed, the dots are thought to represent stars, with the cluster representing the Pleiades, and the large circle and the crescent representing the Sun and Moon. The purpose of the disk remains unknown -- hypotheses including an astronomical clock, a work of art, and a religious symbol. Valued at about $11 million, some believe that the Nebra sky disk is only one of a pair, with the other disk still out there waiting to be discovered. via NASA http://ift.tt/2FJZOCO

Rotating Moon from LRO Rotating Moon from LRO

No one, presently, sees the Moon rotate like this. That's because the Earth's moon is tidally locked to the Earth, showing us only one side. Given modern digital technology, however, combined with many detailed images returned by the Lunar Reconnaissance Orbiter (LRO), a high resolution virtual Moon rotation movie has been composed. The above time-lapse video starts with the standard Earth view of the Moon. Quickly, though, Mare Orientale, a large crater with a dark center that is difficult to see from the Earth, rotates into view just below the equator. From an entire lunar month condensed into 24 seconds, the video clearly shows that the Earth side of the Moon contains an abundance of dark lunar maria, while the lunar far side is dominated by bright lunar highlands. Currently, over 20 new missions to the Moon are under active development from four different countries, most of which have expected launch dates either this year or next. via NASA http://ift.tt/2FKI3Di

The Crab from Space The Crab from Space

The Crab Nebula is cataloged as M1, the first object on Charles Messier's famous list of things which are not comets. In fact, the Crab is now known to be a supernova remnant, expanding debris from the death explosion of a massive star. This intriguing false-color image combines data from space-based observatories, Chandra, Hubble, and Spitzer, to explore the debris cloud in X-rays (blue-white), optical (purple), and infrared (pink) light. One of the most exotic objects known to modern astronomers, the Crab Pulsar, a neutron star spinning 30 times a second, is the bright spot near picture center. Like a cosmic dynamo, this collapsed remnant of the stellar core powers the Crab's emission across the electromagnetic spectrum. Spanning about 12 light-years, the Crab Nebula is 6,500 light-years away in the constellation Taurus. via NASA http://ift.tt/2FIPDhW

The Seagull and The Duck The Seagull and The Duck

Seen as a seagull and a duck, these nebulae are not the only cosmic clouds to evoke images of flight. But both are winging their way across this broad celestial landscape, spanning almost 7 degrees across planet Earth's night sky toward the constellation Canis Major. The expansive Seagull (top center) is itself composed of two major cataloged emission nebulae. Brighter NGC 2327 forms the head with the more diffuse IC 2177 as the wings and body. Impressively, the Seagull's wingspan would correspond to about 250 light-years at the nebula's estimated distance of 3,800 light-years. At the lower right, the Duck appears much more compact and would span only about 50 light-years given its 15,000 light-year distance estimate. Blown by energetic winds from an extremely massive, hot star near its center, the Duck nebula is cataloged as NGC 2359. Of course, the Duck's thick body and winged appendages also lend it the slightly more dramatic popular moniker, Thor's Helmet. via NASA http://ift.tt/2tR9INp

Catalog Entry Number 1 Catalog Entry Number 1

Every journey has first step and every catalog a first entry. First entries in six well-known deep sky catalogs appear in these panels, from upper left to lower right in chronological order of original catalog publication. From 1774, Charles Messier's catalog entry number 1 is M1, famous cosmic crustacean and supernova remnant the Crab Nebula. J.L.E. Dreyer's (not so new) New General Catalog was published in 1888. A spiral galaxy in Pegasus, his NGC 1 is centered in the next panel. Just below it in the frame is another spiral galaxy cataloged as NGC 2. In Dreyer's follow-on Index Catalog (next panel), IC 1 is actually a faint double star, though. Now recognized as part of the Perseus molecular cloud complex, dark nebula Barnard 1 begins the bottom row from Dark Markings of the Sky, a 1919 catalog by E.E. Barnard. Abell 1 is a distant galaxy cluster in Pegasus, from George Abell's 1958 catalog of Rich Clusters of Galaxies. The final panel is centered on vdB 1, from Sidney van den Bergh's 1966 study. The pretty, blue galactic reflection nebula is found in the constellation Cassiopeia. via NASA http://ift.tt/2pbQsEK

Flying over the Earth at Night II Flying over the Earth at Night II

What would it be like to orbit the Earth? The International Space Station (ISS) does this every 90 minutes, and sometimes the astronauts on board take image sequences that are made into videos. The featured time-lapse video shows many visual spectacles of the dark Earth below. First, as the video begins, green and red auroras are visible on the upper left above white clouds. Soon city lights come into view, and it becomes clear you are flying over North America, eventually passing over Florida. In the second sequence you fly over Europe and Africa, eventually passing over the Nile River. Brief flashes of light are lightning in storms. Stars far in the distance can be seen rising through the greenish-gold glow of the Earth's atmosphere. via NASA http://ift.tt/2HrQDTJ

Flying over the Earth at Night II Flying over the Earth at Night II

What would it be like to orbit the Earth? The International Space Station (ISS) does this every 90 minutes, and sometimes the astronauts on board take image sequences that are made into videos. The featured time-lapse video shows many visual spectacles of the dark Earth below. First, as the video begins, green and red auroras are visible on the upper left above white clouds. Soon city lights come into view, and it becomes clear you are flying over North America, eventually passing over Florida. In the second sequence you fly over Europe and Africa, eventually passing over the Nile River. Brief flashes of light are lightning in storms. Stars far in the distance can be seen rising through the greenish-gold glow of the Earth's atmosphere. via NASA http://ift.tt/2HrQDTJ

