Astronomy Picture of the Day 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. 2023 January 1 The Largest Rock in our Solar System Image Credit: NASA, Voyager 1 spacecraft Explanation: There, that dot on the right, that's the largest rock known in our Solar System.It is larger than every known asteroid, moon, and comet nucleus. It is larger than any other local rocky planet. This rock is so large its gravity makes it into a large ball that holds heavy gases near its surface. (It used to be the largest known rock of any type until the recent discoveries of large dense planets orbiting other stars.) The Voyager 1 spacecraft took the featured picture -- famously called Pale Blue Dot --of this giant space rock in 1990 from the outer Solar System. Today, this rock starts another orbit around its parent star, for roughly the 5 billionth time, spinning over 350 times during each trip. Happy Gregorian Calendar New Year to all inhabitants of this rock we call Earth. Tomorrow's picture: planets align <| Archive| Submissions | Index| Search| Calendar| RSS| Education| About APOD| Discuss|...

APOD: 2022 December 30 - Mars and the Star Clusters 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 December 30 Mars and the Star Clusters Image Credit &Copyright:Gabor Balazs Explanation: At this year'sendMars stillshines brightly inplanet Earth's nightas it wanders through the head-strong constellation Taurus.Its bright yellowish hue dominates thisstarry field of viewthat includes Taurus' alpha star Aldebaran and theHyades and Pleiades star clusters.Whilered giant Aldebaranappears to anchor theV-shape of the Hyadesat the left of the frame, Aldebaran is not a member of the Hyades starcluster.The Hyades cluster is 151 light-years away making it the nearestestablished open star cluster, but Aldebaran lies at less than halfthat distance, along the same line-of-sight. At the right, some 400 light-years distant is the open star clustercataloged as Messier 45,also known as the Pleiades or Seven Sisters.In Greek myth, the Pleiades weredaughters of theastronomicaltitan Atlas and sea-nymphPleione. Tomorrow's picture: so nice, they named it twice <| 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...

Astronomy Picture of the Day 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 December 31 Moon over Makemake Illustration Credit: Alex H. Parker(Southwest Research Institute) Explanation: Makemake(sounds like MAH-kay MAH-kay),second brightest dwarf planet of theKuiperbelt,has a moon.Nicknamed MK2, Makemake's moon reflects sunlight witha charcoal-dark surface, about 1,300 times fainter than its parent body.Still, in 2016 it was spotted inHubble Space Telescope observationsintended to search for faint companions with the sametechnique used to find the smallsatellites of Pluto.Just as for Pluto and its satellites, further observations ofMakemake and orbiting moonwill measure the system's mass and densityand allow a broader understanding of the distant worlds.About 160 kilometers (100 miles) across compared toMakemake's 1,400 kilometer diameter,MK2's relative size and contrast are shown in this artist's vision.An imagined scene of an unexplored frontier of the Solar System,it looks back from a spacecraft'svantage as the dim Sun shines alongthe Milky Way.Of course, the Sun is over 50 times farther from Makemake thanit is from planet Earth. Tomorrow's picture: planet Earth <| Archive| Submissions | Index| Search| Calendar| RSS| Education| About APOD| Discuss| > Authors & editors: Robert Nemiroff(MTU) &Jerry...

APOD: 2022 December 26 - NGC 6164: Dragon's Egg Nebula and Halo 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 December 26 NGC 6164: Dragon's Egg Nebula and Halo Image Credit & Copyright: Russell Croman Explanation: The star at the center created everything. Known as the Dragon's Egg, this star -- a rare, hot, luminousO-typestar some 40 times as massive as the Sun -- created not only the complex nebula (NGC 6164) that immediately surrounds it, but also the encompassing blue halo.Its name is derived, in part, from the region's proximity to the picturesque NGC 6188, known as the fighting Dragons of Ara.In another three to four million years the massive star will likely end itslife in a supernova explosion.Spanning around 4 light-years,the nebula itselfhas a bipolar symmetry making it similar in appearance to more common planetarynebulae - the gaseous shroudssurrounding dying sun-like stars.Also like many planetary nebulae, NGC 6164 has been found to havean extensive, faint halo, revealed in blue in this deep telescopic image of the region.Expanding into the surroundinginterstellar medium,the material in the blue halo was likely expelled from an earlier...

APOD: 2022 December 29 - Horsehead and Flame 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 December 29 Horsehead and Flame Image Credit &Copyright:Jason Close Explanation: The Horsehead Nebula,famous celestialdark marking also known as Barnard 33,is notched against a background glow of emission nebulae inthis sharp cosmic skyscape.About five light-years "tall" the Horsehead lies some 1,500 light-years away in the constellation of Orion.Within the region's fertile molecular cloud complex,the expanse of obscuring dust has a recognizable shape onlyby chance fromour perspectivein theMilky Waythough.Orion's easternmost belt star, bright Alnitak,is to the left of center. Energetic ultraviolet light fromAlnitak powers the glow ofdusty NGC 2024, the Flame Nebula, just below it.Completing a study in cosmic contrasts, bluish reflectionnebula NGC 2023 is below the Horsehead itself.This well-framed telescopic field spans about 3 full moons onthe sky. Tomorrow's picture: Mars and the stars <| 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,NASA Science Activation& Michigan Tech. U.

