Space snowmen in the Kuiper Belt: a new clue to their formation

New simulations show that spinning clouds of pebble-sized particles can form contact binaries—two linked bodies—and even triple planetesimals, offering a simple explanation for space snowmen in the Kuiper Belt; the study finds about 4% of simulated planetesimals become contact binaries, a share below the previously thought 10–25%, and notes that more detailed particle modeling could raise that fraction.