APOD: 2021 July 19 - Framed by Trees: A Window to the Galaxy Discover the cosmos!Each day a different image or photograph of our fascinating universe isfeatured, along with a brief explanation written by a professional astronomer. 2021 July 19 Framed by Trees: A Window to the Galaxy Image Credit & Copyright: Will Godward Explanation: The photographer had this shot in mind for some time.He knew that objects overhead are the brightest -- since their light is scattered the least by atmospheric air.He also that knew the core of our Milky Way Galaxy was just about straight up near midnight around this time of year in South Australia. Chasing his mental picture, he ventured deep inside the Kuipto Forest where tall radiata pines blocked out much of the sky -- but not in this clearing. There, through a window framed by trees, he captured his envisioned combination of local and distant nature.Sixteen exposures of both trees and the Milky Way Galaxy were recorded.Antares is the bright orange star to left of our Galaxy's central plane, while Alpha Centauri is the bright star just to the right of the image center. The direction toward our Galaxy's center is below Antares. Although in...

APOD: 2021 July 18 - The Andromeda Galaxy in Ultraviolet Discover the cosmos!Each day a different image or photograph of our fascinating universe isfeatured, along with a brief explanation written by a professional astronomer. 2021 July 18 The Andromeda Galaxy in Ultraviolet Image Credit: NASA, JPL-Caltech, GALEX Explanation: What does the Andromeda galaxy look like in ultraviolet light?Young blue stars circling the galactic center dominate. A mere 2.5 million light-years away, the Andromeda Galaxy, alsoknown as M31, really is just next door as large galaxies go.Spanningabout 230,000 light-years, it took 11 different image fields from NASA's Galaxy Evolution Explorer (GALEX) satellitetelescope to produce this gorgeous portrait of the spiral galaxy inultraviolet light in 2003.While its spiral arms stand out invisible light images,Andromeda's arms look more like rings in ultraviolet.The rings are sites of intense star formation and have been interpreted asevidence that Andromeda collided with its smaller neighboring elliptical galaxy M32 more than 200 million years ago.The Andromeda galaxy and our own comparable Milky Way galaxy are the most massive members of theLocal Groupof galaxies and are projected to collide in several billion years -- perhaps around the time that our Sun's atmosphere will expand to engulf the Earth. Tomorrow's picture:...

APOD: 2021 July 17 - Alphonsus and Arzachel Discover the cosmos!Each day a different image or photograph of our fascinating universe isfeatured, along with a brief explanation written by a professional astronomer. 2021 July 17 Alphonsus and Arzachel Image Credit &Copyright: Noel Donnard Explanation: Point your telescopeat tonight's first quarter Moon.Along the terminator,the shadow line between night and day,you might find these two large cratersstaring back at you withan owlish gaze.Alphonsus(left) andArzachelare ancient impact craters onthe north eastern shores of Mare Nubium, the lunar Sea of Clouds.The larger Alphonsus is over 100 kilometers in diameter.A low sun angle highlights the crater'ssharp 1.5 kilometer high centralpeak in bright sunlight and dark shadow.Scouting for potential Apollo moon landing sites, theRanger 9 spacecraftreturned closeup pictures of Alphonsus beforeit crashed in the crater just northeast (toward the upper left)of its central mountain in 1965.Alpetragius,between Alphonsus and Arzachel,is the small crater with the deeply shadowed floor andoverly large central beak. Tomorrow's picture: 2.5 million light-years away<| Archive| Submissions | Index| Search| Calendar| RSS| Education| About APOD| Discuss| > Authors & editors: Robert Nemiroff(MTU) &Jerry Bonnell (UMCP)NASA Official: Phillip NewmanSpecific rights apply.NASA WebPrivacy Policy and Important NoticesA service of:ASD atNASA /GSFC& Michigan Tech. U.

APOD: 2021 July 16 - Love and War by Moonlight Discover the cosmos!Each day a different image or photograph of our fascinating universe isfeatured, along with a brief explanation written by a professional astronomer. 2021 July 16 Love and War by Moonlight Image Credit &Copyright: Shi Huan Explanation: Venus,named for the Roman goddess of love, andMars,the war god's namesake, come togetherby moonlightin this serene skyview, recorded on July 11from Lualaba province, Democratic Republic of Congo, planet Earth.Taken in the western twilight sky shortly after sunsetthe exposure also recordsearthshine illuminating the otherwisedark surface of theyoung crescent Moon.Of course the Moon has moved on.Venus still shines in the west though as theeveningstar, third brightest object in Earth's sky,after the Sun and the Moon itself.Seen here above a brilliant Venus,Mars moved even closerto the brighter planet and by July 13 could be seen onlyabout a Moon's width away.Mars has since slowly wandered away from much brighter Venus in thetwilight, but both are sliding toward bright star Regulus.Alpha star of the constellation Leo, Regulus lies off thetop of this frame and anticipates avisit from Venusand then Mars in twilight skies ofthe coming days. Tomorrow's picture: when the moon watches you<| Archive| Submissions | Index| Search|...

