APOD: 2022 May 3 - Mercurys Sodium Tail 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. 2022 May 3 Mercury's Sodium Tail Image Credit & Copyright: Sebastian Voltmer Explanation: That's no comet. Below the Pleiades star cluster is actually a planet: Mercury.Long exposures of our Solar System's innermost planet may reveal something unexpected: a tail.Mercury's thin atmosphere contains small amounts of sodium that glow when excited by light from the Sun.Sunlight also liberates these atoms from Mercury's surface and pushes them away.The yellow glow from sodium, in particular, is relatively bright. Pictured, Mercury and its sodium tail are visible in a deep image taken last week from La Palma, Spainthrough a filter that primarily transmits yellow light emitted by sodium.First predicted in the 1980s, Mercury's tail was first discovered in 2001.Many tail details were revealed in multiple observations by NASA's robotic MESSENGER spacecraft that orbited Mercury between 2011 and 2015. Tails, of course, are usually associated with comets. Tomorrow's picture: planet pyramid parade <| Archive| Submissions | Index| Search| Calendar| RSS| Education| About APOD| Discuss| > Authors & editors: Robert Nemiroff(MTU) &Jerry Bonnell (UMCP)NASA Official:...

APOD: 2022 May 2 - Partial Solar Eclipse over Argentina 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. 2022 May 2 Partial Solar Eclipse over Argentina Image Credit & Copyright: Aixa Andrada Explanation: What's happened to the Sun?Two days ago, parts of South America were treated to a partial solar eclipse -- where the Moon blocked out part of the Sun. The featured image shows an image of the partially eclipsed Sun through clouds as it was setting over Patagonia, Argentina.In the tilted image, Earth is toward the right.During the eclipse, the Moon moved partly between Earth and the Sun.Although a visually impressive sight, the slight dimming of surroundings during this partial eclipse was less noticeable than dimming created by a thick cloud.In about two weeks, all of South America and part of North America will experience a total lunar eclipse -- where the Earth moves completely between the Moon and the Sun. In about two years, a total solar eclipse will cross North America. Tomorrow's picture: planet tail <| Archive| Submissions | Index| Search| Calendar| RSS| Education| About APOD| Discuss| > Authors & editors:...

APOD: 2022 May 1 - First Horizon Scale Image of a Black Hole 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. 2022 May 1 First Horizon-Scale Image of a Black Hole Image Credit: Event Horizon Telescope Collaboration Explanation: What does a black hole look like?To find out, radio telescopes from around the Earth coordinated observations of black holes with the largest known event horizons on the sky. Alone, black holes are just black, but these monster attractors are known to be surrounded by glowing gas. This first image resolves the area around the black hole at the center of galaxy M87 on a scale below that expected for its event horizon. Pictured, the dark central region is not the event horizon, but rather the black hole's shadow -- the central region of emitting gas darkened by the central black hole's gravity.The size and shape of the shadow is determined by bright gas near the event horizon, by strong gravitational lensing deflections, and by the black hole's spin. In resolving this black hole's shadow, the Event Horizon Telescope(EHT) bolstered evidence that Einstein's gravity works even in...

APOD: 2022 April 30 - M44: The Beehive Cluster 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. 2022 April 30 M44: The Beehive Cluster Image Credit &Copyright:Drew Evans Explanation: A mere 600 light-years away,M44 is one of the closeststar clusters to our solar system.Also known as thePraesepeor the Beehive cluster its starsare young though, about 600 million years old compared to our Sun's4.5 billionyears.Based on similar ages and motion through space, M44 and theeven closer Hyades star cluster in Taurusare thought to havebeen born together in the same large molecular cloud.An open clusterspanning some 15 light-years, M44 holds 1,000 stars or soand covers about 3 full moons (1.5 degrees) on thesky in the constellation Cancer.Visible to the unaided eye, M44 has been recognized since antiquity.Described as a faint cloud or celestial mist long beforebeing included as the 44th entry inCharles Messier's18th century catalog, the cluster was not resolved into its individualstars until telescopes were available.A popular target for modern, binocular-equipped sky gazers,the cluster's fewyellowish tinted, cool,red giants are scatteredthrough the field of its brighter hot blue main sequencestars in thistelescopic group snapshot.Dramaticdiffraction spikeshighlighting the brighter...

