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It was December and the sky lit up like a Christmas tree. Shimmering, the vivid green, blue, and purple auroral colors that formed the tree-like apparition were caused by high atmospheric oxygen and nitrogen reacting to a burst of incoming electrons. Collisions caused the orbital electrons of atoms and molecules to jump into excited energy states and emit visible light when returning to their normal state. The featured image was captured in Djúpivogur , Iceland during the last month of 2023. Our Sun is currently in its most energetic phase of its 11-year cycle, with its high number of active regions and sunspots likely to last into next year. Of course, the Sun has been near solar maximum during this entire year, with its outbursts sometimes resulting in spectacular Earthly auroras . from NASA https://ift.tt/N3jmp4S

The stars are not alone. In the disk of our Milky Way Galaxy , about 10 percent of visible matter is in the form of gas called the interstellar medium (ISM). The ISM is not uniform and shows patchiness even near our Sun . It can be quite difficult to detect the local ISM because it is so tenuous and emits so little light. This mostly hydrogen gas, however, absorbs some very specific colors that can be detected in the light of the nearest stars . A working map of the local ISM within 20 light-years, based on ongoing observations and particle detections from the Earth-orbiting Interstellar Boundary Exporer satellite ( IBEX ), is shown here . These observations indicate that our Sun is moving through a Local Interstellar Cloud as this cloud flows outwards from the Scorpius-Centaurus Association star forming region . Our Sun may exit the Local Cloud , also called the Local Fluff, during the next 10,000 years. Much remains unknown about the local ISM , including details of its dis...

A year in sunsets, from April 2023 to March 2024, track along the western horizon in these stacked panoramic views. The well-planed sequence is constructed of images recorded near the 21st day of the indicated month from the same location overlooking Cairo, Egypt. But for any location on planet Earth the yearly extreme northern (picture right) and southern limits of the setting Sun mark the solstice days. The word solstice is from Latin for "Sun" and "stand still". On the solstice date the seasonal drift of the Sun's daily path through the sky appears to pause and reverse direction in its annual celestial journey . Of course the Sun reaches a stand still on today's date. The 21 December 2024 solstice at 09:21 UTC is the moment of the Sun's southernmost declination, the start of astronomical winter in the north and summer in the south . from NASA https://ift.tt/hgeATRF

On the night of December 15, the Full Moon was bright. Known to some as the Cold Moon or the Long Night Moon, it was the closest Full Moon to the northern winter solstice and the last Full Moon of 2024 . This Full Moon was also at a major lunar standstill . A major lunar standstill is an extreme in the monthly north-south range of moonrise and moonset caused by the precession of the Moon's orbit over an 18.6 year cycle. As a result, the full lunar phase was near the Moon's northernmost moonrise (and moonset) along the horizon. December's Full Moon is rising in this stacked image, a composite of exposures recording the range of brightness visible to the eye on the northern winter night. Along with a colorful lunar corona and aircraft contrail this Long Night Moon shines in a cold sky above the rugged, snowy peaks of the Italian Dolomites. from NASA https://ift.tt/nWmicaN

After the Crab Nebula , this giant star cluster is the second entry in 18th century astronomer Charles Messier's famous list of things that are not comets. M2 is one of the largest globular star clusters now known to roam the halo of our Milky Way galaxy. Though Messier originally described it as a nebula without stars, this stunning Hubble image resolves stars across the cluster's central 40 light-years. Its population of stars numbers close to 150,000, concentrated within a total diameter of around 175 light-years. About 55,000 light-years distant toward the constellation Aquarius, this ancient denizen of the Milky Way, also known as NGC 7089 , is 13 billion years old. An extended stellar debris stream , a signature of past gravitational tidal disruption, was recently found to be associated with Messier 2. from NASA https://ift.tt/ClaITXg

What kind of strange galaxy is this? This rare structure is known as a polar ring galaxy , and it seems to have two different rings of stars. In this galaxy, NGC 660 , one ring of bright stars, gas, and dark dust appears nearly vertical, while another similar but shorter ring runs diagonally from the upper left. How polar ring galaxies obtain their striking appearance remains a topic of research , but a leading theory holds that it is usually the result of two galaxies with different central ring planes colliding . NGC 660 spans about 50,000 light years and is located about 40 million light years away toward the constellation of the Fish ( Pisces ). The featured image was captured recently from Observatorio El Sauce in Chile . from NASA https://ift.tt/DknQS36

