Astronomy Picture of the Day

© Alessandro Cipolat Bares

🌌A Beautiful Trifid The beautiful Trifid Nebula is a cosmic study in contrasts. Also known as M20, it lies about 5,000 light-years away toward the nebula rich constellation Sagittarius. A star forming region in the plane of our galaxy, the Trifid does illustrate three different types of astronomical nebulae; red emission nebulae dominated by light from hydrogen atoms, blue reflection nebulae pro ...

© Ogetay Kayali (Michigan Tech U.) Text: Ogetay Kayali (Michigan Tech U.)

🌌The Pleiades in Red and Blue If you have looked at the sky and seen a group of stars about the size of the full Moon, that's the Pleiades (M45). Perhaps the most famous star cluster in the sky, its brightest stars can be seen even from the light-polluted cities. But your unaided eye can also see its nebulosity -- the gas and dust surrounding it -- under dark skies. However, telescopes can catch ...

🌌Interstellar Comet 3I/ATLAS It came from outer space. An object from outside our Solar System is now passing through at high speed. Classified as a comet because of its gaseous coma, 3I/ATLAS is only the third identified macroscopic object as being so alien. The comet's trajectory is shown in white on the featured map, where the orbits of Jupiter, Mars, and Earth are shown in gold, red, and blu ...

🌌The Spiral North Pole of Mars Why is there a spiral around the North Pole of Mars? Each winter this pole develops a new outer layer about one meter thick composed of carbon dioxide frozen out of the thin Martian atmosphere. This fresh layer is deposited on a water-ice layer that exists year round. Strong winds blow down from above the cap's center and swirl due to the spin of the red planet -- ...

© Massimo Di Fusco

🌌Ou4: The Giant Squid Nebula Difficult to capture, this mysterious, squid-shaped interstellar cloud spans nearly three full moons in planet Earth's sky. Discovered in 2011 by French astro-imager Nicolas Outters, the Squid Nebula's bipolar shape is distinguished here by the telltale blue emission from doubly ionized oxygen atoms. Though apparently surrounded by the reddish hydrogen emission regio ...

© Alberto Pisabarro

🌌NGC 6946 and NGC 6939 Face-on spiral galaxy NGC 6946 and open star cluster NGC 6939 share this cosmic snapshot, composed with over 68 hours of image data captured with a small telescope on planet Earth. The field of view spans spans about 1 degree or 2 full moons on the sky toward the northern constellation Cepheus. Seen through faint interstellar dust couds near the plane of our Milky Way gala ...

© Matipon Tangmatitham (NARIT)

🌌Nova V462 Lupi Now Visible If you know where to look, you can see a thermonuclear explosion from a white dwarf star. Possibly two. Such explosions are known as novas and the detonations are currently faintly visible with the unaided eye in Earth's southern hemisphere -- but are more easily seen with binoculars. Pictured, Nova Lupi 2025 (V462 Lupi) was captured toward the southern constellation ...

© Kavan Chay; Text: Ogetay Kayali (Michigan Tech U.)

🌌Milky Way Through Otago Spires Does the Milky Way always rise between these two rocks? No. Capturing this stunning alignment took careful planning: being in the right place at the right time. In the featured image taken in June 2024 from Otago, New Zealand, the bright central core of our Milky Way Galaxy, home to the many of our Galaxy's 400 billion stars, can be seen between two picturesque ro ...

© Anton Komlev

🌌Eye Sky a Dragon What do you see when you look into this sky? In the center, in the dark, do you see a night sky filled with stars? Do you see a sunset to the left? Clouds all around? Do you see the central band of our Milky Way Galaxy running down the middle? Do you see the ruins of an abandoned outpost on a hill? (The outpost is on Askold Island, Russia.) Do you see a photographer with a head ...