Η Αστρονομική Εικόνα της Ημέρας από τη NASA
W5: The Soul Nebula
17/12/2025
Stars are forming in the Soul of the Queen of Aethopia. More specifically, a large star forming region called the Soul Nebula can be found in the direction of the constellation Cassiopeia, whom Greek mythology credits as the vain wife of a King who long ago ruled lands surrounding the upper Nile river. Also known as Westerhout 5 (W5), the Soul Nebula houses several open clusters of stars, ridges and pillars darkened by cosmic dust, and huge evacuated bubbles formed by the winds of young massive stars. Located about 6,500 light years away, the Soul Nebula spans about 100 light years and is usually imaged next to its celestial neighbor the Heart Nebula (IC 1805). The featured image, taken from near Nashville, Tennessee, USA, is a composite of 234 hours of exposures made in different colors: red as emitted by hydrogen gas, yellow as emitted by sulfur, and blue as emitted by oxygen. Explore the Universe: Random APOD Generator
Copyright: Jeffrey Horne
Προηγούμενες Αστρονομικές Εικόνες της Ημέρας από τη NASA
25 Brightest Stars in the Night Sky
11/06/2025
Do you know the names of some of the brightest stars? It's likely that you do, even though some bright stars have names so old they date back to near the beginning of written language. Many world cultures have their own names for the brightest stars, and it is culturally and historically important to remember them. In the interest of clear global communication, however, the International Astronomical Union (IAU) has begun to designate standardized star names. Featured here in true color are the 25 brightest stars in the night sky, currently as seen by humans, coupled with their IAU-recognized names. Some star names have interesting meanings, including Sirius ("the scorcher" in Latin), Vega ("falling" in Arabic), and Antares ("rival to Mars" in Greek). You are likely even familiar with the name of at least one star too dim to make this list: Polaris. APOD Turns 30!: Free public lecture in Anchorage TONIGHT (Wednesday) at 7 pm
Copyright: Tragoolchitr Jittasaiyapan
Enceladus in True Color
10/06/2025
Do oceans under the ice of Saturn's moon Enceladus contain life? A reason to think so involves long features -- some dubbed tiger stripes -- that are known to be spewing ice from the moon's icy interior into space. These surface cracks create clouds of fine ice particles over the moon's South Pole and create Saturn's mysterious E-ring. Evidence for this has come from the robot Cassini spacecraft that orbited Saturn from 2004 to 2017. Pictured here, a high resolution image of Enceladus is shown in true color from a close flyby. The deep crevasses are partly shadowed. Why Enceladus is active remains a mystery, as the neighboring moon Mimas, approximately the same size, appears quite dead. A analysis of ejected ice grains has yielded evidence that complex organic molecules. These large carbon-rich molecules bolster -- but do not prove -- that oceans under Enceladus' surface could contain life. APOD Turns 30!: Free public lecture in Anchorage tomorrow (Wednesday) at 7 pm
Copyright: NASA
Between Scylla and Charybdis: A Double Cosmic Discovery
09/06/2025
Can you identify this celestial object? Likely not — because this is a discovery image. Massive stars forge heavy elements in their cores and, after a few million years, end their lives in powerful supernova explosions. These remnants cool relatively quickly and fade, making them difficult to detect. To uncover such faint, previously unknown supernova remnants, a dedicated group of amateur astrophotographers searched through sky surveys for possible supernova remnant candidates. The result: the first-ever image of supernova remnant G115.5+9.1 — named Scylla by its discoverers—glowing faintly in the constellation of the mythological King of Aethiopia: Cepheus. Emission from hydrogen atoms in the remnant is shown in red, and faint emission from oxygen is shown in hues of blue. Surprisingly, another discovery lurked to the upper right: a faint, previously unknown planetary nebula candidate. In keeping with mythological tradition, it was named Charybdis (Sai 2) — a nod to the ancient Greek expression "caught between Scylla and Charybdis" from Homer’s Odyssey.
