Astronomy Picture of the Day

🌌The Belt of Venus over Mount Everest You've surely seen it, but you might not have noticed it. During a cloudless twilight, just before sunrise or after sunset, part of the atmosphere above the horizon appears slightly dark and off-color. Called the Belt of Venus, this transitional band between the dark eclipsed sky and the bright day sky can be seen most prominently in the direction opposite t ...

🌌Lightning on Jupiter Does lightning occur only on Earth? No. Spacecraft in our Solar System have detected lightning on other planets, including Mars, Jupiter and Saturn, and lightning is likely on Venus, Uranus, and Neptune. Lightning is a sudden rush of electrically charged particles from one location to another. On Earth, drafts of colliding ice and water droplets usually create lightning-gen ...

🌌3D Ingenuity The multicolor, stereo imaging Mastcam-Z on the Perseverance rover zoomed in to capture this 3D close-up (get out your red/blue glasses) of the Mars Ingenuity helicopter on mission sol 45. That's Earth-date 2021 April 5. Casting a shadow on the Martian surface, Ingenuity is standing alone on its four landing legs next to the rover's wheel tracks. The experimental helicopter's solar ...

© Mike Selby

🌌Giant Galaxies in Pavo Over 500,000 light years across, NGC 6872 (top right) is a truly enormous barred spiral galaxy, at least 5 times the size of our own very large Milky Way. The appearance of this giant galaxy's distorted and stretched out spiral arms suggests the magnificent wings of a giant bird. Of course its popular moniker is the Condor galaxy. It lies about 200 million light-years dis ...

© Alessandro Cipolat Bares

🌌Stars and Dust across Corona Australis Cosmic dust clouds cross a rich field of stars in this telescopic vista near the northern boundary of Corona Australis, the Southern Crown. Part of a sprawling molecular cloud complex this star forming region is a mere 500 light-years away. That's about one third the distance of the more famous stellar nursery known as the Orion Nebula. The 2 degree wide f ...

© Marcella Giulia Pace & Giuseppe De Donà

🌌Three Sun Paths Does the Sun follow the same path every day? No. The Sun's path changes during the year, tracing a longer route during the summer than the winter. Pictured here, the Sun's arc was captured from noon to sunset on three days, from highest in the sky to lowest: summer solstice, equinox, and winter solstice. The images were taken near Gatto Corvino Village in Sicily, Italy in 2020 a ...

© Fefo Bouvier; Line Drawing: Alfonso Rosso

🌌The Ñandú in the Milky Way Have you seen the bird in the Milky Way? Beyond the man in the Moon, the night sky is filled with stories, and cultures throughout history have projected some of their most enduring legends onto the stars and dust above. Generations of people see these celestial icons, hear their associated stories, and pass them down. Pictured here is not only a segment of the centra ...

🌌The Busy Center of the Lagoon Nebula The center of the Lagoon Nebula is a whirlwind of spectacular star formation. Visible near the image center, at least two long funnel-shaped clouds, each roughly half a light-year long, have been formed by extreme stellar winds and intense energetic starlight. A tremendously bright nearby star, Herschel 36, lights the area. Vast walls of dust hide and redden ...

© NASA, ESA, JPL, SSI, Cassini Imaging Team

🌌Saturn's Northern Hexagon Why would clouds form a hexagon on Saturn? Nobody is sure. 🔗 https://apod.nasa.gov/apod/ap230618.html

🌌Planet Earth at Night II Recorded during 2017, timelapse sequences from the International Space Station are compiled in this serene video of planet Earth at Night. Fans of low Earth orbit can start by enjoying the view as green and red aurora borealis slather up the sky. The night scene tracks from northwest to southeast across North America, toward the Gulf of Mexico and the Florida coast. A s ...

© Bernd Pröschold

🌌Sunset to Sunrise over the Baltic Sea This serene view from the coast of Sweden looks across the Baltic sea and compresses time, presenting the passage of one night in a single photograph. From sunset to sunrise, moonlight illuminates the creative sea and skyscape. Fleeting clouds, fixed stars, and flowing northern lights leave their traces in planet Earth's sky. To construct the timelapse imag ...

🌌M15: Dense Globular Star Cluster Messier 15 is an immense swarm of over 100,000 stars. A 13 billion year old relic of the early formative years of our galaxy it's one of about 170 globular star clusters that still roam the halo of the Milky Way. Centered in this sharp reprocessed Hubble image, M15 lies some 35,000 light-years away toward the constellation Pegasus. Its diameter is about 200 ligh ...

© Stephen Kennedy

🌌The Shark Nebula There is no sea on Earth large enough to contain the Shark nebula. This predator apparition poses us no danger as it is composed only of interstellar gas and dust. Dark dust like that featured here is somewhat like cigarette smoke and created in the cool atmospheres of giant stars. After being expelled with gas and gravitationally recondensing, massive stars may carve intricate ...

