HubbleSite
The Bullet Cluster
Two galaxy clusters collide in this combined image. The red is hot gas recorded by the Chandra X-ray Observatory, and the blue represents invisible “dark matter” whose presence is inferred from gravitational effects seen by Hubble. Notice the separation between the dark matter particles, which pass through one another, and the hot regular gas that collided and formed a bow shock. Dark matter is the second-most abundant form of energy in the universe, and we see here how it is different from ordinary matter. Learn more
The Bullet Cluster
Two galaxy clusters collide in this combined image. The red is hot gas recorded by the Chandra X-ray Observatory, and the blue represents invisible “dark matter” whose presence is inferred from gravitational effects seen by Hubble. Notice the separation between the dark matter particles, which pass through one another, and the hot regular gas that collided and formed a bow shock. Dark matter is the second-most abundant form of energy in the universe, and we see here how it is different from ordinary matter. Learn more