Copyright: NASA
Facing NGC 3344
08/06/2025
From our vantage point in the Milky Way Galaxy, we see NGC 3344 face-on. Nearly 40,000 light-years across, the big, beautiful spiral galaxy is located just 20 million light-years away in the constellation of Leo Minor. This multi-color Hubble Space Telescope close-up of NGC 3344 includes remarkable details from near infrared to ultraviolet wavelengths. The frame extends some 15,000 light-years across the spiral's central regions. From the core outward, the galaxy's colors change from the yellowish light of old stars in the center to young blue star clusters and reddish star forming regions along the loose, fragmented spiral arms. Of course, the bright stars with a spiky appearance are in front of NGC 3344 and lie well within our own Milky Way. APOD Turns 30!: Free Public Lecture in Anchorage on Wednesday, June 11 at 7 pm
Copyright: NASA
Perseverance Selfie with Ingenuity
07/06/2025
On the Mars rover's mission Sol 46 or Earth date April 6, 2021, Perseverance held out a robotic arm to take its first selfie on Mars. The WATSON camera at the end of the arm was designed to take close-ups of Martian rocks and surface details though, and not a quick snap shot of friends and smiling faces. In the end, teamwork and weeks of planning on Mars time was required to program a complex series of exposures and camera motions to include Perseverance and its surroundings. The resulting 62 frames were composed into a detailed mosaic, one of the most complicated Mars rover selfies ever taken. In this version of the selfie, the rover's Mastcam-Z and SuperCam instruments are looking toward WATSON and the end of the rover's outstretched arm. About 4 meters (13 feet) from Perseverance is a robotic companion, the Mars Ingenuity helicopter. Perseverance has now spent over 1,500 sols exploring the surface of the Red Planet. On Earth date January 18, 2024, Ingenuity made its 72nd and final flight through the thin Martian atmosphere.
Copyright: NASA
NGC 6302: The Butterfly Nebula
06/06/2025
The bright clusters and nebulae of planet Earth's night sky are often given the names of flowers or insects, and its whopping 3 light-year wingspan, NGC 6302 is no exception. With an estimated surface temperature of about 250,000 degrees C, the central star of the planetary nebula is transforming into a white dwarf star, becoming exceptionally hot, and shining brightly in ultraviolet light. The central star is hidden from direct view by a torus of dust, but its energetic ultraviolet light ionizes atoms in the nebula. In this sharp, telescopic view composed with narrowband image data, the ionized hydrogen and doubly ionized oxygen atoms are shown in their characteristic red and blue-green hues to reveal a stunning complex of knots and filaments within the nebula's wing-like bipolar outflows. NGC 6302 lies about 4,000 light-years away in the arachnologically correct constellation of the Scorpion (Scorpius).
Copyright: Mike Selby
Savudrija Star Trails
05/06/2025
Savudrija lighthouse shines along the coast near the northern end of the Istrian peninsula in this well-composed night skyscape. A navigational aid for sailors on the Adriatic Sea, the historic lighthouse was constructed in the early 19th century. But an even older aid to navigation shines in the sky above, Polaris, alpha star of the constellation Ursa Minor and also known as the North Star. In this scene Polaris forms the shortest bright arc near the North Celestial Pole, the extension of Earth's axis of rotation into space. Of course, the North Celestial Pole lies exactly at the center of all the concentric startrails. The composite image is a digital stack of 400 exposures, each 30 seconds long, taken with camera and tripod fixed to a rotating planet.
Copyright: Branko Nadj
A Milky Road to the Rubin Observatory
04/06/2025
Is the sky the same every night? No -- the night sky changes every night in many ways. To better explore how the night sky changes, the USA's NSF and DOE commissioned the Vera C. Rubin Observatory in Cerro Pachón, Chile. In final testing before routine operations, Rubin will begin to explore these nightly changes -- slight differences that can tell us much about our amazing universe and its surprising zoo of objects. With a mirror over 8 meters across, Rubin will continually reimage the entire visible sky every few nights to discover new supernovas, potentially dangerous asteroids, faint comets, and variable stars -- as well as mapping out the visible universe's large-scale structure. Pictured, the distant central band of our Milky Way Galaxy appears to flow out from the newly operational observatory. Taken last month, the featured picture is a composite of 21 images across the night sky, capturing airglow on the horizon and the Small Magellanic Cloud galaxy on the lower left. APOD Turns 30!: Free Public Lecture in Anchorage on June 11
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.