Antariksha

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This is a unique NASA Hubble Space Telescope view of the disk galaxy NGC 5866 tilted nearly edge-on to our line-of-sight.

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M33: Triangulum Galaxy via #NASA #APOD Astronomy Picture Of the Day https://buff.ly/2Ar55eX⠀ ⠀ The small, #northern #constellation #Triangulum harbors this magnificent face-on #spiralgalaxy, #M33. Its popular names include the Pinwheel Galaxy or just the #TriangulumGalaxy. M33 is over 50,000 light-years in diameter, third largest in the Local Group of galaxies after the #Andromeda #Galaxy (#M31), and our own #MilkyWay. About 3 million light-years from the Milky Way, M33 is itself thought to be a satellite of the Andromeda Galaxy and #astronomers in these two galaxies would likely have spectacular views of each other's grand spiral star systems. As for the view from planet Earth, this sharp composite image nicely shows off M33's blue star clusters and pinkish star forming regions along the galaxy's loosely wound spiral arms. In fact, the cavernous #NGC604 is the brightest star forming region, seen here at about the 7 o'clock position from the galaxy center. Like M31, M33's population of well-measured variable stars have helped make this nearby spiral a #cosmic yardstick for establishing the distance scale of the #Universe.

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M42: The Great Orion Nebula via #NASA #APOD Astronomy Picture Of the Day https://buff.ly/2ilmrDc⠀ ⠀ Few astronomical sights excite the imagination like the nearby stellar nursery known as the #OrionNebula. The Nebula's glowing gas surrounds hot young stars at the edge of an immense #interstellar molecular cloud. Many of the filamentary structures visible in the featured image are actually shock waves - fronts where fast moving material encounters slow moving gas. The #Orion #Nebula spans about 40 light years and is located about 1500 light years away in the same spiral arm of our #Galaxy as the #Sun. The Great Nebula in Orion can be found with the unaided eye just below and to the left of the easily identifiable belt of three stars in the popular #constellation Orion. The featured image, taken last month, shows a two-hour exposure of the nebula in three colors. The whole Orion Nebula cloud complex, which includes the #HorseheadNebula, will slowly disperse over the next 100,000 years.

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A Colourful Moon via #NASA #APOD Astronomy Picture Of the Day https://buff.ly/2zuMVIM⠀ ⠀ The #Moon is normally seen in subtle shades of grey. But small, measurable color differences have been greatly exaggerated in this mosaic of high-resolution images captured near the Moon's full phase, to construct a multicolored, central moonscape. The different colors are recognized to correspond to real differences in the mineral makeup of the #lunar surface. Blue hues reveal #titanium rich areas while more orange and purple colors show regions relatively poor in titanium and iron. The intriguing Sea of Vapors, or Mare Vaporum, is below center in the frame with the sweeping arc of the lunar #MontesApenninus (#ApennineMountains) above it. The dark floor of 83 kilometer diameter #Archimedes #crater within the Sea of Rains, or #MareImbrium, is toward the top left. Near the gap at the top of the Apennine's arc is the #Apollo15 landing site. Calibrated by rock samples returned by the #Apollo missions, similar multicolor images from #spacecraft have been used to explore the Moon's global surface composition.

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Williamina Fleming s Triangular Wisp via #NASA #APOD Astronomy Picture Of the Day https://buff.ly/2hZqfpZ⠀ ⠀ Chaotic in appearance, these tangled filaments of shocked, glowing gas are spread across planet Earth's #sky toward the #constellation of #Cygnus as part of the #VeilNebula. The #Veil #Nebula itself is a large #supernovaremnant, an expanding cloud born of the death explosion of a massive #star. #Light from the original #supernova explosion likely reached Earth over 5,000 years ago. Blasted out in the cataclysmic event, the #interstellar shock waves plow through space sweeping up and exciting interstellar material. The glowing filaments are really more like long ripples in a sheet seen almost edge on, remarkably well separated into the glow of ionized #hydrogen atoms shown in red and oxygen in blue hues. Also known as the Cygnus Loop, the Veil Nebula now spans nearly 3 degrees or about 6 times the diameter of the full #Moon. While that translates to over 70 light-years at its estimated distance of 1,500 light-years, this field of view spans less than one third that distance. Often identified as Pickering's Triangle for a director of Harvard College #Observatory, the the complex of filaments is cataloged as #NGC 6979. It is also known for its discoverer, #astronomer Williamina Fleming, as Fleming's Triangular Wisp.