APOD: 2021 July 15 - The Dark Tower in Scorpius Discover the cosmos!Each day a different image or photograph of our fascinating universe isfeatured, along with a brief explanation written by a professional astronomer. 2021 July 15 The Dark Tower in Scorpius Image Credit &Copyright:Data - Martin Pugh,Processing - Rocco Sung Explanation: In silhouette against a crowded star fieldalong the tail of the arachnalogical constellationScorpius,this dusty cosmic cloud evokes for some the image of anominousdark tower.In fact, clumps of dust and molecular gascollapsingto form stars may well lurk within the dark nebula,a structure that spans almost 40 light-years across thisgorgeous telescopic portrait.Known as acometary globule, the swept-back cloud,is shaped by intense ultraviolet radiation fromthe OB association of veryhot stars in NGC 6231,off the upper edge of the scene.That energetic ultraviolet light also powers the globule's borderingreddish glow of hydrogen gas.Hot stars embedded in the dustcan be seen as bluishreflection nebulae.This dark tower, NGC 6231, andassociated nebulae are about 5,000 light-years away. Tomorrow's picture: love and war by moonlight<| Archive| Submissions | Index| Search| Calendar| RSS| Education| About APOD| Discuss| > Authors & editors: Robert Nemiroff(MTU) &Jerry Bonnell (UMCP)NASA Official: Phillip NewmanSpecific rights apply.NASA WebPrivacy Policy and Important NoticesA service of:ASD atNASA...

APOD: 2021 July 14 - GW200115: Simulation of a Black Hole Merging with a Neutron Star Discover the cosmos!Each day a different image or photograph of our fascinating universe isfeatured, along with a brief explanation written by a professional astronomer. GW200115: Simulation of a Black Hole Merging with a Neutron Star Video Credit: Simulation: S.V. Chaurasia (Stockholm U.), T. Dietrich (Potsdam U. & MPIGP); Visualization: T. Dietrich (Potsdam U. & MPIGP),N. Fischer, S. Ossokine, H. Pfeiffer (MPIGP) Explanation: What happens when a black hole destroys a neutron star?Analyses indicate that just such an event created gravitational wave event GW200115, detected in 2020 January by LIGO and Virgo observatories.To better understand the unusual event, the featured visualization was created from a computer simulation.The visualization video starts with the black hole (about 6 times the Sun's mass) and neutron star (about 1.5 times the Sun's mass) circling each other, together emitting an increasing amount of gravitational radiation.The picturesque pattern of gravitational wave emission is shown in blue.The duo spiral together increasingly fast until the neutron star becomes completely absorbed by the black hole. Since the neutron star did not break apart during the collision, little light escaped -- which matches the lack of...

APOD: 2021 July 13 - Saturns Iapetus: Painted Moon in 3D Discover the cosmos!Each day a different image or photograph of our fascinating universe isfeatured, along with a brief explanation written by a professional astronomer. 2021 July 13 Saturn's Iapetus: Painted Moon in 3D Image Credit: NASA,ESA,JPL,SSI,Cassini Imaging Team; 3D Rendering: NASA's VTAD Explanation: What has happened to Saturn's moon Iapetus? Vast sections ofthis strange world are dark brown, while others are as bright white. The composition of the dark material is unknown, butinfrared spectra indicate that it possibly contains some dark form ofcarbon.Iapetus also has an unusualequatorial ridgethat makes it appear like a walnut. To help better understand this seemingly painted moon,NASA directed therobotic Cassini spacecraft orbiting Saturn to swoopwithin 2,000 kilometers in 2007.Iapetus is pictured here in 3D. A huge impact crater seen in the south spans a tremendous 450 kilometersand appears superposed on anolder crater of similar size.The dark materialis seen increasingly coating the easternmost part ofIapetus, darkening craters and highlands alike. Close inspection indicates that the dark coating typically faces the moon's equator and is less than a meter thick.A leading hypothesis is that the dark material is mostlydirt leftover when relatively warm but dirty icesublimates.An initial...

