Η Αστρονομική Εικόνα της Ημέρας από τη NASA
Rubin's Galaxy
13/06/2025
In this Hubble Space Telescope image the bright, spiky stars lie in the foreground toward the heroic northern constellation Perseus and well within our own Milky Way galaxy. In sharp focus beyond is UGC 2885, a giant spiral galaxy about 232 million light-years distant. Some 800,000 light-years across compared to the Milky Way's diameter of 100,000 light-years or so, it has around 1 trillion stars. That's about 10 times as many stars as the Milky Way. Part of an investigation to understand how galaxies can grow to such enormous sizes, UGC 2885 was also part of An Interesting Voyage and American astronomer Vera Rubin's pioneering study of the rotation of spiral galaxies. Her work was the first to convincingly demonstrate the dominating presence of dark matter in our universe. A new U.S. coin has been issured to honor Vera Rubin, while the Vera C. Rubin Observatory is scheduled to unveil images from its first look at the cosmos on June 23.
Copyright: NASA
Προηγούμενες Αστρονομικές Εικόνες της Ημέρας από τη NASA
CG4: The Globule and the Galaxy
21/05/2024
Can a gas cloud eat a galaxy? It's not even close. The "claw" of this odd looking "creature" in the featured photo is a gas cloud known as a cometary globule. This globule, however, has ruptured. Cometary globules are typically characterized by dusty heads and elongated tails. These features cause cometary globules to have visual similarities to comets, but in reality they are very much different. Globules are frequently the birthplaces of stars, and many show very young stars in their heads. The reason for the rupture in the head of this object is not yet known. The galaxy to the left of the globule is huge, very far in the distance, and only placed near CG4 by chance superposition.
Copyright: NASA
Aurora Dome Sky
20/05/2024
It seemed like night, but part of the sky glowed purple. It was the now famous night of May 10, 2024, when people over much of the world reported beautiful aurora-filled skies. The featured image was captured this night during early morning hours from Arlington, Wisconsin, USA. The panorama is a composite of several 6-second exposures covering two thirds of the visible sky, with north in the center, and processed to heighten the colors and remove electrical wires. The photographer (in the foreground) reported that the aurora appeared to flow from a point overhead but illuminated the sky only toward the north. The aurora's energetic particles originated from CMEs ejected from our Sun over sunspot AR 3664 a few days before. This large active region rotated to the far side of the Sun last week, but may well survive to rotate back toward the Earth next week.
Copyright: Xuecheng Liu & Yuxuan Liu
Jupiter Diving
19/05/2024
Take this simulated plunge and dive into the upper atmosphere of Jupiter, the Solar System's ruling gas giant. The awesome animation is based on image data from JunoCam, and the microwave radiometer on board the Jupiter-orbiting Juno spacecraft. Your view will start about 3,000 kilometers above the southern Jovian cloud tops, and you can track your progress on the display at the left. As altitude decreases, temperature increases while you dive deeper at the location of Jupiter's famous Great Red Spot. In fact, Juno data indicates the Great Red Spot, the Solar System's largest storm system, penetrates some 300 kilometers into the giant planet's atmosphere. For comparison, the deepest point for planet Earth's oceans is just under 11 kilometers down. Don't worry though, you'll fly back out again. Dive into the Universe: Random APOD Generator
Copyright: NASA
North Celestial Aurora
18/05/2024
Graceful star trail arcs reflect planet Earth's daily rotation in this colorful night skyscape. To create the timelapse composite, on May 12 consecutive exposures were recorded with a camera fixed to a tripod on the shores of the Ashokan Reservoir, in the Catskills region of New York, USA. North star Polaris is near the center of the star trail arcs. The broad trail of a waxing crescent Moon is on the left, casting a strong reflection across the reservoir waters. With intense solar activity driving recent geomagnetic storms, the colorful aurora borealis or northern lights, rare to the region, shine under Polaris and the north celestial pole. AuroraSaurus: Report your aurora observations
Copyright: Chirag Upreti
Aurora Banks Peninsula
17/05/2024
This well-composed composite panoramic view looks due south from Banks Peninsula near Christchurch on New Zealand's South Island. The base of a tower-like rocky sea stack is awash in the foreground, with stars of the Southern Cross at the top of the frame and planet Earth's south celestial pole near center. Still, captured on May 11, vibrant aurora australis dominate the starry southern sea and skyscape. The shimmering southern lights were part of extensive auroral displays that entertained skywatchers in northern and southern hemispheres around planet Earth, caused by intense geomagnetic storms. The extreme spaceweather was triggered by the impact of coronal mass ejections launched from powerful solar active region AR 3664. AuroraSaurus: Report your aurora observations
Copyright: Kavan Chay
Aurora Georgia
16/05/2024
A familiar sight from Georgia, USA, the Moon sets near the western horizon in this rural night skyscape. Captured on May 10 before local midnight, the image overexposes the Moon's bright waxing crescent at left in the frame. A long irrigation rig stretches across farmland about 15 miles north of the city of Bainbridge. Shimmering curtains of aurora shine across the starry sky, definitely an unfamiliar sight for southern Georgia nights. Last weekend, extreme geomagnetic storms triggered by the recent intense activity from solar active region AR 3664 brought epic displays of aurora, usually seen closer to the poles, to southern Georgia and even lower latitudes on planet Earth. As solar activity ramps up, more storms are possible. AuroraSaurus: Report your aurora observations
Copyright: Wright Dobbs
AR 3664 at the Sun's Edge
15/05/2024
What did the monster active region that created the recent auroras look like when at the Sun's edge? There, AR 3664 better showed its 3D structure. Pictured, a large multi-pronged solar prominence was captured extending from chaotic sunspot region AR 3664 out into space, just one example of the particle clouds ejected from this violent solar region. The Earth could easily fit under this long-extended prominence. The featured image was captured two days ago from this constantly changing region. Yesterday, the strongest solar flare in years was expelled (not shown), a blast classified in the upper X-class. Ultraviolet light from that flare quickly hit the Earth's atmosphere and caused shortwave radio blackouts across both North and South America. Although now rotated to be facing slightly away from the Earth, particles from AR 3664 and subsequent coronal mass ejections (CMEs) might still follow curved magnetic field lines across the inner Solar System and create more Earthly auroras. Gallery: Earth Aurora from Solar Active Region 3664
Copyright: Sebastian Voltmer
The 37 Cluster
14/05/2024
For the mostly harmless denizens of planet Earth, the brighter stars of open cluster NGC 2169 seem to form a cosmic 37. Did you expect 42? From our perspective, the improbable numerical asterism appears solely by chance. It lies at an estimated distance of 3,300 light-years toward the constellation Orion. As far as galactic or open star clusters go, NGC 2169 is a small one, spanning about 7 light-years. Formed at the same time from the same cloud of dust and gas, the stars of NGC 2169 are only about 11 million years old. Such clusters are expected to disperse over time as they encounter other stars, interstellar clouds, and experience gravitational tides while hitchhiking through the galaxy. Over four billion years ago, our own Sun was likely formed in a similar open cluster of stars. Gallery: Earth Aurora from Solar Active Region 3664
Copyright: Sergio Eguivar
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.