Astronomy Picture of the Day

🌌Crescent Enceladus Peering from the shadows, the Saturn-facing hemisphere of tantalizing inner moon Enceladus poses in this Cassini spacecraft image. North is up in the dramatic scene captured during November 2016 as Cassini's camera was pointed in a nearly sunward direction about 130,000 kilometers from the moon's bright crescent. In fact, the distant world reflects over 90 percent of the sunl ...

© Sebastian Voltmer

🌌Betelgeuse Eclipsed Asteroid 319 Leona cast a shadow across planet Earth on December 12, as it passed in front of bright star Betelgeuse. But to see everyone's favorite red giant star fade this time, you had to stand near the center of the narrow shadow path starting in central Mexico and extending eastward across southern Florida, the Atlantic Ocean, southern Europe, and Eurasia. The geocentri ...

🌌Supernova Remnant Cassiopeia A Massive stars in our Milky Way Galaxy live spectacular lives. Collapsing from vast cosmic clouds, their nuclear furnaces ignite and create heavy elements in their cores. After only a few million years for the most massive stars, the enriched material is blasted back into interstellar space where star formation can begin anew. The expanding debris cloud known as Ca ...

© William Ostling, Telescope Live

🌌Deep Field: The Heart Nebula What excites the Heart Nebula? First, the large emission nebula on the left, catalogued as IC 1805, looks somewhat like a human heart. The nebula glows brightly in red light emitted by its most prominent element, hydrogen, but this long-exposure image was also blended with light emitted by silicon (yellow) and oxygen (blue). In the center of the Heart Nebula are you ...

© Giulio Cobianchi

🌌Aurora and Milky Way over Norway What are these two giant arches across the sky? Perhaps the more familiar one, on the left, is the central band of our Milky Way Galaxy. This grand disk of stars and nebulas here appears to encircle much of the southern sky. Visible below the stellar arch is the rusty-orange planet Mars and the extended Andromeda galaxy. But this night had more! For a few minute ...

🌌Solar Minimum versus Solar Maximum The surface of our Sun is constantly changing. Some years it is quiet, showing relatively few sunspots and active regions. Other years it is churning, showing many sunspots and throwing frequent Coronal Mass Ejections (CMEs) and flares. Reacting to magnetism, our Sun's surface goes through periods of relative calm, called Solar Minimum and relative unrest, cal ...

© Steve Cullen

🌌Big Dipper over Pyramid Mountain When did you first learn to identify this group of stars? Although they are familiar to many people around the world, different cultures have associated this asterism with different icons and folklore. Known in the USA as the Big Dipper, the stars are part of a constellation designated by the International Astronomical Union in 1922 as the Great Bear (Ursa Major ...

© Jean-Francois Graffand

🌌Pic du Pleiades Near dawn on November 19 the Pleiades stood in still dark skies over the French Pyrenees. But just before sunrise a serendipitous moment was captured in this single 3 second exposure; a bright meteor streak appeared to pierce the heart of the galactic star cluster. From the camera's perspective, star cluster and meteor were poised directly above the mountain top observatory on t ...

© Dan Bartlett

🌌Vega and Comet 12P/Pons-Brooks On December 4, periodic Comet 12P/Pons-Brooks shared this telescopic field of view with Vega, alpha star of the northern constellation Lyra. Fifth brightest star in planet Earth's night, Vega is some 25 light-years distant while the much fainter comet was about 21 light-minutes away. In recent months, outbursts have caused dramatic increases in brightness for Pons ...

🌌Orion and the Ocean of Storms On December 5, 2022, a camera on board the uncrewed Orion spacecraft captured this view as Orion approached its return powered flyby of the Moon. Beyond one of Orion's extended solar arrays lies dark, smooth, terrain along the western edge of the Oceanus Procellarum. Prominent on the lunar nearside Oceanus Procellarum, the Ocean of Storms, is the largest of the Moo ...

🌌Stars Versus Dust in the Carina Nebula It's stars versus dust in the Carina Nebula and the stars are winning. More precisely, the energetic light and winds from massive newly formed stars are evaporating and dispersing the dusty stellar nurseries in which they formed. Located in the Carina Nebula and inside a region known informally as Mystic Mountain, these pillars' appearance is dominated by ...

🌌Energetic Particle Strikes the Earth It was one of the most energetic particles ever known to strike the Earth -- but where did it come from? Dubbed Amaterasu after the Shinto sun goddess, this particle, as do all cosmic rays that strike the Earth's atmosphere, caused an air shower of electrons, protons, and other elementary particles to spray down onto the Earth below. In the featured illustra ...

© Juned Patel

🌌Plane Crossing Crescent Moon No, the Moon is not a bow, and no, it did not shoot out a plane like an arrow. What is pictured is a chance superposition. The plane's contrail would normally appear white, but the large volume of air toward the rising Sun preferentially knocked away blue light, not only making the sky blue, but giving the reflected trail a bright red hue. Far in the distance, well ...