What excites the Heart Nebula? First, the large emission nebula on the upper left, catalogued as IC 1805 , looks somewhat like a human heart . The nebula glows brightly in red light emitted by its most prominent element, hydrogen , but this long-exposure image was also blended with light emitted by sulfur (yellow) and oxygen (blue). In the center of the Heart Nebula are young stars from the open star cluster Melotte 15 that are eroding away several picturesque dust pillars with their atom-exciting energetic light and winds. The Heart Nebula is located about 7,500 light years away toward the constellation of Cassiopeia . This wide field image shows much more, though, including the Fishhead Nebula just below the Heart, a supernova remnant on the lower left, and three planetary nebulas on the image right. Taken over 57 nights, this image is so deep, though, that it clearly shows fainter long and complex filaments. from NASA https://ift.tt/BblUPnR

This kilometer high cliff occurs on the surface of a comet. It was discovered on the dark nucleus of Comet Churyumov - Gerasimenko (CG) by Rosetta , a robotic spacecraft launched by ESA , which orbited the comet from 2014 to 2016. The ragged cliff, as featured here , was imaged by Rosetta early in its mission. Although towering about one kilometer high, the low surface gravity of Comet CG would likely make a jump from the cliffs by a human survivable. At the foot of the cliffs is relatively smooth terrain dotted with boulders as large as 20 meters across. Data from Rosetta indicates that the ice in Comet CG has a significantly different deuterium fraction -- and hence likely a different origin -- than the water in Earth's oceans. The probe was named after the Rosetta Stone , a rock slab featuring the same text written in three different languages that helped humanity decipher ancient Egyptian writing. from NASA https://ift.tt/Bf2jhvR

Meteors have been flowing out from the constellation Gemini . This was expected, as mid-December is the time of the Geminid Meteor Shower . Pictured here, over two dozen meteors were caught in successively added exposures taken over several hours early Saturday morning from a snowy forest in Poland . The fleeting streaks were bright enough to be seen over the din of the nearly full Moon on the upper right. These streaks can all be traced back to a point on the sky called the radiant toward the bright stars Pollux and Castor in the image center. The Geminid meteors started as sand sized bits expelled from asteroid 3200 Phaethon during its elliptical orbit through the inner Solar System . from NASA https://ift.tt/tzpijUg

Awkward and angular looking, Apollo 17's lunar module Challenger was designed for flight in the near vacuum of space. Digitally enhanced and reprocessed, this picture taken from Apollo 17's command module America shows Challenger's ascent stage in lunar orbit. Small reaction control thrusters are at the sides of the moonship with the bell of the ascent rocket engine underneath. The hatch allowing access to the lunar surface is seen at the front, with a round radar antenna at the top. Mission commander Gene Cernan is clearly visible through the triangular window. This spaceship performed gracefully, landing on the Moon and returning the Apollo astronauts to the orbiting command module in December of 1972. So where is Challenger now ? Its descent stage remains at the Apollo 17 landing site in the Taurus-Littrow valley . The ascent stage pictured was intentionally crashed nearby after being jettisoned from the command module prior to the astronauts' return to planet Ea...

An intriguing pair of interacting galaxies, M51 is the 51st entry in Charles Messier's famous catalog. Perhaps the original spiral nebula , the large galaxy with whirlpool-like spiral structure seen nearly face-on is also cataloged as NGC 5194. Its spiral arms and dust lanes sweep in front of its smaller companion galaxy, NGC 5195 . Some 31 million light-years distant, within the boundaries of the well-trained constellation Canes Venatici , M51 looks faint and fuzzy to the eye in direct telescopic views. But this remarkably deep image shows off stunning details of the galaxy pair's striking colors and fainter tidal streams . The image includes extensive narrowband data to highlight a vast reddish cloud of ionized hydrogen gas recently discovered in the M51 system and known to some as the H-alpha cliffs. Foreground dust clouds in the Milky Way and distant background galaxies are captured in the wide-field view. A continuing collaboration of astro-imagers using telescopes ...

Based on its well-measured orbit, 3200 Phaethon (sounds like FAY-eh-thon) is recognized as the source of the meteoroid stream responsible for the annual Geminid meteor shower . Even though most meteor shower parents are comets, 3200 Phaethon is a known and closely tracked near-Earth asteroid with a 1.4 year orbital period. Rocky and sun-baked , its perihelion or closest approach to the Sun is well within the orbit of innermost planet Mercury. In this telescopic field of view, the asteroid's rapid motion against faint background stars of the heroic constellation Perseus left a short trail during the two minute total exposure time. The (faint) parallel streaks of its meteoric children flashed much more quickly across the scene. The family portrait was recorded near the Geminid meteor shower's very active peak on 2017 December 13. That was just three days before 3200 Phaethon's historic close approach to planet Earth. This year, the night of December 13 should again see ...

