Photo of the Day APOD is 30 years old today. In celebration, today's picture uses past APODs as tiles arranged to create a single pixelated image that might remind you of one of the most well-known and evocative depictions of planet Earth's night sky. In fact, this Starry Night consists of 1,836 individual images [...]
Photo of the Day What are all those streaks in the sky? A galaxy, many satellite trails, and a few meteors. First, far in the distance, the majestic band of our Milky Way Galaxy runs down the left. Mirroring it on the right are several parallel trails of Earth-orbiting Starlink satellites. Many fainter satellite [...]
Photo of the Day Do you know the names of some of the brightest stars? It's likely that you do, even though some bright stars have names so old they date back to near the beginning of written language. Many world cultures have their own names for the brightest stars, and it is culturally [...]
Photo of the Day Can you identify this celestial object? Likely not — because this is a discovery image. Massive stars forge heavy elements in their cores and, after a few million years, end their lives in powerful supernova explosions. These remnants cool relatively quickly and fade, making them difficult to detect. To uncover [...]
Photo of the Day Is the sky the same every night? No -- the night sky changes every night in many ways. To better explore how the night sky changes, the USA's NSF and DOE commissioned the Vera C. Rubin Observatory in Cerro Pachón, Chile. In final testing before routine operations, Rubin will begin [...]
Photo of the Day Why would the sky glow like a giant repeating rainbow? Airglow. Now, air glows all of the time, but it is usually hard to see. A disturbance however -- like an approaching storm -- may cause noticeable rippling in the Earth's atmosphere. These gravity waves are oscillations in air analogous [...]
Photo of the Day Wisps like this are all that remain visible of a Milky Way star. About 7,000 years ago that star exploded in a supernova, leaving the Veil Nebula. At the time, the expanding cloud was likely as bright as a crescent Moon, remaining visible for weeks to people living at the [...]
Photo of the Day What's happening to this spiral galaxy? Although details remain uncertain, it surely has to do with an ongoing battle with its smaller galactic neighbor. The featured galaxy is labelled UGC 1810 by itself, but together with its collisional partner is known as Arp 273. The overall shape of UGC 1810 [...]
Photo of the Day Grand spiral galaxies often seem to get all the attention, flaunting young, bright, blue star clusters and pinkish star forming regions along graceful, symmetric spiral arms. But small galaxies form stars too, like irregular dwarf galaxy Sextans A. Its young star clusters and star forming regions are gathered into a [...]
Photo of the Day Behold one of the most photogenic regions of the night sky, captured impressively. Featured, the band of our Milky Way Galaxy runs diagonally along the bottom-left corner, while the colorful Rho Ophiuchi cloud complex is visible just right of center and the large red circular Zeta Ophiuchi Nebula appears near [...]