APOD: 2021 July 12 - M27: The Dumbbell Nebula Discover the cosmos!Each day a different image or photograph of our fascinating universe isfeatured, along with a brief explanation written by a professional astronomer. 2021 July 12 M27: The Dumbbell Nebula Image Credit & Copyright: Bray Falls & Keith Quattrocchi Explanation: What will become of our Sun?The first hint of our Sun's future was discovered inadvertently in1764.At that time,Charles Messier was compiling a listof diffuse objects not to be confused with comets.The 27th object onMessier's list, now known asM27 or the Dumbbell Nebula, is aplanetary nebula,one of the brightestplanetary nebulae on the sky -- and visibletoward the constellation of the Fox (Vulpecula) with binoculars.It takes light about 1000 years to reach us from M27, featured here in colors emitted byhydrogen andoxygen.We now know that in about 6 billion years, our Sun will shed its outer gases into a planetary nebula like M27, while its remaining center will become an X-ray hot white dwarf star. Understanding the physics and significance ofM27was well beyond 18th century science, though.Even today, many things remain mysterious aboutplanetary nebulas, including how their intricate shapes are created. Tomorrow's picture: Iapetus 3D <| Archive| Submissions | Index| Search| Calendar| RSS|...

APOD: 2021 July 11 - Find the Moon Discover the cosmos!Each day a different image or photograph of our fascinating universe isfeatured, along with a brief explanation written by a professional astronomer. 2021 July 11 Find the Moon Image Credit & Copyright: Jimmy Westlake(Colorado Mountain College) Explanation: Where's the Moon?Somewhere in this image, the Earth's Moon is hiding. The entire Moon is visible, in its completely full phase, in plain sight.Even the photographer's keen eye couldn't find it even though he knew exactly where to look -- only thelong exposure of his camera picked it up -- barely. Although by now you might be congratulating yourself on finding it, why was it so difficult to see?For one reason, this photograph was taken during atotal lunar eclipse, when the Earth's shadow made the Moon much dimmer than a normal full Moon.For another, the image, taken inColorado,USA,was captured just before sunrise.With the Moon on the exact opposite side of the sky from the Sun, this meant that the Sun was just below the horizon, but stillslightly illuminatingthe sky.Last, as theMoon was only about two degrees above the horizon, thelarge volume of air between the camera and the horizon scattered a lot of light...

APOD: 2021 July 10 - Mercury and the Da Vinci Glow Discover the cosmos!Each day a different image or photograph of our fascinating universe isfeatured, along with a brief explanation written by a professional astronomer. 2021 July 10 Mercury and the Da Vinci Glow Image Credit &Copyright:Gabriel Funes Explanation: On July 8th early morning risers saw Mercury near an old Moonlow on the eastern horizon.On that datebright planet, faint glow of lunar night side, and sunlit crescentwere captured in this predawn skyscape from Tenerife'sTeide National Park in the Canary Islands. Never far from the Sun in planet Earth's sky, thefleeting inner planetshines near its brightest in the morning twilight scene.Mercury lies just below the zeta star of the constellation Taurus,Zeta Tauri,near thetipof the celestial bull's horn.Of course the Moon's ashen glow is earthshine, earthlight reflectedfrom the Moon's night side.A description of earthshine, in terms of sunlightreflected by Earth's oceans illuminatingthe Moon's dark surface, was written over 500 years ago byLeonardo da Vinci.Waiting for the coming dawn in the foreground are theTeide Observatory'ssentinels of the Sun, also known as (large domes left to right) theTHEMIS,VTT, and GREGOR solar telescopes. Tomorrow's picture: try to see the Moon<| Archive| Submissions | Index| Search| Calendar|...

APOD: 2021 July 9 - M82: Starburst Galaxy with a Superwind Discover the cosmos!Each day a different image or photograph of our fascinating universe isfeatured, along with a brief explanation written by a professional astronomer. 2021 July 9 M82: Starburst Galaxy with a Superwind Image Credit &Copyright:Team ARO,Alentejo Remote Observatory Explanation: M82 is a starburst galaxywith a superwind.In fact,through ensuing supernova explosions andpowerful winds from massive stars,the burst of star formation in M82is driving a prodigious outflow.Evidence for the superwindfrom the galaxy's central regionsis clear in sharp telescopic snapshot.The composite image highlights emission fromlong outflow filaments of atomic hydrogen gas in reddish hues.Some of the gas in the superwind,enriched in heavy elementsforged in the massive stars,will eventually escape intointergalactic space.Triggered by aclose encounter withnearby large galaxy M81,the furious burst of star formation in M82 should last about100 million years or so.Also known as the Cigar Galaxy for its elongated visual appearance,M82 is about 30,000 light-years across.It lies 12 million light-years away near the northern boundary ofUrsa Major. Tomorrow's picture: Mercury and the Da Vinci Glow<| Archive| Submissions | Index| Search| Calendar| RSS| Education| About APOD| Discuss| > Authors & editors: Robert Nemiroff(MTU) &Jerry Bonnell (UMCP)NASA Official: Phillip NewmanSpecific rights apply.NASA WebPrivacy...

