Astronomy Picture of the Day

🌌Aurorae and Lightning on Jupiter Why does so much of Jupiter's lightning occur near its poles? Similar to Earth, Jupiter experiences both aurorae and lightning. Different from Earth, though, Jupiter's lightning usually occurs near its poles -- while much of Earth's lightning occurs near its equator. To help understand the difference, NASA's Juno spacecraft, currently orbiting Jupiter, has obser ...

© Ged Kivlehan

🌌Mars over Duddo Stone Circle Why are these large stones here? One the more famous stone circles is the Duddo Five Stones of Northumberland, England. Set in the open near the top of a modest incline, a short hike across empty fields will bring you to unusual human -sized stones that are unlike anything surrounding them. The grooved, pitted, and deeply weathered surfaces of the soft sandstones ar ...

© Alistair Symon

🌌From Auriga to Orion What's up in the sky from Auriga to Orion? Many of the famous stars and nebulas in this region were captured on 34 separate images, taking over 430 hours of exposure, and digitally combined to reveal the featured image. Starting on the far upper left, toward the constellation of Auriga (the Chariot driver), is the picturesque Flaming Star Nebula (IC 405). Continuing down al ...

🌌The Antikythera Mechanism No one knew that 2,000 years ago, the technology existed to build such a device. The Antikythera mechanism, pictured, is now widely regarded as the first computer. Found at the bottom of the sea aboard a decaying Greek ship, its complexity prompted decades of study, and even today some of its functions likely remain unknown. X-ray images of the device, however, have co ...

© Francis Bozon

🌌The Leo Trio This popular group leaps into the early evening sky around the March equinox and the northern hemisphere spring. Famous as the Leo Triplet, the three magnificent galaxies found in the prominent constellation Leo gather here in one astronomical field of view. Crowd pleasers when imaged with even modest telescopes, they can be introduced individually as NGC 3628 (right), M66 (upper l ...

🌌Central Lagoon in Infrared Stars fill this infrared view, spanning 4 light-years across the center of the Lagoon Nebula. Visible light images show the glowing gas and obscuring dust clouds that dominate the scene. But this infrared image, constructed from Hubble Space Telescope data, peers closer to the heart of the active star-forming region revealing newborn stars scattered within, against a ...

© Kerry-Ann Lecky Hepburn

🌌Stardust in the Perseus Molecular Cloud Clouds of stardust drift through this deep skyscape, across the Perseus molecular cloud some 850 light-years away. Dusty nebulae reflecting light from embedded young stars stand out in the nearly 2 degree wide telescopic field of view. With a characteristic bluish color reflection nebula NGC 1333 is at center, vdB 13 at top right, with rare yellowish refl ...

© Donald Mitchell

🌌The Surface of Venus from Venera 13 If you could stand on Venus -- what would you see? Pictured is the view from Venera 13, a robotic Soviet lander which parachuted and air-braked down through the thick Venusian atmosphere in March of 1982. The desolate landscape it saw included flat rocks, vast empty terrain, and a featureless sky above Phoebe Regio near Venus' equator. On the lower left is th ...

© Alan Pham

🌌IC 1318: The Butterfly Nebula in Gas and Dust In the constellation of the swan near the nebula of the pelican lies the gas cloud of the butterfly next to a star known as the hen. That star, given the proper name Sadr, is just to the right of the featured frame, but the central Butterfly Nebula, designated IC 1318, is shown in high resolution. The intricate patterns in the bright gas and dark du ...

🌌Meteor Fireballs in Light and Sound Yes, but have you ever heard a meteor? Usually, meteors are too far away to make any audible sound. However, a meteor will briefly create an ionization trail that can reflect a distant radio signal. If the geometry is right, you may momentarily hear -- through your radio -- a distant radio station even over static. In the featured video, the sounds of distant ...

© Mia Stålnacke

🌌A Flag Shaped Aurora over Sweden It appeared, momentarily, like a 50-km tall banded flag. In mid-March of 2015, an energetic Coronal Mass Ejection directed toward a clear magnetic channel to Earth led to one of the more intense geomagnetic storms of recent years. A visual result was wide spread auroras being seen over many countries near Earth's magnetic poles. Captured over Kiruna, Sweden, the ...

🌌SuperCam Target on Ma'az What's the sound of one laser zapping? There's no need to consult a Zen master to find out, just listen to the first acoustic recording of laser shots on Mars. On Perseverance mission sol 12 (March 2) the SuperCam instrument atop the rover's mast zapped a rock dubbed Ma'az 30 times from a range of about 3.1 meters. Its microphone recorded the soft staccato popping sound ...

© Wissam Ayoub

🌌Messier 81 One of the brightest galaxies in planet Earth's sky is similar in size to our Milky Way Galaxy: big, beautiful Messier 81. Also known as NGC 3031 or Bode's galaxy for its 18th century discoverer, this grand spiral can be found toward the northern constellation of Ursa Major, the Great Bear. The sharp, detailed telescopic view reveals M81's bright yellow nucleus, blue spiral arms, pin ...

