APOD: 2023 October 25 Б Gone in 60 Seconds: A Green Flash Sunset
25.10.2023

In 60 seconds, this setting Sun will turn green. Actually, the top of the Sun already appears not only green, but wavey -- along with all of its edges. The Sun itself is unchanged -- both effects are caused by looking along hot and cold layers in Earth's atmosphere.

APOD: 2024 March 4 Б Light Pillars Over Inner Mongolia
4.03.2024

What's happening across that field? Pictured here are not auroras but nearby light pillars, a phenomenon typically much closer. In most places on Earth, a lucky viewer can see a Sun pillar, a column of light appearing to extend up from the Sun caused by flat fluttering ice-crystals reflecting sunlight from the upper atmosphere.

APOD: 2025 February 4 Б Anticrepuscular Rays: A Rainbow Fan over Spain
4.02.2025

Yes, but can your rainbow do this? Late in the day, the Sun set as usual toward the west. However, on this day, the more interesting display was 180 degrees around -- toward the east. There, not only was a rainbow visible, but an impressive display of anticrepuscular rays from the rainbow's center.

APOD: 2025 April 22 Б 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.

APOD: 2025 August 23 Б Fishing for the Moon
23.08.2025

How big is planet Earth's Moon? Compared to other moons of the Solar System, it's number 5 on the largest to smallest ranked list, following Jupiter's moon Ganymede, Saturn's moon Titan, and Jovian moons Callisto and Io. Continuing the list, the Moon comes before Jupiter's Europa and Neptune's Triton.

APOD: 2026 March 23 Б Light Pillars and Orion over Mohe
23.03.2026

What's happening at the end of that street? Pictured here are not auroras but light pillars, a phenomenon typically much closer. In most places on Earth, a lucky viewer...

APOD: 2023 October 30 Б Reflections of the Ghost Nebula
30.10.2023

Do any shapes seem to jump out at you from this interstellar field of stars and dust? The jeweled expanse, filled with faint, starlight-reflecting clouds, drifts through the night in the royal constellation of Cepheus.

APOD: 2024 April 10 Б Planets Around a Total Eclipse
10.04.2024

What wonders appear when the Moon blocks the Sun? For many eager observers of MondayБs total eclipse of the Sun, the suddenly dark sky included the expected corona and two (perhaps surprise) planets: Venus and Jupiter.

APOD: 2026 August 2 Б A Fire Rainbow over West Virginia
2.08.2026

What's happening to this cloud? Ice crystals in a distant cirrus cloud are acting like little floating prisms. Known informally as a fire rainbow for its flame-like appearance, a circumhorizon arc appears parallel to the horizon.

APOD: 2023 December 4 Б Plane Crossing Crescent Moon
4.12.2023

No, the Moon is not a bow, and no, it did not shoot out a plane like an arrow. What is pictured is a chance superposition. The plane's contrail would normally appear white...