The growth of super-large pre-planetary pebbles to an impact erosion limit

Abstract

Early dust evolution in protoplanetary disks is dominated by sticking collisions. However, this initial phase of particle growth faces constraints - notably from destructive encounters. To find the maximum particle size achievable, we studied collisional processes during a prolonged microgravity experiment aboard a suborbital flight. Here, we specifically report an impact erosion limit. We observed individual basalt beads, each measuring 0.5 mm in diameter, colliding with and either eroding or adhering to a cluster several centimeters in size. This cluster, formed from tribocharged particles, simulates an electrostatic growth phase that surpasses the classical bouncing barrier. We find a threshold velocity of about 0.5 m/s, distinguishing between additive and erosive impacts of individual beads. Numerical simulations of grain impacts into clusters, testing both low and high charge constituents corroborate the experimental findings of surface erosion within the observed velocity range. This specific velocity threshold suggests the potential formation of pebbles several centimeters in size within protoplanetary disks. Such dimensions place these pebbles well into a regime where hydrodynamic interaction might facilitate the formation of planetesimals.

References in corpus (23)

• Dust size distributions in coagulation/fragmentation equilibrium: Numerical solutions and analytical fits
• Can dust coagulation trigger streaming instability?
• Erosion and the limits to planetesimal growth
• How dust fragmentation may be beneficial to planetary growth by pebble accretion
• Requirements for gravitational collapse in planetesimal formation --- the impact of scales set by Kelvin-Helmholtz and nonlinear streaming instability
• Understanding planet formation using microgravity experiments
• Self-charging of identical grains in the absence of an external field
• The Streaming Instability Cannot Form Planetesimals from mm-size Grains in Pressure Bumps
• Failed Growth at the Bouncing Barrier in Planetesimal Formation
• Seeding the Formation of Mercurys: An Iron-sensitive Bouncing Barrier in Disk Magnetic Fields
• Drifting inwards in protoplanetary discs II: The effect of water on sticking properties at increasing temperatures
• How to make giant planets via pebble accretion
• A challenge for Martian lightning: Limits of collisional charging at low pressure
• Size Dependence of the Bouncing Barrier in Protoplanetary Dust Growth
• A Smoking Gun for Planetesimal Formation: Charge Driven Growth into a New Size Range
• Inhibited Coagulation of Micron-size Dust Due to the Electrostatic Barrier
• Observation of bottom-up formation for charged grain aggregates related to pre-planetary evolution beyond the bouncing barrier
• Aggregation of Sub-mm Particles in Strong Electric Fields under Microgravity Conditions
• Rocky sub-Neptunes formed by pebble accretion: Rain of rocks from polluted envelopes
• Measuring Electric Dipole Moments of Trapped Sub-mm Particles
• The Curie line in protoplanetary disks and the formation of Mercury-like planets
• Experimental study of clusters in dense granular gas and implications for the particle stopping time in protoplanetary disks
• Accretion of eroding pebbles and planetesimals in planetary envelopes

Cited by in corpus (7)

• Charged Clouds of Ionized Gas Emerge from Tribocharging Grains
• Dust dynamics in RAMSES -- II. Equilibrium drift velocity distributions of charged dust grains
• From small dust to micron-sized aggregates: the influence of structure and composition on the dust optical properties
• A fast tree algorithm for multi-component coagulation equation
• Gas Phase Ion Species Released During Grain Collisions: Implications For Protoplanetary Disks
• Impact of Initial Charge Distributions on the Kinetics of Charged Particle Coagulation
• Experiments on Settling of Granular and Cohesive Material in Low Gravity