APOD: 2022 April 29 - Portrait of NGC 3628 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. 2022 April 29 Portrait of NGC 3628 Image Credit &Copyright:Wilhelm Michael Kasakow,Olaf Guillaume Explanation: Sharp telescopic views ofNGC 3628show a puffy galactic disk divided by dark dust lanes.Of course,this portraitof the magnificent, edge-on spiral galaxy puts some astronomersin mind of its popular moniker,the Hamburger Galaxy.It also reveals a small galaxy nearby (below), likely a satellite ofNGC 3628, and a very faint but extensivetidal tail.The drawn out tail stretches for about 300,000light-years, even beyond the upper left edge of the frame.NGC 3628 shares its neighborhood in thelocal universe with two other large spiralsM65 andM66 in a groupingotherwise known as the Leo Triplet.Gravitational interactions with itscosmic neighborsare likely responsible for creating the tidal tail,as well as the extended flare and warp of this spiral's disk.The tantalizingisland universeitself is about 100,000 light-years across and 35 million light-yearsaway in the northern springtime constellation Leo. Tomorrow's picture: diffraction attraction<| Archive| Submissions | Index| Search| Calendar| RSS| Education| About APOD| Discuss| > Authors & editors: Robert Nemiroff(MTU) &Jerry Bonnell (UMCP)NASA Official: Phillip NewmanSpecific rights...

APOD: 2022 April 28 - Lyrid of the Lake 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. 2022 April 28 Lyrid of the Lake Image Credit &Copyright:Jeff Dai(TWAN) Explanation: In the early hours of April 24 this brightLyrid meteorflashed along the central Milky Way.For a moment, it cast a bright reflection acrossLake Nian, Yunnan province, China.Theannual Lyrid meteor shower,one of the oldest known,is active in late April, as our fair planet plowsthrough dust left along the orbit of long-period comet Thatcher.The trail of the brightfireball points back towardthe shower's radiant in theconstellation Lyra high in the northern springtime sky and off the topof the frame.Just rising in that starry sky, light from a third quarter moonalso cast a glow on the peaceful waters of the lake. Tomorrow's picture: a springtime appetizer<| 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: 2022 April 27 - Moon Shadow on Jupiter 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. 2022 April 27 Moon Shadow on Jupiter Image Credit: NASA/JPL-Caltech/SwRI/MSSS; Processing & License: Thomas Thomopoulos Explanation: What is that large dark spot on Jupiter?It's the shadow of Ganymede, Jupiter's largest moon.When Jupiter's moons cross between the Jovian giant and the Sun, they created shadows just like when the Earth's moon crosses between the Earth and the Sun.Also like on Earth, if you were in a dark shadow on Jupiter, you would see a moon completely eclipse the Sun.Unlike on Earth, moon shadows occur most days on Jupiter -- what's more unusual is that a spacecraft was close enough to record one with ahigh-resolution image. That spacecraft, Juno, was passing so close to Jupiter in late February that nearby clouds and the dark eclipse shadow appear relatively large.Juno has made many discoveries about our Solar System's largest planet, including, recently, rapidly expanding circular auroras. Explore Your Universe: Random APOD Generator Tomorrow's picture: open space <| Archive| Submissions | Index| Search| Calendar| RSS| Education| About APOD| Discuss| > Authors &...

APOD: 2022 April 26 - Planet Parade over Sydney Opera House 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. 2022 April 26 Planet Parade over Sydney Opera House Image Credit & Copyright: Prasun Agrawal Explanation: The world is waking up to a picturesque planet parade.Just before dawn, the eastern skies over much of planet Earth are decorated by a notable line of familiar planets.In much of Earth's northern hemisphere, this line of planets appears most nearly horizontal, but in much of Earth's southern hemisphere, the line appears more nearly vertical.Pictured over the Sydney Opera House in southern Australia, the planet line was captured nearly vertical about five days ago. From top to bottom, the morning planets are Saturn, Mars, Venus, and Jupiter. As April ends, the angular distance between Venus and Jupiter will gradually pass below a degree as they switch places. Then, as May ends, Jupiter will pass near Mars as those two planets switch places. In June, the parade will briefly expand to include Mercury. Notable Submissions to APOD: Morning Planet Parade 2022 Tomorrow's picture: Jupiter eclipse <| Archive| Submissions | Index| Search|...