APOD: 2021 July 8 - Perihelion to Aphelion Discover the cosmos!Each day a different image or photograph of our fascinating universe isfeatured, along with a brief explanation written by a professional astronomer. 2021 July 8 Perihelion to Aphelion Image Credit &Copyright:Richard Jaworski Explanation: Aphelion for 2021 occurred on July 5th.That's the point in Earth's elliptical orbit when it is farthest from the Sun.Of course, the distance from the Sun doesn't determine the seasons.Those are governed bythe tilt of Earth's axis of rotation,so July is still summer in the north and winter in the southernhemisphere.But it does mean that on July 5 the Sun was at its smallestapparent size when viewed from planet Earth.This composite neatly compares two pictures of the Sun,both taken with the same telescope and camera.The left half was captured close to the date of the2021 perihelion (January 2), the closest point in Earth's orbit.The right was recorded just before the aphelion in 2021.Otherwise difficult to notice, the change in theSun's apparent diameter betweenperihelion and aphelionamounts to a little over 3 percent. Tomorrow's picture: starburst and superwind<| Archive| Submissions | Index| Search| Calendar| RSS| Education| About APOD| Discuss| > Authors & editors: Robert Nemiroff(MTU) &Jerry Bonnell (UMCP)NASA Official: Phillip...

APOD: 2021 July 7 - Flight Through the Orion Nebula in Infrared Light Discover the cosmos!Each day a different image or photograph of our fascinating universe isfeatured, along with a brief explanation written by a professional astronomer. Flight Through the Orion Nebula in Infrared Light Video Credit: NASA, Spitzer Space Telescope, Universe of Learning; Visualization: F. Summers (STScI) et al.; Music & License: Serenade for Strings (A. Dvořák), Advent Chamber Orch. Explanation: What would it look like to fly into the Orion Nebula? The exciting dynamic visualizationof the Orion Nebula is based on real astronomical dataand adept movie rendering techniques.Up close and personal with a famous stellar nurserynormally seenfrom 1,500 light-years away, the digitally modeledrepresentation based is based on infrared data from the Spitzer Space Telescope.The perspective moves along a valley over alight-year wide, in the wall of the region's giant molecular cloud.Orion's valley ends in a cavity carved by the energetic winds and radiation of the massive central stars of theTrapezium star cluster.The entire Orion Nebula spans about 40 light years and is located in the same spiral arm of our Galaxy as the Sun. Tomorrow's picture: open space <| Archive| Submissions | Index| Search| Calendar| RSS| Education| About APOD|...

APOD: 2021 July 6 - Saturn and Six Moons Discover the cosmos!Each day a different image or photograph of our fascinating universe isfeatured, along with a brief explanation written by a professional astronomer. 2021 July 6 Saturn and Six Moons Image Credit & Copyright: Mohammad Ranjbaran; MR Thanks: Amir Ehteshami Explanation: How many moons does Saturn have?So far 82 have been confirmed, the smallest being only a fractionof a kilometer across.Six of its largest satellites can be seen here in a composite image with 13 short exposure of the bright planet, and13 long exposures of the brightest of its faint moons, taken over two weeks last month. Larger than Earth's Moon and even slightly larger than Mercury,Saturn's largest moonTitan has a diameter of 5,150 kilometers and was captured making nearly a complete orbit around its ringed parent planet. Saturn's first known natural satellite, Titan wasdiscovered in 1655 byDutch astronomer Christiaan Huygens, in contrast with several newly discovered moons announced in 2019. The trail on the far right belongs to Iapetus, Saturn's third largest moon.The radius of painted Iapetus' orbit is so large that only a portion of it was captured here.Saturn leads Jupiter across the night sky this month, rising soon...

You go, Tuesday! You're so Fetch!  

Do you see the horse's head?

APOD: 2021 July 4 - The Face on Mars Discover the cosmos!Each day a different image or photograph of our fascinating universe isfeatured, along with a brief explanation written by a professional astronomer. 2021 July 4 The Face on Mars Image Credit: NASA, Viking 1 Orbiter Explanation: Wouldn't it be fun if clouds were castles? Wouldn't it be fun if the laundry on the bedroom chair was a superhero? Wouldn't it be fun if rock mesas on Mars were interplanetary monuments to the human face? Clouds, though, are floating droplets of water and ice. Laundry is cotton, wool, or plastic, woven into garments. Famous Martian rock mesas known by names like the Face on Mars appear quite natural when seen more clearly on better images. Is reality boring?Nobody knows why some clouds make rain. Nobody knows if life ever developed on Mars. Nobody knows why the laundry on the bedroom chair smells like root beer. Scientific exploration can not only resolve mysteries, but uncover new knowledge, greater mysteries, and yet deeper questions. As humanity explores our universe, perhaps fun -- through discovery -- is just beginning. Tomorrow's picture: horse of blue <| Archive| Submissions | Index| Search| Calendar| RSS| Education| About...