What's the closest active galaxy to planet Earth? That would be Centaurus A , cataloged as NGC 5128, which is only 12 million light-year s distant. Forged in a collision of two otherwise normal galaxies, Centaurus A shows several distinctive features including a dark dust lane across its center, outer shells of stars and gas, and jets of particles shooting out from a supermassive black hole at its center. The featured image captures all of these in a composite series of visible light images totaling over 310 hours captured over the past 10 years with a homebuilt telescope operating in Auckland , New Zealand . The brightness of Cen A's center from low-energy radio waves to high-energy gamma rays underlies its designation as an active galaxy . from NASA https://ift.tt/NHbOFLm

It was a night of 100,000 meteors. The Great Meteor Storm of 1833 was perhaps the most impressive meteor event in recent history. Best visible over eastern North America during the pre-dawn hours of November 13, many people -- including a young Abraham Lincoln -- were woken up to see the sky erupt in streaks and flash es. Hundreds of thousands of meteors blazed across the sky, seemingly pouring out of the constellation of the Lion ( Leo ). The featured image is a digitization of a wood engraving which itself was based on a painting from a first-person account. We know today that the Great Meteor Storm of 1833 was caused by the Earth moving through a dense part of the dust trail expelled from Comet Tempel-Tuttle . The Earth moves through this dust stream every November during the Leonid meteor shower . Later this week you might get a slight taste of the intensity of that 1833 meteor storm by witnessing the annual Geminid meteor shower . from NASA https://ift.tt/9JhjgO...

Have you ever seen the Pleiades star cluster? Even if you have, you probably have never seen it as large and clear as this. Perhaps the most famous star cluster on the sky, the bright stars of the Pleiades can be seen with the unaided eye even from the depths of a light-polluted city . With a long exposure from a dark location, though, the dust cloud surrounding the Pleiades star cluster becomes very evident. The featured 23-hour exposure , taken from Fagagna , Italy covers a sky area several times the size of the full moon . Also known as the Seven Sisters and M45 , the Pleiades lies about 400 light years away toward the constellation of the Bull ( Taurus ). A common legend with a modern twist is that one of the brighter stars faded since the cluster was named, leaving only six of the sister stars visible to the unaided eye. The actual number of Pleiades stars visible, however, may be more or less than seven, depending on the darkness of the surrounding sky and the clarit...

Are Saturn's auroras like Earth's? To help answer this question, the Hubble Space Telescope and the Cassini spacecraft monitored Saturn's North Pole simultaneously during Cassini's final orbits around the gas giant in September 2017. During this time, Saturn 's tilt caused its North Pole to be clearly visible from Earth. The featured image is a composite of ultraviolet images of auroras and optical images of Saturn's clouds and rings, all taken by Hubble. Like on Earth, Saturn's northern auroras can make total or partial rings around the pole. Unlike on Earth, however, Saturn's auroras are frequently spirals -- and more likely to peak in brightness just before midnight and dawn. In contrast to Jupiter's auroras , Saturn's auroras appear better related to connecting Saturn's internal magnetic field to the nearby, variable, solar wind . Saturn's southern auroras were similarly imaged back in 2004 when the planet's South Pole...

You might not think a close up view of rocket engines producing 8.8 million pounds of thrust would be relaxing, but here it can be. In fact, you can get a warm and cozy feeling just spending a few moments watching NASA's holiday rocket engine fireplace . The video features a loop of the Space Launch System rocket's RS-25 main engines throttled up and running flanked by solid rocket boosters and framed by a stone fireplace. The accompanying audio track mixes the drastically muted sounds of the rocket engines firing with the more familiar sounds of a burning, crackling wood fire. AI elements are included in the composed video along with an image and logo from the Artemis I mission. The Artemis I uncrewed mission to the Moon and back again launched in November 2022 on a Space Launch System rocket. from NASA https://ift.tt/5slm4Xy

Colorful and bright, this streaking fireball meteor was captured in a single exposure taken at Purple Mountain (Tsuchinshan) Observatory’s Xuyi Station in 2020, during planet Earth's annual Perseid meteor shower. The dome in the foreground houses the China Near Earth Object Survey Telescope (CNEOST), the largest multi-purpose Schmidt telescope in China. Located in Xuyi County, Jiangsu Province, the station began its operation as an extension of China's Purple Mountain Observatory in 2006. Darling of planet Earth's night skies in 2024, the bright comet designated Tsuchinshan-ATLAS (C/2023 A3) was discovered in images taken there on 2023 January 9. The discovery is jointly credited to NASA's ATLAS robotic survey telescope at Sutherland Observatory, South Africa. Other comet discoveries associated with the historic Purple Mountain Observatory and bearing the observatory's transliterated Mandarin name include periodic comets 60/P Tsuchinshan and 62/P Tsuchinshan. ...

