
The Chandra X-ray Observatory has been capturing unique images of our universe for 20 years. In this new picture, a star cluster called Cygnus OB2 is full of massive stars that survive for just a few million years. For comparison, our sun has a 10 billion-year lifespan.

This "First Light" image from NASA's Chandra X-ray Observatory shows the location of different elements in the Cassiopeia A supernova remnant.

The Messier 33 galaxy has a star-forming region, known as NGC 604, full of 200 hot and young massive stars.

This remnant of a supernova was produced by a massive exploding star in the Small Magellanic Cloud nearby.

This is the galactic center of the Milky Way, full of intriguing celestial objects.

This rare supernova remnant, called G292.0+1.8, still contains a large amount of oxygen.

Abell 2146 is the result of a collision between two galaxy clusters, creating an even larger system.

This is 30 Doradus, one of the largest regions of star formations close to our galaxy. Here, thousands of stars are releasing material and radiation, accelerated by powerful wind.

Another view of Messier 33, also known as the Triangulum Galaxy. It's 3 million light years from Earth in the Local Group of galaxies, which includes our own as well as the Andromeda galaxy.

Pandora's Cluster is like a crime scene. It's the aftermath of a collision including four galaxy clusters 3.5 billion light years away. Astronomers are intrigued by all of the structures within this cluster.

Galaxy cluster Abell 370 contains several hundred galaxies 4 billion light years from Earth.