Η Αστρονομική Εικόνα της Ημέρας από τη NASA
NASA Science
02/11/2026
What’s causing this unusually long cloud on Mars? Known as the Arsia Mons Elongated Cloud (AMEC) and first recorded by NASA’s Viking Orbiter 2 in 1977, the strange cloud has been imaged in greater detail more recently by ESA’s robotic Mars Express spacecraft. The featured image is from 2018. The cloud forms only during spring and summer seasons and then only during morning hours. Made of water-ice, the most familiar process that causes cloud crystals to form around bits of dust would fail due to the thinness and lack of dust high in the Martian atmosphere. Leading speculation holds that dust is not involved. After the cloud forms near the volcano Arsia Mons, wind blows the cloud downstream — creating a tail that can extend over 1500 kilometers. Efforts to better understand AMECs will continue, an understanding that may bolster a more complete view of cloud formation on Earth.Tomorrow's picture: eyeing a cat
Copyright: NASA
Προηγούμενες Αστρονομικές Εικόνες της Ημέρας από τη NASA
NASA Science
08/10/2026
How was the Saturn system imaged so clearly? Astrophotographer Tom Williams captured such exquisite details due to one night of exceptional atmospheric conditions above the United Kingdom. This means more than a cloudless sky. Pockets of air at different temperatures and densities move around and bend light as it travels through Earth’s atmosphere, distorting astronomy images. This is called “seeing”. Less atmospheric turbulence means clearer images. The astrophotographer reduced the impact of seeing with the lucky imaging technique: thousands of short-exposure images are taken very quickly with a high-speed camera and the clearest images are added up. Which object in this smörgåsbord interests you? Perhaps Titan or the icy stripes of Enceladus? Maybe the gaps and spokes in Saturn’s rings? Saturn's opposition, when Earth passes in between the planet and the Sun, occurred on October 4th. Due to the planet's proximity and full illumination from the Sun, now is a great time of year to observe it!Tomorrow's picture: bumpy
Copyright: NASA
NASA Science
07/10/2026
"Happy New Year!" No, wait, this is not a fireworks display. This image shows Nebula Pa 30, observed with the Gemini North Telescope in Hawai'i. It is likely the remnant of an old supernova explosion: separate historical records by Chinese, Japanese and Arabic astronomers tell of a "guest star" that appeared in the sky for 185 days in the year 1181. It is believed that this bright new point of light came from the supernova that caused the fireworks in Pa 30. Astronomers don't know exactly what happened in this unusual explosion, classified as a Type Iax supernova, but it is thought to be caused by the merger of two white dwarfs. The mysterious central star in the image is extremely hot and produces a strong wind, possibly forming the radial filaments. Look closely at them: those pearl-like knots stringing the filaments are 4 light-days in diameter. Understanding how a supernova created this amazing nebula continues an 845-year old mystery (and counting).Tomorrow's picture: smörgåsbord
Copyright: NASA
NASA Science
06/10/2026
Have you ever seen a complete auroral oval? You can't see one from the ground because it makes too large a circle around one of Earth's magnetic poles. But spacecraft high above the Earth can see them. The featured video from ESA and CAS's robotic SMILE spacecraft shows not only a full auroral oval, but using ultraviolet light, one that occurred during the day. The time-lapse covers about an hour in late July and shows visually how variable and turbulent auroras really are. The points of light on the sides are distant stars that appear to move only because SMILE's camera view shifts as the spacecraft orbits the Earth. A goal of SMILE is to better understand how the Sun's wind interacts with the Earth's magnetosphere -- and so better understand how to protect astronauts, spacecraft, and ground-based electrical grids from solar storms.Tomorrow's picture: a ghost
Copyright: NASA
NASA Science
05/10/2026
A deep image of the Sombrero galaxy reveals surprises. M104 is named the Sombrero galaxy because, on shorter exposures, it looks like a hat. A key defining feature of this huge galaxy is a dark brim of dust that circles the disk galaxy's center. A much longer exposure, however, brings up a hairy past where a bright, hazy halo is revealed that extends well past the central disk and contains many unresolved stars. Surprisingly, in this stellar haze, structures can be seen that include a diagonal ring. These structures and tidal streams provide fresh evidence that M104 had a violent past and is surely the result of collisions and mergers of smaller galaxies. Light takes about 30 million years to reach us from the Sombrero galaxy, which fully spans about 150 thousand light years across. The featured image was taken over seven days in mid-2026 from Namibia.Your Sky Surprise: What picture did APOD feature on your birthday? (post 1995)Tomorrow's picture: a smile
