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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 sharp image spiral NGC 1532 spans about 100,000 light-years. The NGC 1532/1531 pair is thought to be similar to the well-studied system of face-on spiral and small companion known as M51 . from NASA https://ift.tt/PIXrCLG

Sculpted by stellar winds and radiation, this dusty interstellar molecular cloud has by chance has 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 late 19th 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 interstellar cloud will slowly shift its apparent shape over the next few million years. But for now the Horsehead Nebula is a rewarding though difficult object to view with small telescopes from planet Earth . from NASA https://ift.tt/HEr35gh

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-year s 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 by the intense winds and radiation of the region's massive young stars. This color image adopts a palette made popular in Hubble images of star-forming regions. from NASA https://ift.tt/AL6doB7

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 thunderstorm s, 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 purple auroral peaks. Solar panels of the ISS are seen around the frame edges. The ominous wave of approaching brightness at the end of each sequence is just the dawn of the sunlit half of Earth , a dawn that occurs every 90 minutes. from NASA https://ift.tt/4AwenmK

It is still not known why the Sun's light is missing some colors. Here are all the visible colors of the Sun , produced by passing the Sun's light through a prism -like device. The spectrum was created at the McMath-Pierce Solar Observatory and shows, first off, that although our white -appearing Sun emits light of nearly every color , it appears brightest in yellow-green light. The dark patches in the featured spectrum arise from gas at or above the Sun's surface absorbing sunlight emitted below. Since different types of gas absorb different colors of light , it is possible to determine what gasses compose the Sun. Helium , for example, was first discovered in 1868 on a solar spectrum and only later found here on Earth . Today, the majority of spectral absorption lines have been identified - but not all . from NASA https://ift.tt/isXW58J

Fifty three years ago , in December of 1972, Apollo 17 astronauts Eugene Cernan and Harrison Schmitt spent about 75 hours on the Moon exploring the Taurus-Littrow valley, while colleague Ronald Evans orbited overhead . This snapshot from another world was taken by Cernan as he and Schmitt roamed the lunar valley's floor. The image shows Schmitt next to the lunar rover parked at the southeast rim of Shorty Crater . That location is near the spot where geologist Schmitt discovered orange lunar soil. The Apollo 17 crew returned with 110 kilograms of rock and soil samples , more than was returned from any of the other lunar landing sites. And for now , Cernan and Schmitt are the last to walk on the Moon . from NASA https://ift.tt/dOi4y5Z

Blasting outward from variable star KX Andromedae, these stunning bipolar jets are 19 light-years long. Recently discovered , they are revealed in unprecedented detail in this deep telescopic image centered on KX And and composed from over 692 hours of combined image data . In fact, KX And is spectroscopically found to be an interacting binary star system consisting of a bright, hot B-type star with a swollen cool giant star as its co-orbiting, close companion. The stellar material from the cool giant star is likely being transferred to the hot B-type star through an accretion disk , with spectacular symmetric jets driven outward perpendicular to the disk itself. The known distance to KX And of 2,500 light-years, angular size of the jets, and estimated inclination of the accretion disk lead to the size estimate for each jet of an astonishing 19 light-years . from NASA https://ift.tt/idAcswl

An example of violence on a cosmic scale, enormous elliptical galaxy NGC 1316 lies about 75 million light-years away toward Fornax , the southern constellation of the Furnace. Investigating the startling sight, astronomers suspect the giant galaxy of colliding with smaller neighbor NGC 1317 seen just right of the large galaxy's center, producing far flung star streams in loops and shells. Light from their close encounter would have reached Earth some 100 million years ago. In the sharp telescopic image , the central regions of NGC 1316 and NGC 1317 appear separated by over 100,000 light-years. Complex dust lanes visible within also indicate that NGC 1316 is itself the result of a merger of galaxies in the distant past. Found on the outskirts of the Fornax galaxy cluster , NGC 1316 is known as Fornax A. One of the visually brightest of the Fornax cluster galaxies it is one of the strongest and largest celestial radio sources with radio emission extending well beyond this one ...

