Αστρονομική Εικόνα της Ημέρας από τη NASA

Προηγούμενες Αστρονομικές Εικόνες της Ημέρας από τη NASA

Terminator Moon: A Moonscape of Shadows

22/04/2025

What's different about this Moon? It's the terminators. In the featured image, you can't directly see any terminator -- the line that divides the light of day from the dark of night. That's because the featured image is a digital composite of many near-terminator lunar strips over a full Moon. Terminator regions show the longest and most prominent shadows -- shadows which, by their contrast and length, allow a flat photograph to appear three-dimensional. The overlay images were taken over two weeks in early April. Many of the Moon's craters stand out because of the shadows they all cast to the right. The image shows in graphic detail that the darker regions known as maria are not just darker than the rest of the Moon -- they are also flatter. Dial-A-Moon: Find the Moon phase on your birthday this year

Galaxy Lenses Galaxy from Webb

21/04/2025

Is this one galaxy or two? Although it looks like one, the answer is two. One path to this happening is when a small galaxy collides with a larger galaxy and ends up in the center. But in the featured image, something more rare is going on. Here, the central light-colored elliptical galaxy is much closer than the blue and red-colored spiral galaxy that surrounds it. This can happen when near and far galaxies are exactly aligned, causing the gravity of the near galaxy to pull the light from the far galaxy around it in an effect called gravitational lensing. The featured galaxy double was taken by the Webb Space Telescope and shows a complete Einstein ring, with great detail visible for both galaxies. Galaxy lenses like this can reveal new information about the mass distribution of the foreground lens and the light distribution of the background source.

The Orion Nebula in Visible and Infrared

20/04/2025

The Great Nebula in Orion is a colorful place. Visible to the unaided eye, it appears as a small fuzzy patch in the constellation of Orion. Long exposure, multi-wavelength images like this, however, show the Orion Nebula to be a busy neighborhood of young stars, hot gas, and dark dust. This digital composite features not only three colors of visible light but four colors of infrared light taken by NASA's orbiting Spitzer Space Telescope as well. The power behind much of the Orion Nebula (M42) is the Trapezium - four of the brightest stars in the nebula. Many of the filamentary structures visible are actually shock waves - fronts where fast moving material encounters slow moving gas. The Orion Nebula spans about 40 light years and is located about 1500 light years away in the same spiral arm of our Galaxy as the Sun.

Painting with Jupiter

19/04/2025

In digital brush strokes, Jupiter's signature atmospheric bands and vortices were used to form this interplanetary post-impressionist work of art. The creative image from citizen scientist Rick Lundh uses data from the Juno spacecraft's JunoCam. To paint on the digital canvas, a JunoCam image with contrasting light and dark tones was chosen for processing and an oil-painting software filter applied. The image data was captured during perijove 10. That was Juno's December 16, 2017 close encounter with the solar system's ruling gas giant. At the time the spacecraft was cruising about 13,000 kilometers above northern Jovian cloud tops. Now in an extended mission, Juno has explored Jupiter and its moons since entering orbit around Jupiter in July of 2016.

Comet C/2025 F2 SWAN

18/04/2025

In late March, the comet now designated C/2025 F2 SWAN was found independently by citizen scientists Vladimir Bezugly, Michael Mattiazzo, and Rob Matson while examining publicly available image data from the Solar Wind ANisotropies (SWAN) camera on the sun-staring SOHO spacecraft. Comet SWAN's coma, its greenish color a signature of diatomic carbon molecules fluorescing in sunlight, is at lower left in this telescopic image. SWAN's faint ion tail extends nearly two degrees toward the upper right across the field of view. The interplanetary scene was captured in clear but moonlit skies from June Lake, California on April 14. Seen against background of stars toward the constellation Andromeda, the comet was then some 10 light-minutes from our fair planet. Now a target for binoculars and small telescopes in northern hemisphere morning skies this comet SWAN is headed for a perihelion, its closest approach to the Sun, on May 1. That will bring this visitor from the distant Oort cloud almost as close to the Sun as the orbit of inner planet Mercury.

Virgo Cluster Galaxies

17/04/2025

Galaxies of the Virgo Cluster are scattered across this nearly 4 degree wide telescopic field of view. About 50 million light-years distant, the Virgo Cluster is the closest large galaxy cluster to our own local galaxy group. Prominent here are Virgo's bright elliptical galaxies from the Messier catalog, M87 at bottom left, and M86 and M84 near center right. M86 and M84 are recognized as part of Markarian's Chain, the visually striking line-up of galaxies on the that runs through the upper portion of this frame. Near the middle of the chain lies an intriguing interacting pair of galaxies, NGC 4438 and NGC 4435, known to some as Markarian's Eyes. Still, giant elliptical galaxy M87 dominates the Virgo cluster. It's the home of a super massive black hole, the first black hole ever imaged by planet Earth's Event Horizon Telescope.

Halo of the Cat's Eye

16/04/2025

What created the unusual halo around the Cat's Eye Nebula? No one is sure. What is sure is that the Cat's Eye Nebula (NGC 6543) is one of the best known planetary nebulae on the sky. Although haunting symmetries are seen in the bright central region, this image was taken to feature its intricately structured outer halo, which spans over three light-years across. Planetary nebulae have long been appreciated as a final phase in the life of a Sun-like star. Only recently however, have some planetaries been found to have expansive halos, likely formed from material shrugged off during earlier puzzling episodes in the star's evolution. While the planetary nebula phase is thought to last for around 10,000 years, astronomers estimate the age of the outer filamentary portions of the Cat's Eye Nebula's halo to be 50,000 to 90,000 years.

Planetary Nebula NGC 1514 from Webb

15/04/2025

What happens when a star runs out of nuclear fuel? For stars like our Sun, the center condenses into a white dwarf while the outer atmosphere is expelled into space to appear as a planetary nebula. The expelled outer atmosphere of planetary nebula NGC 1514 appears to be a jumble of bubbles -- when seen in visible light. But the view from the James Webb Space Telescope in infrared, as featured here, confirms a different story: in this light the nebula shows a distinct hourglass shape, which is interpreted as a cylinder seen along a diagonal. If you look closely at the center of the nebula, you can also see a bright central star that is part of a binary system. More observations might better reveal how this nebula is evolving and how the central stars are working together to produce the interesting cylinder and bubbles observed. Jump Around the Universe: Random APOD Generator

Η Αστρονομική Εικόνα της Ημέρας από τη NASA

An Almost Everything Sky

23/04/2025