Circular Sun Halo
14.10.2023

Want to see a ring around the Sun? It's easy to do in daytime skies around the world. Created by randomly oriented ice crystals in thin high cirrus clouds, circular 22 degree halos are visible much more often than rainbows.

A Supernova Starfield
9.02.1999

Bright stars don't last forever. A bright star similar to others in this field exploded in a spectacular supernova that was witnessed on Earth in 1987. The result is visible even today as unusual rings and glowing gas. The above picture is a composite of recent images taken over several years.

Cassinis Grand Finale Tour at Saturn
25.01.2017

Cassini is being prepared to dive into Saturn. The robotic spacecraft that has been orbiting and exploring Saturn for over a decade will end its mission in September with a spectacular atmospheric plunge. Pictured here is a diagram of Cassini's remaining orbits, each taking about one week.

When Black Holes Collide
11.04.2021

What happens when two black holes collide? This extreme scenario occurs in the centers of many merging galaxies and multiple star systems. The featured video shows a computer animation of the final stages of such a merger, while highlighting the gravitational lensing effects that would appear on a background starfield.

Triton: Neptune's Largest Moon
10.10.1996

Today marks the 150^th anniversary of the discovery of Triton. On October 10 1846, William Lassell was observing the newly discovered planet Neptune. He was attempting to confirm his observation, made just the previous week, that Neptune had a ring. But this time he discovered that Neptune had a satellite as well.

APOD: 2025 July 24 Б Titan Shadow Transit
24.07.2025

Every 15 years or so, Saturn's rings are tilted edge-on to our line of sight. As the bright, beautiful ring system grows narrower and fainter it becomes increasingly difficult to see for denizens of planet Earth.

APOD: 2025 October 5 Б A Long Storm System on Saturn
5.10.2025

It was one of the largest and longest lived storms ever recorded in our Solar System. First seen in late 2010, the featured cloud formation in the northern hemisphere of Saturn started larger than the Earth and soon spread completely around the planet.

Triton: Neptunes Largest Moon
4.03.2007

In October of 1846, William Lassell was observing the newly discovered planet Neptune. He was attempting to confirm his observation, made just the previous week, that Neptune had a ring. But this time he discovered that Neptune had a satellite as well.

Possible Planets And Infrared Dust
20.01.1999

These near-infrared Hubble images of dust surrounding young stars offer the latest tantalizing evidence for planets beyond our Solar System. At left, the dark gap seen in the dust disk is reminiscent of a similar large gap in Saturn's rings believed to be sculpted by orbiting moons.

Barred Spiral Galaxy M95
14.03.2007

Why do some spiral galaxies have a ring around the center? First and foremost, M95 is one of the closer examples of a big and beautiful barred spiral galaxy. Visible in the above recent...