What would it look like to plunge into a monster black hole? This image from a supercomputer visualization shows the entire sky as seen from a simulated camera plunging toward a 4-million-solar-mass black hole, similar to the one at the center of our galaxy . The camera lies about 16 million kilometers from the black hole’s event horizon and is moving inward at 62% the speed of light . Thanks to gravity’s funhouse effects , the starry band of the Milky Way appears both as a compact loop at the top of this view and as a secondary image stretching across the bottom. Move the cursor over the image for additional explanations. Visualizations like this allow astronomers to explore black holes in ways not otherwise possible. from NASA https://ift.tt/R50nxAg

What's happening in the center of nearby spiral galaxy M77? The face-on galaxy lies a mere 47 million light-years away toward the constellation of the Sea Monster ( Cetus ). At that estimated distance, this gorgeous island universe is about 100 thousand light-years across. Also known as NGC 1068 , its compact and very bright core is well studied by astronomers exploring the mysteries of supermassive black holes in active Seyfert galaxies . M77's active core glows bright at x-ray , ultraviolet , visible , infrared , and radio wavelengths. The featured sharp image of M77 was taken by the Hubble Space Telescope . The image shows details of the spiral's winding spiral arms as traced by obscuring red dust clouds and blue star clusters , all circling the galaxy's bright white luminous center . from NASA https://ift.tt/FMW3Nca

How typical is our Solar System? Studying 3I/ATLAS , a comet just passing through, is providing clues. Confirmed previous interstellar visitors include an asteroid , a comet , a meteor , and a gas wind dominated by hydrogen and helium. Comet 3I/ATLAS appears relatively normal when compared to Solar System comets , therefore providing more evidence that our Solar System is a somewhat typical star system. For example, Comet 3I/ATLAS has a broadly similar chemical composition and ejected dust . The featured image was captured last week from Texas and shows a green coma , a wandering blue-tinted ion tail likely deflected by our Sun's wind , and a slight anti-tail , all typical cometary attributes. The comet, visible with a telescope , passed its closest to the Sun in late October and will pass its closest to the Earth in mid-December, after which it will return to interstellar space and never return. from NASA https://ift.tt/DXdjEah

If you could stand on Titan -- what would you see? The featured color view from Titan gazes across an unfamiliar and distant landscape on Saturn's largest moon . The scene was recorded by ESA 's Huygens probe in 2005 after a 2.5-hour descent through a thick atmosphere of nitrogen laced with methane. Bathed in an eerie orange light at ground level, rocks strewn about the scene could well be composed of water and hydrocarbons frozen solid at an inhospitable temperature of negative 179 degrees C. The large light-toned rock below and left of center is only about 15 centimeters across and lies 85 centimeters away. The saucer-shaped spacecraft is believed to have penetrated about 15 centimeters into a place on Titan's surface that had the consistency of wet sand or clay. Huygen's batteries enabled the probe to take and transmit data for more than 90 minutes after landing. Titan's bizarre chemical environment may bear similarities to planet Earth's before ...

This is not a screen from a video game . Nestled below the tree-line, the small mountain church does look like it might be hiding from Moon though. In the well-composed telephoto snapshot, taken on November 23, the church walls are partly reflecting light from terrestrial flood lights. Of course, the Moon is reflecting light from the Sun. At any given time the Sun illuminates fully half of the Moon's surface, also known as the lunar dayside, but on that night only a sliver of its sunlit surface was visible. About three days after New Moon, the Moon was in a waxing crescent phase . The single exposure was captured shortly after sunset in skies near Danta di Cadore, northern Italy, planet Earth. from NASA https://ift.tt/FBo3v6R

NGC 6888, also known as the Crescent Nebula, is a about 25 light-years across, a cosmic bubble blown by winds from its central, massive star. This deep telescopic image includes narrowband image data, to isolate light from hydrogen and oxygen atoms . The oxygen atoms produce the blue-green hue that seems to enshroud the nebula's detailed folds and filaments. Visible within the nebula, NGC 6888's central star is classified as a Wolf-Rayet star (WR 136). The star is shedding its outer envelope in a strong stellar wind , ejecting the equivalent of the Sun's mass every 10,000 years. In fact, the Crescent Nebula's complex structures are likely the result of this strong wind interacting with material ejected in an earlier phase. Burning fuel at a prodigious rate and near the end of its stellar life, this star should ultimately go out with a bang in a spectacular supernova explosion. Found in the nebula rich constellation Cygnus, NGC 6888 is about 5,000 light-years awa...

