An estimation of the galaxy's span resulted in a conclusion of 150,000 light years, which is slightly larger than the Milky Way.
The Cartwheel galaxy shows non-thermal radio and optical spokes, but they are not the same spokes.
The galaxy was once a normal spiral galaxy like the Milky Way before it apparently underwent a head-on collision with a smaller companion approximately 200 million years ago (i.e., 200 million years prior to the image). When the nearby galaxy passed through the Cartwheel Galaxy, the force of the collision caused a powerful shock wave through the galaxy, like a rock being tossed into a sandbed. Moving at high speed, the shock wave swept up gas and dust, creating a starburst around the galaxy's center portion that were unscathed. This... Read More