Astronomy (General/Chat)
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Explanation: 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, whom Greek mythology credits as the vain wife of a King who long ago ruled lands surrounding the upper Nile river. Also known as Westerhout 5 (W5), the Soul Nebula houses several open clusters of stars, ridges and pillars darkened by cosmic dust, 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...
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Explanation: The lovely Pleiades star cluster shines in Earth's night sky, a compact group of stars some 400 light-years distant toward the constellation Taurus and the Orion Arm of our Milky Way galaxy. Recognized since ancient times, the remarkable celestial gathering is visible to the unaided eye. The Pleiades cluster is also well-placed for viewing from both northern and southern hemispheres, and over the centuries has become connected to many cultural traditions and celebrations, including the cross-quarter day celebration Halloween. In Greek myth, the Pleiades were seven daughters of the astronomical titan Atlas and sea-nymph Pleione. Galileo first sketched the...
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Explanation: What’s happening over that tree? Two very different things. On the left is the Andromeda galaxy, an object that is older than humanity and will last billions of years into the future. Andromeda (M31) is similar in size and shape to our own Milky Way Galaxy. On the right is a red sprite, a type of lightning that lasts a fraction of a second and occurs above violent thunderstorms. Red sprites were verified as real atmospheric phenomena only about 35 years ago. The tree in the center is a boab, which may live for as long as a thousand...
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Explanation: Halloween is an astronomy holiday and spooky shapes always seem to lurk in planet Earth's night skies. In fact, near the center of this telescopic view toward the constellation Cassiopeia these swept-back interstellar clouds IC 59 (left) and IC 63 look ghostly on a cosmic scale. About 600 light-years distant, the clouds aren't actually ghosts. They are slowly disappearing though, under the influence of energetic radiation from hot, luminous star gamma Cas. The brightest bluish star in the frame, Gamma Cas is physically located only 3 to 4 light-years from the nebulae. Slightly closer to gamma Cas, IC 63...
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The Dec. 19 flyby of Comet 3I/ATLAS gives astronomers a rare chance to study only the third known interstellar object to pass through our solar system. VIDEO AT LINK............... Astronomers and skywatchers are hoping to spot interstellar Comet 3I/ATLAS on Dec. 19 when it makes its closest — but safely distant — flyby of Earth. The comet has drawn global attention as only the third confirmed interstellar object observed passing through our solar system. According to NASA, Comet 3I/ATLAS will not pose any threat to Earth during its pass. The object is expected to remain about 170 million miles from...
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Explanation: Where are all of these meteors coming from? In terms of direction on the sky, the pointed answer is the constellation of Gemini. That is why the major meteor shower in December is known as the Geminids -- because shower meteors all appear to come from a radiant toward Gemini. Three dimensionally, however, sand-sized debris expelled from the unusual asteroid 3200 Phaethon follows a well-defined orbit about our Sun, and the part of the orbit that approaches Earth is superposed in front of the constellation of Gemini. Therefore, when Earth crosses this orbit, the radiant point of falling debris...
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Explanation: Sure, Halloween is an astronomy holiday. But astronomers always enjoy scanning the heavens for spook-tacular galaxies, stars, and nebulae. This favorite is item number 43 from the Beverly Lynds 1962 Catalog of Dark Nebulae, fondly known as the Cosmic Bat nebula. While its visage looks alarmingly like a scary flying mammal, Lynds Dark Nebula 43 is over 12 light-years across. Glowing with eerie light, stars are forming within the dusty interstellar molecular cloud that is dense enough to appear in silhouette against a luminous background of Milky Way stars. Watch out. This Cosmic Bat nebula is a mere 400...
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Explanation: What would it be like to fly over the largest moon in the Solar System? In 2021, the robotic Juno spacecraft flew past Jupiter's huge moon Ganymede and took images that have been digitally constructed into a detailed flyby. As the featured video begins, Juno swoops over the two-toned surface of the 2,000-km wide moon, revealing an icy alien landscape filled with grooves and craters. The grooves are likely caused by shifting surface plates, while the craters are caused by violent impacts. Continuing on in its orbit, Juno then performed its 34th close pass over Jupiter's clouds. The digitally-constructed...
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Explanation: Do any shapes seem to jump out at you from this interstellar field of stars and dust? The jeweled expanse, filled with faint, starlight-reflecting clouds, drifts through the night in the royal constellation of Cepheus. Far from your own neighborhood on planet Earth, these ghostly apparitions lurk along the plane of the Milky Way at the edge of the Cepheus Flare molecular cloud complex some 1,200 light-years away. Over two light-years across and brighter than the other spooky chimeras, VdB 141 or Sh2-136 is also known as the Ghost Nebula, seen across the middle of the featured image. Within...
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Explanation: On December 5, 2022, a camera on board the uncrewed Orion spacecraft captured this view as Orion approached its return powered flyby of the Moon. Beyond one of Orion's extended solar arrays lies dark, smooth, terrain along the western edge of the Oceanus Procellarum. Prominent on the lunar nearside Oceanus Procellarum, the Ocean of Storms, is the largest of the Moon's lava-flooded maria. The lunar terminator, the shadow line between lunar night and day, runs along the left of this frame. The 41 kilometer diameter crater Marius is top center, with ray crater Kepler peeking in at the edge,...