Big, beautiful spiral galaxy NGC 1055 is a dominant member of a small galaxy group a mere 60 million light-years 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 Milky Way galaxy. The colorful, spiky stars decorating this cosmic portrait of NGC 1055 are in the foreground, well within the Milky Way. But telltale pinkish star forming regions and young blue star clusters 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 bulge 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 . from NASA https://ift.tt/TK5lAwP

Stars, like bees, swarm around the center of bright globular cluster M15. The central ball of over 100,000 stars is a relic from the early years of our Galaxy , and continues to orbit the Milky Way's center . M15 , one of about 150 globular cluster s remaining, is noted for being easily visible with only binoculars , having at its center one of the densest concentrations of stars known, and containing a high abundance of variable stars and pulsars . The featured image of M15 was taken by combining very long exposures -- 122 hours in all -- and so brings up faint wisps of gas and dust in front of the giant ball of stars. M15 lies about 35,000 light years away toward the constellation of the Winged Horse ( Pegasus ). from NASA https://ift.tt/8I2A9iE

What did Comet Lemmon look like when it was at its best? One example is pictured here, featuring three celestial spectacles all at different distances. The closest spectacle is the snowcapped Meili Mountains , part of the Himalayas in China . The middle marvel is Comet Lemmon near its picturesque best early this month, showing not only a white dust tail trailing off to the right but its blue solar wind-distorted ion tail trailing off to the left. Far in the distance on the left is the magnificent central plane of our Milky Way Galaxy , featuring dark dust , red nebula , and including billions of Sun -like stars. Comet C/2025 A6 (Lemmon) is already fading as it heads back into the outer Solar System, while the Himalayan mountains will gradually erode over the next billion years. The Milky Way Galaxy , though, will live on -- forming new mountains and comets -- for many billions of years into the future. from NASA https://ift.tt/CIqRDG0

What created this unusual space sculpture? Stars . This unusual system of swirls and shells, known as Apep , was observed in unprecedented detail by NASA ’s James Webb Space Telescope in infrared light in 2024. Observations indicate that the unusual shape originates from two massive Wolf-Rayet star s orbiting each other every 190 years with each close passes causing a new shell of dust and gas to be expelled . Holes in these shells are thought to be caused by a third orbiting star . This stellar dust dance will likely continue for hundreds of thousands of years, possibly ending only when one of the massive stars runs out of internal nuclear fuel and explodes in a supernova punctuated by a burst of gamma-rays . from NASA https://ift.tt/KztZqMY

How far can you see? Everything you can see, and everything you could possibly see, right now, assuming your eyes could detect all types of radiations around you -- is the observable universe . In light, the farthest we can see comes from the cosmic microwave background , a time 13.8 billion years ago when the universe was opaque like thick fog. Some neutrinos and gravitational waves that surround us come from even farther out, but humanity does not yet have the technology to detect them. The featured image illustrates the observable universe on an increasingly compact scale , with the Earth and Sun at the center surrounded by our Solar System , nearby stars , nearby galaxies , distant galaxies , filaments of early matter , and the cosmic microwave background . Cosmologists typically assume that our observable universe is just the nearby part of a greater entity known as "the universe" where the same physics applies. However, there are several lines of popular but sp...

Seen to the left of Saturn's banded planetary disk, small icy moons Dione and Rhea are caught passing in front of the gas giant's extensive ring system in this sharp telescopic snapshot. The remarkable image was recorded on November 20 , when Saturn's rings were nearly edge-on when viewed from planet Earth. In fact, every 13 to 16 years the view from planet Earth aligns with Saturn's ring plane to produce a series of ring plane crossings . During a ring plane crossing, the interplanetary edge-on perspective makes the thin but otherwise bright rings seem to disappear. By November 23rd Saturn's rings will have reached a minimum angle for now, at their narrowest for viewing from planet Earth, but then start to widen again. Of course, Dione and Rhea orbit Saturn near the ring plane once every 2.7 and 4.5 days respectively, while the next series of Saturn ring plane crossings as seen from Earth will begin again in 2038. from NASA https://ift.tt/pwHcMtm

Now outbound after its perihelion or closest approach to the Sun on October 29, Comet 3I/ATLAS is only the third known interstellar object to pass through our fair Solar System. Its greenish coma and faint tails are seen against a background of stars in the constellation Virgo in this view from planet Earth , recorded with a small telescope on November 14. But this interstellar interloper is the subject of an on-going, unprecedented Solar System-wide observing campaign involving spacecraft and space telescopes from Earth orbit to the surface of Mars and beyond . And while the comet from another star-system has recently grown brighter , you'll still need a telescope if you want to see 3I/ATLAS from planet Earth. It's now above the horizon in November morning skies and will make its closest approach to Earth, a comfortable 270 million kilometers distant, around December 19. from NASA https://ift.tt/yDtjAsd