Jupiter looks sharp in these two rooftop telescope images . Both were captured last year on November 17 from Singapore, planet Earth, about two weeks after Jupiter's 2023 opposition . Climbing high in midnight skies the giant planet was a mere 33.4 light-minutes from Singapore. That's about 4 astronomical units away. Jupiter's planet girdling dark belts and light zones are visible in remarkable detail, along with the giant world's whitish oval vortices. Its signature Great Red Spot is prominent in the south. Jupiter rotates rapidly on its axis once every 10 hours. So, based on video frames taken only 15 minutes apart, these images form a stereo pair. Look at the center of the pair and cross your eyes until the separate images come together to see the 3D effect. Of course Jupiter is now not far from its 2024 opposition. Planet Earth is set to pass between the Solar System's ruling gas giant and the Sun on December 7. from NASA https://ift.tt/JqSghIU

Does the Sun return to the same spot on the sky every day?  No.  A more visual answer is an analemma , a composite of sky images taken at the same time and from the same place over a year.  At completion, you can see that the Sun makes a f i g u r e 8 on the sky. The featured unusual analemma does not, however, picture the Sun directly: it was created by looking in the opposite direction . All that was required was noting where the shadow of an edge of a house was in the driveway every clear day at the same time. Starting in March in Falcon , Colorado , USA , the photographer methodically marked the shadow's 1 pm location. In one frame you can even see the photographer himself. Although this analemma will be completed in 2025, you can start drawing your own driveway analemma -- using no fancy equipment -- as soon as today. from NASA https://ift.tt/HwT94E5

If you could stand on Mars -- what might you see? You might look out over a vast orange landscape covered with rocks under a dusty orange sky, with a blue-tinted Sun setting over the horizon, and odd-shaped water clouds hovering high overhead. This was just the view captured last March by NASA's rolling explorer, Perseverance . The orange coloring is caused by rusted iron in the Martian dirt, some of which is small enough to be swept up by winds into the atmosphere. The blue tint near the setting Sun is caused by blue light being preferentially scattered out from the Sun by the floating dust. The light-colored clouds on the right are likely composed of water-ice and appear high in the Martian atmosphere . The shapes of some of these clouds are unusual for Earth and remain a topic of research. from NASA https://ift.tt/7eb8g9m

This galaxy is unusual for how many stars it seems that you can see. Stars are so abundantly evident in this deep exposure of the spiral galaxy NGC 300 because so many of these stars are bright blue and grouped into resolvable bright star clusters. Additionally, NGC 300 is so clear because it is one of the closest spiral galaxies to Earth, as light takes only about 6 million years to get here. Of course, galaxies are composed of many more faint stars than bright, and even more of a galaxy's mass is attributed to unseen dark matter . NGC 300 spans nearly the same amount of sky as the full moon and is visible with a small telescope toward the southern constellation of the Sculptor . The featured image was captured in October from Rio Hurtado , Chile and is a composite of over 20 hours of exposure. from NASA https://ift.tt/5IRYDwV

What color is the universe? More precisely, if the entire sky were smeared out, what color would the final mix be? This whimsical question came up when trying to determine what stars are commonplace in nearby galaxies. The answer, depicted here, is a conditionally perceived shade of beige . In computer parlance: # FFF8E7 . To determine this, astronomers computationally averaged the light emitted by one of the larger samples of galaxies analyzed: the 200,000 galaxies of the 2dF Galaxy Redshift Survey . The resulting cosmic spectrum has some emission in all parts of the electromagnetic spectrum , but a single perceived composite color. This color has become much less blue over the past 10 billion years, indicating that redder stars are becoming more prevalent . In a contest to better name the color, notable entries included skyvory, univeige, and the winner: cosmic latte . from NASA https://ift.tt/KW7wahf

Winter and summer appear to come on a single night to this stunning little planet . It's planet Earth of course. The digitally mapped , nadir centered panorama covers 360x180 degrees and is composed of frames recorded during January and July from the Col du Galibier in the French Alps. Stars and nebulae of the northern winter (bottom) and summer Milky Way form the complete arcs traversing the rugged, curved horizon. Cars driving along on the road during a summer night illuminate the 2,642 meter high mountain pass, but snow makes access difficult during winter months except by serious ski touring . Cycling fans will recognize the Col du Galibier as one of the most famous climbs in planet Earth's Tour de France. from NASA https://ift.tt/YhQAURP

Messier 4 can be found west of bright red-giant star Antares, alpha star of the constellation Scorpius. M4 itself is only just visible from dark sky locations, even though the globular cluster of 100,000 stars or so is a mere 5,500 light-years away. Still, its proximity to prying telescopic eyes makes it a prime target for astronomical explorations. Recent studies have included Hubble observations of M4's pulsating cepheid variable stars, cooling white dwarf stars, and ancient, pulsar orbiting exoplanet PSR B1620-26 b . This sharp image was captured with a small telescope on planet Earth . At M4's estimated distance it spans about 50 light-years across the core of the globular star cluster. from NASA https://ift.tt/jJ5xmSP

