NASA’s Hubble Space Telescope captured merging spiral galaxies NGC 4038 and NGC 4039 — known as the Antennae because they resemble insect antennae — October 21, 1997. Each galaxy has a supermassive black holes at its center, shown in red in Hubble’s close-up view (right). The area outlined in green (left) in this collaged image shows a sweeping view of the colliding galaxies.