Η Αστρονομική Εικόνα της Ημέρας από τη NASA
Red Sun through Wildfire Smoke
30/07/2026
This could be the view from an exoplanet orbiting around a red dwarf star, but it is our own Sun. This image was taken on July 22, 2026, in the Okanagan region in the Canadian province of British Columbia. Wildfire smoke from the Pacific Northwest acted as a solar filter, allowing the photographer to take this photo of the Sun directly. Several sunspots are also visible in this eerie image; just below and right of the center is AR 4493, a fast evolving, giant active solar region and sunspot group. The smoke is made of tiny particles that help block and scatter light with bluer colors, so the light we see coming from the Sun is dimmer and redder than usual (but it is never safe to stare directly at the Sun). Sunsets and sunrises are also more colorful because of the smoke. Some 6 billion years from now, the Sun will actually start to turn redder as it approaches its red giant phase.
Copyright: Debra Ceravolo Text: Cecilia Chirenti (NASA GSFC, UMCP, CRESST II)
Προηγούμενες Αστρονομικές Εικόνες της Ημέρας από τη NASA
Western Moon, Eastern Sea
10/07/2026
The Mare Orientale, Latin for Eastern Sea, is one of the most striking large scale lunar features. The youngest of the large lunar impact basins it's very difficult to see from an earthbound perspective. Still, captured on July 7 during a period of favorable tilt, or libration of the lunar nearside, the Eastern Sea can be found at the upper right in this sharp telescopic view. In the image, the large lunar mare is extremely foreshortened and stretches along the Moon's western edge. Formed by the impact of an asteroid over 3 billion years ago and nearly 1000 kilometers across, the impact basin's concentric circular features are ripples in the lunar crust. But they are a little easier to spot in more direct images of the region taken from lunar orbit. So why is the Eastern Sea at the Moon's western edge? The Mare Orientale lunar feature was named before 1961. That's when the convention labeling east and west on lunar maps was reversed.
Copyright: The Mare Orientale
The Red Glow of the Cosmic Bat Nebula
09/07/2026
This Cosmic Bat wishes you a happy Summerween! This mid-year celebration of Halloween transcends hemispheres, even though summer in the Northern hemisphere is winter in the South. Contrary to its eery aura, the Cosmic Bat Nebula (LDN 43), not to be confused with the Bat Nebula (NGC 6995), is a vibrant birthplace for stars. A bit of young starlight peeks through the dense clouds of gas and dust that make up the Cosmic Bat’s 12 lightyear wingspan. The ultraviolet light from the young stars energizes the nebula’s hydrogen gas, causing it to glow an ominous red. The jet of glowing hydrogen gas emerging from the bat’s head hints at the star formation hidden within.
Copyright: Humbert Cédric Text: Keighley Rockcliffe (NASA GSFC, UMBC CSST, CRESST II)
NGC 6188: Dragons of Ara
07/07/2026
Where can you find dragons fighting in the night sky? In the southern constellation of the Altar: Ara. The dragons are, of course, actually made of suggestively shaped gas and dust. The celestial home of the mythological battling beasts is cataloged as NGC 6188 and located about 4,000 light years away near the edge of a large molecular cloud. Massive, young stars of the embedded Ara OB1 association were formed there only a few million years ago, sculpting the dark shapes and powering the nebular glow with stellar winds and intense ultraviolet radiation. Joining NGC 6188 on this cosmic canvas, visible toward the lower right, is unusual emission nebula NGC 6164, also created by one of the region's massive stars. This impressively wide field picture, captured from Queensland, Australia, spans over 2 degrees (four full Moons).
Copyright: Rod Prazeres
Dueling Bands over the Atacama Desert
06/07/2026
What are these two bands in the sky? The more commonly seen band is on the left and is the central band of our Milky Way galaxy. Our Sun orbits in the disk of this spiral galaxy so that from inside, it appears as a band of comparable brightness all the way around the sky. The less commonly seen band, on the right, is zodiacal light -- sunlight reflected from dust orbiting the Sun in our Solar System. Zodiacal light is brightest near the Sun and so is best seen just before sunrise or just after sunset. On some evenings, this ribbon of zodiacal light can appear quite prominent. It was discovered only in this century that zodiacal dust was mostly expelled by comets that have passed near Jupiter. The featured image was captured about a year ago from the Atacama Desert in Chile.
