Η Αστρονομική Εικόνα της Ημέρας από τη NASA
Interplanetary Earth
23/11/2024
In an interplanetary first, on July 19, 2013 Earth was photographed on the same day from two other worlds of the Solar System, innermost planet Mercury and ringed gas giant Saturn. Pictured on the left, Earth is the pale blue dot just below the rings of Saturn, as captured by the robotic Cassini spacecraft then orbiting the outermost gas giant. On that same day people across planet Earth snapped many of their own pictures of Saturn. On the right, the Earth-Moon system is seen against the dark background of space as captured by the sunward MESSENGER spacecraft, then in Mercury orbit. MESSENGER took its image as part of a search for small natural satellites of Mercury, moons that would be expected to be quite dim. In the MESSENGER image, the brighter Earth and Moon are both overexposed and shine brightly with reflected sunlight. Destined not to return to their home world, both Cassini and MESSENGER have since retired from their missions of Solar System exploration.
Copyright: NASA
Προηγούμενες Αστρονομικές Εικόνες της Ημέρας από τη NASA
Diamonds in the Sky
20/04/2024
When the dark shadow of the Moon raced across North America on April 8, sky watchers along the shadow's narrow central path were treated to a total solar eclipse. During the New Moon's shadow play diamonds glistened twice in the eclipse-darkened skies. The transient celestial jewels appeared immediately before and after the total eclipse phase. That's when the rays of a vanishing and then emerging sliver of solar disk are just visible behind the silhouetted Moon's edge, creating the appearance of a shiny diamond set in a dark ring. This dramatic timelapse composite from north-central Arkansas captures both diamond ring moments of this total solar eclipse. The diamond rings are separated by the ethereal beauty of the solar corona visible during totality.
Copyright: Wright Dobbs
The Great Carina Nebula
19/04/2024
A jewel of the southern sky, the Great Carina Nebula is more modestly known as NGC 3372. One of our Galaxy's largest star forming regions, it spans over 300 light-years. Like the smaller, more northerly Great Orion Nebula, the Carina Nebula is easily visible to the unaided eye. But at a distance of 7,500 light-years it lies some 5 times farther away. This stunning telescopic view reveals remarkable details of the region's glowing filaments of interstellar gas and obscuring cosmic dust clouds. The Carina Nebula is home to young, extremely massive stars, including the still enigmatic variable Eta Carinae, a star with well over 100 times the mass of the Sun. Eta Carinae is the bright star above the central dark notch in this field and left of the dusty Keyhole Nebula (NGC 3324).
Copyright: Demison Lopes
Facing NGC 1232
18/04/2024
From our vantage point in the Milky Way Galaxy, we see NGC 1232 face-on. Nearly 200,000 light-years across, the big, beautiful spiral galaxy is located some 47 million light-years away in the flowing southern constellation of Eridanus. This sharp, multi-color, telescopic image of NGC 1232 includes remarkable details of the distant island universe. 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 grand, sweeping spiral arms. NGC 1232's apparent, small, barred-spiral companion galaxy is cataloged as NGC 1232A. Distance estimates place it much farther though, around 300 million light-years away, and unlikely to be interacting with NGC 1232. Of course, the prominent bright star with the spiky appearance is much closer than NGC 1232 and lies well within our own Milky Way.
Copyright: Neil Corke
Total Eclipse and Comets
17/04/2024
Not one, but two comets appeared near the Sun during last week's total solar eclipse. The expected comet was Comet 12P/Pons-Brooks, but it was disappointingly dimmer than many had hoped. However, relatively unknown Comet SOHO-5008 also appeared in long duration camera exposures. This comet was the 5008th comet identified on images taken by ESA & NASA's Sun-orbiting SOHO spacecraft. Likely much smaller, Comet SOHO-5008 was a sungrazer which disintegrated within hours as it passed too near the Sun. The featured image is not only unusual for capturing two comets during an eclipse, but one of the rare times that a sungrazing comet has been photographed from the Earth's surface. Also visible in the image is the sprawling corona of our Sun and the planets Mercury (left) and Venus (right). Of these planets and comets, only Venus was easily visible to millions of people in the dark shadow of the Moon that crossed North America on April 8. Solar Eclipse Imagery: Notable Submissions to APOD
Copyright: Lin Zixuan (Tsinghua U.)
Filaments of the Vela Supernova Remnant
16/04/2024
The explosion is over, but the consequences continue. About eleven thousand years ago, a star in the constellation of Vela could be seen to explode, creating a strange point of light briefly visible to humans living near the beginning of recorded history. The outer layers of the star crashed into the interstellar medium, driving a shock wave that is still visible today. The featured image captures some of that filamentary and gigantic shock in visible light. As gas flies away from the detonated star, it decays and reacts with the interstellar medium, producing light in many different colors and energy bands. Remaining at the center of the Vela Supernova Remnant is a pulsar, a star as dense as nuclear matter that spins around more than ten times in a single second. Monday's Eclipse Imagery: Notable Submissions to APOD
Copyright: NASA
The Cigar Galaxy from Hubble and Webb
15/04/2024
Something strange happened to this galaxy, but what? Known as the Cigar Galaxy and cataloged as M82, red glowing gas and dust are being cast out from the center. Although this starburst galaxy was surely stirred up by a recent pass near its neighbor, large spiral galaxy M81, this doesn't fully explain the source of the red-glowing outwardly expanding gas and dust. Evidence indicates that this material is being driven out by the combined emerging particle winds of many stars, together creating a galactic superwind. In the featured images, a Hubble Space Telescope image in visible light is shown on the left, while a James Webb Space Telescope image of the central region in infrared light is shown on the right. Detailed inspection of the new Webb image shows, unexpectedly, that this red-glowing dust is associated with hot plasma. Research into the nature of this strange nearby galaxy will surely continue. Total Eclipse Imagery: Notable Submissions to APOD
Copyright: NASA
How a Total Solar Eclipse Ended
14/04/2024
How does a total solar eclipse end? Yes, the Moon moves out from fully blocking the Sun, but in the first few seconds of transition, interesting things appear. The first is called a diamond ring. Light might stream between mountains or through relative lowlands around the Moon's edge, as seen from your location, making this sudden first light, when combined with the corona that surrounds the Moon, look like a diamond ring. Within seconds other light streams appear that are called, collectively, Bailey's beads. In the featured video, it may seem that the pink triangular prominence on the Sun is somehow related to where the Sun begins to reappear, but it is not. Observers from other locations saw Bailey's beads emerge from different places around the Moon, away from the iconic triangular solar prominence visible to all. The video was captured with specialized equipment from New Boston, Texas, USA on April 8, 2024. Solar Eclipse Imagery: Notable Submissions to APOD
Copyright: David Duarte
Palm Tree Partial Eclipse
13/04/2024
Only those along the narrow track of the Moon's shadow on April 8 saw a total solar eclipse. But most of North America still saw a partial eclipse of the Sun. From Clearwater, Florida, USA this single snapshot captured multiple images of that more widely viewed celestial event without observing the Sun directly. In the shade of a palm tree, criss-crossing fronds are projecting recognizable eclipse images on the ground, pinhole camera style. In Clearwater the maximum eclipse phase was about 53 percent. Solar Eclipse Imagery: Notable Submissions to APOD
Copyright: Lori Haffelt
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.