Pebbles Form Planets

The secret to the formation of planets may lie in ordinary static electricity—the same phenomenon that can make your hair stand on end or give you an electric shock after walking across a carpet. A new study, published in Nature Astronomy, suggests that static electricity allows tiny dust particles in protoplanetary disks—the rotating platters of gas and dust that form around young stars—to clump together into “pebbles” that are large enough to play a role in the formation of planets. The image above shows basaltic beads, each measuring 0.55 millimeters, that were used in an experiment, which took place aboard a suborbital rocket. The findings help resolve a mystery that has shrouded something called the bouncing barrier—the size threshold that particles must reach in order to rely on gravity to join with other particles—says lead author of the study Jens Teiser, an astrophysicist at the University of Duisburg-Essen in Germany. The dust particles need static electricity to make the ... Read full article.