Alnitak , Alnilam , and Mintaka are the bright bluish stars from east to west (upper right to lower left) along the diagonal in this cosmic vista . Otherwise known as the Belt of Orion , these three blue supergiant stars are hotter and much more massive than the Sun. They lie from 700 to 2,000 light-years away , born of Orion's well-studied interstellar clouds. In fact, clouds of gas and dust adrift in this region have some surprisingly familiar shapes, including the dark Horsehead Nebula and Flame Nebula near Alnitak at the upper right. The famous Orion Nebula itself is off the right edge of this colorful starfield. The telescopic frame spans almost 4 degrees on the sky . from NASA https://ift.tt/q2UnGok

Sometimes the dark dust of interstellar space has an angular elegance. Such is the case toward the far-south constellation of Chamaeleon . Normally too faint to see , dark dust is best known for blocking visible light from stars and galaxies behind it. In this 11.4-hour exposure , however, the dust is seen mostly in light of its own, with its strong red and near- infrared colors creating a brown hue. Contrastingly blue, a bright star Beta Chamaeleontis is visible on the upper right of the V, with the dust that surrounds it preferentially reflecting blue light from its primarily blue-white color. All of the pictured stars and dust occur in our own Milky Way Galaxy with one notable exception : a white spot just below Beta Chamaeleontis is the galaxy IC 3104 , which lies far in the distance. Interstellar dust is mostly created in the cool atmospheres of giant stars and dispersed into space by stellar light, stellar winds , and stellar explosions such as supernovas . from NASA h...

What has happened to Comet Lemmon's tail? The answer is blowing in the wind — the wind from the Sun in this case. This continuous outflow of charged particles from the Sun has been quite variable of late, as the Sun emits bursts of energy, CME s, that push out and deflect charged particles emitted by the comet itself. The result is a blue hued ion tail for Comet C/2025 A6 (Lemmon) that is not only impressively intricate but takes some unusual turns. This long-duration composite image taken from Alfacar , Spain last month captured this inner Solar System ionic tumult. Comet Lemmon is now fading as it heads out away from the Earth and Sun and back into the outer Solar System . from NASA https://ift.tt/2Zj8AFI

If this is Saturn, where are the rings? When Saturn's "appendages" disappeared in 1612, Galileo did not understand why. Later that century, it became understood that Saturn 's unusual protrusion s were rings and that when the Earth crosses the ring plane , the edge-on rings will appear to disappear . This is because Saturn's rings are confined to a plane many times thinner , in proportion, than a razor blade . In modern times, the robotic Cassini spacecraft that orbited Saturn frequently crossed Saturn's ring plane during its mission to Saturn, from 2004 to 2017. A series of plane crossing images from 2005 February was dug out of the vast online Cassini raw image archive by interested Spanish amateur Fernando Garcia Navarro. Pictured here , digitally cropped and set in representative colors, is the striking result. Saturn's thin ring plane appears in blue, bands and clouds in Saturn's upper atmosphere appear in gold. Details of Saturn's rin...

This magnificent extragalactic skyscape looks toward the Andromeda Galaxy, the closest large spiral galaxy to the Milky Way. It also accomplishes a Messier catalog trifecta by including Andromeda, cataloged as Messier 31 (M31) , along with Messier 32 (M32) , and Messier 110 (M110) in the same telescopic field of view . In this frame, M32 is just left of the Andromeda Galaxy's bright core with M110 below and to the right. M32 and M110 are both elliptical galaxies themselves and satellites of the larger spiral Andromeda. By combining 60 hours of broadband and narrowband image data, the deep telescopic view also reveals tantalizing details of dust lanes, young star clusters, and star-forming regions along Andromeda's spiral arms, and faint, foreground clouds of glowing hydrogen gas. For now , Andromeda and friends are some 2.5 million light-years from our own large spiral Milky Way. from NASA https://ift.tt/O3ph7EB

Few cosmic vistas can excite the imagination like The Great Nebula in Orion . Visible as a faint, bland celestial smudge to the naked-eye, the nearest large star-forming region sprawls across this sharp colorful telescopic image . Designated M42 in the Messier Catalog, the Orion Nebula's glowing gas and dust surrounds hot, young stars . About 40 light-years across, M42 is at the edge of an immense interstellar molecular cloud only 1,500 light-years away that lies within the same spiral arm of our Milky Way galaxy as the Sun. Including dusty bluish reflection nebula NGC 1977 , also known as the Running Man nebula at left in the frame, the natal nebulae represent only a small fraction of our galactic neighborhood's wealth of star-forming material. Within the well-studied stellar nursery, astronomers have also identified what appear to be numerous infant solar systems . from NASA https://ift.tt/kBahS7M