Astronomy Picture of the Day 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 December 30 Mars and the Star Clusters Image Credit &Copyright:Gabor Balazs Explanation: At this year'sendMars stillshines brightly inplanet Earth's nightas it wanders through the head-strong constellation Taurus.Its bright yellowish hue dominates thisstarry field of viewthat includes Taurus' alpha star Aldebaran and theHyades and Pleiades star clusters.Whilered giant Aldebaranappears to anchor theV-shape of the Hyadesat the left of the frame, Aldebaran is not a member of the Hyades starcluster.The Hyades cluster is 151 light-years away making it the nearestestablished open star cluster, but Aldebaran lies at less than halfthat distance, along the same line-of-sight. At the right, some 400 light-years distant is the open star clustercataloged as Messier 45,also known as the Pleiades or Seven Sisters.In Greek myth, the Pleiades weredaughters of theastronomicaltitan Atlas and sea-nymphPleione. Tomorrow's picture: so nice, they named it twice <| 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,NASA Science Activation& Michigan...

Astronomy Picture of the Day 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 December 29 Horsehead and Flame Image Credit &Copyright:Jason Close Explanation: The Horsehead Nebula,famous celestialdark marking also known as Barnard 33,is notched against a background glow of emission nebulae inthis sharp cosmic skyscape.About five light-years "tall" the Horsehead lies some 1,500 light-years away in the constellation of Orion.Within the region's fertile molecular cloud complex,the expanse of obscuring dust has a recognizable shape onlyby chance fromour perspectivein theMilky Waythough.Orion's easternmost belt star, bright Alnitak,is to the left of center. Energetic ultraviolet light fromAlnitak powers the glow ofdusty NGC 2024, the Flame Nebula, just below it.Completing a study in cosmic contrasts, bluish reflectionnebula NGC 2023 is below the Horsehead itself.This well-framed telescopic field spans about 3 full moons onthe sky. 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 of:ASD atNASA /GSFC,NASA Science Activation& Michigan Tech. U.

APOD: 2022 December 28 - Messier 88 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 December 28 Messier 88 Image Credit &Copyright:Adam Block,Mt. Lemmon SkyCenter,U. Arizona Explanation: Charles Messierdescribed the 88th entry in his 18th century catalog ofNebulae and Star Clustersas a nebula without stars.Of course thegorgeous M88is now understood tobe a spiral galaxy full of stars, gas, and dust, not unlikeour own Milky Way.In fact, M88 is one of the brightest galaxies in theVirgo Galaxy Clustersome 50 million light-yearsaway.M88's beautiful spiral arms are easy to trace in thissharp cosmic portait. The arms are lined with young bluestar clusters, pinkstar-forming regions,and obscuring dust lanesextending from a yellowishcore dominated by an older population of stars.Spiral galaxy M88 spans over 100,000 light-years. Tomorrow's picture: Barnard 33 <| 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,NASA Science Activation& Michigan Tech. U.

APOD: 2022 December 27 - A Full Circle Rainbow over Norway 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 December 27 A Full Circle Rainbow over Norway Image Credit & Copyright: Lukas Moesch Explanation: Have you ever seen an entire rainbow?From the ground, typically, only the top portion of a rainbow is visible because directions toward the ground have fewer raindrops.From the air, though, the entire 360-degree circle of a rainbow is more commonly visible.Pictured here, a full-circle rainbow was captured over the Lofoten Islands of Norway in September by a drone passing through a rain shower.An observer-dependent phenomenon primarily caused by the internal reflection of sunlight by raindrops, the rainbow has a full diameter of 84 degrees.The Sun is in the exact opposite direction from the rainbow's center. As a bonus, a second rainbow that was more faint and color-reversed was visible outside the first. Tomorrow's picture: open 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 of:ASD atNASA...

Astronomy Picture of the Day 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 December 28 Messier 88 Image Credit &Copyright:Adam Block,Mt. Lemmon SkyCenter,U. Arizona Explanation: Charles Messierdescribed the 88th entry in his 18th century catalog ofNebulae and Star Clustersas a spiral nebula without stars.Of course thegorgeous M88is now understood tobe a galaxy full of stars, gas, and dust, not unlikeour own Milky Way.In fact, M88 is one of the brightest galaxies in theVirgo Galaxy Clustersome 50 million light-yearsaway.M88's beautiful spiral arms are easy to trace in thissharp cosmic portait. The arms are lined with young bluestar clusters, pinkstar-forming regions,and obscuring dust lanesextending from a yellowishcore dominated by an older population of stars.Spiral galaxy M88 spans over 100,000 light-years. 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 of:ASD atNASA /GSFC,NASA Science Activation& Michigan Tech. U.