APOD: 2022 April 25 - The Great Nebula in Carina 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. 2022 April 25 The Great Nebula in Carina Image Credit & Copyright: Ignacio Javier Diaz Bobillo Explanation: In one of the brightest parts ofMilky Way lies a nebula where some of the oddest things occur.NGC 3372, known as theGreat Nebula in Carina,is home to massive stars and changing nebulas.The Keyhole Nebula (NGC 3324), the bright structure just below the image center, houses several of these massive stars.The entire Carina Nebula, captured here, spans over 300 light years and lies about 7,500 light-years away in the constellation of Carina. Eta Carinae, the most energetic star in the nebula,was one of the brightest stars in the sky in the 1830s, but then faded dramatically.While Eta Carinae itself maybe on the verge of a supernova explosion,X-ray images indicate that much of the Great Nebula in Carina has been a veritablesupernovafactory. Tomorrow's picture: opera of the planets <| Archive| Submissions | Index| Search| Calendar| RSS| Education| About APOD| Discuss| > Authors & editors: Robert Nemiroff(MTU) &Jerry Bonnell (UMCP)NASA Official: Phillip NewmanSpecific...

APOD: 2022 April 24 - Split the Universe 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. 2022 April 24 Split the Universe Image Credit: NASA, Erwin Schrödinger's cat Explanation: Just now, before you hit the button, two future universes are possible. After pressing the button, though, you will live in only one. A real-web version of the famous Schrödinger's cat experimentclicking the red button in the featured astronaut image should transform that image into a picture of the same astronaut holding one of two cats -- one living, or one dead. The timing of your click, combined with the wiring of your brain and the millisecond timing of your device, will all conspire together to create a result dominated, potentially, by the randomness of quantum mechanics. Some believe that your personally-initiated quantum decision will split the universe in two, and that both the live-cat and dead-cat universes exist in separate parts of a larger multiverse.Others believe that the result of your click will collapse the two possible universes into one -- in a way that could not have been predicted beforehand. Yet others believe that...

APOD: 2022 April 23 - Messier 104 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. 2022 April 23 Messier 104 Image Credit: NASA, ESA, Hubble Legacy Archive; Processing & Copyright: Ignacio Diaz Bobillo Explanation: A gorgeous spiral galaxy,Messier 104 is famousfor its nearly edge-onprofile featuring a broad ring of obscuring dust lanes.Seen in silhouette against an extensive central bulge of stars,the swath of cosmic dust lends abroad brimmed hat-like appearance to the galaxy suggestinga more popular moniker, the Sombrero Galaxy.This sharp viewof the well-known galaxy was madefrom over 10 hours ofHubble Space Telescopeimage data, processed tobring out faint details often lost in the overwhelming glare of M104'sbright central bulge.Also known as NGC 4594, the Sombrero galaxy can be seenacross the spectrum, andis host to a centralsupermassive black hole.About 50,000 light-years across and 28 million light-years away,M104 is one of thelargest galaxies at the southern edge of theVirgo Galaxy Cluster.Still, the spiky foreground stars in this field of viewlie well within our own Milky Way. Tomorrow's picture: just press the button<| Archive| Submissions | Index| Search| Calendar| RSS| Education| About APOD| Discuss| > Authors & editors:...

