Astronomy Picture of the Day

🌌Planet Earth at Twilight No sudden, sharp boundary marks the passage of day into night in this gorgeous view of ocean and clouds over our fair planet Earth. Instead, the shadow line or terminator is diffuse and shows the gradual transition to darkness we experience as twilight. With the Sun illuminating the scene from the right, the cloud tops reflect gently reddened sunlight filtered through t ...

© Miguel Claro

🌌Eye on the Milky Way Have you ever had stars in your eyes? It appears that the eye on the left does, and moreover it appears to be gazing at even more stars. The featured 27-frame mosaic was taken last July from Ojas de Salar in the Atacama Desert of Chile. The eye is actually a small lagoon captured reflecting the dark night sky as the Milky Way Galaxy arched overhead. The seemingly smooth ban ...

© Juan Filas

🌌IC 2944: The Running Chicken Nebula To some, it looks like a giant chicken running across the sky. To others, it looks like a gaseous nebula where star formation takes place. Cataloged as IC 2944, the Running Chicken Nebula spans about 100 light years and lies about 6,000 light years away toward the constellation of the Centaur (Centaurus). The featured image, shown in scientifically assigned c ...

🌌Cassini Approaches Saturn What would it look like to approach Saturn in a spaceship? One doesn't have to just imagine -- the Cassini spacecraft did just this in 2004, recording thousands of images along the way, and hundreds of thousands more since entering orbit. Some of Cassini's early images have been digitally tweaked, cropped, and compiled into the featured inspiring video which is part of ...

🌌Just Another Day on Aerosol Earth It was just another day on aerosol Earth. For August 23, 2018, the identification and distribution of aerosols in the Earth's atmosphere is shown in this dramatic, planet-wide digital visualization. Produced in real time, the Goddard Earth Observing System Forward Processing (GEOS FP) model relies on a combination of Earth-observing satellite and ground-based d ...

© Antonio Gonzalez

🌌The Windmill and the Star Trails Stars can't turn these old wooden arms, but it does look like they might in this scene from a rotating planet. The well-composed night skyscape was recorded from Garafia, a municipality on the island of La Palma, Canary Islands, planet Earth. The center of the once working windmill, retired since 1953, is lined-up with the north celestial pole, the planet's rota ...

© NAO Rozhen

🌌Comet ATLAS Breaks Up Cruising through the inner solar system, Comet ATLAS C2019/Y4 has apparently fragmented. Multiple separate condensations within its diffuse coma are visible in this telescopic close-up from April 12, composed of frames tracking the comet's motion against trailing background stars. Discovered at the end of December 2019, this comet ATLAS showed a remarkably rapid increase i ...

© ScottAspinall

🌌A Cosmic Triangle It was an astronomical triple play. Setting on the left, just after sunset near the end of last month, was our Moon -- showing a bright crescent phase. Setting on the right was Venus, the brightest planet in the evening sky last month -- and this month, too. With a small telescope, you could tell that Venus' phase was half, meaning that only half of the planet, as visible from ...

🌌NGC 253: The Silver Coin Galaxy NGC 253 is one of the brightest spiral galaxies visible, but also one of the dustiest. Dubbed the Silver Coin for its appearance in smalltelescopes, it is more formally known as the Sculptor Galaxy for its location within the boundaries of the southern constellation Sculptor. Discovered in 1783 by mathematician and astronomer Caroline Herschel, the dusty island u ...

🌌A Sailing Stone across Death Valley How did this big rock end up on this strange terrain? One of the more unusual places here on Earth occurs inside Death Valley, California, USA. There a dried lakebed named Racetrack Playa exists that is almost perfectly flat, with the odd exception of some very large stones, one of which is pictured here in April of 2019 beneath a dark, Milky-Way filled sky. ...

🌌The Horsehead Nebula in Infrared from Hubble While drifting through the cosmos, a magnificent interstellar dust cloud became sculpted by stellar winds and radiation to assume a recognizable shape. Fittingly named the Horsehead Nebula, it is embedded in the vast and complex Orion Nebula (M42). A potentially rewarding but difficult object to view personally with a small telescope, the above gorge ...

© Antonio Finazzi

🌌Venus and the Pleiades in April Shared around world in early April skies Venus, our brilliant evening star, wandered across the face of the lovely Pleiades star cluster. This timelapse image follows the path of the inner planet during the beautiful conjunction showing its daily approach to the stars of the Seven Sisters. From a composite of tracked exposures made with a telephoto lens, the fiel ...