🌌Moons Across Jupiter Jupiter's moons circle Jupiter. The featured video depicts Europa and Io, two of Jupiter's largest moons, crossing in front of the grand planet's Great Red Spot, the largest known storm system in our Solar System. The video was composed from images taken by the robotic Cassini spacecraft as it passed Jupiter in 2000, on its way to Saturn. The two moons visible are volcanic ...

🌌The Largest Satellites of Earth What’s that near the Moon? It’s the International Space Station (ISS). Although the ISS may appear to be physically near the Moon, it is not — it is physically near the Earth. In low Earth orbit and circulating around our big blue marble about every 90 minutes, the ISS was captured photographically as it crossed nearly in front of the Moon. The Moon, itself in a ...

🌌The Sun and Its Missing 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 g ...

🌌Mars and the Beehive This month, bright Mars and brilliant Venus are the prominent celestial beacons in planet Earth's western skies after sunset. Wandering through the constellation Cancer the Crab, the Red Planet was captured here on the evening of June 3 near the stars of open cluster Messier 44. Recognized since antiquity this nearby, naked-eye star cluster is also known as the Praesepe or ...

🌌Pandora's Cluster of Galaxies This deep field mosaicked image presents a stunning view of galaxy cluster Abell 2744 from the James Webb Space Telescope's NIRCam. Also dubbed Pandora's Cluster, Abell 2744 itself appears to be a ponderous merger of three different massive galaxy clusters some 3.5 billion light-years away toward the constellation Sculptor. Dominated by dark matter, the mega-cluste ...

🌌Elephant's Trunk and Caravan Like an illustration in a galactic Just So Story, the Elephant's Trunk Nebula winds through the emission region and young star cluster complex IC 1396, in the high and far off constellation of Cepheus. Seen on the left the cosmic elephant's trunk, also known as vdB 142, is over 20 light-years long. This detailed telescopic view features the bright swept-back ridges ...

🌌M94: A Double Ring Galaxy Most galaxies don't have any rings of stars and gas -- why does M94 have two? First, spiral galaxy M94 has an inner ring of newly formed stars surrounding its nucleus, giving it not only an unusual appearance but also a strong interior glow. A leading origin hypothesis holds that an elongated knot of stars known as a bar rotates in M94 and has generated a burst of star ...

🌌Star Eats Planet It’s the end of a world as we know it. Specifically, the Sun-like star ZTF SLRN-2020 was seen eating one of its own planets. Although many a planet eventually dies by spiraling into their central star, the 2020 event, involving a Jupiter-like planet, was the first time it was seen directly. The star ZTF SLRN-2020 lies about 12,000 light years from the Sun toward the constellati ...

🌌In the Center of the Trifid Nebula What's happening at the center of the Trifid Nebula? Three prominent dust lanes that give the Trifid its name all come together. Mountains of opaque dust appear near the bottom, while other dark filaments of dust are visible threaded throughout the nebula. A single massive star visible near the center causes much of the Trifid's glow. The Trifid, cataloged as ...

🌌Color the Universe Wouldn't it be fun to color in the universe? If you think so, please accept this famous astronomical illustration as a preliminary substitute. You, your friends, your parents or children, can print it out or even color it digitally. While coloring, you might be interested to know that even though this illustration has appeared in numerous places over the past 100 years, the a ...

🌌Charon: Moon of Pluto A darkened and mysterious north polar region known to some as Mordor Macula caps this premier high-resolution view. The portrait of Charon, Pluto's largest moon, was captured by New Horizons near the spacecraft's closest approach on July 14, 2015. The combined blue, red, and infrared data was processed to enhance colors and follow variations in Charon's surface properties ...

🌌Messier 101 Big, beautiful spiral galaxy M101 is one of the last entries in Charles Messier's famous catalog, but definitely not one of the least. About 170,000 light-years across, this galaxy is enormous, almost twice the size of our own Milky Way. M101 was also one of the original spiral nebulae observed by Lord Rosse's large 19th century telescope, the Leviathan of Parsontown. Assembled from ...

🌌Simulation: A Disk Galaxy Forms How did we get here? We know that we live on a planet orbiting a star orbiting a galaxy, but how did all of this form? Since our universe moves too slowly to watch, faster-moving computer simulations are created to help find out. Specifically, this featured video from the IllustrisTNG collaboration tracks gas from the early universe (redshift 12) until today (red ...

© Patrick A. Cosgrove

🌌M27: The Dumbbell Nebula Is this what will become of our Sun? Quite possibly. The first hint of our Sun's future was discovered inadvertently in 1764. At that time, Charles Messier was compiling a list of diffuse objects not to be confused with comets. The 27th object on Messier's list, now known as M27 or the Dumbbell Nebula, is a planetary nebula, one of the brightest planetary nebulae on the ...