Copyright: NASA
NASA Science
04/10/2026
Yes, but can your rainbow do this? After the remnants of Hurricane Florence passed over the Jersey Shore, New Jersey, USA in 2018, the Sun came out in one direction but something quite unusual appeared in the opposite direction: a hall of rainbows. Over the course of the next half hour, to the delight of the photographer and his daughter, vibrant supernumerary rainbows faded in and out, with at least five captured in this featured single shot. Supernumerary rainbows only form when falling water droplets are all nearly the same size and typically less than a millimeter across. Then, sunlight will not only reflect from inside the raindrops, but interfere, a wave phenomenon similar to ripples on a pond when a stone is thrown in. In fact, supernumerary rainbows can only be explained with waves, and their noted existence in the early 1800s was considered early evidence of light's wave nature.Your Sky Surprise: What picture did APOD feature on your birthday? (post 1995)Tomorrow's picture: open space
Copyright: NASA
NASA Science
03/10/2026
On sol 1943 of its journey of exploration across the surface of Mars, the Curiosity Rover recorded this selfie at the south rim of Vera Rubin Ridge. Of course a sol is a Martian solar day, about 40 minutes longer than an Earth day. Curiosity's sol 1943 corresponds to Earth date January 23, 2018. Also composed as an interactive 360 degree VR, the mosaicked panorama combines 61 exposures taken by the small car-sized rover's Mars Hand Lens Imager (MAHLI). Frames containing the imager's arm have been edited out while the extended background used was taken by the rover's Mastcam on sol 1903. At the top of the rover's mast, sitting above the Mastcam, the laser-firing ChemCam housing blocks out the distant, 5 kilometer high peak of Mount Sharp. On Earth date August 26, 2026, Curiosity marked an total elevation gain of 1 kilometer in its trek from the floor of Gale Crater up the slope of Mount Sharp.APOD's email for image submissions has changed. Please see: APOD Submissions.Tomorrow's picture: Sunday's Childe
Copyright: NASA
NASA Science
02/10/2026
What does it take to image hundreds of nebulas? Today’s image contains the entire Sharpless Catalog of H II Regions, totaling 313 objects. Zoom in and explore! You may spot fan favorites like the Eagle (Sh2-49), Heart (Sh2-190), and Orion (Sh2-281) Nebulas. Despite its name, this catalog contains more than the glow of ionized hydrogen that makes up H II regions. There are planetary nebulas (the Medusa Nebula, Sh2-274) and supernova remnants (the Spaghetti Nebula, Sh2-240) as well. Astrophotographer Bing Xin traversed the dark skies of Eastern China and Inner Mongolia to catch them all. Narrowband filters that primarily capture light from ionized hydrogen and oxygen as well as red-green-blue filters were used. Each object took 2 to 6 hours to capture, with the entire catalog taking around 800 hours to complete! Which object is your favorite?APOD's email for image submissions has changed. Please see: APOD SubmissionsTomorrow's picture: just Curiosity
Copyright: NASA
NASA Science
01/10/2026
Have you ever seen the full moon rise? This colorful image was photographed last weekend in Sicily, just outside the town of Nicosia, in Italy. It is a composite photograph that shows the Moon rising as the sky turns darker. Lower clouds are reflecting the colors of antitwilight, while ash and gas from Mount Etna are seen higher in the background. The pink band lower in the sky is called the Belt of Venus. During a full moon, the Moon and the Sun are in opposition in the sky: the moon rises as the sun sets. The lunar phase cycle lasts approximately 29.5 days (but the Moon takes approximately 27 days to orbit the Earth). In some cultures of the Northern Hemisphere, the September full moon is called the Harvest Moon. Does your culture have a special name for it? (A full moon by any other name would shine as bright.)APOD's email for image submissions has changed. Please see: APOD SubmissionsAPOD's main NASA site has moved : From apod.nasa.gov to science.nasa.gov/apodTomorrow's picture: sharpless
Copyright: NASA
Η Αστρονομική Εικόνα της Ημέρας από τη NASA (NASA Astronomy Picture of the Day) είναι μια δωρεάν υπηρεσία που παρέχει καθημερινά μια εντυπωσιακή εικόνα από το σύμπαν, την λήψη της οποίας έχει πραγματοποιήσει κάποιος από τους αστρονόμους της NASA ή από κάποιον από τους δορυφόρους ή τα τηλεσκόπια που η NASA λειτουργεί. Οι εικόνες που εμφανίζονται καλύπτουν μια ευρεία γκάμα από θέματα, συμπεριλαμβανομένων των αστερισμών, των γαλαξιών, των πλανητικών συστημάτων, των κομητών, των αστρικών σωμάτων και των παρατηρητηρίων. Κάθε εικόνα συνοδεύεται από μια σύντομη εξήγηση και πληροφορίες σχετικά με το τι παρατηρείται στην εικόνα.