Selective Aggregation Experiments on Planetesimal Formation and Mercury-Like Planets
arXiv:1808.10246 · doi:10.3390/geosciences8090310
Abstract
Much of a planet's composition could be determined right at the onset of formation. Laboratory experiments can constrain these early steps. This includes static tensile strength measurements or collisions carried out under Earth's gravity and on various microgravity platforms. Among the variety of extrasolar planets which eventually form are (Exo)-Mercury, terrestrial planets with high density. If they form in inner protoplanetary disks, high temperature experiments are mandatory but they are still rare. Beyond the initial process of hit-and-stick collisions, some additional selective processing might be needed to explain Mercury. In analogy to icy worlds, such planets might, e.g., form in environments which are enriched in iron. This requires methods to separate iron and silicate at early stages. Photophoresis might be one viable way. Mercury and Mercury-like planets might also form due to the ferromagnetic properties of iron and mechanisms like magnetic aggregation in disk magnetic fields might become important. This review highlights some of the mechanisms with the potential to trigger Mercury formation.
This article belongs to the Special Issue of Geosciences: Detection and Characterization of Extrasolar Planets
References in corpus (37)
- Gas- and dust evolution in protoplanetary disks
- Closed-form expressions for particle relative velocities induced by turbulence
- The stickiness of micrometer-sized water-ice particles
- Planetesimal formation starts at the snow line
- Challenges in Planet Formation
- Dust evolution in protoplanetary discs and the formation of planetesimals. What have we learned from laboratory experiments?
- Dust Density Distribution and Imaging Analysis of Different Ice Lines in Protoplanetary Disks
- Circumstellar Disk Lifetimes In Numerous Galactic Young Stellar Clusters
- High Velocity Dust Collisions: Forming Planetesimals in a Fragmentation Cascade with Final Accretion
- An Earth-sized exoplanet with a Mercury-like composition
- Formation of recurring slope lineae on Mars by rarefied gas-triggered granular flows
- The formation of the solar system
- Ice Grain Collisions in Comparison: CO, HO and their Mixtures
- The photophoretic sweeping of dust in transient protoplanetary disks
- Modeling dust growth in protoplanetary disks: The breakthrough case
- The maximum mass of planetary embryos formed in core-accretion models
- Fossil magnetic field of accretion disks of young stars
- K2-66b and K2-106b: Two extremely hot sub-Neptune-size planets with high densities
- Self-charging of identical grains in the absence of an external field
- Submillimetre-sized dust aggregate collision and growth properties
- Failed Growth at the Bouncing Barrier in Planetesimal Formation
- Seeding the Formation of Mercurys: An Iron-sensitive Bouncing Barrier in Disk Magnetic Fields
- Experiments on the Photophoretic Motion of Chondrules and Dust Aggregates - Indications for the Transport of Matter in Protoplanetary Disks
- Crossing barriers in planetesimal formation: The growth of mm-dust aggregates with large constituent grains
- Magnetic fields in circumstellar disks: The potential of Zeeman observations
- Is There a Temperature Limit in Planet Formation at 1000 K?
- Effects of photophoresis on the evolution of transitional circumstellar disks
- Light-induced disassembly of dusty bodies in inner protoplanetary discs: implications for the formation of planets
- Photophoretic Structuring of Circumstellar Dust Disks
- Photophoresis on particles hotter/colder than the ambient gas for the entire range of pressures
- Explaining Mercury's Density through Magnetic Erosion
- Constraints on Compound Chondrule Formation from Laboratory High-Temperature Collisions
- Analog Experiments on Tensile Strength of Dusty and Cometary Matter
- NanoRocks: Design and Performance of an Experiment Studying Planet Formation on the International Space Station
- Self-Sustained Recycling in the Inner Dust Ring of Pre-Transitional Disks
- The motion of chondrules and other particles in a protoplanetary disc with temperature fluctuations
- Photophoretic Levitation and Trapping of Dust in the Inner Regions of Protoplanetary Disks