🌌Moon Setting Behind Teide Volcano These people are not in danger. What is coming down from the left is just the Moon, far in the distance. Luna appears so large here because she is being photographed through a telescopic lens. What is moving is mostly the Earth, whose spin causes the Moon to slowly disappear behind Mount Teide, a volcano in the Canary Islands off the northwest coast of Africa. ...

© Jeff Dai

🌌Startrails over Beijing Ancient Observatory You can take a subway ride to visit this observatory in Beijing, China but you won't find any telescopes there. Starting in the 1400s astronomers erected devices at the Beijing Ancient Observatory site to enable them to accurately measure and track the positions of naked-eye stars and planets. Some of the large, ornate astronomical instruments are sti ...

© José Rodrigues

🌌Milky Way Rising The core of the Milky Way is rising beyond the Chilean mountain-top La Silla Observatory in this deep night skyscape. Seen toward the constellation Sagittarius, our home galaxy's center is flanked on the left, by the European Southern Observatory's New Technology Telescope which pioneered the use of active optics to accurately control the shape of large telescope mirrors. To th ...

🌌Artemis 1: Flight Day 13 On flight day 13 (November 28, 2022) of the Artemis I mission, the Orion spacecraft reached its maximum distance from its home world. Over 430,000 kilometers from Earth in a distant retrograde orbit, Orion surpassed the record for most distant spacecraft designed to carry humans. That record was previously set in 1970 during the Apollo 13 mission to the Moon. Both Earth ...

© Brad Hannon

🌌A Landspout Tornado over Kansas Could there be a tornado inside another tornado? In general, no. OK, but could there be a tornado inside a wider dust devil? No again, for one reason because tornados comes down from the sky, but dust devils rise up from the ground. What is pictured is a landspout, an unusual type of tornado known to occur on the edge of a violent thunderstorm. The featured lands ...

© NASA/JPL-Caltech/SwRI/MSSS; Processing & License: Kevin M. Gill;

🌌Ganymede from Juno What does the largest moon in the Solar System look like? Jupiter's moon Ganymede, larger than even Mercury and Pluto, has an icy surface speckled with bright young craters overlying a mixture of older, darker, more cratered terrain laced with grooves and ridges. The cause of the grooved terrain remains a topic of research, with a leading hypothesis relating it to shifting ic ...

© Vikas Chander

🌌LBN 86: The Eagle Ray Nebula This eagle ray glides across a cosmic sea. Officially cataloged as SH2-63 and LBN 86, the dark nebula is composed of gas and dust that just happens to appear shaped like a common ocean fish. The interstellar dust nebula appears light brown as it blocks and reddens visible light emitted behind it. Dark nebulas glow primarily in infrared light, but also reflect visibl ...

🌌A Dust Jet from the Surface of Comet 67P Where do comet tails come from? There are no obvious places on the nuclei of comets from which the jets that create comet tails emanate. In 2016, though, ESA's Rosetta spacecraft not only imaged a jet emerging from Comet 67P/Churyumov-Gerasimenko, but flew right through it. Featured is a telling picture showing a bright plume emerging from a small circul ...

© Victor Lima

🌌Little Planet Aurora Immersed in an eerie greenish light, this rugged little planet appears to be home to stunning water falls and an impossibly tall mountain. It's planet Earth of course. On the night of November 9 the nadir-centered 360 degree mosaic was captured by digital camera from the Kirkjufell mountain area of western Iceland. Curtains of shimmering Aurora Borealis or Northern Lights p ...

© Marco Lorenzi

🌌Stereo Jupiter near Opposition Jupiter looks sharp in these two rooftop telescope images. Both were captured on November 17 from Singapore, planet Earth, about two weeks after Jupiter's 2023 opposition. Climbing high in midnight skies the giant planet was a mere 33.4 light-minutes from Singapore. That's about 4 astronomical units away. Jupiter's planet girdling dark belts and light zones are vi ...

© Yuexiao Shen

🌌Along the Taurus Molecular Cloud The cosmic brush of star formation composed this interstellar canvas of emission, dust, and dark nebulae. A 5 degree wide telescopic mosaic, it frames a region found north of bright star Aldebaran on the sky, at an inner wall of the local bubble along the Taurus molecular cloud. At lower left, emission cataloged as Sh2-239 shows signs of embedded young stellar o ...

© Steve Cannistra

🌌IC 342: Hidden Galaxy in Camelopardalis Similar in size to large, bright spiral galaxies in our neighborhood, IC 342 is a mere 10 million light-years distant in the long-necked, northern constellation Camelopardalis. A sprawling island universe, IC 342 would otherwise be a prominent galaxy in our night sky, but it is hidden from clear view and only glimpsed through the veil of stars, gas and du ...

© Cristiano Gualco

🌌Fleming's Triangular Wisp These chaotic and tangled filaments of shocked, glowing gas are spread across planet Earth's sky toward the constellation of Cygnus as part of the Veil Nebula. The Veil Nebula itself is a large supernova remnant, an expanding cloud born of the death explosion of a massive star. Light from the original supernova explosion likely reached Earth over 5,000 years ago. The g ...