The Stickiness of Cosmic Dust Aggregates: Size Determines Whether They Stick or Bounce

The Stickiness of Cosmic Dust Aggregates: Size Determines Whether They Stick or Bounce

Microparticle ⁢dust aggregates, which are believed to contribute to‌ the formation of new planets, exhibit reduced stickiness after collisions when ​they are‌ larger​ in ⁣size.

Existing ‍evidence​ suggests ‍that cosmic dust ​microparticles collide and adhere to ⁢form larger‌ dust aggregates, which may eventually merge⁤ and evolve into ⁢planets. Accurate‍ numerical ​models that describe the conditions necessary ​for these colliding​ microparticle ⁢aggregates ⁢to stick together,‌ rather than separate, ‍are crucial⁣ for understanding‌ planetary ​evolution. Recent simulations ‌indicate that as the size​ of dust aggregates increases, their ⁣likelihood of ​sticking together ⁢after a collision decreases.

A team of ‌astrophysicists conducted ⁢numerical​ simulations of⁤ dust aggregate collisions using soft-sphere discrete element methods. The simulations involved ⁢equal-mass aggregates⁤ ranging ‌in ‍size ‍from ⁣10,000 to 140,000 microns. ​The discrete modeling ⁢system ⁣accounted for each individual‍ particle within the aggregate, ‌considering them as separate entities. The ​soft-sphere simulation assumed​ the rigidity of each⁤ particle ⁢but allowed for deformations during collisions.

Their⁤ modeling revealed that increasing ⁣the radius ​of microparticle dust aggregates ​decreased ‌the⁤ probability of sticking, meaning that‌ two aggregates ⁤were less likely⁢ to adhere and form a larger aggregate‍ after‌ a collision. The team published their findings in ‌the⁣ Astrophysical Journal ⁣Letters.

“The formation process of kilometer-sized bodies, known as planetesimals, from cosmic dust, which ⁢represents⁤ the initial stage ​of planet formation, has been one of the major ‍challenges in⁢ the ​theory of⁤ planet⁤ formation,”⁣ said ⁣Hidekazu Tanaka, one of the⁤ study’s ⁣authors and⁤ a ⁤professor at⁢ the ⁤Astronomical Institute in the Graduate School of⁣ Science at Tohoku University in ​Sendai, Japan.

2023-07-22 12:48:02
Source⁣ from phys.org

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