"Hundreds of trillions of comets orbit around 49 CETI and one other star whose age is about 30 million years. Imagine so many trillions of comets, each the size of the UCLA campus — approximately 1 mile in diameter — orbiting around 49 CETI and bashing into one another," Zuckerman said. "These young comets likely contain more carbon monoxide than typical comets in our solar system. When they collide, the carbon monoxide escapes as a gas. The gas seen around these two stars is the result of the incredible number of collisions among these comets.