APOD: 2022 April 22 - Planet Earth at Twilight 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. 2022 April 22 Planet Earth at Twilight Image Credit: ISS Expedition 2 Crew,Gateway to Astronaut Photography of Earth,NASA Explanation: No sudden, sharp boundary marks the passage of day into night inthis gorgeous viewof ocean and clouds overour fair planet Earth.Instead, the shadow line or terminator is diffuse and showsthe gradual transition to darkness we experience as twilight.With the Sun illuminating the scene from the right,the cloud tops reflect gently reddenedsunlight filteredthrough the dusty troposphere,the lowest layer of the planet's nurturing atmosphere.A clear high altitude layer,visible along the dayside's upper edge,scatters bluesunlight and fades into the blackness of space.This picture was taken in June of 2001 from the InternationalSpace Station orbiting at an altitude of 211 nautical miles.Of course from home,you can check out the Earth Now. Celebrate: Today is Earth Day Tomorrow's picture: Messier 104<| 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: 2022 April 21 - Apollo 16 Moon Panorama 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. 2022 April 21 Apollo 16 Moon Panorama Image Credit: Apollo 16,NASA; Panorama Assembly: Mike Constantine Explanation: Fifty years ago, April 20, 1972,Apollo 16'slunar module Orion toucheddown on the Moon's near side in the south-central Descartes Highlands.While astronautKen Mattinglyorbited overhead in Casper thefriendly command and service modulethe Orion broughtJohn Young and Charles Duketo the lunar surface.The pair would spend nearlythree days on the Moon.Constructed from images(AS16-117-18814 to AS16-117-18820)taken near the end of their third and final surface excursion this panoramic view puts the lunar module in thedistance toward the left.Theirelectric lunar rovingvehicle in the foreground, Duke is operating thecamera while Young aims the high gain communications antenna skyward,toward planet Earth. Celebrate: Earth Day Tomorrow's picture: our fair planet <| 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: 2022 April 20 - Planet Line over New York Bridge 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. 2022 April 20 Planet Line over New York Bridge Image Credit &Copyright: Stan Honda Explanation: There's an interesting sky to see if you wake up before the Sun.Lined up on toward the eastern horizon are four planets in a row.The planets are so bright they can even be seen from the bright sky inside a city.In fact, the featured image was taken from New York City, USA, with the foreground highlighted by the RFK (Triborough) Bridge.Pictured, the planets are, left to right, Jupiter, Venus, Mars, and Saturn. The planets all appear in a row because they all orbit the Sun in the same plane.This plane, called the ecliptic plane, was created in the early days of our Solar System and includes all planets, including Earth. The morning planet parade will continue throughout April and May, and will even be joined by Mercury in June. APOD volunteer programming opportunity: Discord Tomorrow's picture: open space <| Archive| Submissions | Index| Search| Calendar| RSS| Education| About APOD| Discuss| >...

APOD: 2022 April 19 - Stars and Globules in the Running Chicken 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. 2022 April 19 Stars and Globules in the Running Chicken Nebula Image Credit & Copyright: Stefan Steve Bemmerl Explanation: The eggs from this gigantic chicken may form into stars. The featured emission nebula, shown in scientifically assigned colors, is cataloged as IC 2944 but known as the Running Chicken Nebula for the shape of its greater appearance. Seen toward the bottom of the image are small, dark molecular clouds rich in obscuring cosmic dust.Called Thackeray's Globules for their discoverer, these "eggs" are potential sites for the gravitational condensation of new stars, although their fates are uncertain as they are also being rapidly eroded away by the intense radiation from nearby young stars.Together with patchy glowing gas and complex regions of reflecting dust, these massive and energetic stars form the open cluster Collinder 249.This gorgeous skyscape spans about 60 light-yearsat the nebula's estimated 6,500 light-year distance. Tomorrow's picture: planetary bridge <| Archive| Submissions | Index| Search| Calendar| RSS| Education| About APOD| Discuss| > Authors &...

APOD: 2022 April 18 - Stars and Planets over Portugal 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. 2022 April 18 Stars and Planets over Portugal Image Credit & Copyright: Miguel Claro(TWAN, Dark Sky Alqueva) Explanation: The mission was to document night-flying birds -- but it ended up also documenting a beautiful sky.The featured wide-angle mosaic was taken over the steppe golden fields in Mértola, Portugal in 2020.From such a dark location, an immediately-evident breathtaking glow arched over the night sky: the central band of our Milky Way galaxy. But this sky had much more.Thin clouds crossed the sky like golden ribbons.The planet Mars appeared on the far left, while the planets Saturn and Jupiter were also simultaneously visible -- but on the opposite side of the sky, here seen on the far right. Near the top of the image the bright star Vega can be found, while the far-distant and faint Andromeda Galaxy can be seen toward the left, just below Milky Way's arch. As the current month progresses, several planets are lining up in the pre-dawn sky: Jupiter, Venus, Mars, and Saturn. Did...