The large stellar association cataloged as NGC 206 is nestled within the dusty arms of the neighboring Andromeda galaxy along with the galaxy's pinkish star-forming regions. Also known as M31, the spiral galaxy is a mere 2.5 million light-years away. NGC 206 is found at the center of this sharp and detailed close-up of the southwestern extent of Andromeda's disk. The bright, blue stars of NGC 206 indicate its youth. In fact, its youngest massive stars are less than 10 million years old. Much larger than the open or galactic clusters of young stars in the disk of our Milky Way galaxy, NGC 206 spans about 4,000 light-years. That's comparable in size to the giant stellar nurseries NGC 604 in nearby spiral M33 and the Tarantula Nebula in the Large Magellanic Cloud. from NASA https://ift.tt/xrMcSFP

How different are these two streaks? The streak on the upper right is Comet Tsuchinshan-Atlas showing an impressive dust tail . The comet is a large and dirty iceberg that entered the inner Solar System and is shedding gas and dust as it is warmed by the Sun's light. The streak on the lower left is a meteor showing an impressive evaporation trail . The meteor is a small and cold rock that entered the Earth's atmosphere and is shedding gas and dust as it is warmed by molecular collisions. The meteor was likely once part of a comet or asteroid -- perhaps later composing part of its tail. The meteor was gone in a flash and was only caught by coincidence during a series of exposures documenting the comet's long tail . The featured image was captured just over a month ago from Sichuan Province in China . from NASA https://ift.tt/69X1GBu

This floating ring is the size of a galaxy. In fact, it is a galaxy -- or at least part of one: the photogenic Sombrero Galaxy is one of the largest galaxies in the nearby Virgo Cluster of Galaxies . The dark band of dust that obscures the mid-section of the Sombrero Galaxy in visible light (bottom panel) actually glows brightly in infrared light (top panel). The featured image shows the infrared glow in false blue, recorded recently by the space-based James Webb Space Telescope (JWST) and released yesterday, pictured above an archival image taken by NASA's Hubble Space Telescope in visible light. The Sombrero Galaxy, also known as M104 , spans about 50,000 light years and lies 28 million light years away. M104 can be seen with a small telescope in the direction of the constellation Virgo . from NASA https://ift.tt/XyUvDZ1

One of the most identifiable nebulas in the sky, the Horsehead Nebula in Orion , is part of a large, dark, molecular cloud . Also known as Barnard 33, the unusual shape was first discovered on a photographic plate in the late 1800s. The red glow originates from hydrogen gas predominantly behind the nebula, ionized by the nearby bright star Sigma Orionis . The darkness of the Horsehead is caused mostly by thick dust , although the lower part of the Horsehead 's neck casts a shadow to the left. Streams of gas leaving the nebula are funneled by a strong magnetic field . Bright spots in the Horsehead Nebula 's base are young stars just in the process of forming . Light takes about 1,500 years to reach us from the Horsehead Nebula . The featured image was taken from the Chilescope Observatory in the mountains of Chile . from NASA https://ift.tt/d5ufQEM

What lies at the center of our galaxy? In Jules Verne 's science fiction classic, A Journey to the Center of the Earth , Professor Liedenbrock and his fellow explorers encounter many strange and exciting wonders. Astronomers already know of some of the bizarre objects that exist at our Galactic Center , including vast cosmic dust clouds , bright star clusters , swirling rings of gas , and even a supermassive black hole . Much of the Galactic Center is shielded from our view in visible light by the intervening dust and gas, but it can be explored using other forms of electromagnetic radiation . The featured video is actually a digital zoom into the Milky Way's center which starts by utilizing visible light images from the Digitized Sky Survey . As the movie proceeds, the light shown shifts to dust-penetrating infrared and highlights gas clouds that were recently discovered in 2013 to be falling toward the central black hole. from NASA https://ift.tt/jg7AKa1

In an interplanetary first, on July 19, 2013 Earth was photographed on the same day from two other worlds of the Solar System, innermost planet Mercury and ringed gas giant Saturn. Pictured on the left, Earth is the pale blue dot just below the rings of Saturn, as captured by the robotic Cassini spacecraft then orbiting the outermost gas giant. On that same day people across planet Earth snapped many of their own pictures of Saturn. On the right, the Earth-Moon system is seen against the dark background of space as captured by the sunward MESSENGER spacecraft , then in Mercury orbit. MESSENGER took its image as part of a search for small natural satellites of Mercury, moons that would be expected to be quite dim. In the MESSENGER image , the brighter Earth and Moon are both overexposed and shine brightly with reflected sunlight. Destined not to return to their home world, both Cassini and MESSENGER have since retired from their missions of Solar System exploration. from NAS...