APOD: 2021 July 3 - Along the Milky Way Discover the cosmos!Each day a different image or photograph of our fascinating universe isfeatured, along with a brief explanation written by a professional astronomer. 2021 July 3 Along the Milky Way Image Credit &Copyright:Rolf Weisenfeld Explanation: You can'twalk along the Milky Way.Still, under a dark skyyou can explore it.To the eye the pale luminous trail of light arcingthrough the sky on a dark, moonless night does appear to bea path through the heavens.The glowing celestial band is the faint,collectivelight of distant starscut by swaths of obscuring interstellar dust clouds.It lies along the plane ofour home galaxy,so named because it looks like a milky way.Since Galileo's time, the Milky Way has been revealedto telescopic skygazers to be filled withcongeries of innumerable starsandcosmic wonders. Tomorrow's picture: Facing Mars<| Archive| Submissions | Index| Search| Calendar| RSS| Education| About APOD| Discuss| > Authors & editors: Robert Nemiroff(MTU) &Jerry Bonnell (UMCP)NASA Official: Phillip NewmanSpecific rights apply.NASA WebPrivacy Policy and Important NoticesA service of:ASD atNASA /GSFC& Michigan Tech. U.

APOD: 2021 July 2 - AR2835: Islands in the Photosphere Discover the cosmos!Each day a different image or photograph of our fascinating universe isfeatured, along with a brief explanation written by a professional astronomer. 2021 July 2 AR2835: Islands in the Photosphere Image Credit &Copyright:MichaelTeoh,Heng Ee Observatory, Penang, Malaysia Explanation: Awash in a sea ofincandescent plasmaand anchored in strongmagnetic fields,sunspots are planet-sized dark islands inthe solar photosphere,the bright surface of the Sun.Found in solar active regions, sunspots lookdarkonly because they are slightly cooler though,with temperatures of about 4,000kelvinscompared to 6,000 kelvins for the surrounding solar surface.These sunspots lie in active region AR2835.The largest active regionnow crossing the Sun,AR2835 is captured in this sharp telescopic close-up from July 1in a field of view that spans about 150,000 kilometersor over ten Earth diameters.With powerful magnetic fields,solar active regionsare often responsible for solar flares and coronal mass ejections, storms which affectspace weathernearplanet Earth. Tomorrow's picture: Got telescope?<| Archive| Submissions | Index| Search| Calendar| RSS| Education| About APOD| Discuss| > Authors & editors: Robert Nemiroff(MTU) &Jerry Bonnell (UMCP)NASA Official: Phillip NewmanSpecific rights apply.NASA WebPrivacy Policy and Important NoticesA service of:ASD atNASA /GSFC& Michigan Tech. U.

APOD: 2021 July 1 - Perseverance Selfie with Ingenuity Discover the cosmos!Each day a different image or photograph of our fascinating universe isfeatured, along with a brief explanation written by a professional astronomer. 2021 July 1 Perseverance Selfie with Ingenuity Image Credit: NASA,JPL-Caltech,MSSS Explanation: On sol 46 (April 6, 2021) the Perseverance rover held out arobotic arm to takeits first selfie on Mars.The WATSON camera at the end of the armwas designed to take close-ups of martian rocks andsurface details though, and not a quick snap shot of friends andsmiling faces.In the end,teamworkand weeks of planning on Mars timewas required to program a complex series ofexposures and camera motions to include Perseverance and itssurroundings.The resulting 62 frames were composed into a detailed mosiac,one of the most complicated Mars rover selfies ever taken.In this version of theselfie, the rover'sMastcam-Z and SuperCam instruments are lookingtoward WATSON and the end of the rover's outstretched arm.About 4 meters (13 feet) from Perseverance is a robotic companion,the Mars Ingenuity helicopter. Tomorrow's picture: pixels in space<| Archive| Submissions | Index| Search| Calendar| RSS| Education| About APOD| Discuss| > Authors & editors: Robert Nemiroff(MTU) &Jerry Bonnell (UMCP)NASA Official: Phillip NewmanSpecific rights apply.NASA WebPrivacy Policy and Important NoticesA service...