X Ray Stars of Orion
6.10.2007

The stars of Orion shine brightly in visible light in planet Earth's night sky. The constellation harbors the closest large stellar nursery, the Great Nebula of Orion, a mere 1,500 light-years away.

Visual Effects: Wonders of the Universe
18.04.2011

What visual effects are depicted in this video? The effects were created by BDH for the BBC television show Wonders of the Universe, but are unlabeled on the above version posted to Vimeo. Even...

The Gegenschein Over Chile
2.12.2012

Is the night sky darkest in the direction opposite the Sun? No. In fact, a rarely discernable faint glow known as the gegenschein (German for "counter glow") can be seen 180 degrees around from the Sun in an extremely dark sky. The gegenschein is sunlight back-scattered off small interplanetary dust particles.

Ou4: A Giant Squid Nebula
18.07.2014

A mysterious, squid-like apparition, this nebula is very faint, but also very large in planet Earth's sky. In the mosaic image, composed with narrowband data from the 2.5 meter Isaac Newton Telescope, it spans some 2.5 full moons toward the constellation Cepheus.

Trifid, Lagoon, and Mars
6.10.2016

Bright nebulae and star clusters along this 5 degree wide field of view are popular stops on telescopic tours of the constellation Sagittarius and the crowded starfields of the central Milky Way. Cataloged...

Moon and Venus Appulse over a Tree
6.02.2019

What's that bright spot near the Moon? Venus. About a week ago, Earth's Moon appeared unusually close to the distant planet Venus, an angular coincidence known as an appulse. Similar to a conjunction, which is a coordinate term, an appulse refers more generally to when two celestial objects appear close together.

NGC 6302: The Butterfly Nebula
2.03.2019

The bright clusters and nebulae of planet Earth's night sky are often named for flowers or insects. Though its wingspan covers over 3 light-years, NGC 6302 is no exception. With an estimated surface...

North America and the Pelican
8.09.2022

Fans of our fair planet might recognize the outlines of these cosmic clouds. On the left, bright emission outlined by dark, obscuring dust lanes seems to trace a continental shape, lending the popular name North America Nebula to the emission region cataloged as NGC 7000.

Total Lunar Eclipse
10.11.2022

The beginning, middle, and end of a journey through planet Earth's colorful umbral shadow is captured in this timelapse composite image of a total lunar eclipse. Taken on November 8 from Kitt Peak...

APOD: 2025 September 1 Б Callisto: Dirty Battered Iceball
1.09.2025

Its surface is the most densely cratered in the Solar System -- but what's inside? Jupiter's moon Callisto is a battered ball of dirty ice that is larger than the planet Mercury.