planetesimal
Solar system seed
A planetesimal is a small rocky or icy body in space, typically ranging from meters to kilometers across, formed in the early stages of a solar system's development.
These objects collide and merge over millions of years, gradually building up into planets—the process called accretion.
The asteroid belt contains planetesimals that never coalesced into a planet.
Growth through external addition
- coalescenceUniting into one mass
- aggregationCombined collection of items
- nucleationInitial cluster formation
- condensationVapor turning to liquid
dust · grain · collision · clump · growth · coagulation · adhesion · cohesion
Organism before birth
- oligarchMember of small ruling class
- differentiationRecognizing meaningful differences
- coreCentral essential portion
- accretionGrowth through external addition
gravity · growth · moonlet · nucleus · collision · merger · terrestrial
Sun-orbiting rocky mass
- cometIcy orbiting body
- KuiperOuter solar system region
- trans-NeptunianBeyond the eighth planet
- centaurHalf-human, half-equine being
meteoroid · orbit · belt · debris · remnant · leftover · primordial · ancient
Silicon-oxygen bonded minerals
- iceWater's solid form
- metallicResembling ore-based elements
- dustFine settled particles
- rockSolid earthen material
iron · nickel · carbon · volatile · refractory · mineral · organic · rocky
Forceful contact or consequence
- fragmentationBreaking into smaller pieces
- shrapnelScattered explosion fragments
- debrisScattered broken fragments
- rubbleBroken building fragments
crater · disruption · breakup · ejecta · catastrophic · erosion · grinding · cascade
Imitation of real processes
- modelRepresentation or paradigm
- observationAttentive watching or remark
- telescopeInstrument magnifying faraway objects
- spectroscopyStudy of light-matter interaction
radiometric · dating · isotope · chronology · spacecraft · mission · discovery · theory
accretion
Growth through external addition
- coalescenceUniting into one mass
- aggregationCombined collection of items
- nucleationInitial cluster formation
condensation · dust · grain · collision · clump · growth · coagulation · adhesion · cohesion · agglomeration
embryo
Organism before birth
- oligarchMember of small ruling class
- differentiationRecognizing meaningful differences
- coreCentral essential portion
accretion · gravity · growth · moonlet · nucleus · collision · merger · terrestrial
asteroid
Sun-orbiting rocky mass
- cometIcy orbiting body
- KuiperOuter solar system region
- trans-NeptunianBeyond the eighth planet
centaur · meteoroid · orbit · belt · debris · remnant · leftover · primordial · ancient · Vesta
silicates
Silicon-oxygen bonded minerals
rock · iron · nickel · carbon · volatile · refractory · mineral · organic · rocky · primitive
impact
Forceful contact or consequence
- fragmentationBreaking into smaller pieces
- shrapnelScattered explosion fragments
- debrisScattered broken fragments
rubble · crater · disruption · breakup · ejecta · catastrophic · erosion · grinding · cascade · bombardment
simulation
Imitation of real processes
- modelRepresentation or paradigm
- observationAttentive watching or remark
- telescopeInstrument magnifying faraway objects
spectroscopy · radiometric · dating · isotope · chronology · spacecraft · mission · discovery · theory · hypothesis