This map of the SMACK
Beta Pictoris simulation shows where collisions among icy and rocky debris occur most frequently in the disk. The planet’s slightly elongated orbit drives a spiral density wave across the disk. The spacing of the pattern steadily increases with greater distance from the planet’s orbit. Collisions driven by the density wave grind away larger particles and, after the 21 million years of the simulation, already have cleared them out of the central region near the star. The orbit of the planet, Beta Pictoris b, is shown in green. At top, the solar system is shown to scale. One Astronomical Unit (AU) equals the average distance between Earth and the Sun.