APOD: 2022 April 17 - Shuttle Over Earth 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. 2022 April 17 Shuttle Over Earth Image Credit: NASA, Expedition 22 Crew Explanation: What's that approaching?Astronauts on board theInternational Space Station in 2010 first saw it far in the distance. Soon it enlarged to become adark silhouette.As it came even closer, thesilhouette appeared to be a spaceship.Finally, the object revealed itself to be theSpace Shuttle Endeavour, and it soon docked as expected with theEarth-orbiting space station. Pictured here, Endeavour was imaged near Earth's horizon as it approached, where several layers of theEarth's atmosphere were visible.Directly behind the shuttle is themesosphere, which appears blue. The atmospheric layer that appears white is thestratosphere,while the orange layer is Earth'sTroposphere.Together, these thin layers of air -- collectively spanning less than 2 percent of Earth's radius -- sustain us all in many ways, including providing oxygen to breath and a barrier to dangerous radiations from space. Coming up Friday: Earth Day 2022 Tomorrow's picture: steppe sky <| Archive| Submissions | Index| Search| Calendar| RSS| Education| About APOD| Discuss| > Authors & editors: Robert Nemiroff(MTU)...

APOD: 2022 April 16 - Orion Pines 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. 2022 April 16 Orion Pines Image Credit &Copyright: Juan Carlos Casado(Starry Earth,TWAN) Explanation: Taken with a camera fixed to a tripod, many short exposureswere aligned with the stars to unveil this beautiful, dark night sky.Captured nearthe rural village of Albany`aat the northeastern corner of Spain, the threestars of Orion's belt stretch across top center in the starry frame.Alnitak, the easternmost (left) of thebelt stars is seen next to the more diffuse glow of theFlame Nebulaand the dark notch of the famous Horsehead.Easily visible to the naked-eyeThe Great Nebula of Orionis below the belt stars.A mere 1,500 light-years distant, it is the closest largestellar nursery to our fair planet.Best seen in photographs, the broad and faint arc ofBarnard's Loop seems toembrace Orion's brighterstars and nebulae though.In the northern spring the familiarnorthern winter constellationis setting.Near the western horizon toward lower right Orion'sapparently brightblue supergiant Rigel just touches the branches of a pine tree. Tomorrow's picture: Endeavour in Orbit <| Archive| Submissions | Index| Search| Calendar| RSS| Education| About APOD| Discuss| > Authors...

APOD: 2022 April 15 - The Gator-Back Rocks of 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. 2022 April 15 The Gator-Back Rocks of Mars Image Credit: NASA,JPL-Caltech,MSSS Explanation: Wind-sharpened rocksknown as ventifactscover this broad sloping plain in the foot hillsof Mount Sharp, Gale crater, Mars.Dubbed gator-back rocks their rugged, scaly appearance iscaptured in these digitally stitched Mastcam framesfrom the Curiosity rover on mission sol 3,415 (March 15, 2022).Driving over gator-back rocks before hasresulted in damage tothe rover's wheels, so Curiosity team members decided toturn around andtake another pathto continue the rover's climb.Curiosity has been on an ascent of Gale crater's central 5.5 kilometerhigh mountain since 2014.As it climbs, the durable rover has been able to explore layers shaped bywater on Mars billions of years ago. Tomorrow's picture: the pines of Orion <| 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: 2022 April 14 - Messier 96 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. 2022 April 14 Messier 96 Image Credit &Copyright:Mark HansonandMike Selby Explanation: Spiral arms seem to swirl around the core ofMessier 96 inthiscolorful, detailed portraitof a beautiful island universe.Of course M96 is a spiral galaxy,and counting the faint arms extendingbeyond the brighter central region it spans 100 thousandlight-years or so.That's about the size of our own Milky Way.M96 is known to be 38 million light-years distant, a dominantmember of theLeo I galaxy group.Background galaxies and smaller Leo I group memberscan be found by examining the picture.The most intriguing one is itself a spiral galaxy seennearly edge onbehind the outer spiral arm near the 1 o'clock position fromcenter.Its bright central bulge cut by its own dark dust clouds,the edge-on background spiral appears to be about 1/5 the size of M96.If that background galaxy is similar in actual size to M96, then itwould be about 5 timesfartheraway. Tomorrow's picture: the red planet rocks <| Archive| Submissions | Index| Search| Calendar| RSS| Education| About APOD| Discuss| > Authors & editors: Robert Nemiroff(MTU) &Jerry Bonnell...