Modern studies of planet formation include
Comparing exoplanetary systems
Identification of protoplanetary disks around newborn stars
And computer models to trace the creation of planets from their origins in interstellar dust and gas.
Center for Astrophysics | Harvard & Smithsonian astronomers study the formation of planets:
The leftover gas and dust inside that protoplanetary disk become the ingredients for planet formation.
For that reason
The chemical composition of the protoplanetary disk determines the composition of the eventual planets that form from it.
The Stages of Planetary Formation Our knowledge of the process of planetary formation comes from a number of diverse sources which include:
The physical observation of stars The physical properties of the planets of the solar system The study of meteorites Theoretical calculations
We still know very little about planet formation even within our own Solar System.
The above is the discovery image for a new member of our solar system.
Named Sedna
It is nearly as large as Pluto
But much more distant from the Sun.
How far out in the protoplanetary disk can a planet or other large body form?
In the conventional scenario for terrestrial planet formation in the Solar System, on the other hand, the gas disk is assumed to have dissipated prior to the final assembly of the terrestrial planets, and if this is the case then fully-formed planets never co-exist with a significant gas disk
Giant planet formation via core accretion is thus a mid- or late-stage event in the lifetime of protoplanetary disks (though whether it typically occurs after 1 Myr or several Myr is less certain)
It is likely to occur in the inner disk beyond the snowline and be much more difficult beyond some maximum radius that may be of the order of 10–20 AU
The physics during this initial phase is identical to that discussed in the context of terrestrial planet formation in Chapter 5, with the rate of growth being controlled by the initial surface density of rocky and icy bodies and by the extent of gravitational focusing
,f 61 Core accretion 187 r Hydrostatic growth
