N49's Cosmic Blast
Scattered debris from a cosmic supernova explosion lights up the sky in this gorgeous composited image based on data from the Hubble Space Telescope. Cataloged as N49, these glowing filaments of shocked gas span about 30 light-years in our ...
V838 Mon: Echoes from the Edge
Variable star V838 Monocerotis lies near the edge of our Milky Way Galaxy, about 20,000 light-years from the Sun. Still, ever since a sudden outburst was detected in January 2002, this enigmatic star has taken the center of an astronomical stage ...
Cold Mountain Sky
This lovely celestial view is surely a familiar one to winter skygazers in the northern hemisphere. Lights silhouetting the trees are from nearby towns Morganton and Rutherford College, North Carolina, USA. But the scene may also look familiar to ...
Opportunity Rover Indicates Ancient...
Was Mars ever wet enough to support life? To help answer this question, NASA launched two rover missions to the red planet and landed them in regions that satellite images indicated might have been covered with water. Yesterday, mounting ...
NGC 6960: The Witch's Broom Nebula
Ten thousand years ago, before the dawn of recorded human history, a new light must suddenly have appeared in the night sky and faded after a few weeks. Today we know this light was an exploding star and record the colorful expanding cloud as ...
Cassini Closes in on Saturn
Are they gone? They were not originally predicted to even be there. The mystery revolves around strange shadow-like spokes that appeared on Saturn's large B-ring, the large middle ring in the complex system of particles that orbits Saturn. The ...
Julius Caesar and Leap Days
Today, February 29th, is a leap day - a relatively rare occurrence. In 46 BC, Julius Caesar, pictured above in a self-decreed minted coin, created a calendar system that added one leap day every four years. Acting on advice by Alexandrian ...
POX 186: Not So Long Ago
Not so long ago and not so far, far away, a galaxy was born. Seen in this Hubble Space Telescope image, the island universe of stars, gas, and dust cataloged as POX 186 is a mere 68 million light-years distant toward an uncrowded region in the ...
Rumors of a Strange Universe
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 ...
Galaxy Cluster in the Early Universe
Long before medieval alchemists dreamed of transmuting base metals to gold, stellar furnaces in this massive cluster of galaxies - cataloged as RDCS 1252.9-2927 - had transformed light elements into heavy ones. In the false-color composite image ...
