Η Αστρονομική Εικόνα της Ημέρας από τη NASA
Spring Equinox at Teide Observatory
20/03/2026
The defining astronomical moment of the equinox today is at 14:46 UTC (March 20). That's when the Sun crosses the celestial equator moving north in its yearly journey through planet Earth's sky, marking the beginning of spring for our fair planet in the northern hemisphere and fall in the southern hemisphere. Then, day and night are nearly equal around the globe. In fact, both day and nighttime exposures from a spring equinox at the Observatorio del Teide in Tenerife, Canary Islands, Spain, are used in this composited skyscape. Over 1,000 images were taken with a fisheye lens and merged in the ambitious equinox project. The apparent motion of the Sun setting along the celestial equator on the equinox date follows the bright linear, diagonal track from the sequence of daytime exposures taken over 6 hours. After sunset, nighttime exposures recorded startrails, with the celestial equator as a linear track and concentric arcs circling the north celestial pole near Polaris at upper right and the south celestial pole beyond the lower left edge (and below the Teide horizon). The foreground includes the distant Teide volcano peak and the observatory's pyramid-shaped solar laboratory building.
Copyright: Juan Carlos Casado
Προηγούμενες Αστρονομικές Εικόνες της Ημέρας από τη NASA
Rima Hyginus
22/02/2025
Rima Hyginus is a spectacular fissure, some 220 kilometers long, found near the center of the lunar near side. Easy to spot in telescopic views of the Moon, it stretches top left to bottom right across this lunar closeup. The image was made with exaggerated colors that reflect the mineral composition of the lunar soil. Hyginus crater lies near the center of the narrow lunar surface groove. About 10 kilometers in diameter, the low-walled crater is a volcanic caldera, one of the larger non-impact craters on the lunar surface. Dotted with small pits formed by surface collapse, Hyginus rima itself was likely created by stresses due to internal magma upwelling and collapse along a long surface fault. The intriguing region was a candidate landing site for the canceled Apollo 19 mission.
Copyright: Vincenzo Mirabella
Hubble's Andromeda Galaxy Mosaic
21/02/2025
The largest photomosaic ever assembled from Hubble Space Telescope image data is a panoramic view of our neighboring spiral Andromeda Galaxy. With 600 overlapping frames assembled from observations made from July 2010 to December 2022, the full Hubble Andromeda Galaxy mosaic spans almost six full moons across planet Earth's sky. A cropped version shown above is nearly two full moons across and partially covers Andromeda's core and inner spiral arms. Also known as M31, the Andromeda Galaxy is 2.5 million light-years away. That makes it the closest large spiral galaxy to our own Milky Way. Our perspective on the spiral Milky Way is anchored to the view from the location of the Sun, a star found within the Milky Way's galactic disk. But Hubble's magnificent Andromeda mosaic offers an expansive view of a large spiral galaxy from the outside looking in. Hubble's comprehensive, detailed data set extending across the Andromeda Galaxy will allow astronomers to make an unprecedented holistic exploration of the mysteries of spiral galaxy structure and evolution.
Copyright: NASA
Messier 87
20/02/2025
rmous elliptical galaxy Messier 87 is about 50 million light-years away. Also known as NGC 4486, the giant galaxy holds trillions of stars compared to the mere billions of stars in our large spiral Milky Way. M87 reigns as the large central elliptical galaxy in the Virgo galaxy cluster. An energetic jet from the giant galaxy's core is seen to stretch outward for about 5,000 light-years in this sharp optical and near-infrared view from the Hubble Space Telescope. In fact, the cosmic blow torch is seen across the electromagnetic spectrum from gamma-rays to radio wavelengths. Its ultimate power source is M87's central, supermassive black hole. An image of this monster in the middle of M87 has been captured by planet Earth's Event Horizon Telescope.