Ten thousand years ago, before the dawn of recorded human history, a new light would suddenly have appeared in the night sky and faded after a few weeks. Today we know this light was from a supernova, or exploding star , and record the expanding debris cloud as the Veil Nebula , a supernova remnant . This sharp telescopic view is centered on a western segment of the Veil Nebula cataloged as NGC 6960 but less formally known as the Witch's Broom Nebula. Blasted out in the cataclysmic explosion, an interstellar shock wave plows through space sweeping up and exciting interstellar material. Imaged with narrow band filters, the glowing filaments are like long ripples in a sheet seen almost edge on, remarkably well separated into atomic hydrogen (red) and oxygen (blue-green) gas. The complete supernova remnant lies about 1400 light-years away towards the constellation Cygnus . This Witch's Broom actually spans about 35 light-years. The bright star in the frame is 52 Cygni , vis...

Comet Lemmon is brightening and moving into morning northern skies. Besides Comet SWAN25B and Comet ATLAS , Comet C/2025 A6 (Lemmon) is now the third comet currently visible with binoculars and on long camera exposures. Comet Lemmon was discovered early this year and is still headed into the inner Solar System . The comet will round the Sun on November 8, but first it will pass its nearest to the Earth -- at about half the Earth-Sun distance -- on October 21. Although the brightnesses of comets are notoriously hard to predict , optimistic estimates have Comet Lemmon then becoming visible to the unaided eye. The comet should be best seen in predawn skies until mid-October, when it also becomes visible in evening skies. The featured image showing the comet's split and rapidly changing ion tail was taken in Texas , USA late last week. from NASA https://ift.tt/MPm1p3s

It may look like these comets are racing, but they are not. Comets C/2025 K1 ATLAS (left) and C/2025 R2 SWAN (right) appeared near each other by chance last week in the featured image taken from France's Reunion Island in the southern Indian Ocean . Fainter Comet ATLAS is approaching our Sun and will reach its closest approach in early October when it is also expected to be its brightest -- although still only likely visible with long exposures on a camera. The brighter comet, nicknamed SWAN25B , is now headed away from our Sun , although its closest approach to Earth is expected in mid-October, when optimistic estimates have it becoming bright enough to see with the unaided eye. Each comet has a greenish coma of expelled gas and an ion tail pointing away from the Sun. from NASA https://ift.tt/bvJaqmN

What is creating these unusual spots? Light-colored spots on Martian rocks , each surrounded by a dark border, were discovered last year by NASA 's Perseverance Rover currently exploring Mars . Dubbed leopard spots because of their seemingly similarity to markings on famous Earth-bound predators , these curious patterns are being studied with the possibility they were created by ancient Martian life . The pictured spots measure only millimeter s across and were discovered on a larger rock named Cheyava Falls . The exciting but unproven speculation is that long ago, microbe s generated energy with chemical reactions that turned rock from red to white while leaving a dark biosignature ring, like some similarly appearing spots on Earth rocks . Although other non-biological explanations have not been ruled out, speculation focusing on this potential biological origin is causing much intrigue . from NASA https://ift.tt/yYoldgq

On the morning of September 24 a rocket crosses the bright solar disk in this long range telescopic snapshot captured from Orlando, Florida. That's about 50 miles north of its Kennedy Space Center launch site. This rocket carried three new space weather missions to space. Signals have now been successfully acquired from all three - NASA's Interstellar Mapping and Acceleration Probe, NASA’s Carruthers Geocorona Observatory, and the National Oceanic and Atmospheric Administration (NOAA) Space Weather Follow-On Lagrange 1 (SWFO-L1) - as they begin their journey to L1, an Earth-Sun lagrange point. L1 is about 1.5 million kilometers in the sunward direction from planet Earth. Appropriately, major space weather influencers, aka dark sunspots in active regions across the Sun, are posing with the transiting rocket. In fact, large active region AR4225 is just right of the rocket's nose. from NASA https://ift.tt/neWrOZF

A new visitor to the inner Solar System, comet C/2025 R2 (SWAN) sports a long ion tail extending diagonally across this almost 7 degree wide telescopic field of view recorded on September 21 . A fainter fellow comet also making its inner Solar System debut, C/2025 K1 (ATLAS) , can be spotted above and left of SWAN's greenish coma, just visible against the background sea of stars in the constellation Virgo. Both new comets were only discovered in 2025 and are joined in this celestial frame by ruddy planet Mars (bottom), a more familiar wanderer in planet Earth's night skies. The comets may appear to be in a race, nearly neck and neck in their voyage through the inner Solar System and around the Sun. But this comet SWAN has already reached its perihelion or closest approach to the Sun on September 12 and is now outbound along its orbit. This comet ATLAS is still inbound though, and will make its perihelion passage on October 8. from NASA https://ift.tt/v4nYWom

