A Flock of Stars
6.09.2008

Only a few stars can be found within ten light-years of our lonely Sun, situated near an outer spiral arm of the Milky Way galaxy. But if the Sun were found within one of our galaxy's star clusters, thousands of stars might occupy a similar space.

Airglow Ripples over Tibet
1.09.2014

Why would the sky look like a giant target? Airglow. Following a giant thunderstorm over Bangladesh in late April, giant circular ripples of glowing air appeared over Tibet, China, as pictured above. The unusual...

A Conjunction of Crescents
8.02.2025

A waxing crescent Moon and a waning crescent Venus are found at opposite corners of this twilight telephoto field of view. The close conjunction of the two brightest celestial beacons in planet Earth's western evening sky was captured on February 1 from Rosario, Argentina.

APOD: 2025 October 15 Б Rocket Launch Plume over Tucson
15.10.2025

Yes, but can your sunset do this? Looking west from Tucson, Arizona, USA one day last month, the sunset sky looked strange when it briefly lit up with the plume of a rocket launched from California a few minutes earlier.

APOD: 2025 October 27 Б Two Tails of Comet Lemmon
27.10.2025

How many bright tails does Comet Lemmon have? Two. In the featured image it appears to have three, but why? The reason is that the zigzagging brown filament is a persistent meteor train that by luck appeared in front of the distant comet C/2025 A6 (Lemmon).

Spacecrafts Streak Over Colorado
14.03.2011

Have you ever seen a "star" drifting slowly overhead, but not known what it was? Sometimes even pointing it out to friends or family will only lead to a shrug. What you are seeing...

Saturn at the Lunar Limb
22.02.2002

Gliding through the sky on Wednesday evening, February 20th, a first quarter Moon seemed to run over bright planet Saturn as viewed from much of North America. In this sharp sequence of telescopic digital...

Old Moon and Sister Stars
29.06.2006

An old crescent Moon shares the eastern sky over Menton, France with the sister stars of the Pleiades cluster in this early morning skyscape recorded just last Friday, June 23rd. (Bright Venus was also...

The Virgo Cluster of Galaxies
20.02.2000

Pictured are several galaxies of the Virgo Cluster, the closest cluster of galaxies to our Milky Way Galaxy. The Virgo Cluster spans more than 5 degrees on the sky - about 10 times the angle made by a full Moon. It contains over 100 galaxies of many types - including spirals, ellipticals, and irregular galaxies.

A Geminid Meteor Over Iran
19.12.2011

Some beautiful things begin as grains of sand. Locked in an oyster, a granule grows into an iridescent pearl, lustrous and lovely to behold. While hurtling through the atmosphere at 35 kilometers per second, a generous cosmic sand grain becomes an awe-inspiring meteor, its transient beauty displayed for any who care to watch.