Astronomy Picture Of the Day (APOD)APOD: 2023 April 4 Б Olympus Mons: Largest Volcano in the Solar System
The largest volcano in our Solar System is on Mars. Although three times higher than Earth's Mount Everest, Olympus Mons will not be difficult for humans to climb because of the volcano's shallow slopes and Mars' low gravity.
APOD: 2023 April 3 Б The Galactic Center Radio Arc
What causes this unusual curving structure near the center of our Galaxy? The long parallel rays slanting across the top of the featured radio image are known collectively as the Galactic Center Radio Arc and point out from the Galactic plane.
APOD: 2023 April 2 Б M57: The Ring Nebula from Hubble
It was noticed hundreds of years ago by stargazers who could not understand its unusual shape. It looked like a ring on the sky. Except for the rings of Saturn, the Ring Nebula (M57) may be the most famous celestial circle.
NGC 2442: Galaxy in Volans
Distorted galaxy NGC 2442 can be found in the southern constellation of the flying fish, (Piscis) Volans. Located about 50 million light-years away, the galaxy's two spiral arms extending from a pronounced central...
Shrouded in a thick atmosphere, Saturn's largest moon Titan really is hard to see. Small particles suspended in the upper atmosphere cause an almost impenetrable haze, strongly scattering light at visible wavelengths and hiding Titan's surface features from prying eyes.
NGC 4372 and the Dark Doodad
The delightful Dark Doodad Nebula drifts through southern skies, a tantalizing target for binoculars toward the small constellation Musca, The Fly. The dusty cosmic cloud is seen against rich starfields just south of the Coalsack Nebula and the Southern Cross.
APOD: 2023 March 29 Б Sh2-308: A Dolphin Shaped Star Bubble
Which star created this bubble? It wasn't the bright star on the bubble's right. And it also wasn't a giant space dolphin. It was the star in the blue nebula's center, a famously energetic Wolf-Rayet star.
APOD: 2023 March 28 Б A Multiple Green Flash Sunset
Yes, but can your green flash do this? A green flash at sunset is a rare event that many Sun watchers pride themselvesбon having seen.б Once thought to be a myth, a green flash is now understood to occur when the Earth's atmosphere acts like both a prism and a lens.
APOD: 2023 March 27 Б Aurora Over Arctic Henge
Reports of powerful solar flares started a seven-hour quest north to capture modern monuments against an aurora-filled sky. The peaks of iconic Arctic Henge in Raufarhцfn in northern Iceland were already aligned with the stars: some are lined up toward the exact north from one side and toward exact south from the other.
APOD: 2023 March 26 Б Wanderers
How far out will humanity explore? If this video's fusion of real space imagery and fictional space visualizations is on the right track, then at least the Solar System. Some of the video...