APOD: 2023 March 22 Б M31: The Andromeda Galaxy
21.03.2023

How far can you see? The most distant object easily visible to the unaided eye is M31, the great Andromeda Galaxy, over two million light-years away. Without a telescope, even this immense spiral galaxy appears as an unremarkable, faint, nebulous cloud in the constellation Andromeda.

APOD: 2023 September 17 Б Moon Mountains Magnified during Ring of Fire Eclipse
16.09.2023

What are those dark streaks in this composite image of a solar eclipse? They are reversed shadows of mountains at the edge of the Moon. The center image, captured from Xiamen, China, has the Moon's center directly in front of the Sun's center.

APOD: 2025 June 27 Б Messier 109
26.06.2025

Big beautiful barred spiral galaxy Messier 109 is the 109th entry in Charles Messier's famous catalog of bright Nebulae and Star Clusters. You can find it just below the Big Dipper's bowl in the northern constellation Ursa Major.

APOD: 2026 March 27 Б Hickson 44 in Leo
26.03.2026

Scanning the skies for galaxies, Canadian astronomer Paul Hickson and colleagues identified some 100 compact groups of galaxies, now appropriately called Hickson Compact Groups. The four prominent galaxies seen in this intriguing telescopic skyscape are one such group, Hickson 44.

APOD: 2023 May 31 Б Simulation: A Disk Galaxy Forms
30.05.2023

How did we get here? We know that we live on a planet orbiting a star orbiting a galaxy, but how did all of this form? Since our universe moves too slowly to watch, faster-moving computer simulations are created to help find out.

APOD: 2005 August 28 ? Muon Wobble Possible Door to Supersymmetric Universe
28.08.2005

How fast do fundamental particles wobble? A surprising answer to this seemingly inconsequential question has come out of Brookhaven National Laboratory in New York, USA and may not only indicate that the Standard Model of Particle Physics is incomplete but also that our universe is filled with a previously undetected type of fundamental particle.

APOD: 2023 July 5 Б A Map of the Observable Universe
4.07.2023

What if you could see out to the edge of the observable universe? You would see galaxies, galaxies, galaxies, and then, well, quasars, which are the bright centers of distant galaxies. To expand understanding...

APOD: 2025 June 3 Б Rainbow Airglow over the Azores
2.06.2025

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.

APOD: 2023 June 18 Б Saturns Northern Hexagon
17.06.2023

Why would clouds form a hexagon on Saturn? Nobody is sure. Originally discovered during the Voyager flybys of Saturn in the 1980s, nobody has ever seen anything like it anywhere else in the Solar System.

APOD: 2023 July 3 Б Venus in Ultraviolet from Akatsuki
2.07.2023

Why is Venus so different from Earth? To help find out, Japan launched the robotic Akatsuki spacecraft which entered orbit around Venus late in 2015 after an unplanned five-year adventure around the inner Solar System.