Horsehead: A Wider View Horsehead: A Wider View

Combined image data from the massive, ground-based VISTA telescope and the Hubble Space Telescope was used to create this wide perspective of the interstellar landscape surrounding the famous Horsehead Nebula. Captured at near-infrared wavelengths, the region's dusty molecular cloud sprawls across the scene that covers an angle about two-thirds the size of the Full Moon on the sky. Left to right the frame spans just over 10 light-years at the Horsehead's estimated distance of 1,600 light-years. Also known as Barnard 33, the still recognizable Horsehead Nebula stands at the upper right, the near-infrared glow of a dusty pillar topped with newborn stars. Below and left, the bright reflection nebula NGC 2023 is itself the illuminated environs of a hot young star. Obscuring clouds below the base of the Horsehead and on the outskirts of NGC 2023 show the tell-tale far red emission of energetic jets, known as Herbig-Haro objects, also associated with newborn stars. via NASA http://ift.tt/2HkOLMJ

Cyclones at Jupiter s North Pole Cyclones at Jupiter s North Pole

Juno's Jovian Infrared Auroral Mapper data was used to construct this stunning view of cyclones at Jupiter's North Pole. Measuring the thermal emission from Jovian cloud tops, the infrared the observations are not restricted to the hemisphere illuminated by sunlight. They reveal eight cyclonic features that surround a cyclone about 4,000 kilometers in diameter, just offset from the giant planet's geographic North Pole. Similar data show a cyclone at the Jovian South Pole with five circumpolar cyclones. The South Pole cyclones are slightly larger than their northern cousins. Cassini data has shown that gas giant Saturn's north and south poles each have a single cyclonic storm system. via NASA http://ift.tt/2Fq3HIN

Arcs, Jets, and Shocks near NGC 1999 Arcs, Jets, and Shocks near NGC 1999

This tantalizing array of nebulas and stars can be found about two 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 bluish nebula below and left of center is NGC 1999, a dusty cloud reflecting light from an embedded variable star. The entire cosmic vista spans over 30 light-years, near the edge of the Orion Molecular Cloud Complex some 1,500 light-years distant. via NASA http://ift.tt/2oPtLHf

Colorful Airglow Bands Surround Milky Way Colorful Airglow Bands Surround Milky Way

Why would the sky glow like a giant repeating rainbow? Airglow. Now air glows all of the time, but it is usually hard to see. A disturbance however -- like an approaching storm -- may cause noticeable rippling in the Earth's atmosphere. These gravity waves are oscillations in air analogous to those created when a rock is thrown in calm water. Red airglow likely originates from OH molecules about 87-kilometers high, excited by ultraviolet light from the Sun, while orange and green airglow is likely caused by sodium and oxygen atoms slightly higher up. While driving near Keluke Lake in Qinghai Provence in China, the photographer originally noticed mainly the impressive central band of the Milky Way Galaxy. Stopping to photograph it, surprisingly, the resulting sensitive camera image showed airglow bands to be quite prominent and span the entire sky. The featured image has been digitally enhanced to make the colors more vibrant. via NASA http://ift.tt/2FhJXqI

Clouds, Birds, Moon, Venus Clouds, Birds, Moon, Venus

Sometimes the sky above can become quite a show. In early September of 2010, for example, the Moon and Venus converged, creating quite a sight by itself for sky enthusiasts around the globe. From some locations, though, the sky was even more picturesque. In the featured image taken in Spain, a crescent Moon and the planet Venus, on the far right, were captured during sunset posing against a deep blue sky. In the foreground, dark storm clouds loom across the image bottom, while a white anvil cloud shape appears above. Black specks dot the frame, caused by a flock of birds taking flight. Very soon after this picture was taken, however, the birds passed by, the storm ended, and Venus and the Moon set. Bright Venus is again visible just after sunset this month (2018 March) and will appear quite near Mercury tonight and the rest of this week. via NASA http://ift.tt/2F7vb9Y

Southwest Mare Fecunditatis Southwest Mare Fecunditatis

Frank Borman, James Lovell, and William Anders journeyed from Earth to the Moon and back again in December of 1968. From lunar orbit, their view of craters in southwest Mare Fecunditatis is featured in this stereo anaglyph, best experienced from armchairs on planet Earth with red/blue glasses. Goclenius is the large impact crater in the foreground. About 70 kilometers (45 miles) in diameter its lava-flooded floor is scarred by rilles or grooves, long, narrow depressions in the surface. Crossing the crater walls and central peaks the rilles were likely formed after the crater itself. In the background, the two large craters with smooth floors are Colombo A (top) and Magelhaens. Magelhaens A, the background crater with the irregular floor, is about 35 kilometers (20 miles) in diameter. via NASA http://ift.tt/2oMkChI

The Lunar X The Lunar X

The striking X in this lunarscape is easily visible in binoculars or a small telescope, but not too many have seen it. The catch is, this lunar X is fleeting and only apparent in the hours before the Moon's first quarter phase. Along the shadow line between lunar day and night, the X illusion is produced by a configuration of craters seen here toward the left, Blanchinus, La Caille and Purbach. Near the Moon's first quarter phase, an astronaut standing close to the craters' position would see the slowly rising Sun very near the horizon. Temporarily, crater walls would be in sunlight while crater floors would still be in darkness. Seen from planet Earth, contrasting sections of bright walls against the dark floors by chance look remarkably like an X. This sharp image of the Lunar X was captured on February 22nd. For extra credit, sweep your gaze along the lunar terminator and you can also spot the Lunar V. via NASA http://ift.tt/2HSh71Q