Evolution of the Evolution of the Solar SystemSolar System

Matt RogersMatt Rogers

AT350AT350

9 September 20039 September 2003

OverviewOverview

Evolution of a starEvolution of a star Interstellar NebulaInterstellar Nebula Formation of protostar and Formation of protostar and

protostellar nebulaprotostellar nebula Evolution of early sequences and Evolution of early sequences and

dissipation of protostellar nebuladissipation of protostellar nebula

Overview (continued)Overview (continued)

Evolution of planetsEvolution of planets Protostellar nebula makeupProtostellar nebula makeup Evolution of protostellar nebulaEvolution of protostellar nebula Formation of planetisimalsFormation of planetisimals

Terrestrial PlanetsTerrestrial Planets Jovian PlanetsJovian Planets

EndgameEndgame

Interplanetary NebulaInterplanetary Nebula

Protostars and Protostellar Protostars and Protostellar NebulaeNebulae

Accretion of nebular gases form protostar

Protostar starts sucking in nearby nebular gases, forms local increase in nebular gas amount – we call this a protostellar nebula

A Star Is BornA Star Is Born

Protostar continues accreting mass, Protostar continues accreting mass, becomes more and more massivebecomes more and more massive

Fusion process in star core initiatesFusion process in star core initiates Increase in Increase in solar windsolar wind blows blows

protostellar nebula away (but not protostellar nebula away (but not planets)planets)

Star enters Star enters main sequencemain sequence

Protostellar Nebulae and Protostellar Nebulae and You:You:How Planets Are FormedHow Planets Are Formed

Mostly H and He, with Mostly H and He, with other interesting other interesting elements (but nothing elements (but nothing heavier than Iron)heavier than Iron)

Depending on Depending on protostellar nebula protostellar nebula temperatures, can temperatures, can combine to form other combine to form other molecules – carbon molecules – carbon dioxide, water, dioxide, water, hydrocarbons, even hydrocarbons, even rocks!rocks!

Protostellar Nebulae and Protostellar Nebulae and You:You:How Planets Are FormedHow Planets Are Formed

Near hot protostar, Near hot protostar, only rocks accrete – only rocks accrete – too hot for too hot for hydrocarbon/water hydrocarbon/water icesices

Outside of the Outside of the frost frost lineline, both rocks , both rocks andand solid ices formsolid ices form

Composition of Composition of planetesimals depends planetesimals depends on where you are in on where you are in regards to the frost regards to the frost lineline

Formation of terrestrial Formation of terrestrial planetesimalsplanetesimals

Chunks of rock orbiting the protostar slam into Chunks of rock orbiting the protostar slam into each other, form rudimentary planets, called each other, form rudimentary planets, called planetesimalsplanetesimals

Planetesimals contain rocks and heavy gases Planetesimals contain rocks and heavy gases such as water vapor, CO2, nitrogen, etc., with such as water vapor, CO2, nitrogen, etc., with a rudimentary H and He atmospherea rudimentary H and He atmosphere

Formation of Jovian Formation of Jovian planetesimalsplanetesimals

Planetesimals similar to Planetesimals similar to terrestrial variety, except terrestrial variety, except that they grow faster, since that they grow faster, since they’re accreting rocks they’re accreting rocks andand solid icessolid ices

Become massive more Become massive more rapidly, eventually become rapidly, eventually become large enough to capture H large enough to capture H and He from the surrounding and He from the surrounding nebula (if it’s dense enough) nebula (if it’s dense enough) – this is how – this is how gas giantsgas giants are are formedformed

If there’s not enough nebular If there’s not enough nebular gas (i.e. a long way from the gas (i.e. a long way from the sun) the small planetesimals sun) the small planetesimals remain as cometsremain as comets

Final StagesFinal Stages

Nebular gas ejected from solar system, planets remain Nebular gas ejected from solar system, planets remain and begin to cooland begin to cool

The Early EarthThe Early Earth Earth cools (having Earth cools (having

lost early H and He lost early H and He atmosphere), begins atmosphere), begins outgassing water, outgassing water, cabon dioxide and cabon dioxide and nitrogen gasnitrogen gas

Early oxygen Early oxygen released from silicate released from silicate materials, bulk from materials, bulk from photosynthesis later photosynthesis later

From here on out, From here on out, just like in the notes!just like in the notes!

Fin.