Copyright: NASA
HH 30: A Star System with Planets Now Forming
19/02/2025
How do stars and planets form? New clues have been found in the protoplanetary system Herbig-Haro 30 by the James Webb Space Telescope in concert with Hubble and the Earth-bound ALMA. The observations show, among other things, that large dust grains are more concentrated into a central disk where they can form planets. The featured image from Webb shows many attributes of the active HH-30 system. Jets of particles are being expelled vertically, shown in red, while a dark dust-rich disk is seen across the center, blocking the light from the star or stars still forming there. Blue-reflecting dust is seen in a parabolic arc above and below the central disk, although why a tail appears on the lower left is currently unknown. Studying how planets form in HH 30 can help astronomers better understand how planets in our own Solar System once formed, including our Earth.
Copyright: NASA
Thor's Helmet versus the Seagull
18/02/2025
Seen as a seagull and a duck, these nebulae are not the only cosmic clouds to evoke images of flight. But both are winging their way across this broad celestial landscape, spanning almost 7 degrees across planet Earth's night sky toward the constellation of the Big Dog (Canis Major). The expansive Seagull (top center) is itself composed of two major cataloged emission nebulas. Brighter NGC 2327 forms the head with the more diffuse IC 2177 as the wings and body. Impressively, the Seagull's wingspan would correspond to about 250 light-years at the nebula's estimated distance of 3,800 light-years. At the lower right, the Duck appears much more compact and would span only about 50 light-years given its 15,000 light-year distance estimate. Blown by energetic winds from an extremely massive, hot star near its center, the Duck nebula is cataloged as NGC 2359. Of course, the Duck's thick body and winged appendages also lend it the slightly more dramatic popular moniker, Thor's Helmet. Portal Universe: Random APOD Generator
Copyright: Nicolas Martino, Adrien Soto, Louis Leroux & Yann Sainty
SpaceX Rocket Launch Plume over California
17/02/2025
What's happened to the sky? Last Monday, the photogenic launch plume from a SpaceX rocket launch created quite a spectacle over parts of southern California and Arizona. Looking at times like a giant space fish, the impressive rocket launch from Vandenberg Air Force Base near Lompoc, California, was so bright because it was backlit by the setting Sun. The Falcon 9 rocket successfully delivered to low Earth orbit 23 Starlink communications satellites. The plume from the first stage is seen on the right, while the soaring upper stage rocket is seen at the apex of the plume toward the left. Venus appears at the top of the frame, while a bright streetlight shines on the far right. The featured image was captured toward the west after sunset from near Phoenix, Arizona.
Copyright: Martin LaMontagne
Parhelia at Abisko
15/02/2025
Three suns seem to hug the horizon in this otherworldly winterscape. But the evocative scene was captured during a February 3rd snowmobile exploration of the mountainous region around Abisko National Park, northern Sweden, planet Earth. The two bright spots on either side of Earth's Sun are parhelia (singular parhelion), also known as mock suns or sun dogs. The parhelia are caused by hexagonal ice crystals suspended in the hazy atmosphere that reflect and refract sunlight. Commonly seen in winter and at high latitudes, the bright parhelia lie along the visible 22 degree ice halo of the Sun.
Copyright: planet Earth
A Cosmic Rose: NGC 2237 in Monoceros
14/02/2025
The Rosette Nebula, NGC 2237, is not the only cosmic cloud of gas and dust to evoke the imagery of flowers, but it is probably the most famous. At the edge of a large molecular cloud in Monoceros some 5,000 light years away, the petals of this cosmic rose are actually a stellar nursery. The lovely, symmetric shape is sculpted by the winds and radiation from its central cluster of hot young, O-type stars. Stars in the energetic cluster, cataloged as NGC 2244, are only a few million years young, while the central cavity in the Rosette Nebula, is about 50 light-years in diameter. The nebula can be seen with a small telescope toward the constellation of Monoceros, the Unicorn. This natural appearing telescopic portrait of the Rosette Nebula was made using broadband color filters, but sometimes roses aren't red.
Copyright: Harry Karamitsos
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.