An Ultraviolet Image of M101
27.06.1995

This giant spiral galaxy, Messier 101 (M101), was photographed by the Ultraviolet Imaging Telescope onboard the Space Shuttle Endeavour during the Astro-2 mission (March 2 - 18, 1995). The image has been computer processed so that the colors represent the intensity of ultraviolet light.

Sunspots: Magnetic Depressions
12.01.1997

Our Sun has spots! These spots appear dark in photographs like the one above, but in fact sunspots are quite bright - they are just dark compared to the rest of the Sun. Sunspots are about the size of the Earth and frequently occur in groups, as shown above.

Shadow of a Martian Robot
3.08.2004

What if you saw your shadow on Mars and it wasn't human? Then you might be the Opportunity rover currently exploring Mars. Opportunity and sister robot Spirit have been probing the red planet since January, finding evidence of ancient water, and sending breathtaking images across the inner Solar System.

Moon Lightning
7.10.2004

Moonsets are not often quite as exciting as this one. But amateur astronomer Marc-Andre Besel was impressed by the brilliant lighting displays that joined the first quarter Moon and stars of the constellation Scorpius in western skies.

Looking Back Over Mars
14.12.2004

Pictured above, the path of the robot rover Spirit on Mars can be traced far into the distance. Spirit has now crossed kilometers of plains covered with rocks and sand, approached the lip of a crater 200-meters across, and climbed a series of hills.

The Fairy of Eagle Nebula
21.08.2011

The dust sculptures of the Eagle Nebula are evaporating. As powerful starlight whittles away these cool cosmic mountains, the statuesque pillars that remain might be imagined as mythical beasts. Pictured above is one of several striking dust pillars of the Eagle Nebula that might be described as a gigantic alien fairy.

Comet ISON Approaches
7.10.2013

How impressive will Comet ISON become? No one is sure, but unfortunately, as the comet approaches the inner Solar System, it is brightening more slowly than many early predictions. Pictured above, Comet ISON is seen about two weeks ago as it continued to develop a tail.

Milky Way over Chilean Volcanoes
20.08.2017

Sometimes, the sky mimics the ground. Taken in 2017 May from the Atacama Desert in Chile, the foreground of the featured image encompasses the dipping edge of the caldera of an extinct volcano. Poetically echoing the dip below is the arch of our Milky Way Galaxy above.

Dust Clouds of the Pacman Nebula
9.08.2022

Stars can create huge and intricate dust sculptures from the dense and dark molecular clouds from which they are born. The tools the stars use to carve their detailed works are high energy light and fast stellar winds.

APOD: 2026 February 22 Б Shadow of a Martian Robot
21.02.2026

What if you saw your shadow on Mars and it wasn't human? Then you might be the Opportunity rover exploring Mars. Opportunity explored the Red Planet from 2004 to 2018, finding evidence of ancient water, and sending breathtaking images across the inner Solar System.