M7: Open Star Cluster in Scorpius
7.01.2014

M7 is one of the most prominent open clusters of stars on the sky. The cluster, dominated by bright blue stars, can be seen with the naked eye in a dark sky in the tail of the constellation of the Scorpion (Scorpius).

Planet Line over New York Bridge
20.04.2022

There's an interesting sky to see if you wake up before the Sun. Lined up on toward the eastern horizon are four planets in a row. The planets are so bright they can even be seen from the bright sky inside a city.

ZTF meets ATLAS
10.02.2023

Fading as it races across planet Earth's northern skies comet C/2022 E3 (ZTF) shares this telescopic frame with comet C/2022 U2 (ATLAS). Captured on the night of February 6 from a garden observatory in Germany's Bavarian Forest, the starry field of view toward the constellation Auriga spans about 2.5 degrees.

The Carina Nebula in Three Colors
17.07.2001

Stars, like people, do not always go gentle into that good night. The above Carina Nebula, also known as the Keyhole Nebula and NGC 3372, results from dying star Eta Carinae's violently casting off dust and gas during its final centuries.

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...