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NGC 1055 Close up via #NASA #APOD Astronomy Picture Of the Day https://buff.ly/2hX2jnd⠀⠀ ⠀⠀ Big, beautiful #spiralgalaxy #NGC1055 is a dominant member of a small #galaxy group a mere 60 million #lightyears away toward the aquatically intimidating #constellation #Cetus. Seen edge-on, the island #universe spans over 100,000 light-years, a little larger than our own #MilkyWay. The colorful #stars in this #cosmic close-up of #NGC 1055 are in the foreground, well within the #MilkyWay. But the telltale pinkish star forming regions are scattered through winding dust lanes along the distant galaxy's thin disk. With a smattering of even more distant background #galaxies, the deep image also reveals a boxy halo that extends far above and below the central bluge and disk of NGC 1055. The halo itself is laced with faint, narrow structures, and could represent the mixed and spread out debris from a #satellite galaxy disrupted by the larger spiral some 10 billion years ago.

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The Prague Astronomical Clock via #NASA #APOD Astronomy Picture Of the Day https://buff.ly/2yDd0G0⠀ ⠀ In the center of #Prague there's a clock the size of a building. During the day, crowds gather to watch the show when it chimes in a new hour. The Prague #AstronomicalClock's face is impressively complex, giving not only the expected time with respect to the #Sun (#solar time), but the time relative to the #stars (sidereal time), the times of sunrise and sunset, the time at the #equator, the phase of the #Moon, and much more. The clock began operation in 1410, and even though much of its inner workings have been modernized several times, original parts remain. Below the clock is a nearly-equal sized, but static, #solarcalendar. Pictured, the #PragueAstronomicalClock was photographed alone during an early morning in 2009 March. The Prague Astronomical Clock and the Old Town Tower behind it are currently being renovated once again, with the clock expected to be restarted in 2018 June.

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A Year of Full Moons via #NASA #APOD Astronomy Picture Of the Day https://buff.ly/2zezuwu⠀ ⠀ Do all full #moons look the same? No. To see the slight differences, consider this grid of twelve full moons. From upper left to lower right, the images represent every lunation from 2016 November through 2017 October, as imaged from Pakistan. The consecutive full moons are all shown at the same scale, so unlike the famous #Moon Illusion, the change in apparent size seen here is real. The change is caused by the variation in lunar distance due to the Moon's significantly non-circular orbit. The dark notch at the bottom of the #fullmoon of 2017 August is the shadow of the #Earth -- making this a partial #lunar #eclipse. Besides the sometimes exaggerated coloring, a subtler change in appearance can also be noticed on close examination, as the Moon seems to wobble slightly from one full moon to the next. This effect, known as libration, is more dramatic and easier to see in this lunation video highlighting all of the ways that the Moon appears to change over a month (moon-th).

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Mirach s Ghost via #NASA #APOD Astronomy Picture Of the Day https://buff.ly/2xt5etG⠀ ⠀ As far as ghosts go, Mirach's Ghost isn't really that scary. Mirach's Ghost is just a faint, #fuzzygalaxy, well known to #astronomers, that happens to be seen nearly along the line-of-sight to #Mirach, a #brightstar. Centered in this star field, Mirach is also called Beta #Andromedae. About 200 light-years distant, Mirach is a #redgiant star, cooler than the #Sun but much larger and so intrinsically much brighter than our parent star. In most telescopic views, glare and diffraction spikes tend to hide things that lie near Mirach and make the faint, fuzzy #galaxy look like a ghostly internal reflection of the almost overwhelming starlight. Still, appearing in this sharp image just above and to the left of Mirach, Mirach's Ghost is cataloged as galaxy #NGC 404 and is estimated to be some 10 million light-years away.

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NGC 7635: Bubble in a Cosmic Sea via #NASA #APOD Astronomy Picture Of the Day https://buff.ly/2gLTYWn⠀⠀ ⠀⠀ Adrift in a #cosmicsea of #stars and glowing gas the delicate, floating apparition left of center in this widefield view is cataloged as #NGC7635, the Bubble #Nebula. A mere 10 light-years wide, the tiny #BubbleNebula was blown by the winds of a #massivestar. It lies within a larger complex of #interstellar gas and dust clouds found about 11,000 #lightyears distant, straddling the boundary between the parental #constellations #Cepheus and #Cassiopeia. Included in the breathtaking vista is open #starcluster #M52 (lower left), some 5,000 light-years away. Above and right of the Bubble Nebula is an emission region identified as Sh2-157, also known as the #ClawNebula. Constructed from 47 hours of narrow-band and broad-band exposures, this image spans about 3 degrees on the #sky. That corresponds to a width of 500 light-years at the estimated distance of the Bubble Nebula.

