The Galaxy and the Quasar
7.10.2002

Is the galaxy in the center connected to the quasar on the upper right? Disagreements about systems like this have raged for decades and have been used to challenge the foundations of modern cosmology.

In the Center of the Trapezium
10.07.2005

Start with the constellation of Orion. Near Orion's belt is a fuzzy area known as the Great Nebula of Orion or M42. In this nebula is a bright star cluster known as the Trapezium, shown above. New stellar systems are forming there in gigantic globs of gas and dust known as Proplyds.

The Ecliptic Plane
29.05.1999

The Plane of the Ecliptic is illustrated in this Clementine star tracker camera image which reveals (from right to left) the Moon lit by Earthshine, the Sun's corona rising over the Moon's dark limb, and the planets Saturn, Mars, and Mercury.

Rays from an Unexpected Aurora
20.11.2005

This aurora was a bit of a surprise. For starters, on this Friday morning in August 2002, no intense auroral activity was expected at all. Possibly more surprising, however, the aurora appeared to show an usual structure of green rays from some locations.

Skyscape with Comet Holmes
9.11.2007

This gorgeous skyscape spans some 10 degrees across the heroic constellation Perseus, about the size of a generous binocular field of view. The deep exposure includes bright stars, emission nebulae, star clusters, and, of course, the famous Comet Holmes. To identify the celestial landmarks, just place your cursor over the image.

NGC 6334: The Cats Paw Nebula
18.06.2014

Nebulas are perhaps as famous for being identified with familiar shapes as perhaps cats are for getting into trouble. Still, no known cat could have created the vast Cat's Paw Nebula visible in Scorpius.

Pluto at Night
9.06.2016

The night side of Pluto spans this shadowy scene. The spacebased view with the Sun behind the distant world was captured by New Horizons last July. The spacecraft was at a range of over 21,000 kilometers, about 19 minutes after its closest approach.

A Moon Dressed Like Saturn
16.03.2020

Why does Saturn appear so big? It doesn't -- what is pictured are foreground clouds on Earth crossing in front of the Moon. The Moon shows a slight crescent phase with most of its surface visible by reflected Earthlight known as ashen glow.

Fireball over Iceland
16.09.2023

On September 12, from a location just south of the Arctic Circle, stones of Iceland's modern Arctic Henge point skyward in this startling scene. Entertaining an intrepid group of aurora hunters during a geomagnetic storm, alluring northern lights dance across the darkened sky when a stunning fireball meteor explodes.

APOD: 2025 July 12 Б Clouds and the Golden Moon
12.07.2025

As the Sun set, a bright Full Moon rose on July 10. Its golden light illuminates clouds drifting through southern hemisphere skies in this well-composed telephoto image from Conceiццёo do Coitц, Bahia, Brazil. The brightest lunar phase is captured here with both a short and long exposure.