Astronomy Picture of the Day

© 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

🌌Stars Trail over Ragusa In trying times, stars still trail in the night. Taken on March 14, this night skyscape was made by combining 230 exposures each 15 seconds long to follow the stars' circular paths. The camera was fixed to a tripod on an isolated terrace near the center of Ragusa, Italy, on the island of Sicily. But the night sky was shared around the rotating planet. A friend to celesti ...

© Massimo Tamajo

🌌A Little Drop of Galaxy A drop of water seems to hold an entire galaxy in this creative macro-astrophotograph. In the imaginative work of cosmic nature photography a close-up lens was used to image a previously made picture of a galaxy, viewed through a water drop suspended from a stem. A favorite of many telescope-wielding astroimagers, the galaxy is the Andromeda Galaxy, also known as M31. Ab ...

© Ralf Rohner

🌌Andromeda Station This surreal picture isn't from a special effects sci-fi movie. It is a digital composite of frames of the real Andromeda Galaxy, also known as M31, rising over a real mountain. Exposures tracking the galaxy and background stars have been digitally combined with separate exposures of the foreground terrain. All background and foreground exposures were made back to back with th ...

© Utkarsh Mishra

🌌Star Forming Region S106 Massive star IRS 4 is beginning to spread its wings. Born only about 100,000 years ago, material streaming out from this newborn star has formed the nebula dubbed Sharpless 2-106 Nebula (S106), featured here. A large disk of dust and gas orbiting Infrared Source 4 (IRS 4), visible in brown near the image center, gives the nebula an hourglass or butterfly shape. S106 gas ...

🌌A Black Hole Disrupts a Passing Star What happens to a star that goes near a black hole? If the star directly impacts a massive black hole, then the star falls in completely -- and everything vanishes. More likely, though, the star goes close enough to have the black hole's gravity pull away the outer layers of the star, or disrupt the star. Then most of the star's gas does not fall into the bl ...

© Hirofumi Okubo

🌌From the Pleiades to the Eridanus Loop If you stare at an interesting patch of sky long enough, will it look different? In the case of Pleiades and Hyades star clusters -- and surrounding regions -- the answer is: yes, pretty different. Long duration camera exposures reveal an intricate network of interwoven interstellar dust and gas that was previously invisible not only to the eye but to lowe ...