APOD: 2022 December 26 - NGC 6164: Dragons Egg Nebula and Halo 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 December 26 NGC 6164: Dragon's Egg Nebula and Halo Image Credit & Copyright: Russell Croman Explanation: The star at the center created everything. Known as the Dragon's Egg, this star -- a rare, hot, luminousO-typestar some 40 times as massive as the Sun -- created not only the complex nebula (NGC 6164) that immediately surrounds it, but also the encompassing blue halo.Its name is derived, in part, from the region's proximity to the picturesque NGC 6188, known as the fighting Dragons of Ara.In another three to four million years the massive star will likely end itslife in a supernova explosion.Spanning around 4 light-years,the nebula itselfhas a bipolar symmetry making it similar in appearance to more common planetarynebulae - the gaseous shroudssurrounding dying sun-like stars.Also like many planetary nebulae, NGC 6164 has been found to havean extensive, faint halo, revealed in blue in this deep telescopic image of the region.Expanding into the surroundinginterstellar medium,the material in the blue halo was likely expelled from an earlier...

Astronomy Picture of the Day 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 December 27 A Full Circle Rainbow over Norway Image Credit & Copyright: Lukas Moesch Explanation: Have you ever seen an entire rainbow?From the ground, typically, only the top portion of a rainbow is visible because directions toward the ground have fewer raindrops.From the air, though, the entire 360-degree circle of a rainbow is more commonly visible.Pictured here, a full-circle rainbow was captured over the Lofoten Islands of Norway in September by a drone passing through a rain shower.An observer-dependent phenomenon primarily caused by the internal reflection of sunlight by raindrops, the rainbow has a full diameter of 84 degrees.The Sun is in the exact opposite direction from the rainbow's center. As a bonus, a second rainbow that was more faint and color-reversed was visible outside the first. Tomorrow's picture: open 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 of:ASD atNASA /GSFC,NASA Science Activation& Michigan Tech. U.

APOD: 2022 December 25 - Geminids and the Mittens 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 December 25 Geminids and the Mittens Image Credit &Copyright:Chuck Derus Explanation: Asteroid 3200 Phaethon'sannualgift to planet Earthalways arrivesin December.Otherwise known asthe Geminid meteor shower,the source of the meteroid stream isdust shed along the orbit of themysterious asteroid.Near the December 13/14 peak of the shower's activity,geminid meteors are captured in this night skyscape,composited from 22 images of starry skytaken before the moon rose overMonument Valleyin the American southwest.The bright stars near the position of the shower's radiantare the constellation Gemini's twin starsCastor (blue) and Pollux (yellow).As Earth sweeps through the dusty stream,the parallel meteor trails appear to radiate from a pointon the sky in Gemini due to perspective,and so the yearly shower is named for the constellation.From the camera's perspective, this view of three prominentbuttes across Monument Valley also suggests appropriate names fortwo of them.The third one is calledMerrick Butte. Tomorrow's picture: the dragon's egg <| Archive| Submissions | Index| Search| Calendar| RSS| Education| About APOD| Discuss| > Authors & editors: Robert Nemiroff(MTU) &Jerry Bonnell (UMCP)NASA Official: Phillip...

Astronomy Picture of the Day 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 December 26 NGC 6164: Dragon's Egg Nebula and Halo Image Credit & Copyright: Russell Croman Explanation: The star at the center created everything. Known as the Dragon's Egg, this star -- a rare, hot, luminousO-typestar some 40 times as massive as the Sun -- created not only the complex nebula (NGC 6164) that immediately surrounds it, but also the encompassing blue halo.Its name is derived, in part, from the region's proximity to the picturesque NGC 6188, known as the fighting Dragons of Ara.In another three to four million years the massive star will likely end itslife in a supernova explosion.Spanning around 4 light-years,the nebula itselfhas a bipolar symmetry making it similar in appearance to more common planetarynebulae - the gaseous shroudssurrounding dying sun-like stars.Also like many planetary nebulae, NGC 6164 has been found to havean extensive, faint halo, revealed in blue in this deep telescopic image of the region.Expanding into the surroundinginterstellar medium,the material in the blue halo was likely expelled from an earlier active phase of the O-star.NGC 6164 lies...

APOD: 2022 December 24 - Comet 2022 E3 ZTF 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 December 24 Comet 2022 E3 (ZTF) Image Credit &Copyright:Dan Bartlett Explanation: Comet C/2022 E3 (ZTF)was discovered by astronomers using the wide-field survey camera at theZwicky Transient Facility this year in early March.Since then the newlong-period comethas brightened substantially and is nowsweeping across the northernconstellation Corona Borealis in predawn skies.It's still too dim to see without a telescope though.But this fine telescopic imagefrom December 19 does showthe comet'sbrighter greenish coma, short broad dust tail, and long faint ion tailstretching across a 2.5 degree wide field-of-view.On a voyage throughthe inner Solar System comet 2022 E3 will beat perihelion,its closest to the Sun, in the new year on January 12 and atperigee, its closest to our fair planet, on February 1.The brightness of comets isnotoriouslyunpredictable, but by then C/2022 E3 (ZTF)could become only just visible to the eye in dark night skies. Tomorrow's picture: stars and mittens <| Archive| Submissions | Index| Search| Calendar| RSS| Education| About APOD| Discuss| > Authors & editors: Robert Nemiroff(MTU) &Jerry Bonnell (UMCP)NASA Official: Phillip...