Braided and serpentine filaments of glowing gas suggest this nebula's popular name, The Medusa Nebula . Also known as Abell 21, this Medusa is an old planetary nebula some 1,500 light-years away in the constellation Gemini. Like its mythological namesake, the nebula is associated with a dramatic transformation. The planetary nebula phase represents a final stage in the evolution of low mass stars like the sun as they transform themselves from red giants to hot white dwarf stars and in the process shrug off their outer layers. Ultraviolet radiation from the hot star powers the nebular glow. The Medusa's transforming star is the faint one near the center of the overall bright crescent shape. In this deep telescopic view, fainter filaments clearly extend below and to the left. The Medusa Nebula is estimated to be over 4 light-years across . from NASA https://ift.tt/Hl7iGAu

Like an illustration in a galactic Just So Story , the Elephant's Trunk Nebula winds through the emission region and young star cluster complex IC 1396, in the high and far off constellation of Cepheus . Also known as vdB 142, this cosmic elephant's trunk is over 20 light-years long. The detailed telescopic view features the bright swept-back ridges and pockets of cool interstellar dust and gas that abound in the region. But the dark, tendril-shaped clouds contain the raw material for star formation and hide protostars within . Nearly 3,000 light-years distant, the relatively faint IC 1396 complex covers a large region on the sky, spanning over 5 degrees. This rendition spans a 1 degree wide field of view though, about the angular size of 2 full moons. from NASA https://ift.tt/sKORHdq

Eight billion people are about to disappear in this snapshot from space taken on 2022 November 21. On the sixth day of the Artemis I mission , their home world is setting behind the Moon's bright edge as viewed by an external camera on the outbound Orion spacecraft. Orion was headed for a powered flyby that took it to within 130 kilometers of the lunar surface. Velocity gained in the flyby maneuver was used to reach a distant retrograde orbit around the Moon. That orbit is considered distant because it's another 92,000 kilometers beyond the Moon, and retrograde because the spacecraft orbited in the opposite direction of the Moon's orbit around planet Earth. Orion entered its distant retrograde orbit on November 25. Swinging around the Moon , Orion reached a maximum distance (just over 400,000 kilometers) from Earth on November 28, exceeding a record set by Apollo 13 for most distant spacecraft designed for human space exploration . The Artemis II mission , carrying 4 ...

What's happening with these clouds? While it may seem that these long and thin clouds are pointing toward the top of a hill, and that maybe a world-famous observatory is located there, only part of that is true. In terms of cloud s, the formation is a chance superposition of impressively periodic undulating air currents in Earth's lower atmosphere. Undulatus , a type of Asper it as cloud, form at the peaks where the air is cool enough to cause the condensation of opaque water droplets. The wide-angle nature of the panorama creates the illusion that the clouds converge over the hill. In terms of land, there really is a world-famous observatory at the top of that peak: the Carnegie Science 's Las Campanas Observatory in the Atacama Desert of Chile . The two telescope domes visible are the 6.5-meter Magellan Telescopes . The featured coincidental vista was a surprise but was captured by the phone of a quick-thinking photographer in late September. from NASA https...

Stars can create huge and intricate dust sculptures from the dense and dark molecular cloud s from which they are born. The tools the stars use to carve their detailed works are high energy light and fast stellar winds . The heat they generate evaporates the dark molecular dust as well as causing ambient hydrogen gas to disperse and glow . Pictured here , a new open cluster of stars designated IC 1590 is nearing completion around the intricate interstellar dust structures in the emission nebula NGC 281 , dubbed the Pac-man Nebula because of its overall shape . The dust cloud just above center is classified as a Bok Globule as it may gravitationally collapse and form a star -- or stars. The Pacman Nebula lies about 10,000 light years away toward the constellation of Cassiopeia . from NASA https://ift.tt/4HNoBn3

What is the cause of this unusual parabolic structure? This illuminated cavity, known as LDN 1471 , was created by a newly forming star , seen as the bright source at the peak of the parabola . This protostar is experiencing a stellar outflow which is then interacting with the surrounding material in the Perseus Molecular Cloud , causing it to brighten. We see only one side of the cavity -- the other side is hidden by dark dust . The parabolic shape is caused by the widening of the stellar-wind blown cavity over time. Two additional structures can also be seen either side of the protostar ; these are known as Herbig-Haro object s, again caused by the interaction of the outflow with the surrounding material. What causes the striations on the cavity walls, though, remains unknown . The featured image was taken by NASA and ESA’s Hubble Space Telescope after an original detection by the Spitzer Space Telescope . from NASA https://ift.tt/TEDcM90