This year Saturn was at opposition on September 21, opposite the Sun in planet Earth's sky. At its closest to Earth, Saturn was also at its brightest of the year, rising as the Sun set and shining above the horizon all night long among the fainter stars of the constellation Pisces. In this snapshot from the Qinghai Lenghu Observatory , Tibetan Plateau, southwestern China, the outer planet is immersed in a faint, diffuse oval of light known as the gegenschein or counter glow. The diffuse gegenschein is produced by sunlight backscattered by interplanetary dust along the Solar System's ecliptic plane , opposite the Sun in planet Earth's sky. Like a giant eye, on this dark night Saturn and gegenschein seem to stare down on the observatory's telescope domes seen against a colorful background of airglow along the horizon. from NASA https://ift.tt/BE3QUXL

It was the strongest gravitational wave signal yet measured -- what did it show? GW250114 was detected by both arms of the Laser Interferometer Gravitational-wave Observatory (LIGO) in Washington and Louisiana USA earlier this year. Analysis showed that the event was created when two black holes , each of mass around 33 times the mass of the Sun , coalesced into one larger black hole with a mass of around 63 solar masses. Even though the event happened about a billion light years away, the signal was so strong that the spin of all black holes , as well as initial ringing of the final black hole, was deduced with exceptional accuracy . Furthermore, it was confirmed better than before, as previously predicted , that the total event horizon area of the combined black hole was greater than those of the merging black holes . Featured, an artist's illustration depicts an imaginative and conceptual view from near one of the black holes before collision. from NASA https://ift.t...

How massive can a normal star be? Estimates made from distance, brightness and standard solar models had given one star in the open cluster Pismis 24 over 200 times the mass of our Sun , making it one of the most massive stars known. This star is the brightest object located in the central cavity near the bottom center of the featured image taken with the Webb Space Telescope in infrared light. For comparison, a rollover image from the Hubble Space Telescope is also featured in visible light. Close inspection of the images , however, has shown that Pismis 24-1 derives its brilliant luminosity not from a single star but from three at least. Component stars would still remain near 100 solar masses, making them among the more massive stars currently on record. Toward the bottom of the image, stars are still forming in the associated emission nebula NGC 6357 . Appearing perhaps like a Gothic cathedral , energetic stars near the center appear to be breaking out and illu...

On Saturn, the rings tell you the season. On Earth , today marks an equinox, the time when the Earth's equator tilts directly toward the Sun. Since Saturn's grand rings orbit along the planet's equator, these rings appear most prominent -- from the direction of the Sun -- when the spin axis of Saturn points toward the Sun . Conversely, when Saturn 's spin axis points to the side, an equinox occurs, and the edge-on rings are hard to see from not only the Sun -- but Earth . In the featured montage , images of Saturn between the years of 2020 and 2025 have been superposed to show the giant planet passing, with this year's equinox, from summer in the north to summer in the south. Yesterday , Saturn was coincidently about as close as it gets to planet Earth, and so this month the ringed giant's orb is relatively bright and visible throughout the night. from NASA https://ift.tt/Qn7sJde

Does the Sun set in the same direction every day? No, the direction of sunset depends on the time of the year. Although the Sun always sets approximately toward the west, on an equinox like today the Sun sets directly toward the west . After tomorrow's September equinox, the Sun will set increasingly toward the southwest, reaching its maximum displacement at the December solstice . Before today's September equinox, the Sun had set toward the northwest, reaching its maximum displacement at the June solstice . The featured time-lapse image shows seven bands of the Sun setting one day each month from 2019 December through 2020 June. These image sequences were taken from Alberta , Canada -- well north of the Earth's equator -- and feature the city of Edmonton in the foreground. The middle band shows the Sun setting during the last equinox -- in March. From this location , the Sun will set along this same equinox band again tomorrow. from NASA https://ift.tt/PCFUaoJ