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Explanation: Can you see the bat? It haunts this cosmic close-up of the eastern Veil Nebula. The Veil Nebula itself is a large supernova remnant, the expanding debris cloud from the death explosion of a massive star. While the Veil is roughly circular in shape and covers nearly 3 degrees on the sky toward the constellation of the Swan (Cygnus), NGC 6995, known informally as the Bat Nebula, spans only 1/2 degree, about the apparent size of the Moon. That translates to 12 light-years at the Veil's estimated distance, a reassuring 1,400 light-years from planet Earth. In the composite of...
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Explanation: In a Finnish myth, when an arctic fox runs so fast that its bushy tail brushes the mountains, flaming sparks are cast into the heavens creating the northern lights. In fact the Finnish word "revontulet", a name for the aurora borealis or northern lights, can be translated as fire fox. So that evocative myth took on a special significance for the photographer of this northern night skyscape from Finnish Lapland near Kilpisjarvi Lake. The snowy scene is illuminated by moonlight. Saana, an iconic fell or mountain of Lapland, rises at the right in the background. But as the beautiful...
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Explanation: How many bright tails does Comet Lemmon have? Two. In the featured image it appears to have three, but why? The reason is that the zigzagging brown filament is a persistent meteor train that by luck appeared in front of the distant comet C/2025 A6 (Lemmon). A meteor train is the hot gas and fine dust that remains in the Earth's atmosphere and disperses in the seconds after a bright meteor flashes by. The two bright tails are the blue ion tail stretching across the image, and the white dust tail nearer the green coma on the upper left....
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Explanation: Large galaxies grow by eating small ones. Even our own galaxy engages in a sort of galactic cannibalism, absorbing small galaxies that are too close and are captured by the Milky Way's gravity. In fact, the practice is common in the universe and illustrated by this striking pair of interacting galaxies from the banks of the southern constellation Eridanus, The River. Located over 50 million light years away, the large, distorted spiral NGC 1532 is seen locked in a gravitational struggle with dwarf galaxy NGC 1531, a struggle the smaller galaxy will eventually lose. Seen nearly edge-on in this...
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Explanation: Halloween's origin is ancient and astronomical. Since the fifth century BC, Halloween has been celebrated as a cross-quarter day, a day halfway between an equinox (equal day / equal night) and a solstice (minimum day / maximum night in the northern hemisphere). With a modern calendar however, even though Halloween is later this week, the real cross-quarter day will occur the next week. Another cross-quarter day is Groundhog Day. Halloween's modern celebration retains historic roots in dressing to scare away the spirits of the dead. Perhaps a fitting tribute to this ancient holiday is this view of the Ghost...
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Explanation: Sculpted by stellar winds and radiation, this dusty interstellar molecular cloud has by chance assumed an immediately recognizable shape. Fittingly known as The Horsehead Nebula, it lies some 1,500 light-years distant, embedded in the vast Orion cloud complex. About five light-years "tall," the dark cloud is cataloged as Barnard 33, first identified on a photographic plate taken in the early 20th century. B33 is visible primarily because its obscuring dust is silhouetted against the glow of emission nebula IC 434. Hubble Space Telescope images from the early 21st century find young stars forming within B33. Of course, the magnificent...
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Explanation: A mere 390 light-years away, Sun-like stars and future planetary systems are forming in the Rho Ophiuchi molecular cloud complex, the closest star-forming region to our fair planet. The James Webb Space Telescope's NIRCam peered into the nearby natal chaos to capture this infrared image at an inspiring scale. The frame spans less than a light-year across the Rho Ophiuchi region and contains about 50 young stars. Brighter stars clearly show Webb's characteristic pattern of diffraction spikes. Huge jets of shocked molecular hydrogen blasting from newborn stars are red in the image, with the large, yellowish dusty cavity carved...
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Explanation: This cosmic close-up looks deep inside the Soul Nebula. The dark and brooding dust clouds outlined by bright ridges of glowing gas are cataloged as IC 1871. About 25 light-years across, the telescopic field of view spans only a small part of the much larger Heart and Soul nebulae. At an estimated distance of 6,500 light-years, the star-forming complex lies within the Perseus spiral arm of the Milky Way, seen in planet Earth's skies toward the constellation of the Queen of Aethiopia (Cassiopeia). An example of triggered star formation, the dense star-forming clouds of IC 1871 are themselves sculpted...
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Explanation: Saturn is bright in Earth's night skies. Telescopic views of the outer gas giant planet and its beautiful rings often make it a star at star parties. But this stunning view of Saturn's rings and night side just isn't possible from telescopes in the vicinity of planet Earth. Peering out from the inner Solar System they can only bring Saturn's day side into view. In fact, this image of Saturn's slender sunlit crescent with night's shadow cast across its broad and complex ring system was captured by the Cassini spacecraft. A robot spacecraft from planet Earth, Cassini called Saturn...
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Explanation: Many wonders are visible when flying over the Earth at night. Such visual spectacles occur every day for astronauts in low Earth orbit, but the featured video captured several from the International Space Station (ISS) in 2011 and set them to rousing music. Passing below are white clouds, orange city lights, lightning flashes in thunderstorms, and dark blue seas. On the horizon is the golden haze of Earth's thin atmosphere, frequently decorated by dancing auroras as the video progresses. The green parts of auroras typically remain below the space station, but the station flies right through the red and...
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