The night side of Pluto spans this shadowy scene . In the stunning spacebased perspective the Sun is 4.9 billion kilometers (almost 4.5 light-hours) behind the dim and distant world. It was captured by far flung New Horizons in July of 2015 when the spacecraft was at a range of some 21,000 kilometers from Pluto, about 19 minutes after its closest approach. A denizen of the Kuiper Belt in dramatic silhouette, the image also reveals Pluto's tenuous, surprisingly complex layers of hazy atmosphere. Near the top of the frame the crescent twilight landscape includes southern areas of nitrogen ice plains now formally known as Sputnik Planitia and rugged mountains of water-ice in the Norgay Montes. from NASA https://ift.tt/ofySKU5

Put on your red/blue glasses and gaze across the western Ocean of Storms on the surface of the Moon. The 3D anaglyph features Apollo 12 astronaut Pete Conrad visiting the Surveyor 3 spacecraft in November of 1969. Surveyor 3 had landed at the site on the inside slope of a small crater about 2 1/2 years earlier in April of 1967. Visible on the horizon beyond the far crater wall, Apollo 12's Lunar Module Intrepid touched down less than 200 meters (650 feet) away, easy moonwalking distance from the robotic Surveyor spacecraft. This stereo image was carefully created from two separate pictures (AS12-48-7133, AS12-48-7134) captured on the lunar surface . They depict the scene from only slightly different viewpoints, approximating the separation between human eyes. from NASA https://ift.tt/qxW1Ukp

A great nebulous region near bright star omicron Persei offers this study in cosmic contrasts. Captured in the telescopic frame the colorful complex of dust, gas, and stars spans about 3 degrees on the sky along the edge of the Perseus molecular cloud some 1000 light-years away. Surrounded by a bluish halo of dust reflected starlight, omicron Persei itself is just left of center. Immediately below it lies the intriguing young star cluster IC 348 recently explored by the James Webb Space Telescope. In silhouette against the diffuse reddish glow of hydrogen gas , dark and obscuring interstellar dust cloud Barnard 3 is at upper right. Of course the cosmic dust also tends to hide newly formed stars and young stellar objects or protostars from prying optical telescopes. At the Perseus molecular cloud's estimated distance, this field of view would span about 50 light-years. from NASA https://ift.tt/SxQNVHp

A mere 56 million light-years distant toward the southern constellation Fornax, NGC 1365 is an enormous barred spiral galaxy about 200,000 light-years in diameter. That's twice the size of our own barred spiral Milky Way. This sharp image from the James Webb Space Telescope 's Mid-Infrared Instrument (MIRI) reveals stunning details of this magnificent spiral in infrared light . Webb's field of view stretches about 60,000 light-years across NGC 1365, exploring the galaxy's core and bright newborn star clusters. The intricate network of dusty filaments and bubbles is created by young stars along spiral arms winding from the galaxy's central bar. Astronomers suspect the gravity field of NGC 1365's bar plays a crucial role in the galaxy's evolution, funneling gas and dust into a star-forming maelstrom and ultimately feeding material into the active galaxy's central, supermassive black hole . from NASA https://ift.tt/UTi31EV

How was the Crescent Nebula created? Looking like an emerging space cocoon , the Crescent Nebula, visible in the center of the featured image , was created by the brightest star in its center. A leading progenitor hypothesis has the Crescent Nebula beginning to form about 250,000 years ago. At that time, the massive central star had evolved to become a Wolf-Rayet star (WR 136), shedding its outer envelope in a strong stellar wind , ejecting the equivalent of our Sun's mass every 10,000 years. This wind impacted surrounding gas left over from a previous phase , compacting it into a series of complex shells , and lighting it up . The Crescent Nebula , also known as NGC 6888, lies about 4,700 light-year s away in the constellation of Cygnus . Star WR 136 will probably undergo a supernova explosion sometime in the next million years. from NASA https://ift.tt/wv7BEod

What created an unusual dark streak in Comet Tsuchinshan-Atlas's tail? Some images of the bright comet during mid-October not only caught its impressively long tail and its thin anti-tail , but a rather unexpected feature: a dark streak in the long tail . The reason for the dark streak is currently unclear and a topic of some debate. Possible reasons include a plume of dark dust , different parts of the bright tail being unusually superposed, and a shadow of a dense part of the coma on smaller dust particles. The streak is visible in the featured image taken on October 14 from Texas, USA. To help future analyses, if you have taken a good image of the comet that clearly shows this dark streak, please send it in to APOD . Comet Tsuchinshan–ATLAS has now faded considerably and is returning to the outer Solar System . from NASA https://ift.tt/Z3DA8LN