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Marius Hills: Holes in the Moon via #NASA #APOD Astronomy Picture Of the Day https://buff.ly/2yIcwh5⠀ ⠀ Could humans live beneath the surface of the #Moon? This intriguing possibility was bolstered in 2009 when Japan's #Moonorbiting #SELENE #spacecraft imaged a curious hole beneath the #MariusHills region on the Moon, possibly a #skylight to an underground lava tube. Follow-up observations by NASA's #Lunar #Reconnaissance #Orbiter (LRO) indicated that the Marius Hills Hole (MHH) visually extends down nearly 100 meters and is several hundred meters wide. Most recently, ground penetrating radar data from SELENE has been re-analyzed to reveal a series of intriguing second echoes -- indicators that the extensive lava tubes exist under Marius Hills might extend down even kilometers and be large enough to house cities. Such tubes could shelter a future Moon colony from large temperature swings, micro-meteor impacts, and harmful solar radiation. Potentially, underground lava tubes might even be sealed to contain breathable air. These lava tubes likely formed when lunar volcanos were active billions of years ago. Pictured, the surface of Marius Hills region was captured in the 1960s by NASA's Lunar Orbiter 2 mission, while an inset image of the MHH is shown from NASA's continuing LRO. Several volcanic domes are visible, while Marius Crater is visible on the upper right.

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Two Black Holes Dancing in 3C 75 via #NASA #APOD Astronomy Picture Of the Day https://buff.ly/2y0YXov⠀ ⠀ What's happening at the center of active galaxy 3C 75? The two bright sources at the center of this composite x-ray (blue)/ radio (pink) image are co-orbiting supermassive black holes powering the giant radio source 3C 75. Surrounded by multimillion degree x-ray emitting gas, and blasting out jets of relativistic particles the supermassive black holes are separated by 25,000 light-years. At the cores of two merging galaxies in the Abell 400 galaxy cluster they are some 300 million light-years away. Astronomers conclude that these two supermassive black holes are bound together by gravity in a binary system in part because the jets' consistent swept back appearance is most likely due to their common motion as they speed through the hot cluster gas at 1200 kilometers per second. Such spectacular cosmic mergers are thought to be common in crowded galaxy cluster environments in the distant universe. In their final stages the mergers are expected to be intense sources of gravitational waves.

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Pluto s Bladed Terrain via #NASA #APOD Astronomy Picture Of the Day https://buff.ly/2xUQGqc⠀ ⠀ Imaged during the #NewHorizons #spacecraft flyby in July 2015, #Pluto's #BladedTerrain is captured in this close-up of the distant world. The bizarre texture belongs to fields of skyscraper-sized, jagged landforms made almost entirely of #methane ice, found at extreme altitudes near Pluto's #equator. Casting dramatic shadows, the tall, knife-like ridges seem to have been formed by sublimation. By that process, condensed methane ice turns directly to methane gas without passing through a liquid phase during Pluto's warmer geological periods. On #planet #Earth, sublimation can also produce standing fields of knife-like ice sheets, found along the high plateau of the Andes mountain range. Known as penitentes, those bladed structures are made of water ice and at most a few meters tall.

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Portrait of NGC 281 via #NASA #APOD Astronomy Picture Of the Day https://buff.ly/2kdQ6OS⠀ ⠀ Look through the cosmic cloud cataloged as #NGC 281 and you might miss the stars of #opencluster IC 1590. Still, formed within the #nebula that cluster's young, #massivestars ultimately power the pervasive nebular glow. The eye-catching shapes looming in this portrait of #NGC281 are sculpted columns and dense dust globules seen in silhouette, eroded by intense, energetic winds and radiation from the hot cluster stars. If they survive long enough, the dusty structures could also be sites of future #starformation. Playfully called the #PacmanNebula because of its overall shape, NGC 281 is about 10,000 #lightyears away in the #constellation #Cassiopeia. This sharp composite image was made through narrow-band filters, combining #emission from the nebula's #hydrogen, #sulfur, and #oxygen atoms in #green, #red, and #blue hues. It spans over 80 light-years at the estimated distance of NGC 281.

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Calm Waters and Geomagnetic Storm⠀ ⠀ Very recognizable stars of the northern sky are a backdrop for calm waters in this moonlit sea and skyscape off Cape Cod, Massachusetts. Taken on September 7, the photo also records a colorful display of northern lights or aurora borealis triggered by a severe geomagnetic storm. Visible crossing the Sun, the giant solar active region responsible, AR 2673, is much larger than planet Earth. It has produced the strongest flare of the current solar cycle and and the Earth-directed coronal mass ejection in the last few days.⠀ ⠀ #skyscape #northernlights #aurora #auroraborealis

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The Great Gig in the Sky via #NASA #APOD #Astronomy Picture Of the Day https://buff.ly/2xgZSWa⠀ ⠀ There were no crowds on the beach at Phillips Lake, #Oregon on August 21. But a few had come there to stand, for a moment, in the dark shadow of the #Moon. From the beach, this unscripted mosaic photo records their much anticipated #solareclipse. In two vertical panels it catches the last few seconds of #totality and the first instant of 3rd contact, just as the #eclipse ends and sunlight faintly returns. Across the US those gathered along the path of totality also took pictures and shared their moment. And like those at #PhillipsLake they may treasure the experience more than any planned or unplanned #photograph of the #totaleclipse of the #Sun.