M27: Not a Comet
1.09.2011

While hunting for comets in the skies above 18th century France, astronomer Charles Messier diligently kept a list of the things he encountered that were definitely not comets. This is number 27 on his now famous not-a-comet list.

M27: Not a Comet
20.08.2015

While hunting for comets in the skies above 18th century France, astronomer Charles Messier diligently kept a list of the things he encountered that were definitely not comets. This is number 27 on his now famous not-a-comet list.

APOD: 2023 October 10 Б Hidden Orion from Webb
10.10.2023

The Great Nebula in Orion has hidden stars. To the unaided eye in visible light, it appears as a small fuzzy patch in the constellation of Orion. But this image was taken by the Webb Space Telescope in a representative-color composite of red and very near infrared light.

Colorful Moon Mosaic
7.09.2006

No single exposure can easily capture faint stars along with the subtle colors of the Moon. But this dramatic composite view highlights both. The mosaic digitally stitches together fifteen carefully exposed high resolution images of a bright, gibbous Moon and a representative background star field.

Barred Spiral Galaxy NGC 1300
16.10.2022

Across the center of this spiral galaxy is a bar. And at the center of this bar is smaller spiral. And at the center of that spiralбis a supermassiveбblack hole.б This all happens...

APOD: 2026 May 17 Б NGC 1300: Barred Spiral Galaxy
17.05.2026

Across the center of this spiral galaxy is a bar. And at the center of this bar is smaller spiral. And at the center of that spiral is a supermassive black hole. This...

APOD: 2025 July 22 Б A Double Detonation Supernova
22.07.2025

Can some supernovas explode twice? Yes, when the first explosion acts like a detonator for the second. This is a leading hypothesis for the cause of supernova remnant (SNR) 0509-67

APOD: 2024 January 31 Б Camera Orion Rising
31.01.2024

What does Orion rising look like to a camera? During this time of the year, the famous constellation is visible to the southeast just after sunset. From most Earthly locations, Orion's familiar star pattern, highlighted by the three-stars-in-a-row belt stars, rises sideways.

X Ray Rainbows
11.05.2001

A drop of water or prism of glass can spread out visible sunlight into a rainbow of colors. In order of increasing energy, the well known spectrum of colors in a rainbow runs red, orange, yellow, green, blue, indigo, violet.

X Ray Rainbows
28.09.2002

A drop of water or prism of glass can spread out visible sunlight into a rainbow of colors. In order of increasing energy, the well known spectrum of colors in a rainbow runs red, orange, yellow, green, blue, indigo, violet.