The largest canyon in the Solar System cuts a wide swath across the face of Mars . Named Valles Marineris , the grand valley extends over 3,000 kilometers long, spans as much as 600 kilometers across, and delves as much as 8 kilometers deep. By comparison, the Earth's Grand Canyon in Arizona, USA is 800 kilometers long, 30 kilometers across, and 1.8 kilometers deep. The origin of the Valles Marineris remains unknown , although a leading hypothesis holds that it started as a crack billions of years ago as the planet cooled. Several geologic processes have been identified in the canyon . The featured mosaic was created from over 100 images of Mars taken by Viking Orbiters in the 1970s. from NASA https://ift.tt/mZoi4FO

Ice giant Neptune is faint in Earth's night sky. Some 30 times farther from the Sun than our fair planet, telescopes are needed to catch a glimpse of the dim and distant world. This dramatic view of Neptune's night just isn't possible for telescopes in the vicinity of planet Earth though. Peering out from the inner Solar System they can only bring Neptune's day side into view. In fact this night side image with Neptune's slender crescent next to the crescent of its large moon Triton was captured by Voyager 2. Launched from planet Earth in 1977 the Voyager 2 spacecraft made a close fly by of the Solar System's outermost planet in 1989, looking back on Neptune as the robotic spacecraft continued its voyage to interstellar space . from NASA https://ift.tt/P36eDQc

Drifting near the plane of our Milky Way galaxy these dusty molecular clouds seem to extend a helping hand on a cosmic scale. Part of a local complex of star-forming interstellar clouds they include LDN 1358, 1357, and 1355 from American astronomer Beverly Lynds' 1962 Catalog of Dark Nebulae . Presenting a challenging target for astro-imagers, the obscuring dark nebulae are nearly 3,000 light-years away, toward rich starfields in the northern constellation Cassiopeia . At that distance, this deep, telescopic field of view would span about 80 light-years. from NASA https://ift.tt/DM2pcb3

This spectacular intergalactic skyscape features Arp 227, a curious system of galaxies from the 1966 Atlas of Peculiar Galaxies . Some 100 million light-years distant within the boundaries of the constellation Pisces, Arp 227 consists of the two galaxies prominent above and left of center, the shell galaxy NGC 474 and its blue, spiral-armed neighbor NGC 470. The readily apparent shells and star streams of NGC 474 are likely tidal features originating from the accretion of another smaller galaxy during close gravitational encounters that began over a billion years ago. The large galaxy on the bottom righthand side of the deep image, NGC 467, appears to be surrounded by faint shells and streams too, evidence of another merging galaxy system . Intriguing background galaxies are scattered around the field that also includes spiky foreground stars. Of course, those stars lie well within our own Milky Way Galaxy . The telescopic field of view spans 25 arc minutes or just under 1/2 degree...

Comet Tsuchinshan-Atlas is now headed back to the outer Solar System . The massive dusty snowball put on quite a show during its trip near the Sun, resulting in many impressive pictures from planet Earth during October. The featured image was taken in mid-October and shows a defining visual feature of the comet -- its impressive anti-tail . The image captures Comet C/2023 A3 (Tsuchinshan–ATLAS) with impressively long dust and ion tails pointing up and away from the Sun, while the strong anti-tail -- composed of more massive dust particles -- trails the comet and points down and (nearly) toward the recently-set Sun . In the foreground is village of Tai di Cadore , Italy , with the tremendous Dolomite Mountains in the background. Another comet, C/2024 S1 (ATLAS) , once a candidate to rival Comet Tsuchinshan-Atlas in brightness, broke up last week during its close approach to our Sun. from NASA https://ift.tt/13NHXbk

Why were the statues on Easter Island built? No one is sure. What is sure is that over 900 large stone statues called moai s exist there. The Rapa Nui (Easter Island) moais stand, on average, over twice as tall as a person and have over 200 times as much mass. It is thought that the unusual statues were created about 600 years ago in the images of local leaders of a vibrant and ancient civilization. Rapa Nui has been declared by UNESCO to a World Heritage Site . Pictured here , some of the stone giants were imaged last month under the central band of our Milky Way galaxy. Previously unknown moais are still being discovered . from NASA https://ift.tt/tArW1pP

The Great Nebula in Orion , an immense, nearby starbirth region , is probably the most famous of all astronomical nebulas . Here, glowing gas surrounds hot young stars at the edge of an immense interstellar molecular cloud only 1500 light-years away. In the featured deep image in assigned colors highlighted by emission in oxygen and hydrogen , wisps and sheets of dust and gas are particularly evident. The Great Nebula in Orion can be found with the unaided eye near the easily identifiable belt of three stars in the popular constellation Orion . In addition to housing a bright open cluster of stars known as the Trapezium , the Orion Nebula contains many stellar nurseries . These nurseries contain much hydrogen gas, hot young stars, proplyds , and stellar jets spewing material at high speeds. Also known as M42 , the Orion Nebula spans about 40 light years and is located in the same spiral arm of our Galaxy as the Sun . from NASA https://ift.tt/uUiaLrQ