© Joshua Rhoades

🌌Zodiacal Light and Mars Just after sunset on March 7, a faint band of light still reaches above the western horizon in this serene, rural Illinois, night skyscape. Taken from an old farmstead, the luminous glow is zodiacal light, prominent in the west after sunset during planet Earth's northern hemisphere spring. On that clear evening the band of zodiacal light seems to engulf bright yellowish ...

© Yannick Akar

🌌NGC 1499: The California Nebula Could Queen Calafia's mythical island exist in space? Perhaps not, but by chance the outline of this molecular space cloud echoes the outline of the state of California, USA. Our Sun has its home within the Milky Way's Orion Arm, only about 1,000 light-years from the California Nebula. Also known as NGC 1499, the classic emission nebula is around 100 light-years ...

🌌Perseverance 360: Unusual Rocks and the Search for Life on Mars Is that a fossil?  Looking through recent images of Mars taken by the new Perseverance rover may seem a bit like treasure hunting, with the possibility of fame coming to the first person to correctly identify a petrified bone, a rock imprinted by an ancient plant, or any clear indication that life once existed on Mars.  Unfortunate ...

© Nicolas Lefaudeux

🌌Three Tails of Comet NEOWISE What created the unusual red tail in Comet NEOWISE? Sodium. A spectacular sight back in the summer of 2020, Comet NEOWISE, at times, displayed something more than just a surprisingly striated white dust tail and a pleasingly patchy blue ion tail. Some color sensitive images showed an unusual red tail, and analysis showed much of this third tail's color was emitted b ...

🌌Pillars of the Eagle Nebula in Infrared Newborn stars are forming in the Eagle Nebula. Gravitationally contracting in pillars of dense gas and dust, the intense radiation of these newly-formed bright stars is causing surrounding material to boil away. This image, taken with the Hubble Space Telescope in near infrared light, allows the viewer to see through much of the thick dust that makes the ...

🌌Perseverance Takes a Spin After arriving at Jezero Crater on Mars, Perseverance went for a spin on March 4. This sharp image from the car-sized rover's Navcam shows tracks left by its wheels in the martian soil. In preparation for operations on the surface of the Red Planet, its first drive lasted about 33 minutes. On a short and successful test drive Perseverance moved forward 4 meters, made a ...

© Robert Barsa

🌌A Little Like Mars The surface of this planet looks a little like Mars. It's really planet Earth though. In a digitally stitched little planet projection, the 360 degree mosaic was captured near San Pedro in the Chilean Atacama desert. Telescopes in domes on the horizon are taking advantage of the region's famously dark, clear nights. Taken in early December, a magnificent Milky Way arcs above ...

© Petr Horalek

🌌Mars in Taurus You can spot Mars in the evening sky tonight. Now home to the Perseverance rover, the Red Planet is presently wandering through the constellation Taurus, close on the sky to the Seven Sisters or Pleiades star cluster. In fact this deep, widefield view of the region captures Mars near its closest conjunction to the Pleiades on March 3. Below center, Mars is the bright yellowish ce ...

© Giuseppe Vella

🌌Stars over an Erupting Volcano Mt. Etna has been erupting for hundreds of thousands of years. Located in Sicily, Italy, the volcano produces lava fountains over one kilometer high. Mt. Etna is not only one of the most active volcanoes on Earth, it is one of the largest, measuring over 50 kilometers at its base and rising nearly 3 kilometers high. Pictured erupting last month, a lava plume shoot ...

🌌Ingenuity: A Mini-Helicopter Now on Mars What if you could fly around Mars? NASA may have achieved that capability last month with the landing of Perseverance, a rover which included a small flight-worthy companion called Ingenuity, nicknamed Ginny. Even though Ginny is small -- a toaster-sized helicopter with four long legs and two even-longer (1.2-meter) rotors, she is the first of her kind - ...

© U. Mishra

🌌The Pelican Nebula in Red and Blue The Pelican Nebula is changing. 🔗 https://apod.nasa.gov/apod/ap210301.html

© Alyn Wallace

🌌The Aurora Tree Yes, but can your tree do this? Pictured is a visual coincidence between the dark branches of a nearby tree and bright glow of a distant aurora. The beauty of the aurora -- combined with how it seemed to mimic a tree right nearby -- mesmerized the photographer to such a degree that he momentarily forgot to take pictures. When viewed at the right angle, it seemed that this tree h ...

🌌Perseverance Landing Site from Mars Reconnaissance Orbiter Seen from orbit a day after a dramatic arrival on the martian surface, the Perseverance landing site is identified in this high-resolution view from the Mars Reconnaissance Orbiter. The orbiter's camera image also reveals the location of the Mars 2020 mission descent stage, heat shield, and parachute and back shell that delivered Persev ...