Early risers around planet Earth have enjoyed a shining crescent Moon near brilliant Venus, close to the eastern horizon in recent morning twilight skies. And yesterday, on September 19, skygazers watching from some locations in Earth's northern hemisphere were also able to witness Venus, in the inner planet's waxing gibbous phase , pass behind the Moon's waning crescent . In fact, this telescopic snapshot was taken moments before that occultation of gibbous Venus by the crescent Moon began. The close-up view of the beautiful celestial alignment records Venus approaching part of the Moon's sunlit edge in clear daytime skies from the Swiss Alps. Tomorrow , the Sun will pass behind a New Moon. But to witness that partial solar eclipse on September 21, skygazers will need to watch from locations in planet Earth's southern hemisphere. from NASA https://ift.tt/WRSHCLl

How does your favorite planet spin? Does it spin rapidly around a nearly vertical axis, or horizontally, or backwards? The featured video animates NASA images of all eight planets in our Solar System to show them spinning side-by-side for an easy comparison. In the time-lapse video , a day on Earth -- one Earth rotation -- takes just a few seconds. Jupiter rotates the fastest, while Venus spins not only the slowest (can you see it?), but backwards. The inner rocky planets across the top underwent dramatic spin-altering collisions during the early days of the Solar System. Why planets spin and tilt as they do remains a topic of research with much insight gained from modern computer modeling and the recent discovery and analysis of hundreds of exoplanets : planets orbiting other stars . from NASA https://ift.tt/FGL4JM7

The steerable 60 foot diameter dish antenna of the One-Mile Telescope at Mullard Radio Astronomy Observatory , Cambridge, UK, is pointing skyward in this evocative night-skyscape. To capture the dramatic scene, consecutive 30 second exposures were recorded over a period of 90 minutes. Combined, the exposures reveal a background of gracefully arcing star trails that reflect planet Earth's daily rotation on its axis . The North Celestial Pole , the extension of Earth's axis of rotation into space, points near Polaris, the North Star . That's the bright star that creates the short trail near the center of the concentric arcs . But the historic One-Mile Telescope array also relied on planet Earth's rotation to operate. Exploring the universe at radio wavelengths , it was the first radio telescope to use Earth-rotation aperture synthesis. That technique uses the rotation of the Earth to change the relative orientation of the telescope array and celestial radio sources to...

September's total lunar eclipse is tracked across night skies from both the northern and southern hemispheres of planet Earth in these two dramatic timelapse series. In the northern hemisphere sequence (top panel) the Moon’s trail arcs from the upper left to the lower right. It passes below bright planet Saturn, seen under mostly clear skies from the international campus of Zhejiang University in China at about 30 degrees north latitude. In contrast, the southern hemisphere view from Lake Griffin, Canberra, Australia at 35 degrees south latitude, records the Moon’s trail from the upper right to the lower left. Multiple lightning flashes from thunderstorms near the horizon appear reflected in the lake. Both sequences were photographed with 16mm wide-angle lenses and both cover the entire eclipse , with the darkened red Moon totally immersed in Earth's umbral shadow near center. But the different orientations of the Moon’s path across the sky reveal the perspective shifts ca...

The dark, inner shadow of planet Earth is called the umbra . Shaped like a cone extending into space, it has a circular cross section most easily seen during a lunar eclipse . And on the night of September 7/8 the Full Moon passed near the center of Earth's umbral cone, entertaining eclipse watchers around much of our fair planet, including parts of Antarctica, Australia, Asia, Europe, and Africa. Recorded from Zhangjiakou City, China, this timelapse composite image uses successive pictures from the total lunar eclipse , progressing left to right, to reveal the curved cross-section of the umbral shadow sliding across the Moon. Sunlight scattered by the atmosphere into Earth's umbra causes the lunar surface to appear reddened during totality. But close to the umbra's edge, the limb of the eclipsed Moon shows a distinct blue hue. The blue eclipsed moonlight originates as rays of sunlight pass through layers high in the upper stratosphere, colored by ozone that scatters r...

It is one of the largest nebulas on the sky -- why isn't it better known? Roughly the same angular size as the Andromeda Galaxy , the Great Lacerta Nebula can be found toward the constellation of the Lizard (Lacerta) . The emission nebula is difficult to see with wide-field binoculars because it is so faint , but also usually difficult to see with a large telescope because it is so great in angle -- spanning about three degrees . The depth, breadth, waves , and beauty of the nebula -- cataloged as Sharpless 126 (Sh2-126) -- can best be seen and appreciated with a long duration camera exposure . The featured image is one such combined exposure -- in this case taken over three nights in August through dark skies in Moses Lake , Washington , USA . The hydrogen gas in the Great Lacerta Nebula glows red because it is excited by light from the bright star 10 Lacertae , one of the bright blue stars just to the left of the red-glowing nebula's center. Most of the stars and nebula...