Copyright: Julien Looten
Saturn's Iapetus: Painted Moon
05/07/2026
What has happened to Saturn's moon Iapetus? Vast sections of this strange world are dark as coal, while others are as bright as snow. To help better understand this unusually tinted moon, in 2007 NASA directed the robotic Cassini spacecraft then orbiting Saturn to swoop within 2,000 kilometers. Pictured here, from about 75,000 kilometers out, is the hemisphere of Iapetus that is always trailing. A large impact crater seen in the south spans 500 kilometers and appears superposed on an older crater of similar size. The dark material is seen increasingly coating the easternmost part of Iapetus, darkening craters and highlands alike. A leading hypothesis is that the dark material is mostly a form of carbon-rich soil leftover from when relatively warm but dirty ice sublimates. An initial coating of this dark material may have been effectively painted on by the accretion of meteor-liberated debris from other moons. Jigsaw Moon: Astronomy Puzzle of the Day
Copyright: NASA
Pathfinder on Mars
04/07/2026
On July 4th, 1997, using its own array of fireworks, a parachute, and a cocoon of airbags, the Mars Pathfinder spacecraft bounced like a giant beach ball at least 15 times before it came to rest on the surface of Mars at 10:07 AM Pacific Daylight Time. After its then novel airbag-assisted landing sequence was completed, Pathfinder transmitted this color mosaic to mission operators on Earth. In the scene from another world, the Mars Sojourner robot rover is visible in the foreground, crouched on top of the unfolded Pathfinder. About the size of a large house cat, the six-wheeled, solar-powered Sojourner became the first successful Martian rover. Surrounding Pathfinder are deflated airbags and the rock-strewn terrain of the Ares Vallis floodplain. In the distance Martian hills appear against a dusty brownish sky. The Pathfinder lander was subsequently renamed the Carl Sagan Memorial Station.
Copyright: NASA
Three Galaxies in Pavo
03/07/2026
Some 190 million light-years away, far beyond the bright stars and nebulae of the Milky Way, these three galaxies are drawn together by gravity in a mesmerizing cosmic dance. Clearly distorted by galactic-scale gravitational interactions, large spiral galaxies NGC6769 and NGC6770 are seen face-on, with luminous galactic disks scarred by obscuring interstellar dust lanes. Their young blue star clusters along drawn out spiral arms are spawned in star forming regions that result from collisions of massive molecular clouds. Below, spiral NGC6771 presents a more edge-on perspective, its boxy central bulge due to tidal star streams. Of course, in the distant future a merger of the three galaxies is inevitable. At the estimated distance of this galaxy trio, known to some as the Devil's Mask, the sharp telescopic frame spans over 300 thousand light-years within the boundaries of the far southern constellation Pavo.
Copyright: Mike Selby
Sibling Supernova Remnants
02/07/2026
What happens when one of the stars in a binary goes supernova? This image combines visible (yellow), ultraviolet (purple) and infrared light (cyan, red and orange) to show two supernova remnants and their surrounding environment, about 6,000 light-years away. The younger one is the well-known Jellyfish Nebula in the center (mostly in yellow). If we could see it by eye, it would appear larger than the full moon in the sky. The filament shown in purple is part of an older, overlapping supernova remnant, G189.6+3.3. A new study used data from NASA's Fermi Gamma-ray Space Telescope to piece together their story. Astronomers believe that there were two stars in a binary system, then the first one exploded as a supernova, kicking away its companion, which also exploded as a supernova tens of thousands of years later, creating the superimposed supernova remnants we see today. The bright star on the right is actually a triple star system named Propus.
Copyright: NASA
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