Distant galaxies abound in this one degree wide field of view toward the southern constellation Grus (The Crane). But the three spiral galaxies at the lower right are quite striking. […]

What’s causing those unusual sky arcs? Ice crystals. While crossing a field of fresh snow near Füssen, Bavaria, Germany, earlier this month, the photographer noticed that he had entered an […]

Are squares A and B the same color? They are! To verify this, either run your cursor over the image or click here to see them connected. The featured illusion, […]

Peering from the shadows, the Saturn-facing hemisphere of tantalizing inner moon Enceladus poses in this Cassini spacecraft image. North is up in the dramatic scene captured during November 2016 as […]

Asteroid 319 Leona cast a shadow across planet Earth on December 12, as it passed in front of bright star Betelgeuse. But to see everyone’s favorite red giant star fade […]

Massive stars in our Milky Way Galaxy live spectacular lives. Collapsing from vast cosmic clouds, their nuclear furnaces ignite and create heavy elements in their cores. After only a few […]

What excites the Heart Nebula? First, the large emission nebula on the left, catalogued as IC 1805, looks somewhat like a human heart. The nebula glows brightly in red light […]

What are these two giant arches across the sky? Perhaps the more familiar one, on the left, is the central band of our Milky Way Galaxy. This grand disk of […]

The surface of our Sun is constantly changing. Some years it is quiet, showing relatively few sunspots and active regions. Other years it is churning, showing many sunspots and throwing […]

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 […]