What's that rising up from the Earth? When circling the Earth on the International Space Station early in July , astronaut Nicole Ayers saw an unusual type of lightning rising up from the Earth: a gigantic jet . The powerful jet appears near the center of the featured image in red, white, and blue. Giant jet lightning has only been known about for the past 25 years. The atmospheric jets are associated with thunderstorms and extend upwards towards Earth's ionosphere . The lower part of the frame shows the Earth at night , with Earth's thin atmosphere tinted green from airglow. City lights are visible, sometimes resolved, but usually creating diffuse white glows in intervening clouds. The top of the frame reveals distant stars in the dark night sky. The nature of gigantic jets and their possible association with other types of Transient Luminous Events (TLEs) such as blue jets and red sprites remain active topics of research . from NASA https://ift.tt/uKfw4s9

This butterfly can hatch planets. The nebula fanning out from the star IRAS 04302+2247 may look like the wings of a butterfly , while the vertical brown stripe down the center may look like the butterfly's body -- but together they indicate an active planet-forming system . The featured picture was captured recently in infrared light by the Webb Space Telescope . Pictured, the vertical disk is thick with the gas and dust from which planets form. The disk shades visible and (most) infrared light from the central star, allowing a good view of the surrounding dust that reflects out light. In the next few million years, the dust disk will likely fragment into rings through the gravity of newly hatched planets. And a billion years from now , the remaining gas and dust will likely dissipate, leaving mainly the planets -- like in our Solar System . from NASA https://ift.tt/gCaPQs3

How much of planet Earth is made of water? Very little, actually. Although oceans of water cover about 70 percent of Earth's surface, these oceans are shallow compared to the Earth's radius. The featured illustration shows what would happen if all of the water on or near the surface of the Earth were bunched up into a ball . The radius of this ball would be only about 700 kilometers, less than half the radius of the Earth's Moon , but slightly larger than Saturn's moon Rhea which, like many moons in our outer Solar System , is mostly water ice. The next smallest ball depicts all of Earth 's liquid fresh water, while the tiniest ball shows the volume of all of Earth's fresh-water lake s and river s. How any of this water came to be on the Earth and whether any significant amount is trapped far beneath Earth 's surface remain topic s of research. from NASA https://ift.tt/x4o6cXC

When the sun sets on September 7 , the Full Moon will rise. And on that date denizens around much of our fair planet, including parts of Antarctica, Australia, Asia, Europe, and Africa can witness a total lunar eclipse, with the Moon completely immersed in Earth's shadow. As the bright Full Moon first enters Earth's shadow it will darken, finally taking on a reddish hue during the total eclipse phase. In fact, the color of the Moon during a total lunar eclipse is due to reddened light from sunrises and sunsets around planet Earth . The reddened sunlight is scattered by a dense atmosphere into the planet's otherwise dark central shadow. When the sun set on August 22, this telephoto snapshot of red skies, blue sea, and the Mangiabarche Lighthouse was captured from Sant'Antioco, Sardinia, Italy. from NASA https://ift.tt/G8FEJCR

Also known as NGC 104 , 47 Tucanae is a jewel of the southern sky. Not a star but a dense cluster of stars, it roams the halo of our Milky Way Galaxy along with some 200 other globular star clusters . The second brightest globular cluster (after Omega Centauri ) as seen from planet Earth, 47 Tuc lies about 13,000 light-years away. It can be spotted with the naked eye close on the sky to the Small Magellanic Cloud in the constellation of the Toucan . The dense cluster is made up of hundreds of thousands of stars in a volume only about 120 light-years across. Red giant stars on the outskirts of the cluster are easy to pick out as yellowish stars in this sharp telescopic portrait . Tightly packed globular star cluster 47 Tuc is also home to a star with the closest known orbit around a black hole . from NASA https://ift.tt/lJYAkie

Magnificent spiral galaxy NGC 4565 is viewed edge-on from planet Earth. Also known as the Needle Galaxy for its narrow profile, bright NGC 4565 is a stop on many telescopic tours of the northern sky, in the faint but well-groomed constellation Coma Berenices . This sharp, colorful image reveals the galaxy's boxy, bulging central core cut by obscuring dust lanes that lace NGC 4565's thin galactic plane. NGC 4565 lies around 40 million light-years distant while the spiral galaxy itself spans some 100,000 light-years. That's about the size of our own Milky Way. Easily spotted with small telescopes, deep sky enthusiasts consider NGC 4565 to be a prominent celestial masterpiece Messier missed . from NASA https://ift.tt/1MuzaRQ