Alpha Cam: Runaway Star
24.11.2006

Runaway stars are massive stars traveling rapidly through interstellar space. Like a ship plowing through cosmic seas, runaway star Alpha Cam has produced this graceful arcing bow wave or bow shock - moving at over 60 kilometers per second and compressing the interstellar material in its path.

Mercury in Accentuated Color
19.03.2008

The colors of Mercury are subtle but beautiful. At first glance, our Solar System's innermost planet appears simply black and white, but images that include infrared colors normally beyond human vision accentuate a world of detail. One such image, shown above, was acquired by the robotic MESSENGER spacecraft that swung by Mercury in mid-January.

Milky Way Over Crater Lake with Airglow
19.06.2013

How many different astronomical phenomena have come together to create the above vista? Several. First, in the foreground, is Crater Lake -- a caldera created by volcanism on planet Earth about 7,700 years ago. Next, inside the lake, is water.

Ganymede from Juno
14.06.2021

What does the largest moon in the Solar System look like? Jupiter's moon Ganymede, larger than even Mercury and Pluto, has an icy surface speckled with bright young craters overlying a mixture of older, darker, more cratered terrain laced with grooves and ridges.

APOD: 2023 October 1 Б A Desert Eclipse
1.10.2023

A good place to see a ring-of-fire eclipse, it seemed, would be from a desert. In a desert, there should be relatively few obscuring clouds and trees. Therefore late December of 2019, a group...

APOD: 2023 December 10 Б Big Dipper over Pyramid Mountain
10.12.2023

When did you first learn to identify this group of stars? Although they are familiar to many people around the world, different cultures have associated this asterism with different icons and folklore. Known...

APOD: 2025 June 9 Б Between Scylla and Charybdis: A Double Cosmic Discovery
9.06.2025

Can you identify this celestial object? Likely not Б because this is a discovery image. Massive stars forge heavy elements in their cores and, after a few million years, end their lives in powerful supernova explosions. These remnants cool relatively quickly and fade, making them difficult to detect.

X Rays From Antennae Galaxies
3.02.2004

A bevy of black holes and neutron stars shine as bright, point-like sources against bubbles of million degree gas in this false-color x-ray image from the orbiting Chandra Observatory. The striking picture spans about...

Rumors of a Strange Universe
27.02.2004

Only a few short years ago, when the APOD editors were in graduate school, the pervasive, cosmic Dark Energy was not even seriously discussed. Of course, it now appears that this strange energy dominates the cosmos (as well as lectures on cosmology) and provides a repulsive force accelerating the large scale expansion of the Universe.

Fornax Cluster in Motion
24.09.2004

Reminiscent of popular images of the lovely Pleiades star cluster that lies within our own Milky Way Galaxy, this false-color x-ray view actually explores the center of a much more extended cosmic family -- the Fornax cluster of galaxies some 65 million light-years away.