© Jeff Dai

🌌Full Moon of Spring From home this Full Moon looked bright. Around our fair planet it rose as the Sun set on April 7/8, the first Full Moon after the vernal equinox and the start of northern hemisphere spring. April's full lunar phase was also near perigee, the closest point in the Moon's elliptical orbit. In fact, it was nearer perigee than any other Full Moon of 2020 making it the brightest F ...

© Paul Schmit

🌌A Flow of Time This surreal timelapse, landscape, panorama spans predawn, blue hour, and sunrise skies. Close to the start of planet Earth's northern hemisphere spring, the flow of time was captured between 4:30 and 7:00 am from a location overlooking northern New Mexico's Rio Grande Valley. In tracked images of the night sky just before twilight begins, the Milky Way is cast across the souther ...

© Tomas Slovinsky Text: Matipon TangmatithamNARIT

🌌Country Sky versus City Sky Dark skies are disappearing from the world. With modernization comes artificial lighting that brightens the night. While these lights allow modern humans to see, much light is wasted up into the sky. This light pollution not only wastes energy, but, when reflected by the Earth's atmosphere back down, creates a nighttime brightness that disrupts wildlife and harms hum ...

© Mario Konang

🌌A Path North What happens if you keep going north? The direction north on the Earth, the place on your horizon below the northern spin pole of the Earth -- around which other stars appear to slowly swirl, will remain the same. This spin-pole-of-the-north will never move from its fixed location on the sky -- night or day -- and its height will always match your latitude. The further north you go ...

🌌NGC 1672: Barred Spiral Galaxy from Hubble Many spiral galaxies have bars across their centers. Even our own Milky Way Galaxy is thought to have a modest central bar. Prominently barred spiral galaxy NGC 1672, featured here, was captured in spectacular detail in an image taken by the orbiting Hubble Space Telescope. Visible are dark filamentary dust lanes, young clusters of bright blue stars, r ...

🌌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 ...

© Fred Espenak

🌌Venus and the Sisters After wandering about as far from the Sun on the sky as Venus can get, the brilliant evening star is crossing paths with the sister stars of the Pleiades cluster. Look west after sunset and you can share the ongoing conjunction with skygazers around the world. Taken on April 2, this celestial group photo captures the view from Portal, Arizona, USA. Even bright naked-eye Pl ...

© Lionel Majzik

🌌The Traffic in Taurus There's a traffic jam in Taurus lately. On April 1, this celestial frame from slightly hazy skies over Tapiobicske, Hungary recorded an impressive pile up toward the zodiacal constellation of the Bull and the Solar System's ecliptic plane. Streaking right to left the International Space Station speeds across the bottom of the telescopic field of view. Wandering about as fa ...

© Fred Espenak

🌌Venus and the Pleiades in April Venus is currently the brilliant evening star. Shared around world, in tonight's sky Venus will begin to wander across the face of the lovely Pleiades star cluster. This digital sky map illustrates the path of the inner planet as the beautiful conjunction evolves, showing its position on the sky over the next few days. The field of view shown is appropriate for b ...

🌌Asteroid or Potato? Is this asteroid Arrokoth or a potato? Perhaps, after all the data was beamed back to Earth from NASA's robotic New Horizons spacecraft, the featured high resolution image of asteroid Arrokoth was constructed. Perhaps, alternatively, the featured image is of a potato. Let's consider some facts. Arrokoth is the most distant asteroid ever visited and a surviving remnant of the ...

🌌The Galactic Center from Radio to X-ray In how many ways does the center of our Galaxy glow? This enigmatic region, about 26,000 light years away toward the constellation of the Archer (Sagittarius), glows in every type of light that we can see. In the featured image, high-energy X-ray emission captured by NASA's orbiting Chandra X-Ray Observatory appears in green and blue, while low-energy rad ...

🌌The Colors of Saturn from Cassini What creates Saturn's colors? The featured picture of Saturn only slightly exaggerates what a human would see if hovering close to the giant ringed world. 🔗 https://apod.nasa.gov/apod/ap200330.html

© Stanislav Volskiy Rollover Annotation: Judy Schmidt

🌌A 212-Hour Exposure of Orion The constellation of Orion is much more than three stars in a row. It is a direction in space that is rich with impressive nebulas. To better appreciate this well-known swath of sky, an extremely long exposure was taken over many clear nights in 2013 and 2014. After 212 hours of camera time and an additional year of processing, the featured 1400-exposure collage spa ...

© Gianni Tumino