Αστρονομική Εικόνα της Ημέρας από τη NASA

Προηγούμενες Αστρονομικές Εικόνες της Ημέρας από τη NASA

Comet 13P/Olbers

28/06/2024

Not a paradox, Comet 13P/Olbers is returning to the inner Solar System after 68 years. The periodic, Halley-type comet will reach its next perihelion or closest approach to the Sun on June 30 and has become a target for binocular viewing low in planet Earth's northern hemisphere night skies. But this sharp telescopic image of 13P is composed of stacked exposures made on the night of June 25. It easily reveals shifting details in the bright comet's torn and tattered ion tail buffeted by the wind from an active Sun, along with a broad, fanned-out dust tail and slightly greenish coma. The frame spans over two degrees across a background of faint stars toward the constellation Lynx.

Protostellar Outflows in Serpens

27/06/2024

Jets of material blasting from newborn stars, are captured in this James Webb Space Telescope close-up of the Serpens Nebula. The powerful protostellar outflows are bipolar, twin jets spewing in opposite directions. Their directions are perpendicular to accretion disks formed around the spinning, collapsing stellar infants. In the NIRcam image, the reddish color represents emission from molecular hydrogen and carbon monoxide produced as the jets collide with the surrounding gas and dust. The sharp image shows for the first time that individual outflows detected in the Serpens Nebula are generally aligned along the same direction. That result was expected, but has only now come into clear view with Webb's detailed exploration of the active young star-forming region. Brighter foreground stars exhibit Webb's characteristic diffraction spikes. At the Serpens Nebula's estimated distance of 1,300 light-years, this cosmic close-up frame is about 1 light-year across.

Timelapse: Aurora, SAR, and the Milky Way

26/06/2024

What's happening in the sky this unusual night? Most striking in the featured 4.5-hour 360-degree panoramic video, perhaps, is the pink and purple aurora. That's because this night, encompassing May 11, was famous for its auroral skies around the world. As the night progresses, auroral bands shimmer, the central band of our Milky Way Galaxy rises, and stars shift as the Earth rotates beneath them. Captured here simultaneously is a rare red band running above the aurora: a SAR arc, seen to change only slightly. The flashing below the horizon is caused by passing cars, while the moving spots in the sky are satellites and airplanes. The featured video was captured from Xinjiang, China with four separate cameras.

The Dark Doodad Nebula

25/06/2024

What is that strange brown ribbon on the sky? When observing the star cluster NGC 4372, observers frequently take note of an unusual dark streak nearby running about three degrees in length. The streak, actually a long molecular cloud, has become known as the Dark Doodad Nebula. (Doodad is slang for a thingy or a whatchamacallit.) Pictured here, the Dark Doodad Nebula sweeps across the center of a rich and colorful starfield. Its dark color comes from a high concentration of interstellar dust that preferentially scatters visible light. The globular star cluster NGC 4372 is visible as the fuzzy white spot on the far left, while the bright blue star gamma Muscae is seen to the cluster's upper right. The Dark Doodad Nebula can be found with strong binoculars toward the southern constellation of the Fly (Musca).

JADES-GS-z14-0: A New Farthest Object

24/06/2024

What if we could see back to the beginning of the universe? We could see galaxies forming. But what did galaxies look like back then? These questions took a step forward recently with the release of the analysis of a James Webb Space Telescope (JWST) image that included the most distant object yet discovered. Most galaxies formed at about 3 billion years after the Big Bang, but some formed earlier. Pictured in the inset box is JADES-GS-z14-0, a faint smudge of a galaxy that formed only 300 million years after the universe started. In technical terms, this galaxy lies at the record redshift of z=14.32, and so existed when the universe was only one fiftieth of the its present age. Practically all of the objects in the featured photograph are galaxies.

The Colors of Saturn from Cassini

23/06/2024

What creates Saturn's colors? The featured picture of Saturn only slightly exaggerates what a human would see if hovering close to the giant ringed world. The image was taken in 2005 by the robot Cassini spacecraft that orbited Saturn from 2004 to 2017. Here Saturn's majestic rings appear directly only as a curved line, appearing brown, in part from its infrared glow. The rings best show their complex structure in the dark shadows they create across the upper part of the planet. The northern hemisphere of Saturn can appear partly blue for the same reason that Earth's skies can appear blue -- molecules in the cloudless portions of both planet's atmospheres are better at scattering blue light than red. When looking deep into Saturn's clouds, however, the natural gold hue of Saturn's clouds becomes dominant. It is not known why southern Saturn does not show the same blue hue -- one hypothesis holds that clouds are higher there. It is also not known why some of Saturn's clouds are colored gold.

Lynds Dark Nebula 1251

22/06/2024

Stars are forming in Lynds Dark Nebula (LDN) 1251. About 1,000 light-years away and drifting above the plane of our Milky Way galaxy, LDN 1251 is also less appetizingly known as "The Rotten Fish Nebula." The dusty molecular cloud is part of a complex of dark nebulae mapped toward the Cepheus flare region. Across the spectrum, astronomical explorations of the obscuring interstellar clouds reveal energetic shocks and outflows associated with newborn stars, including the telltale reddish glow from scattered Herbig-Haro objects hiding in the image. Distant background galaxies also lurk in the scene, almost buried behind the dusty expanse. This alluring view spans over four full moons on the sky, or 35 light-years at the estimated distance of LDN 1251.

Hubble's NGC 1546

21/06/2024

Returning to science operations on June 14, the Hubble Space Telescope used its new pointing mode to capture this sharp image of spiral galaxy NGC 1546. A member of the Dorado galaxy group, the island universe lies a mere 50 million light-years away. The galactic disk of NGC 1546 is tilted to our line-of-sight, with the yellowish light of the old stars and bluish regions of newly formed stars shining through the galaxy's dust lanes. More distant background galaxies are scattered throughout this Hubble view. Launched in 1990, Hubble has been exploring the cosmos for more than three decades, recently celebrating its 34th anniversary.

Η Αστρονομική Εικόνα της Ημέρας από τη NASA

Galaxy Lenses Galaxy from Webb

21/04/2025